Medical imaging has revolutionised medicine by allowing clinicians and researchers to see inside the human body without invasive surgery. What began with the discovery of X-rays in the late 19th century has evolved into a vast field comprising more than a hundred distinct imaging methods. Today, medical imaging encompasses a range of tools, from everyday procedures such as chest X-rays and ultrasound scans to advanced molecular and hybrid systems that can map blood flow, track biochemical activity, and even create interactive holograms.
Each technique offers a unique perspective on anatomy, physiology, or disease. Some methods are indispensable in emergency medicine, where speed is crucial, while others are employed in research to explore conditions at the cellular and molecular levels. Together, they form the backbone of modern diagnostics, guiding everything from cancer treatment and heart surgery to neurology and prenatal care.
In this article, we explore 101 types of medical imaging, ranging from established clinical techniques to cutting-edge innovations. Organised into categories, each entry provides a clear explanation of how the modality works, what it is used for, and why it matters. This guide is designed for both professionals and individuals interested in understanding how doctors can visualise the human body.
X-ray–based Imaging
1. Conventional radiography
Conventional radiography, also known as plain X-ray, is the oldest and most widely used imaging technique in medicine. It works by passing a controlled dose of X-rays through the body to produce shadow-like images on a detector.
Clinical applications – Widely used for fractures, chest conditions such as pneumonia or heart enlargement, and dental examinations.
Advantages – Fast, inexpensive, available everywhere, and capable of providing immediate results.
Limitations – Poor soft tissue contrast, radiation exposure (though minimal), and overlapping structures can obscure pathology.
Research directions – Digital image enhancement and artificial intelligence (AI) algorithms are being integrated to improve diagnostic accuracy and reduce missed findings.
Did you know? The very first medical X-ray ever taken was of Wilhelm Röntgen’s wife’s hand in 1895 — her wedding ring is clearly visible
2. Digital radiography
Digital radiography replaces film with digital detectors, producing images that can be enhanced, stored, and transmitted electronically.
Clinical applications – Used in all areas where plain films are needed, including chest, bone, and dental imaging.
Advantages – Higher image quality at lower radiation dose, easy storage and sharing, and reduced need for repeat imaging.
Limitations – Higher initial equipment cost compared with analogue radiography.
Research directions – Integration with AI-driven systems for automated fracture detection, lung nodule screening, and workflow optimisation.
3. Fluoroscopy
Fluoroscopy provides real-time moving X-ray images, making it ideal for procedures requiring continuous visualisation.
Clinical applications – Gastrointestinal studies (barium swallow, enema), catheter-guided procedures, orthopaedic surgery, and cardiac interventions.
Advantages – Dynamic imaging allows direct observation of movement, function, and device positioning.
Limitations – Higher radiation exposure compared with static imaging, requiring careful dose management.
Research directions – Flat-panel detectors and dose reduction software are making fluoroscopy safer and more efficient.
Fact: Fluoroscopy is used in over 15 million procedures each year in the United States alone.
4. Digital subtraction angiography (DSA)
DSA visualises blood vessels by subtracting pre-contrast images from post-contrast ones, leaving only the vascular structures visible.
Clinical applications – Gold standard for detecting aneurysms, arterial blockages, and vascular malformations.
Advantages – Provides unparalleled vascular detail for diagnosis and surgical planning.
Limitations – Invasive, requires contrast agents, and exposes patients to significant radiation compared with non-invasive vascular imaging.
Research directions – Hybrid angiography suites now combine DSA with CT or MRI for complex interventions.
5. Computed tomography (CT)
CT uses rotating X-ray beams and computer reconstruction to create cross-sectional and 3D images.
Clinical applications – First-line imaging in trauma, oncology staging, vascular imaging, and stroke assessment.
Advantages – Fast, detailed, and excellent for both bone and soft tissue. Whole-body imaging can be completed in a matter of seconds.
Limitations – Relatively high radiation dose; contrast reactions may occur in some patients.
Research directions – Photon-counting CT promises sharper images at lower doses, with improved material differentiation.
6. High-resolution CT (HRCT)
HRCT provides fine detail of lung architecture using thin slices and advanced reconstruction algorithms.
Clinical applications – Diagnosis of interstitial lung disease, emphysema, fibrosis, and occupational lung conditions.
Advantages – Detects subtle lung changes that standard CT may miss.
Limitations – Limited to focused chest studies, not whole-body imaging.
Research directions – AI-based analysis is improving early detection of fibrotic lung disease and predicting disease progression.
7. Cone-beam CT (CBCT)
CBCT uses a cone-shaped beam and a flat-panel detector, offering 3D imaging at lower doses than conventional CT.
Clinical applications – Dental implant planning, orthodontics, and orthopaedic imaging.
Advantages – Compact, relatively affordable, and excellent for bone imaging.
Limitations – Limited soft tissue contrast; smaller field of view compared with hospital CT scanners.
Research directions – Expansion into interventional radiology and radiation therapy planning.
8. Dual-energy CT (DECT)
DECT captures images at two different X-ray energy levels, enabling tissue differentiation based on absorption characteristics.
Clinical applications – Characterisation of kidney stones, diagnosis of gout, and improved vascular imaging.
Advantages – Distinguishes between different tissue types, reduces artefacts, and enhances contrast imaging.
Limitations – More expensive and not yet available in all hospitals.
Research directions – AI-driven material decomposition algorithms are expanding their diagnostic applications.
9. Spiral/helical CT
Spiral CT continuously rotates the X-ray tube as the patient moves through the scanner, producing rapid volumetric datasets.
Clinical applications – Emergency trauma scans, lung imaging, and vascular studies such as CT angiography.
Advantages – Very fast, enabling whole-body scans in critically ill patients.
Limitations – Higher radiation exposure compared with earlier CT methods.
Research directions – Faster acquisition and improved reconstruction methods continue to lower doses while maintaining quality.
10. Micro-CT (µCT)
Micro-CT provides extremely high-resolution imaging at the micron scale.
Clinical applications – Rare in direct patient care but used in dental imaging, pathology, and small structures such as the temporal bones.
Advantages – Reveals fine details of bone and microvascular structure unmatched by standard CT.
Limitations – Limited use in clinical settings due to long scan times and high radiation at microscopic resolution.
Research directions – Widely used in pre-clinical research, small animal studies, and analysis of biological specimens.
11. Low-dose CT (LDCT)
Low-dose CT reduces radiation exposure while maintaining sufficient image quality for diagnostic purposes.
Clinical applications – Most prominently used in lung cancer screening for high-risk populations, such as long-term smokers. It is also applied in follow-up imaging, where repeated scans are necessary.
Advantages – Significantly lowers radiation risk compared with standard CT while still providing clinically useful images.
