It’s a challenge for Healthcare IT personnel who are working in radiology centers to understand exactly what happens during the imaging process. Here is a brief introduction of medical imaging and the modalities used during the process to make healthcare IT guys understand better what they are dealing with.
Medical imaging is a very wide range expression used to describe the process of visualization of the human body either for diagnostic or therapeutic processes. Creating medical images is usually linked to pathological, histological and radiological imaging which is the core subject now, although most of radiological medical imaging procedures are not radiological in nature.
Radiological medical imaging is a branch of medicine carried out by technologists who work to obtain stable and clear images of the different human body regions to be visualized, examined and reported by radiologists who are physician specialized in reading various radiological images to give the proper diagnosis or perform interventional procedures for either diagnostic or therapeutic purposes.
Radiological medical imaging uses integration of multiple sciences including physics, biology, anatomy, mathematics and computer science in combination to produce the medical images according to the human system under investigation by various modalities. Medical imaging is a science in continuous upgrading with unlimited thoughts and applications; in few paragraphs we can review the current radiological medical imaging equipments:
A brief overview of medical imaging modalities
It’s the basic and most simple form of radiological medical imaging. It’s a non visualized rays that come out of the x-ray machine (the tube), directed towards the region under examination of the human body then collected on a sensitive x-ray film. The process is simple, fast and painless; but carries the hazards of ionizing radiation. This medical imaging is mainly concerned about the bones of the human skeleton; it’s widely used in cases of traumas and its poor soft tissue definition inspired the scientists to develop other ways of medical imaging. Conventional x-ray is the simplest form in which the x-ray is collected on a sensitive film within a cassette and the film is developed in a dark room, modern technology (CR) replaced the sensitive films with digital plate which will be computer processed to create the image on monitors; that enabled what’s called wet reporting which is reviewing the images while the patient still in position to ensure the quality, proper dosing and position before dismissing the patient from the imaging room.
X-ray techniques are other forms of medical imaging that introduce contrast media into specific tracts (pathways) within the human body to visualize tubular structures, including for example the spinal canal, blood vessels, gastrointestinal tract and urinary tract. Some of those techniques are performed under fluoroscopy screening which produce real time medical imaging on a TV screen. The images produced enabled the radiologist to approach hidden areas and diagnose intra-luminal pathology.
It’s medical imaging equipment that utile a dedicated low dose x-rays to obtain breast images which is useful in screening and diagnosis of breast cancer plus other diseases. Some techniques introduce contrast media into the breast glands to assess specific pathological conditions.
It’s a dedicated medical imaging for dental purpose. It produces a wide 180° view of the jaws and teeth providing full data for dentists especially before surgical procedures.
Computed Tomography (CT):
It’s the advanced medical imaging form of the x-ray, in which the rays are collected by detectors before computer processing to produce sharp well defined images of soft tissue beside bones. CT images are usually acquired in axial plans and the advanced computer software enabled reconstruction of coronal, sagittal plans and furthermore 3D reconstruction. The usage of contrast media in computed tomography imaging has added further details to vascular structures and gastro-intestinal tract. Better visualization, approaching and diagnosis of various pathological conditions is achieved by the development of computed tomography machines into spiral and multi-slice ones. Advanced cardiac and coronary arteries imaging are now possible providing fast, highly accurate and non invasive procedure that was just a dream before. Computed tomography hazards the ionizing radiation as x-ray, many studies are carried to reduce doses especially for pediatric patients and cases of neoplastic follow up.
It’s the simplest non ionizing medical imaging modality, using the high frequency waves and measures its reflection over human tissue to construct images. It’s safe, non invasive, fast, easy and cheap imaging equipment distributed all over the world. The ultrasound waves are produced by pizzo-electric effect of the probe crystals which convert the electrical current into waves and vice verse the reflected waves into electric pulses which are computer processed to produce the real time images.
Unfortunately, ultrasound waves are not effective against bones and air, so the imaging is restricted to solid soft tissue. The ultrasound medical application is mainly dedicated to abdomen and pelvis examination beside the obstetrical assessment. Other examinations include the small parts, joints and breast. Vascular ultrasound (Doppler) added a great medical value in imaging vascular structures, assessing patency and various pathological conditions. Modern technologies enabled converting images into 3D and even 4D structures which markedly involved in anatomical abnormalities in obstetrical studies of pregnant women.
Dr. Mohamed El-Refaey, MSc