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INNOSC Theranostics and
Pharmacological Sciences Medical imaging technology

The future development of medical imaging will primarily first four are the most widely used and easily popularized.
depend on advancements in computer-led high technology, Different types of medical imaging have complementary
which will subsequently enable modern medical imaging advantages, as detailed in Table 1.
to progress rapidly. Modern medical imaging has evolved
beyond traditional single ordinary X-ray and angiography 3. Principles of medical imaging
examinations to include ultrasound, radionuclide imaging, In recent years, the advent of new imaging methodologies
X-ray computed tomography (CT), digital subtraction such as high-field MRI, spectral CT, and hybrid equipment
angiography, magnetic resonance imaging (MRI), digital has revolutionized medical imaging practices, offering
imaging (computed radiography and digital radiography) enhanced diagnostic capabilities and clinical insights.
of conventional X-ray examinations, and image storage High-field MRI, characterized by magnetic fields exceeding
and transmission of medical imaging system composed 3 Tesla, has enabled unprecedented spatial resolution
of multiple technologies such as picture archiving and and tissue contrast, which is particularly beneficial for
communication systems. Overall, understanding the neurological and musculoskeletal imaging. The improved
strengths and limitations of medical imaging technology is signal-to-noise ratio provided by high-field MRI has
essential for health-care professionals to effectively utilize facilitated enhanced anatomical detail and heightened
these modalities in clinical practice, ensuring optimal sensitivity to pathological changes, advancing the detection
patient care and outcomes. and characterization of various diseases. Similarly, spectral
2. Common characteristics and types of CT, which utilizes energy-sensitive detectors to capture
photon energy information, has emerged as a promising
medical imaging equipment technology for spectral imaging and material differentiation.
Medical imaging equipment is primarily composed of an By discerning subtle differences in tissue composition and
energy emission source, effect tissue, detector, processor, molecular properties, spectral CT enhances diagnostic
display, and other components. As shown in Figure 1, accuracy and enables personalized treatment strategies,
the main types of medical imaging technology include: particularly in oncology and cardiovascular imaging.
(i) X-ray imaging, (ii) MRI, (iii) nuclear imaging (nuclear Moreover, the integration of hybrid imaging systems, such
medicine imaging technology), (iv) ultrasound imaging, as positron emission tomography (PET)/CT and PET/MRI,
(v) impedance imaging, (vi) thermal-microwave imaging, synergistically combines the functional information from
2
and (vii) optical imaging. Among these technologies, the PET with the anatomical detail provided by CT or MRI.

Figure 1. Medical imaging process
Abbreviation: RF: Radiofrequency.

Table 1. Types of medical imaging technologies
Medical image classification Dominant form Description content
Structure image: Describe the X-ray, CT Tissue density distribution
physiological anatomy of the UI Changes in tissue acoustic impedance
human body
MRI Magnetic resonance density distribution and relaxation characteristics
Functional images: Describe the RI (SPECT, PET) Physiological and metabolic functions of tissues and organs
functional activities of human fMRI The functional activity of the human brain
body tissues and organs in
different states DFI Blood flow imaging
Other types of imaging EIT Internal impedance or change in impedance
Thermal and microwave imaging Infrared signal on the body surface and microwave radiation signal in the body
Optical imaging Using optical and television technology to observe the shape of some human organs
Abbreviations: CT: Computed tomography; DFI: Detective flow imaging; EIT: Electrical impedance tomography; fMRI: Functional magnetic resonance
imaging; MRI: Magnetic resonance imaging; PET: Positron emission tomography; RI: Radioisotope; SPECT: Single-photon emission computed
tomography; UI: Ultrasonic imaging.

Volume 7 Issue 3 (2024) 2 doi: 10.36922/itps.3360