Limitations – Reduced image quality compared with full-dose CT, which may limit its use in complex or subtle diagnostic cases.
Research directions – AI-driven reconstruction techniques are being developed to further enhance LDCT image quality without increasing dose.
12. Portable CT
Portable CT scanners are designed for bedside use in intensive care, emergency departments, or operating theatres.
Clinical applications – Particularly valuable in neurosurgery, where intraoperative CT helps confirm tumour resections or check for bleeding. It is also useful for critically ill patients who cannot be transported safely.
Advantages – Increases safety by bringing imaging to the patient, reducing delays and risks.
Limitations – Smaller scanners produce lower-quality images compared to hospital-based CT scanners.
Research directions – Advances in compact design and improved detectors are expanding the use of these technologies in battlefield medicine and rural healthcare.
13. Mammography
Mammography is a dedicated X-ray technique for breast imaging, widely used in cancer screening programmes.
Clinical applications – Early detection of breast cancer, diagnostic evaluation of breast lumps, and post-treatment monitoring.
Advantages – Proven to reduce mortality from breast cancer through early detection. Quick and widely available.
Limitations – Less sensitive in women with dense breast tissue; involves low-dose radiation.
Research directions – Contrast-enhanced mammography and AI interpretation tools are being developed to improve accuracy and reduce false positives.
14. Digital breast tomosynthesis (DBT)
Also known as 3D mammography, DBT takes multiple low-dose X-ray images from different angles and reconstructs them into thin slices.
Clinical applications – Enhances breast cancer screening, particularly in women with dense breasts.
Advantages – Improves detection rates and reduces the need for unnecessary biopsies compared to standard mammography.
Limitations – Higher radiation dose than standard mammography (though still low); interpretation takes longer.
Research directions – Integration with AI to speed up reading and to further reduce false positives.
15. Contrast-enhanced mammography (CEM)
CEM combines mammography with intravenous iodine-based contrast, highlighting suspicious lesions with increased vascularity.
Clinical applications – Alternative to breast MRI in patients who cannot undergo MRI. Used in problem-solving when standard mammography or ultrasound is inconclusive.
Advantages – Adds functional information to structural mammograms, increasing sensitivity.
Limitations – Requires contrast injection, which may not be suitable for all patients; involves a slightly higher radiation dose.
Research directions – Studies are exploring its role in screening high-risk women and in monitoring chemotherapy response.
16. Intraoperative X-ray imaging
Intraoperative X-ray systems, such as mobile C-arms, provide real-time feedback during surgery.
Clinical applications – Orthopaedic fracture fixation, spinal surgeries, and placement of medical devices such as catheters or screws.
Advantages – Improves surgical accuracy and reduces the need for revision surgery.
Limitations – Radiation exposure to both patient and surgical staff must be carefully managed.
Research directions – Development of low-dose systems and integration with navigation software to further increase precision.
17. Biplane X-ray angiography
Biplane angiography captures vascular images from two planes simultaneously, reducing the need for repositioning during procedures.
Clinical applications – Neurointerventional procedures such as aneurysm coiling, thrombectomy for stroke, and paediatric cardiac interventions.
Advantages – Provides enhanced anatomical guidance, shortens procedure time, and reduces contrast use.
Limitations – High equipment costs and radiation exposure remain concerns.
Research directions – Integration with 3D road-mapping and real-time navigation systems for even greater precision.
18. Portable chest X-ray
Portable chest radiographs are widely used in critical care, infectious disease monitoring, and emergency medicine.
Clinical applications – Bedside evaluation of pneumonia, pleural effusion, lung collapse, and confirmation of tube and line placement.
Advantages – Quick, inexpensive, and can be performed on unstable or isolated patients.
Limitations – Lower image quality compared with standard chest radiography; interpretation can be challenging due to patient positioning.
Research directions – AI systems are being trained to assist with rapid detection of pneumonia, tuberculosis, and COVID-19 on portable films.
Fact: More than 3.6 billion X-rays are performed globally each year — making them the most common imaging test worldwide.
Ultrasound Imaging
19. Conventional ultrasound (B-mode)
Conventional or B-mode ultrasound is the standard form of sonography, producing two-dimensional grayscale images by detecting echoes from sound waves reflected by tissues.
Clinical applications – Abdominal organ evaluation, pregnancy monitoring, musculoskeletal injuries, vascular studies, and emergency triage.
Advantages – Safe (no ionising radiation), widely available, portable, and provides immediate results.
Limitations – Image quality depends on the operator’s skill; it is particularly challenging in obese patients or when gas obstructs sound waves.
Research directions – Development of AI tools for automated organ measurements and detection of pathologies such as liver fibrosis or gallstones.
20. Doppler ultrasound
Doppler ultrasound measures the velocity and direction of blood flow by detecting frequency shifts caused by the movement of red blood cells.
Clinical applications – Assessment of blood flow in arteries and veins, including detection of deep vein thrombosis, carotid artery stenosis, and vascular graft patency.
Advantages – Provides real-time haemodynamic information; non-invasive and widely accessible.
Limitations – Susceptible to artefacts; requires skilled interpretation.
Research directions – Combined with 3D ultrasound to provide volumetric flow analysis and with machine learning to automate flow quantification.
21. Colour Doppler imaging
Colour Doppler overlays colour maps on B-mode images to show blood flow direction and speed.
Clinical applications – Used extensively in cardiology, obstetrics, and vascular medicine to visualise circulatory patterns.
Advantages – Easy visualisation of flow dynamics; helps in identifying abnormal shunts, valve regurgitation, or foetal circulation issues.
Limitations – Lower sensitivity for detecting very slow or deep flows compared with spectral or power Doppler.
Research directions – High-frame-rate colour Doppler for improved temporal resolution in cardiac imaging.
22. Power Doppler
Power Doppler is a sensitive ultrasound technique that detects the strength of blood flow signals rather than direction.
Clinical applications – Particularly useful in detecting slow or small-vessel flow, such as in renal transplants or inflamed joints.
Advantages – More sensitive than colour Doppler for low-velocity flows.
Limitations – Does not provide directional information; more prone to motion artefacts.
Research directions – Fusion imaging combining power Doppler with CT or MRI for hybrid vascular assessments.
23. Spectral Doppler
Spectral Doppler produces waveforms representing velocity changes in blood flow over time.
Clinical applications – Widely used in cardiology for valve assessment and in vascular medicine for grading stenoses.
Advantages – Provides quantitative flow data, allowing for precise evaluation of cardiac cycles.
Limitations – Operator dependent and requires careful angle correction for accurate results.
Research directions – Automated spectral analysis systems for real-time cardiovascular monitoring.
24. 3D ultrasound
Three-dimensional ultrasound reconstructs volumetric images from multiple 2D slices.
