Computed Tomography (CT) scan and Magnetic Resonance Imaging (MRI) are advanced imaging methods that use computer processing to reconstruct cross-sectional images (or slices) of different regions of the body. To obtain such images, CT scan uses ionizing radiation in the form of multi-directional X-rays, while MRI applies non-ionizing radiation in the form of magnetic fields and radio waves. Both procedures provide a more detailed depiction of the human anatomy, important in locating and evaluating the extent of a disease. Intravenous (IV) and/or intestinal contrasts may be given during the imaging process to further aid in distinguishing any abnormal masses or lesions from the surrounding normal tissues.
The most common diseases evaluated by CT scan and MRI primarily include, but are not limited to, the following:
Diagnosis and management are guided by CT scan and MRI through localizing and staging of tumors, evaluation of treatment response, and long-term surveillance of the disease.
Extent and severity can be evaluated by cross-sectional imaging through assessment of plaque formation and stenosis (narrowing of a blood vessel) within the coronary arteries, as well as by the detection of vascular aneurysms or dissections. Furthermore, CT scan and MRI can determine and define cardiac anatomy, function, and viability.
Common bone and joint disorders are diagnosed by evaluation of the common causes of pain disorders, assessment of the extent of injury related to trauma or sports, and pre-operative planning for surgically-treatable diseases such as bone and soft tissue tumors
Using high resolution images generated by CT scan, pulmonary diseases, such as pneumonia, tuberculosis, and pleural effusions (water in the lungs) as well as chronic obstructive pulmonary disease (COPD) and pulmonary embolism, are readily diagnosed and evaluated for extent and severity
Can be readily assessed by the identification of its location and extent, along with the area of the brain that can be saved, and by prompt recognition of hemorrhage, vascular occlusion (obstruction), and/or aneurysm
- CT Scan – routine region-specific plain and contrast-enhanced CT imaging of the head, neck, chest, abdomen, extremities, etc.
- Special CT scan procedures:
- Coronary CT Angiography – identifies and evaluates the degree of plaque formation and stenosis within the coronary arteries
- CT Angiography of the Aorta (CT Aortogram) – evaluates aortic vessel diameter and patency, detects aortic aneurysms and dissections, and aids in pre-operative planning of aortic surgical procedures
- CT Brain Perfusion – provides a combination of intracranial vessel angiography and brain parenchymal contrast studies to assess the degree of blood flow in a specific brain region as part of stroke management or to further characterize and evaluate brain mass lesions as an aid for treatment
- CT Virtual Colonoscopy – detects colorectal wall lesions such as polyps and masses, which may be precursors of malignancy and serves as an alternative to those who are not amenable to the standard colonoscopy
- MRI – routine region-specific plain and contrast-enhanced MRI of the head, neck, chest, abdomen, spine, knee, shoulder, etc.
- Special MRI procedures:
- Breast MRI – provides better evaluation of the breast parenchymal and ductal structures, useful for further assessment of breast masses detected in a cancer screening
- Cardiac MRI – evaluates the cardiac anatomy and function better than CT or 2D echocardiogram studies
- Functional Brain MRI – allows the mapping of different body activities into the anatomical brain MR images useful for localizing brain regions and planning for surgical procedures
- Liver MRI with Liver-Specific Contrast – uses an IV contrast dedicated to the liver that allows better characterization of masses or nodules over routine MRI or CT studies, necessary for directing the next course of management
- MR Brain Tractography (Fiber Tracking) – allows the identification of brain neural tracts usually used for the assessment of deformation of white matter (brain nerves) by tumors and for pre-surgical planning
- MR Cholangiopancreatography (MRCP) – yields a more detailed anatomy of the biliary and pancreatic ducts for easy identification of the different causes of obstructions such as stones and masses
- MR Enterography – yields a more detailed anatomy of the intestines beneficial for evaluation of infection, inflammation, and/or malignancy
- MR Spectroscopy of the Brain (MRS) – provides better characterization of brain masses useful for guiding clinical management
- Multiparametric Prostate MRI – assesses the different regions of the prostate, diagnoses nodules and/or masses and their extent to the adjacent structures, and allows their grading according risk of malignancy
Chairperson of the Department of Radiology:
Jackson U. Dy, MD
Section Head of CT-MRI:
Richie A. Pilapil, MD