Computed Tomography II – RAD 473 Prepared By: Ala’a Ali Tayem Abed

ABDOMEN CT SCAN

Abdomen CT is used to: An Abdominal CT scan makes detailed pictures of the structures inside your belly (abdomen). This test may be used to look for: Cause of Abdominal Pain or Swelling. Hernia. Cause of a Fever. Masses and Tumors, including Cancer. Infections or Injury. Kidney Stones. Appendicitis. The abdominal CT scan may show problems with the gallbladder, liver, or pancreas. The abdominal CT scan may reveal kidney problems. The abdominal CT scan may show problems with Vessels.

Protocol: Patient Position: Supine and Arms elevated above Head. Topogram Direction: Craniocaudal. Scan Start / End Locations: Superior to Diaphragm to Lesser Trochanters. Breath Hold: Inspiration. KV / effective mAs / Rotation time (sec): 120 kVp / 250 mAs / 0.75 sec FOV: large 40 cm. Slice Thickness: 5 – 7 mm. Contrast: Oral: Barium Sulfate (BaSO4) or 30 mL Omnipaque in 1000 mL, 1-2 hours before scan. IV: Omni 300 100 ml. Omni 350 100 ml, for Angiogram. Contrast Rate: 2.5 to 4.0 cc per sec. Arterial: 15 sec, or Bolus Tracking. Portal Venous: 55 sec Delay. Venous Only: 70 sec Delay.

Preparations: If a Patient is going to have a Contrast Injection, he or she should not have anything to eat or drink for a few hours (4-6) before the CT scan because the injection may cause Stomach Upset. To receive the Contrast Injection, an IV canula is inserted into the Arm just prior to the scan. The Contrast then enters the Body through the IV. Prior to most CT scans of the Abdomen and Pelvis, it is important to drink an oral contrast agent that contains Dilute Barium. This Contrast Agent helps the radiologist identify the gastrointestinal tract (stomach, small and large bowel), detect abnormalities of these organs, and to separate these structures from other structures within the abdomen. The patient will be asked to drink Barium Sulfate (BaSO4) or 30 mL Omnipaque (Iohexol 300 mgI/mL) in 1000 mL spread out over 1.5 to 2 hours.

Different abdominal Protocols

ABDOMEN-KIDNEY STONE NO ORAL CONTRAST. NO IV CONTRAST. BREATH HOLD: SUSPENDED EXPIRATION. SLICE THICKNESS: 5mm. Recon. Slice Thickness: 1 - 2mm. START LOCATION: ABOVE KIDNEYS. END LOCATION: SYMPHYSIS PUBIS.

ABDOMEN- KIDNEYS ORAL CONTRAST: 500 ml 1 HOUR BEFORE SCAN, 200 ml JUST BEFORE SCAN I.V. CONTRAST: 3 - 5 ml/sec, SCAN DELAY:1. NONCONTRAST. 2. ARTERIAL: 15 SEC, (Bolus Tracking) 3.VENOUS: 70 SEC. 4. NEPHROGRAM: 90 SEC. 5. PYELOGRAM: 3 - 5 MIN. BREATH HOLD: SUSPENDED EXPIRATION SLICE THICKNESS: 5 -7.5 mm. START LOCATION: LUNG BASES. END LOCATION: ILIAC CREST.

LIVER SINGLE PHASE ORAL CONTRAST: 500 ml 1 HOUR BEFORE SCAN, 200 ML JUST BEFORE SCAN. I.V. CONTRAST: 2.5 - 3 ml / sec, 100 - 150 ml. SCAN DELAY: 55 sec. BREATH HOLD: SUSPENDED EXPIRATION. SLICE THICKNESS: 5 - 7.5 mm START LOCATION: LUNG BASES. END LOCATION: ILIAC CREST.

ABDOMEN LIVER MASS-3 PHASE ORAL CONTRAST: 500 ml 1 HOUR BEFORE SCAN, 200 ML JUST BEFORE SCAN I.V. CONTRAST: 4 - 5 ml/sec, 100 - 150 ml. SCAN DELAY: 1. NON-CONTRAST. 2. ARTERIAL 15 SEC, (Bolus Tracking). 3. PORTAL 55 SEC. BREATH HOLD: SUSPENDED EXPIRATION. SLICE THICKNESS: 4 - 5 mm. START LOCATION: LUNG BASES. END LOCATION: ILIAC CREST.

NON-CONTRAST ARTERIAL PORTAL

ABDOMEN- PANCREAS ORAL CONTRAST: 500 ml 1 HOUR BEFORE SCAN, 200 ml 15 MINUTES BEFORE SCAN. I.V. CONTRAST: 2 - 4 ml/sec, 100 - 150 ML. SCAN DELAY: 30 - 35 sec. BREATH HOLD: SUSPENDED EXPIRATION. SLICE THICKNESS: 3 - 5 mm THROUGH. PANCREAS. START LOCATION: LUNG BASES. END LOCATION: ILIAC CREST.