Clinical applications – Foetal imaging, gynaecological evaluation, and assessment of tumours or cardiac structures.
Advantages – Provides clearer spatial representation compared with conventional 2D ultrasound.
Limitations – Lower frame rate and longer acquisition times compared to real-time scanning.
Research directions – Application in oncology for tumour volume assessment and in cardiology for 3D valve reconstructions.
25. 4D ultrasound
4D ultrasound adds time to 3D imaging, creating live, moving volumetric images.
Clinical applications – Widely used in obstetrics to assess foetal development and detect structural abnormalities. Increasingly applied in cardiology for dynamic heart valve studies.
Advantages – Provides real-time motion; improves clinician–patient communication by offering intuitive views.
Limitations – High equipment cost and limited penetration for deep structures.
Research directions – Integration with AI to automatically analyse foetal behaviour and heart function.
26. Elastography (strain imaging)
Elastography measures tissue stiffness by analysing how tissue deforms under applied pressure.
Clinical applications – Differentiation of benign from malignant tumours, especially in breast and thyroid imaging; assessment of liver fibrosis.
Advantages – Non-invasive alternative to biopsy in many cases.
Limitations – Operator dependent and less effective in obese patients or deep organs.
Research directions – Standardisation of elastography parameters for widespread adoption in oncology and hepatology.
27. Shear wave elastography
Shear wave elastography generates and measures the speed of shear waves to quantify tissue stiffness.
Clinical applications – Gold-standard non-invasive method for evaluating liver fibrosis; also used in breast, prostate, and thyroid imaging.
Advantages – Provides reproducible, quantitative measurements of stiffness.
Limitations – Limited accuracy in patients with obesity or ascites.
Research directions – Expanded use in musculoskeletal imaging for assessing tendon and muscle health.
28. Contrast-enhanced ultrasound (CEUS)
CEUS uses injectable microbubble contrast agents that resonate with ultrasound waves, enhancing vascular and perfusion imaging.
Clinical applications – Liver tumour detection, kidney lesion characterisation, and monitoring of ablation therapy.
Advantages – Safe, no radiation, and well-tolerated compared with CT/MRI contrast.
Limitations – Requires intravenous injection; contrast bubbles break down quickly, limiting scan duration.
Research directions – Development of targeted microbubbles for molecular imaging of cancers and inflammatory diseases.
Highlight: Foetal ultrasound is one of the most common scans worldwide, with over 250 million performed annually.
29. Endoscopic ultrasound (EUS)
Endoscopic ultrasound combines endoscopy with a high-frequency ultrasound probe at the tip, allowing clinicians to obtain detailed images of structures adjacent to the gastrointestinal tract.
Clinical applications – Assessment of pancreatic disease, staging of gastrointestinal cancers, and evaluation of submucosal lesions. It also enables fine-needle aspiration for biopsy.
Advantages – Provides high-resolution imaging of areas not well seen by conventional ultrasound or CT; allows real-time tissue sampling.
Limitations – Invasive; requires sedation and skilled operators; limited availability outside specialised centres.
Research directions – Integration with elastography and contrast-enhanced modes to improve cancer detection and therapeutic monitoring.
30. Intravascular ultrasound (IVUS)
IVUS involves inserting a miniature ultrasound probe into blood vessels to provide cross-sectional images of arterial walls.
Clinical applications – Commonly used in interventional cardiology to assess atherosclerotic plaques, guide stent placement, and evaluate stent expansion.
Advantages – Direct visualisation of vessel wall structure; improves accuracy of interventions.
Limitations – Invasive; adds time and cost to procedures.
Research directions – Development of combined IVUS and optical imaging catheters for multimodal vascular assessment.
31. High-frequency ultrasound
High-frequency ultrasound uses probes operating above 15 MHz, providing excellent resolution of superficial tissues.
Clinical applications – Dermatology for skin tumours, ophthalmology for corneal and anterior eye imaging, and musculoskeletal scans of tendons and ligaments.
Advantages – Exceptional spatial resolution for small, superficial structures.
Limitations – Limited penetration depth, making it unsuitable for deeper organs.
Research directions – Expanding applications in oncology for margin assessment and in aesthetic medicine for facial treatments.
32. Transcranial Doppler ultrasound
Transcranial Doppler directs an ultrasound through thin areas of the skull to measure cerebral blood flow velocity in major brain arteries.
Clinical applications – Stroke risk assessment, monitoring vasospasm after subarachnoid haemorrhage, and evaluation in sickle cell disease.
Advantages – Non-invasive, portable, and repeatable.
Limitations – Limited by skull thickness in some patients; operator dependent.
Research directions – Automated systems for continuous bedside monitoring of cerebral haemodynamics.
33. Foetal ultrasound
Foetal ultrasound is one of the most common applications of ultrasound, used throughout pregnancy.
Clinical applications – Monitoring foetal growth, detecting congenital anomalies, evaluating placental function, and confirming gestational age.
Advantages – Safe for mother and baby, real-time imaging, and provides reassurance during pregnancy.
Limitations – Sensitivity varies depending on gestational age and maternal body habitus.
Research directions – Use of 3D/4D ultrasound and AI to improve detection of subtle congenital abnormalities.
34. Point-of-care ultrasound (POCUS)
POCUS is a portable, rapid form of ultrasound used by clinicians directly at the bedside or in the field.
Clinical applications – Emergency evaluation of trauma (FAST scan), detection of pericardial effusion, collapsed lung, or internal bleeding.
Advantages – Immediate, low-cost, and highly versatile; enhances decision-making in critical care.
Limitations – Operator dependent; limited in obese patients or where access is difficult.
Research directions – Increasing integration into medical education and AI-driven interpretation for non-expert users.
Insight: POCUS has been described as “the stethoscope of the future” for its role in bedside decision-making.
35. Portable/handheld ultrasound
Handheld ultrasound devices connect to tablets or smartphones, providing imaging capability outside traditional hospital settings.
Clinical applications – Used in primary care, rural medicine, ambulances, and military environments.
Advantages – Highly portable, affordable, and improves access to imaging worldwide.
Limitations – Lower image quality and fewer advanced features compared with full-sized systems.
Research directions – Cloud connectivity and AI-based diagnostics to assist non-specialists in remote locations.
36. Intraoperative ultrasound
Intraoperative ultrasound provides real-time imaging during surgery, helping guide resections and avoid damage to critical structures.
Clinical applications – Neurosurgery for tumour localisation, liver surgery for identifying lesions, and gynaecology for fibroid removal.
Advantages – Improves surgical precision and outcomes; reduces the likelihood of incomplete tumour removal.
Limitations – Requires specialised equipment and training; limited by sterility requirements and surgical environment constraints.
