Diagnostic Imaging - Computed Tomography (CT) Services

Computed Tomography (CT) Services at RIMA:
Cardiac CT for Calcium Scoring
Computed Tomography (CT) – Abdomen and Pelvis
Computed Tomography (CT) – Angiography
Computed Tomography (CT) – Body
Computed Tomography (CT) – Chest
Computed Tomography (CT) – Head
Computed Tomography (CT) – Sinuses
Computed Tomography (CT) – Spine
Coronary Computed Tomography Angiography (CTA)

Cardiac CT for Calcium Scoring
A cardiac CT scan for coronary calcium is a non-invasive way of obtaining information about the presence, location and extent of calcified plaque in the coronary arteries—the vessels that supply oxygen-containing blood to the heart wall. Calcified plaque is a build-up of fat and other substances, including calcium, and is a sign of atherosclerosis a disease of the vessel wall, which is called coronary artery disease (CAD). People with this disease have an increased risk for heart attacks. In addition, over time, progression of plaque build up (CAD) can narrow the arteries or even close off blood flow to the heart. The result may be painful angina in the chest or a heart attack.
Because calcium is a marker of CAD, the amount of calcium detected on a cardiac CT scan is a helpful prognostic tool. The findings on cardiac CT are expressed as a calcium score. Another name for this test is coronary artery calcium scoring.The goal of cardiac CT for calcium scoring is to determine if CAD is present and to what extent, even if there are no symptoms. It is a screening study that may be recommended by a physician for patients with risk factors for CAD but no clinical symptoms.

Computed Tomography (CT) – Abdomen and Pelvis
CT of the abdomen and pelvis is typically used to help diagnose the cause of abdominal or pelvic pain and diseases of the internal organs, bowel and colon, such as:
• infections such as appendicitis, diverticulitis or infected fluid collections, aka. abscesses.
• inflammatory processes such as pancreatitis, pyelonephritis or inflammatory bowel disease such as Crohn’s disease.
• cancers of the colon, liver, kidneys, pancreas and bladder as well as lymphoma.
• kidney and bladder stones.
• abdominal aortic aneurysms (AAA) and other diseases of the vessels such as blood clots and abnormal narrowings or stenoses of the vessels.
CT scanning of the abdomen/pelvis is also performed to:
• quickly identify injuries to the liver, spleen, kidneys or other internal organs in cases of trauma.
• guide biopsies and other procedures such as abscess drainages and minimally invasive tumor treatments.
• plan for and assess the results of surgery. stage, plan and properly administer radiation treatments for tumors.

Computed Tomography (CT) – Angiography
CT angiography is used to examine blood vessels in key areas of the body. Some of the most common uses of the procedure include to:
• identify disease and aneurysms in the aorta, both in the chest and abdomen, or in other major blood vessels
• detect atherosclerosis disease in the carotid artery of the neck, which may limit blood flow to the brain and cause a stroke
• identify a small aneurysm or arteriovenous malformation inside the brain
• detect atherosclerotic disease that has narrowed the arteries to the legs and help prepare for endovascular intervention or surgery
• indicate disease in the renal artery or visualize blood flow to help prepare for a kidney transplant
• guide surgeons making repairs to diseased blood vessels, such as implanting or evaluating a stent
• detect injury to one of more arteries in the neck, chest, abdomen, pelvis or extremities in trauma patients
• evaluate the details of arteries feeding a tumor prior to surgery or other procedures such as chemoembolization or selective internal radiation therapy
• identify dissection or splitting in the aorta in the chest or abdomen or its major branches
• show the extent and severity of atherosclerosis in the coronary arteries
• plan for a surgical operation, such as coronary bypass
• sample blood from specific veins in the body to detect any endocrine disease
• examine pulmonary arteries in the lungs to detect pulmonary embolism (blood clots from leg veins)

Computed Tomography (CT) – Body
CT Body is:
• one of the best and fastest tools for studying the chest, abdomen and pelvis because it provides detailed, cross-sectional views of all types of tissue.
• often the preferred method for diagnosing many different cancers, including lung, liver and pancreatic cancer, since the image allows a physician to confirm the presence of a tumor and measure its size, precise location and the extent of the tumor’s involvement with other nearby tissue.
• an examination that plays a significant role in the detection, diagnosis and treatment of vascular diseases that can lead to stroke, kidney failure or even death. CT is commonly used to assess for pulmonary embolism (a blood clot in the lung vessels) as well as for abdominal aortic aneurysms (AAA).
• invaluable in diagnosing and treating spinal problems and injuries to the hands, feet and other skeletal structures because it can clearly show even very small bones as well as surrounding tissues such as muscle and blood vessels.
The Body CT examination to:
• quickly identify injuries to the lungs, heart and vessels, liver, spleen, kidneys or other internal organs in cases of trauma
• guide biopsies and other procedures such as abscess drainages and minimally invasive tumor treatments
• plan for and assess the results of surgery
• plan and properly administer radiation treatments for tumors

Computed Tomography (CT) – Chest
CT of the chest is used to:
• further examine abnormalities found on conventional chest x-rays
• help diagnose the cause of clinical signs or symptoms of disease of the chest
• detect and evaluate the extent of tumors that arise in the chest, or tumors that have spread there from other parts of the body
• assess whether tumors are responding to treatment
• help plan radiation therapy
• evaluate injury to the chest, including the blood vessels, lungs, ribs and spine
Chest CT can demonstrate various lung disorders, such as:
• lung cancer
• old or new pneumonia
• tuberculosis
• emphysema
• bronchiectasis
• inflammation or other diseases of the pleura, the membrane covering the lungs
• diffuse interstitial lung disease

