Computed Tomography of Thorax, Abdomen, and Pelvis

CTTAP ●​ Computed tomography of Thorax, Abdomen, and Pelvis ●​ Cross sectional imaging study ○​ X-ray ○​ Computer processing ○​ Assess internal organs ■​ Chest ■​ Abdomen ■​ Pelvic cavity ○​ Detailed image on solid body ■​ Bones ■​ Organs ■​ Blood vessels ■​ Soft tissues Could also search for abnormal growth within the body ●​ CTTAP used for Dx ○​ Detection on tumors and metastases ○​ Internal injuries identification ○​ Inflammation identification within body ○​ Abdominal/chest pain evaluation ○​ Cancer stage monitoring ○​ Vascular abnormalities detection ●​ Thorax ○​ Lungs ○​ Heart ○​ Great vessels ■​ Aorta ■​ Pulmonary arteries ○​ Mediastinum ○​ Esophagus ○​ Pleura ○​ Ribs + thoracic spine ●​ Abdomen ○​ ○​ ○​ ○​ ○​ ○​ ○​ ○​ ●​ Pelvis ○​ ○​ ○​ Liver Gallbladder Pancreas Spleen Kidney Adrenal glands Small and large intestine Abdominal Aorta Urinary bladder Rectum Reproductive organs ■​ Uterus ■​ Ovaries ■​ Prostate ○​ Pelvic bones ○​ Lymph nodes Indications ●​ Cancer staging + follow-up ●​ Trauma assessment ●​ Abdominal/chest pain that can not be explained ●​ Infection ●​ Abscess ●​ Organ injury suspection ●​ Metastasis detection These could also be used in evaluation of suspected symptoms ●​ Gastrointestinal bleeding CTA ●​ CT scan with contrast to visualize blood vessels ○​ X-rays ○​ IV contrast - iodine dye ●​ Will show bodily structures such as: ○​ Arteries ○​ Veins ○​ Blood flow ○​ Blockage ○​ Aneurysms ○​ Clots Why is CTA done - Indications ●​ Pulmonary embolism - look for clot in lungs ●​ Stroke - identify blocked brain artery ●​ Aortic dissection - tear in aorta ●​ Aneurysm - look for dilation ●​ Trauma - internal bleeding ●​ Coronary artery disease - Blocked heart arteries ●​ Peripheral artery disease - Leg artery blockage Common types of CTA ●​ CTA chest - Pulmonary embolism, aorta ●​ CTA head - Stroke,aneurysm ●​ CTA neck - Carotid artery ●​ CTA coronary - Heart arteries ●​ CTA Abdomen - Aorta, renal arteries ●​ CTA legs - Peripheral arteries Procedures ●​ Inserted IV lines ●​ Injection of Iodine contrast ●​ CT scanner makes rapid image ●​ Computer will create 3D image of blood vessels ~5-10 min consumed Contraindication ●​ Kidney failure - Contrast damages kidney ●​ Contrast allergy - Allergic response ●​ Pregnancy - Radiation ●​ Unstable pts - Cannot go to CT Risk of CTA ●​ Contrast-induced nephropathy - kidney damage ●​ Allergic reaction - Contrast ●​ Radiation exposure - CT scan ●​ Contrast extravasation - IV leak CTA vs other imaging techniques ●​ CTA primarily used for blood vessel imaging ●​ CT = organs ●​ MRI = Soft tissue ●​ MRA = Blood vessels, but unlike CTA there is no radiation ●​ Ultrasound = Blood flow ●​ X-ray = Bones Ex ●​ Suspected PE = CTA Chest ●​ Suspected stroke = CTA Head ●​ Aortic dissection = CTA Chest ●​ Aneurysm = CTA ●​ Trauma bleeding = CTA Prior to CTA ●​ Certain levels, and question must be asked ○​ Creatininine check - kidney function ○​ Ask about contrast allergy ○​ Check for IV access, and ensure. Post CTA ●​ Drink fluids to wash out contrasts ●​ Monitor on kidney function ●​ Watch for allergic reactions CTA = CT with contrast to see vessels and is used for PE, stroke, and aortic dissection. It is a fast test method to show clear image of arteries. Cannot be used used if pts has kidney failure V/Q scan ●​ Nuclear medicine test used to evaluate ventilation and perfusion ○​ Used to detect Pulmonary embolism (PE) ●​ V = Ventilation ○​ Air reaching the lungs ●​ Q = Perfusion ○​ Blood reaching the lungs ●​ It is to compare the airflow with the blood flow to the lungs Mechanisms ●​ Ventilation scan ○​ Pts inhales radioactive gas such as xenon or technetium ○​ Will show air distribution in lungs ●​ Perfusion Scan ○​ Radioactive tracers injected into IV ○​ Travels to lung via blood vessels ○​ Will show blood flow in lungs Interpretation ●​ Normal ○​ Ventilation = perfusion (matching) ●​ Pulmonary Embolism ○​ Ventilation normal ○​ Perfusion decreased ○​ V/Q mismatch ○​ Air getting in ○​ Blood is not blocked by clot Other patterns ●​ Mismatch defect = both are decreased and will lead to lung disease ●​ Mismatch (normal V, decreased Q) = PE ●​ Normal scan = PE unlikely Indications ●​ Suspected pulmonary embolism ●​ CTA cannot be used in some consequences ○​ Kidney failure ○​ Contrast allergy ○​ Pregnancy Contraindication ●​ Very few contraindication ●​ Relative to severe lung disease (hard to interpret) Adv ●​ No iodinated contrast = safe to use for kidneys ●​ Lower radiation compared to CT = significant advantage for breast tissue ●​ Better option for: ○​ Pregnancy ○​ Renal failure Disadv ●​ Less specific compared to CTA ●​ Can be indeterminate ●​ Result could be affected by underlying lung disease CTA example VQ scan vs CTA ●​ VQ best used for PE- when CTA contraindicated ●​ CTA best used in PE (first line) ●​ V/Q scan does not need iodine as a contrast agent but CTA need it. Therefore V/Q scan does not follow with kidney risk while CTA follows with risk ●​ V/Q scan has fairly lower radiation then CTA ●​ CTA has higher accuracy then V/Q scan (moderate) Cx ●​ First line for PE ○​ CTA ●​ Use of V/Q scan ○​ Kidney failure ○​ Contrast allergy ○​ Pregnancy