Research directions – Fusion with MRI and navigation systems for enhanced intraoperative guidance.
Magnetic Resonance Imaging (MRI)
37. Conventional MRI
Conventional MRI uses strong magnetic fields and radiofrequency waves to produce highly detailed cross-sectional images of the body’s soft tissues. Unlike CT, it does not involve ionising radiation, making it safer for repeated studies.
Clinical applications – Brain imaging for stroke, tumours, and multiple sclerosis; musculoskeletal imaging of joints and ligaments; spinal cord and intervertebral disc evaluation; abdominal and pelvic organ imaging.
Advantages – Superior soft tissue contrast compared with CT or X-ray; non-invasive; wide range of applications.
Limitations – Longer scan times, claustrophobia, and contraindications in patients with some implants or pacemakers.
Research directions – Faster scanning techniques and AI-enhanced reconstruction for shorter, more comfortable scans.
38. Functional MRI (fMRI)
Functional MRI detects changes in blood oxygenation (the BOLD signal) to map brain activity in response to tasks or rest.
Clinical applications – Pre-surgical planning in epilepsy and brain tumour surgery; research into cognitive processes, memory, and psychiatric disorders.
Advantages – Non-invasive, provides functional maps of brain regions with high spatial resolution.
Limitations – Sensitive to motion artefacts; temporal resolution lower than EEG.
Research directions – Integration with machine learning for real-time brain–computer interfaces and advanced psychiatric research.
Fact: fMRI has been used to map brain networks for memory, language, and emotion — revolutionising neuroscience.
39. Diffusion-weighted imaging (DWI)
DWI measures the random motion of water molecules within tissues, which is altered in disease.
Clinical applications – Gold standard for detecting acute ischaemic stroke within minutes of onset; also used in oncology and infection imaging.
Advantages – Extremely sensitive to early stroke; provides unique information not available from other MRI sequences.
Limitations – Susceptible to image distortion near air–bone interfaces; less specific for differentiating causes of restricted diffusion.
Research directions – Application in whole-body oncology imaging and diffusion imaging of the heart.
40. Diffusion tensor imaging (DTI)
DTI extends DWI by mapping the orientation of water diffusion, allowing visualisation of white matter tracts in the brain.
Clinical applications – Neurosurgical planning to avoid critical fibre pathways; research into brain connectivity in multiple sclerosis, autism, and traumatic brain injury.
Advantages – Provides unique insights into brain wiring and microstructure.
Limitations – Requires long scan times and advanced processing; prone to artefacts.
Research directions – Connectome mapping projects using DTI to build a complete picture of human brain networks.
41. Magnetic resonance angiography (MRA)
MRA uses MRI sequences, sometimes with gadolinium contrast, to visualise arteries non-invasively.
Clinical applications – Detection of aneurysms, arterial narrowing, and vascular malformations in the brain, neck, and peripheral arteries.
Advantages – Non-invasive alternative to catheter angiography; no ionising radiation.
Limitations – May miss very small vessels; image quality is reduced in patients with arrhythmias or movement.
Research directions – Development of contrast-free MRA techniques for patients with renal impairment.
42. Magnetic resonance venography (MRV)
MRV focuses on the venous system, producing images of veins throughout the body.
Clinical applications – Diagnosis of cerebral venous sinus thrombosis, deep vein thrombosis, and evaluation of venous malformations.
Advantages – Provides detailed venous mapping without invasive catheterisation.
Limitations – More sensitive to artefacts than arterial imaging; not always available in smaller centres.
Research directions – 4D flow MRV for dynamic visualisation of venous circulation.
43. MR spectroscopy (MRS)
MRS measures tissue biochemistry by detecting metabolite concentrations, rather than just structure.
Clinical applications – Differentiating between tumour types, assessing metabolic disorders, and monitoring neurodegenerative disease progression.
Advantages – Non-invasive insight into tissue metabolism and biochemistry.
Limitations – Lower spatial resolution; technically challenging to interpret.
Research directions – Application in cancer treatment planning and early Alzheimer’s disease detection.
44. Cardiac MRI
Cardiac MRI provides detailed structural and functional information about the heart and great vessels.
Clinical applications – Diagnosing myocarditis, cardiomyopathy, congenital heart disease, and assessing myocardial viability post-infarction.
Advantages – Gold standard for assessing heart chamber volumes and ejection fraction; no radiation.
Limitations – Requires breath-holding and prolonged scan times; gadolinium contrast may be contraindicated in patients with kidney disease.
Research directions – Real-time cardiac MRI for arrhythmia patients and AI-based automated cardiac measurements.
45. Foetal MRI
Foetal MRI offers detailed cross-sectional images of the developing foetus when ultrasound findings are inconclusive.
Clinical applications – Evaluation of congenital abnormalities, brain development, and complicated pregnancies.
Advantages – Provides superior soft tissue contrast compared with ultrasound; safe for mother and foetus.
Limitations – Motion artefacts from foetal movement; limited availability compared with ultrasound.
Research directions – Faster sequences to reduce motion artefacts; AI-driven analysis of foetal development.
46. Breast MRI
Breast MRI is a highly sensitive imaging technique used in breast cancer detection and monitoring.
Clinical applications – Screening high-risk patients, evaluating the extent of breast cancer, and monitoring response to chemotherapy.
Advantages – Extremely sensitive for detecting small or occult tumours; excellent in dense breast tissue.
Limitations – Expensive, time-consuming, and prone to false positives requiring biopsy.
Research directions – Development of abbreviated MRI protocols for faster, cost-effective screening.
47. Whole-body MRI
Whole-body MRI scans the entire body in a single session, providing a comprehensive overview without the use of radiation.
Clinical applications – Oncology for cancer staging and metastasis detection; screening for genetic cancer syndromes; assessment of systemic inflammatory or muscular disorders.
Advantages – Covers the whole body in one exam; radiation-free.
Limitations – Long scan times and limited availability in many centres.
Research directions – Faster whole-body imaging for use in routine cancer screening and population studies.
History: The first human MRI scan (1977) took nearly 5 hours to produce a single chest image.
48. MR perfusion imaging
MR perfusion measures blood flow through tissues, often using contrast agents or advanced sequences to track perfusion dynamics.
Clinical applications – Widely used in stroke to identify salvageable brain tissue, in oncology for tumour grading, and in cardiology for assessing myocardial perfusion.
Advantages – Provides functional information about blood supply, beyond what is revealed by structural imaging.
Limitations – Requires contrast agents in most cases; sensitive to motion artefacts.
Research directions – Development of non-contrast perfusion techniques, especially important for patients with kidney disease.
49. MR enterography (MRE)
MRE is a specialised MRI technique specifically designed for imaging the intestines.