A CT angiogram (CTA) may be performed to evaluate the blood vessels (arteries and veins) in the chest. This involves the rapid injection of an iodine-containing fluid (contrast material) into a vein while obtaining numerous, thinner CT images. It is very commonly performed today to exclude blood clots within the arteries that supply the lungs ( also known as pulmonary emboli)

Computed Tomography (CT) – Head
CT scanning of the head is typically used to detect:
• bleeding, brain injury and skull fractures in patients with head injuries
• bleeding caused by a ruptured or leaking aneurysm in a patient with a sudden severe headache
• a blood clot or bleeding within the brain shortly after a patient exhibits symptoms of a stroke
• a stroke, especially with a new technique called Perfusion CT
• brain tumors
• enlarged brain cavities (ventricles) in patients with hydrocephalus
• diseases or malformations of the skull
CT scanning is also performed to:
• evaluate the extent of bone and soft tissue damage in patients with facial trauma, and planning surgical reconstruction
• diagnose diseases of the temporal bone on the side of the skull, which may be causing hearing problems
• determine whether inflammation or other changes are present in the paranasal sinuses
• plan radiation therapy for cancer of the brain or other tissues
• guide the passage of a needle used to obtain a tissue sample (biopsy) from the brain
• assess aneurysms or arteriovenous malformations through a technique called CT angiography.

Computed Tomography (CT) – Sinuses
CT of the sinuses primarily is used to:
• detect the presence of inflammatory diseases.
• plan for surgery by defining anatomy or giving further information about tumors of the nasal cavity and sinuses.
• evaluate sinuses that are filled with fluid or thickened sinus membranes. help diagnose sinusitis.

Computed Tomography (CT) – Spine
Perhaps the most frequent use of spinal CT is to detect—or rule out—spinal column damage in patients who have been injured.
CT scanning of the spine is also performed to:
• evaluate the spine before and after surgery.
• detect various types of tumor in the vertebral column, including those that have spread there from another area of the body. Some tumors that arise elsewhere are first identified by finding deposits of malignant cells (metastases) in the vertebrae; prostate cancer is an example.
• help diagnose spinal pain. One of the most common causes of spinal pain that may be diagnosed by CT is a herniated intervertebral disk, sometime with CT myelography
• accurately measure bone density in the spine and predict whether vertebral fractures are likely to occur in patients who are at risk of osteoporosis.
• guide diagnostic procedures such as the biopsy of a suspicious area to detect cancer, or the removal of fluid from a localized infection (abscess).
In patients with narrowing of the spinal canal, vertebral fracture, infection or degenerative disease such as arthritis, CT of the spine may provide important information when performed alone or in addition to magnetic resonance imaging (MRI).

Coronary Computed Tomography Angiography (CTA)

The past thirty years have been witness to continuous improvement in Computed Tomographic (CT) technology with the introduction of substantial advancements in x-dectors, x ray tube generators, circuitry, computers, and software algorithms. All of the these advancements have had the combined effect to dramatically increase the speed of image acquisition and volume coverage. These advancements have progressively allowed CT angiography to be rapidly applied to blood vessel analysis throughout the body and to largely replace invasive catheter angiography for diagnostic purposes. Imaging of the beating heart, however, has up until recently presented additional challenges related to motion artifact introduced by the cardiac motion.

The current generation of 64 slice CT scanners has now opened CT angiography to be applied to analysis of the coronary arteries supply the heart. These advanced scanners acquire 64 slices per rotation of the gantry around the patient and rotate around the patient in less than 500 ms (half of a second). Because the coronary arteries and other cardiac structures move rapidly during the cardiac cycle, these structures have been until now the most difficult to image. Coronary CTA employs cardiac ECG monitoring so that the acquired data can be retrospectively reconstructed at different phases of the cardiac cycle. This further reduces motion artifact and allows for the images of high diagnostic quality.

The rapid improvements in spatial and temporal resolution of the latest generation of 64 slice CT scanners have been complemented by the development of advanced image processing workstations. RIMA physicians currently interpret CCTA studies on five different 64 slice CT scanners and each of these scanners is directly linked to a state of art server based workstation developed by GE Medical Systems (AW Server). This allows RIMA’s team of specialist radiologists to interpret these studies independent of where they were acquired and immediately upon completion of the study. As an increasing number of these studies are performed on an emergency basis, the value of our technology infrastructure is further underscored.

The principal application of CCTA is in the visualization of the coronary arteries and exclusion of coronary artery disease in the low to intermediate risk patient. The negative predictive value of CCTA approaches an astounding 100%. As CCTA can visualize early disease prior to it becoming detectable on invasive cardiac catheterization procedures, it may begin to be used to clear patients for surgery as an alternative to cardiac stress testing. CCTA can also be utilized to assess the patency of bypass grafts and stents, in the evaluation of cardiac and pericardial anatomic abnormalities, and in the emergency setting in conjunction with CTA of the pulmonary arteries and aorta as a “triple” rule out for patients presenting with acute chest pain syndrome.