Clinical applications – Gold standard for assessing Crohn’s disease, identifying strictures, fistulas, and inflammation without radiation exposure.
Advantages – Non-invasive, radiation-free alternative to CT enterography.
Limitations – Requires patient preparation (oral contrast, fasting); long acquisition times.
Research directions – Faster protocols and AI-driven inflammation scoring for improved disease monitoring.
50. MR cholangiopancreatography (MRCP)
MRCP uses heavily T2-weighted MRI sequences to visualise the biliary and pancreatic ducts without invasive procedures.
Clinical applications – Evaluation of gallstones, strictures, and tumours affecting the bile or pancreatic ducts.
Advantages – Non-invasive alternative to endoscopic retrograde cholangiopancreatography (ERCP).
Limitations – May not detect very small stones or subtle strictures; patient motion can compromise image quality.
Research directions – High-resolution 3D MRCP for surgical planning in liver and pancreatic disease.
51. MR urography
MR urography is used to image the kidneys, ureters, and bladder with both anatomical and functional sequences.
Clinical applications – Congenital urinary tract abnormalities, obstructive uropathy, and tumour evaluation.
Advantages – Provides detailed urinary tract imaging without the use of radiation.
Limitations – Requires patient hydration and sometimes contrast; longer scan times than CT.
Research directions – Functional MR urography for assessing kidney drainage dynamics.
52. MR neurography
MR neurography visualises peripheral nerves with high-resolution imaging and special contrast sequences.
Clinical applications – Brachial and lumbosacral plexus injuries, entrapment neuropathies (e.g., carpal tunnel), and nerve tumours.
Advantages – Non-invasive alternative to exploratory surgery or nerve conduction studies.
Limitations – Technically demanding and requires high-quality scanners.
Research directions – 3D MR neurography for surgical planning and regenerative medicine research.
53. MR arthrography
MR arthrography involves injecting contrast into a joint before MRI, improving visualisation of intra-articular structures.
Clinical applications – Shoulder labral tears, hip impingement, and wrist ligament injuries.
Advantages – Superior joint detail compared with conventional MRI.
Limitations – Invasive (requires injection); carries a small risk of infection or contrast reaction.
Research directions – Non-contrast alternatives using high-resolution 3D MRI sequences.
54. MR elastography (MRE)
MRE measures tissue stiffness by applying vibrations and imaging the resulting shear waves with MRI.
Clinical applications – Widely used for liver fibrosis staging, reducing the need for biopsies; also applied in brain, breast, and muscle imaging.
Advantages – Quantitative and reproducible; safe and non-invasive.
Limitations – Requires specialised hardware and longer scan times.
Research directions – Expanding into oncology for tumour characterisation and therapy monitoring.
55. 7-Tesla MRI (Ultra-high-field MRI)
7T MRI scanners offer an ultra-high magnetic field strength, providing unprecedented spatial resolution.
Clinical applications – Primarily research, including detailed brain mapping and musculoskeletal imaging; clinical use is emerging in epilepsy and neurodegenerative disease.
Advantages – Exceptional detail not achievable with 1.5T or 3T systems.
Limitations – Expensive, limited availability, and more prone to artefacts and safety challenges.
Research directions – Routine clinical applications in neurology and cardiology, supported by AI-enhanced correction of artefacts.
56. Interventional MRI
Interventional MRI uses real-time MRI guidance for minimally invasive procedures.
Clinical applications – Biopsies, tumour ablation, targeted drug delivery, and neurosurgical procedures.
Advantages – Provides precise guidance without the use of ionising radiation.
Limitations – Requires specialised MRI-compatible instruments; time-consuming and resource-intensive.
Research directions – MR-guided focused ultrasound for non-invasive treatment of tremors and tumours.
57. Intraoperative MRI (iMRI)
iMRI provides imaging during surgery, particularly in neurosurgery, to monitor progress and refine resections in real-time.
Clinical applications – Brain tumour resections, epilepsy surgery, and pituitary surgery.
Advantages – Improves surgical accuracy and reduces the risk of leaving residual tumour.
Limitations – Requires specialised operating theatres and equipment; costly to install and maintain.
Research directions – Hybrid operating rooms combining iMRI with robotic systems for precision-guided interventions.
Nuclear Medicine Imaging
58. Positron emission tomography (PET)
PET is a functional imaging technique that detects metabolic processes by tracking radioactive tracers, usually fluorodeoxyglucose (FDG). Areas with high glucose metabolism, such as cancers, appear as bright hotspots.
Clinical applications – Cancer detection and staging, monitoring chemotherapy response, assessing myocardial viability, and diagnosing neurological disorders like Alzheimer’s disease.
Advantages – Detects disease at a molecular level, often before structural changes occur; highly sensitive for cancer staging.
Limitations – Expensive, requires on-site access to radiotracers, and involves radiation exposure.
Research directions – Development of disease-specific tracers for prostate cancer, neurodegeneration, and infection imaging.
Insight: PET can detect disease before symptoms appear, making it one of the most sensitive imaging tools in medicine.
59. PET/CT hybrid imaging
PET/CT combines PET’s metabolic information with CT’s anatomical detail in a single scan.
Clinical applications – Oncology staging, radiotherapy planning, infection and inflammation imaging, and cardiac assessment.
Advantages – Accurate localisation of abnormal tracer uptake; combines functional and structural information.
Limitations – Radiation exposure from both PET and CT; limited availability in some centres.
Research directions – AI-based fusion to improve diagnostic accuracy and reduce radiation doses.
60. PET/MRI hybrid imaging
PET/MRI fuses PET’s molecular imaging with MRI’s superior soft tissue resolution.
Clinical applications – Neurological disease research, paediatric oncology, and head and neck cancer imaging.
Advantages – Reduces radiation compared with PET/CT; provides simultaneous structural, functional, and molecular data.
Limitations – Very expensive, time-consuming, and technically complex.
Research directions – Expanding use in neurodegenerative disease imaging and personalised cancer therapy.
61. Single-photon emission computed tomography (SPECT)
SPECT is a nuclear medicine technique that uses gamma-emitting tracers to create 3D images of organ function.
Clinical applications – Myocardial perfusion imaging, bone scans for metastases, and brain perfusion studies in dementia and epilepsy.
Advantages – More widely available and less costly than PET; versatile in many clinical fields.
Limitations – Lower spatial resolution compared with PET; longer acquisition times.
Research directions – Development of hybrid SPECT/CT systems for improved anatomical localisation.
62. SPECT/CT hybrid imaging
SPECT/CT integrates SPECT’s functional data with CT’s anatomical precision.
Clinical applications – Oncology, infection imaging, orthopaedic bone scans, and thyroid cancer assessment.
Advantages – More accurate localisation of abnormal uptake than standalone SPECT.
Limitations – Radiation dose from combined modalities is higher compared with SPECT alone, and the cost is also higher.
Research directions – Quantitative SPECT for therapy monitoring, especially in targeted radionuclide therapies.
63. Gamma camera imaging (planar scintigraphy)
Planar scintigraphy captures two-dimensional images of radiotracer distribution using a gamma camera.
Clinical applications – Thyroid uptake scans, renal scans, whole-body bone scans, and lung perfusion studies.
Advantages – Simple, widely available, and less costly than cross-sectional techniques.
Limitations – Limited anatomical detail; less sensitive compared with PET or SPECT.
Research directions – Enhanced detector technology for higher resolution and faster image acquisition.
64. Whole-body bone scintigraphy
Bone scintigraphy uses radiotracers that accumulate in areas of high bone turnover, highlighting abnormal skeletal activity.
Clinical applications – Cancer staging (detecting bone metastases), evaluating fractures, and diagnosing bone infections.
Advantages – Highly sensitive for detecting skeletal abnormalities across the entire body.
Limitations – Poor specificity; findings must be correlated with CT, MRI, or X-ray.
Research directions – Quantitative bone scintigraphy for more precise disease monitoring in oncology and rheumatology.
65. Myocardial perfusion scintigraphy
Myocardial perfusion scintigraphy assesses blood flow to the heart muscle at rest and stress using radiotracers.
Clinical applications – Detecting coronary artery disease, assessing heart muscle viability, and guiding revascularisation decisions.
Advantages – Non-invasive, provides functional and perfusion data, and predicts cardiac risk.
Limitations – Radiation exposure, time-consuming, and less accurate in obese patients or women with large breasts.
Research directions – New tracers and solid-state detectors for improved resolution and reduced scan times.
66. Renal scintigraphy
Renal scintigraphy evaluates kidney function, perfusion, and drainage using specialised radiotracers.
Clinical applications – Detecting obstructive uropathy, monitoring kidney transplants, and assessing split renal function.
Advantages – Provides functional data not available from ultrasound or CT; useful in children where radiation dose must be minimised.
Limitations – Limited anatomical information; requires correlation with ultrasound or CT.
Research directions – Dynamic renal scintigraphy combined with AI for automated assessment of renal drainage and function.
67. Thyroid scintigraphy
Thyroid scintigraphy uses radioactive iodine or technetium tracers to evaluate thyroid function and structure. Areas of increased uptake (“hot” nodules) suggest hyperfunctioning tissue, while reduced uptake (“cold” nodules) may indicate malignancy.
Clinical applications – Differentiating thyroid nodules, assessing hyperthyroidism, and monitoring thyroid cancer after treatment.
Advantages – Provides functional information beyond ultrasound or CT; relatively simple and inexpensive.
Limitations – Involves radiation exposure; less widely used in centres where ultrasound predominates.
Research directions – Development of hybrid thyroid imaging combining SPECT/CT to improve anatomical localisation.
68. Lung ventilation–perfusion scintigraphy (V/Q scan)
A V/Q scan evaluates ventilation and perfusion in the lungs using inhaled and injected radiotracers.
Clinical applications – Diagnosing pulmonary embolism, especially in patients who cannot undergo CT pulmonary angiography. Also used in pre-operative lung function assessment.
Advantages – Radiation dose is lower than CT; safe in patients with contrast allergies or kidney impairment.
Limitations – Less specific than CT angiography; interpretation can be challenging in patients with underlying lung disease.
Research directions – Advanced SPECT V/Q imaging for more accurate regional lung function assessment in chronic lung disease.
69. Brain perfusion SPECT
Brain perfusion SPECT measures cerebral blood flow by detecting the distribution of gamma-emitting tracers in the brain.
Clinical applications – Dementia assessment, epilepsy localisation, traumatic brain injury evaluation, and cerebrovascular disease.
Advantages – Provides functional information about regional brain activity beyond MRI or CT.
Limitations – Lower spatial resolution than PET; requires longer acquisition times.
Research directions – AI-based interpretation for earlier diagnosis of neurodegenerative disorders.
70. Sentinel lymph node scintigraphy
This technique maps the first lymph node (or nodes) draining a tumour site by injecting radiotracer near the lesion. The sentinel node is then surgically removed and examined.
Clinical applications – Breast cancer and melanoma staging; identifying metastatic spread.
Advantages – Minimally invasive, reduces the need for extensive lymph node dissection.
Limitations – Requires surgical expertise; not all sentinel nodes may be detected in certain cancers.
Research directions – Use of hybrid tracers combining radioisotopes with fluorescent dyes for dual-modality surgical guidance.
71. Positron emission mammography (PEM)
PEM is a dedicated breast PET imaging technique that provides high-resolution metabolic images of breast tissue.
Clinical applications – Detecting breast cancer, especially in women with dense breasts or inconclusive mammography results.
Advantages – Higher sensitivity than standard mammography; functional imaging reduces false negatives.
Limitations – Limited availability; involves radiation exposure.
Research directions – Combination with MRI and contrast-enhanced mammography for comprehensive breast cancer imaging.
72. Oncological PET imaging (FDG-PET)
FDG-PET uses fluorodeoxyglucose, a glucose analogue, to highlight areas of abnormal metabolism.
Clinical applications – Standard imaging modality for most cancers, including lung, colorectal, and lymphoma. Used for staging, treatment monitoring, and detecting recurrence.
Advantages – Highly sensitive for detecting malignant tissue; whole-body imaging in a single session.
Limitations – FDG uptake is not cancer-specific and can be seen in infection or inflammation.
Research directions – Quantitative PET metrics (SUVmax, tumour-to-background ratios) for precision oncology.
73. NeuroPET imaging
NeuroPET employs specialised tracers that target brain receptors, neurotransmitters, or pathological proteins.
Clinical applications – Imaging amyloid or tau protein in Alzheimer’s disease, dopamine transporters in Parkinson’s disease, and receptor binding in psychiatric research.
Advantages – Provides molecular-level information beyond structural neuroimaging.
Limitations – Very expensive, not widely available; requires specialised tracers with short half-lives.
Research directions – Expanding into psychiatry to study depression, schizophrenia, and addiction pathways.
74. PET with novel tracers
Beyond FDG, PET increasingly uses tracers tailored to specific diseases. Examples include PSMA for prostate cancer, gallium-68 for neuroendocrine tumours, and FAPI tracers for fibroblast activation.
Clinical applications – More precise cancer detection, targeted imaging of inflammatory and fibrotic conditions.
Advantages – Highly specific tracers improve accuracy and reduce false positives.
Limitations – Limited access to newer tracers; many are still in the experimental stage.
Research directions – Development of “theranostic” tracers that can both diagnose and deliver therapy (e.g., Lutetium-177 PSMA therapy).
75. Quantitative PET imaging
Quantitative PET provides numerical measurements of tracer uptake, such as standardised uptake values (SUVs).
Clinical applications – Monitoring tumour response to therapy, assessing prognosis, and enabling multicentre clinical trials.
Advantages – Objective and reproducible, improving standardisation of PET interpretation.
Limitations – Requires strict calibration of scanners and protocols; affected by patient factors, such as blood glucose levels.
Research directions – AI and machine learning models for fully automated quantitative PET reporting.
Future: Theranostics — tracers that both detect and treat cancer — is one of the fastest-growing fields in nuclear medicine.
Optical and Light-Based Imaging
76. Optical coherence tomography (OCT)
OCT uses near-infrared light to capture cross-sectional images of tissues, a concept similar to ultrasound, but employing light instead of sound.
Clinical applications – Ophthalmology (retina, macula, glaucoma), cardiology (coronary plaques), and dermatology.
Advantages – Microscopic resolution; non-invasive and rapid; excellent for monitoring disease progression.
Limitations – Limited penetration depth; unsuitable for deeper organs.
Research directions – Swept-source OCT for faster acquisition and OCT angiography for visualising retinal microvasculature.
Fact: OCT is so sensitive it can detect retinal changes thinner than a human hair.
77. Doppler OCT
Doppler OCT builds on OCT by measuring blood flow using frequency shifts caused by the movement of red blood cells.
Clinical applications – Retinal circulation studies; cerebral microcirculation research.
Advantages – Provides both anatomical and functional vascular data at microscopic resolution.
Limitations – Sensitive to motion artefacts; limited field of view.
Research directions – Application in neurovascular disease monitoring and microvascular oncology research.
78. Polarisation-sensitive OCT
This technique analyses changes in light polarisation to assess tissue composition.
Clinical applications – Corneal diseases, fibrous tissues (tendons, cartilage), and cardiovascular plaque characterisation.
Advantages – Adds microstructural information beyond standard OCT.
Limitations – Limited clinical adoption; technically demanding.
Research directions – Early cancer detection by mapping polarisation changes in epithelial tissues.
79. Confocal microscopy imaging
Confocal microscopy uses a pinhole system to block out-of-focus light, enabling cellular-level imaging.
Clinical applications – Dermatology (skin cancers), ophthalmology (corneal imaging), and pathology.
Advantages – High-resolution, real-time imaging of living tissues.
Limitations – Limited penetration depth; small field of view.
Research directions – Integration into handheld probes for point-of-care “optical biopsies.”
80. Fluorescence imaging
Fluorescence imaging utilises dyes or molecules that emit light after being excited by specific wavelengths.
Clinical applications – Surgical tumour margin detection, angiography, and infection imaging.
Advantages – High sensitivity for detecting specific molecules or tissues.
Limitations – Requires injection of fluorescent agents; limited depth penetration.
Research directions – Development of Targeted Fluorescent Probes for Precision Oncology.
81. Bioluminescence imaging
This technique relies on light produced by biological reactions, such as luciferase enzyme activity.
Clinical applications – Not used in humans clinically; widely applied in preclinical animal studies for tracking tumours, infections, and gene expression.
Advantages – Extremely sensitive and specific in laboratory research.
Limitations – Limited to preclinical models; cannot penetrate deep tissue in humans.
Research directions – Expanding use in genetic engineering for live cell tracking and regenerative medicine research.
Future: Photoacoustic imaging combines light and sound, offering non-invasive cancer detection.
82. Photoacoustic imaging
Photoacoustic imaging converts absorbed laser light into ultrasound signals, combining optical contrast with ultrasonic resolution.
Clinical applications – Tumour imaging, vascular assessment, and oxygenation monitoring.
Advantages – Provides both structural and functional data; deeper penetration than purely optical techniques.
Limitations – Still in early clinical adoption; requires expensive equipment.
Research directions – Integration into handheld devices for bedside vascular and oncology imaging.
83. Hyperspectral imaging
Hyperspectral imaging captures data across a wide range of light wavelengths, providing a unique spectral signature for each tissue type.
Clinical applications – Wound assessment, cancer detection, and surgical guidance.
Advantages – Differentiates tissues based on their biochemical composition without the use of contrast agents.
Limitations – Large data volumes require complex processing, which is not yet routine clinically.
Research directions – Miniaturisation for endoscopic and intraoperative use.
84. Endomicroscopy
Endomicroscopy combines endoscopy with microscopy, allowing in vivo cellular-level imaging inside the body.
Clinical applications – Gastrointestinal and pulmonary disease assessment, reducing the need for biopsies.
Advantages – Provides real-time microscopic views of mucosa and submucosa.
Limitations – Invasive; requires the use of contrast dyes, such as fluorescein.
Research directions – Expansion into urology and gynaecology for non-invasive diagnostics.
85. Near-infrared fluorescence imaging (NIRF)
NIRF utilises dyes such as indocyanine green to emit light in the near-infrared spectrum, which penetrates more deeply into tissues.
Clinical applications – Intraoperative imaging for tumour localisation, lymph node mapping, and assessing tissue perfusion.
Advantages – Real-time functional imaging; relatively safe dyes.
Limitations – Limited penetration depth (~1 cm); requires intravenous dye administration.
Research directions – Targeted NIRF probes for molecularly guided cancer surgery.
86. Fundus photography
Fundus photography captures colour images of the retina and optic disc using specialised cameras.
Clinical applications – Screening for diabetic retinopathy, glaucoma, and macular degeneration.
Advantages – Quick, non-invasive, and widely used in ophthalmology and telemedicine.
Limitations – Provides only 2D images; may miss subtle microvascular changes.
Research directions – AI-driven automated screening for diabetic eye disease.
87. Retinal angiography
This technique involves injecting a fluorescent dye (fluorescein or indocyanine green) and imaging retinal circulation.
Clinical applications – Diagnosing diabetic retinopathy, macular degeneration, and retinal vascular occlusions.
Advantages – Provides dynamic imaging of retinal circulation, which is essential in the management of retinal diseases.
Limitations – Invasive; carries a small risk of allergic reactions to the dye.
Research directions – Non-Invasive Alternatives Using OCT Angiography.
88. Corneal topography imaging
Corneal topography maps the surface curvature of the cornea using reflected light.
Clinical applications – Keratoconus detection, refractive surgery planning, and contact lens fitting.
Advantages – Provides highly accurate corneal mapping, essential for customised vision correction.
Limitations – Limited to the anterior corneal surface; cannot assess posterior corneal pathology.
Research directions – Integration with OCT for comprehensive corneal and anterior segment imaging.
89. Slit-lamp biomicroscopy imaging
Slit-lamp biomicroscopy uses a microscope and a slit beam of light to examine the anterior segment of the eye.
Clinical applications – Routine eye exams; detecting cataracts, corneal ulcers, and anterior uveitis.
Advantages – Widely available, inexpensive, and essential in ophthalmic practice.
Limitations – Limited to anterior eye structures; does not provide cross-sectional images.
Research directions – Digital slit-lamp imaging combined with teleophthalmology for remote diagnosis.
Hybrid and Specialised Imaging
90. Multimodal imaging
Multimodal imaging combines two or more imaging modalities, either simultaneously or sequentially, to provide complementary information.
Clinical applications – Oncology (combining anatomical, molecular, and perfusion imaging); neuroscience (structure–function mapping).
Advantages – Provides a more complete picture of disease by combining structural, functional, and molecular insights.
Limitations – More expensive, technically complex, and may increase radiation exposure when CT is included.
Research directions – AI-driven fusion platforms to integrate multimodal data for precision diagnostics.
91. Molecular imaging
Molecular imaging visualises biological processes at the cellular and molecular level using targeted tracers or probes.
Clinical applications – Cancer detection, infection imaging, and monitoring targeted therapies.
Advantages – Detects disease at its earliest stages, before anatomical changes occur.
Limitations – Limited clinical use outside oncology and research; depends on the availability of targeted tracers.
Research directions – Theranostics, where tracers are paired with therapeutic agents for personalised treatment.
92. Hybrid operating theatre imaging
Hybrid operating theatres integrate advanced imaging systems, such as CT, MRI, or angiography, into surgical suites.
Clinical applications – Cardiovascular surgery, neurosurgery, and trauma surgery.
Advantages – Provides intraoperative imaging without requiring patient movement, thereby improving surgical precision and safety.
Limitations – Extremely high cost and infrastructure requirements.
Research directions – Expansion of Robotic-Assisted Procedures in Hybrid Theatres.
93. Interventional fluoroscopic guidance
Fluoroscopy provides continuous X-ray imaging for guiding catheters, wires, and devices during minimally invasive procedures.
Clinical applications – Angioplasty, stent placement, spinal injections, and orthopaedic surgeries.
Advantages – Real-time guidance; reduces the need for open surgery.
Limitations – Radiation exposure to patients and staff; requires the use of contrast agents.
Research directions – Advanced dose-reduction technology and fusion with CT/MRI datasets.
94. Cerenkov luminescence imaging
Cerenkov imaging detects visible light emitted when radioactive tracers interact with biological tissues.
Clinical applications – Currently research-based, with potential in oncology for tracer-based imaging.
Advantages – Utilises existing PET tracers; less expensive compared to PET scanners.
Limitations – Limited penetration depth; still experimental in humans.
Research directions – Development of hybrid optical–nuclear devices for surgical guidance.
95. Electrical impedance tomography (EIT)
EIT reconstructs images of internal conductivity by applying small electrical currents through electrodes on the skin.
Clinical applications – Bedside monitoring of lung ventilation in intensive care.
Advantages – Portable, safe, repeatable, and radiation-free.
Limitations – Low spatial resolution compared with CT or MRI.
Research directions – Expanding use to cardiac and brain monitoring.
96. Magnetoencephalography (MEG)
MEG measures magnetic fields produced by neuronal activity, providing real-time functional maps of the brain.
Clinical applications – Localising seizure foci in epilepsy; pre-surgical mapping.
Advantages – Millisecond temporal resolution; non-invasive and highly precise for brain activity mapping.
Limitations – Requires shielded rooms; extremely expensive and available only in specialised centres.
Research directions – Wearable MEG Devices for Naturalistic Brain Monitoring.
97. Electroencephalography (EEG) source imaging
EEG source imaging reconstructs the origins of brain electrical activity from scalp EEG recordings.
Clinical applications – Epilepsy localisation, cognitive neuroscience, and psychiatric research.
Advantages – Enhances spatial information compared with conventional EEG.
Limitations – Accuracy depends on mathematical modelling; less precise than MEG or fMRI.
Research directions – AI-enhanced source reconstruction for real-time brain mapping.
98. Thermography (infrared imaging)
Thermography records infrared radiation emitted from the skin to create thermal maps.
Clinical applications – Breast cancer adjunct imaging, vascular disease, sports medicine, and pain management.
Advantages – Non-contact, non-invasive, and radiation-free.
Limitations – Limited specificity; influenced by external temperature and patient preparation.
Research directions – Integration with AI for automated inflammatory disease monitoring.
99. Microultrasound imaging
Microultrasound uses very high-frequency probes (up to 29 MHz) for high-resolution imaging of small structures.
Clinical applications – Prostate cancer detection and targeted biopsy guidance; musculoskeletal microstructure evaluation.
Advantages – Provides real-time, detailed imaging of small anatomical features, and is radiation-free.
Limitations – Limited penetration depth; relatively new and not widely available.
Research directions – Broader application in urology and dermatology.
100. Holographic medical imaging
Holography utilises CT, MRI, or ultrasound datasets to generate 3D holographic projections that are viewable without the need for headsets.
Clinical applications – Surgical planning, medical education, and complex anatomy visualisation.
Advantages – Interactive, intuitive visualisation of anatomy; enhances surgical training and preoperative strategy.
Limitations – Requires advanced software and hardware; clinical adoption has been limited so far.
Research directions – Integration with augmented reality (AR) and robotic surgery platforms.
101. Spectral photon-counting CT (SPCCT)
SPCCT is a next-generation CT technology that detects individual X-ray photons and their energy levels.
Clinical applications – Vascular imaging, oncology, and detecting subtle lesions at reduced radiation doses.
Advantages – Sharper images, improved tissue characterisation, and reduced artefacts compared with conventional CT.
Limitations – Currently limited to research centres; very expensive.
Research directions – Broad clinical rollout for cancer and cardiovascular imaging, with AI support for automated material differentiation.
Next-gen CT: Spectral photon-counting CT could halve radiation dose while providing sharper scans than conventional CT.
Future vision: Holographic imaging may soon let surgeons “walk around” a patient’s anatomy before making a single incision.
Conclusion
From the first X-ray of Röntgen’s wife’s hand to experimental holographic reconstructions, medical imaging has continually reshaped healthcare. Each of these 101 modalities adds unique value — some are everyday workhorses, others cutting-edge research. Together, they provide clinicians with structural, functional, and molecular insights into disease.
The future of medical imaging lies in fusion and precision: combining modalities, integrating AI, and tailoring scans to individual patients. Imaging is no longer just about seeing inside the body — it is about predicting, guiding, and transforming treatment itself.
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