ABDOMEN + PELVIS APPENDICITIS OR DIVERTICULITIS ORAL CONTRAST: 800 cc 1 -2 HOURES BEFORE SCAN, 200 ML JUST BEFORE SCAN. I.V. CONTRAST: 1.5 - 2 ml/sec, 100 - 150 ml. SCAN DELAY: 75 - 80 sec. BREATH HOLD: SUSPENDED EXPIRATION. SLICE THICKNESS: 7 mm + 3 – 5 mm LOWER START LOCATION: LUNG BASES. END LOCATION: SYMPHYSIS PUBIS. 7 mm 3-5 mm

CTA OF THE ABDOMEN I.V. CONTRAST: 4 - 5 ml/sec, 100 - 150 ml. SCAN DELAY: 15 sec, (Bolus Tracking). BREATH HOLD: SUSPENDED EXPIRATION. SLICE THICKNESS: 2.5 – 3ml. START LOCATION: ABOVE AORTIC ARCH. END LOCATION: BELOW ILIAC CREST.

ABDOMINAL CYST An abdominal CT scan revealed a large right upper quadrant cyst measuring 14x17x21 cm ( lateral, anteroposterior and craniocaudal)There was mass effect upon the liver and duodenum. The cyst had a thin smooth wall with internal fluid and high density material consistent with a blood clot.

HEPATOMEGALY

SPLENOMEGALY

ASCITES Ascites is the abnormal collection of fluid in the abdominal cavity, most often as a result of chronic liver disease.

APPENDICITS An axial slice of a CT scan done with the use of intravenous and oral contrast is presented. The arrow points to an area of soft tissue indurations within the retrocecal fat. There is a rim like area of higher attenuation within this area. The structure is fluid filled. These features are compatible with a diagnosis of acute appendicitis and the presence of rupture cannot be excluded.

DIVERTICULITS Diverticulitis is inflammation or infection of small pouches, called diverticula, that develop along the walls of your intestines. The formation of the pouches themselves is a relatively benign condition known as diverticulosis. The pouches can develop anywhere on the digestive tract, but they most commonly form at the end of the descending and sigmoid colons, and they also frequently occur on the first section of the small intestine (although they rarely cause problems there).

DIVERTICULITS

ABDOMINAL ABSCESS Psoas abscess (blue arrow), and abscess dissecting anteriorly in transversalis fascia. CT scan with liver abscess (coronal view).

BOWEL OBSTRUCTION

LIVER METS Lung cancer, small cell. Contrast-enhanced CT scan of the abdomen. Axial section through the liver shows multiple hypo attenuating areas in the liver. Poorly defined margins, attenuation greater than that of water, and scattered distribution in a patient with known lung cancer is most consistent with metastatic disease.

LIVER CIRRHOSIS Arterial Pre-Contrast Delay Porto Venous

HEMANGIOMA A cavernous hepatic hemangioma is the most common non-cancerous tumor of the liver. It is believed to be a congenital defect, and is usually not discovered until medical pictures are taken of the liver for some other reason.

CHOLECYSTITIS CHOLELITHIASIS Blocked Biliary System

PANCREATITIS

PANCREATIC CANCER a | In the late arterial contrast-enhancement phase, the tumor can be seen in the pancreatic head (arrows). The hyper vascular (bright) liver metastases are clearly depicted. b | In the venous contrast-enhancement phase, the same nonfunctioning pancreatic NET is less well-depicted but is still evident because of its size. In this phase, the encasement of the superior mesenteric vein by the tumor is evident (arrow), but the liver metastases can no longer be visualized; merely one lesion is seen as a distortion of the hepatic contour (arrowhead).

RENAL CYST NO CONTRAST CONTRAST

Pyelonephritis Xanthogranulomatous Pyelonephritis – Coronal CT of the abdomen and pelvis with intravenous contrast reveals right sided hydronephrosis, cortical thinning, and delayed enhancement. There is extension of the inflammatory process through the perirenal space to the adjacent abdominal wall (yellow arrow). The normal kidney is indicated by the green arrow. Xanthogranulomatous Pyelonephritis – Axial CT of the abdomen at the level of the kidneys shows a right sided percutaneous nephrostomy tube (yellow arrow) which has been placed to drain the chronically obstructed and infected right kidney. The normal left kidney is indicated by the green arrow.

KIDNEY CANCER

RENAL STONE Renal stone. Spiral (unenhanced) CT scan demonstrating a right renal stone (yellow arrow).

HYDRONEPHROSIS Unenhanced abdominal CT with hydronephrosis and hydroureter (double green arrow)and perirenal bands (blue arrow)

HORSESHOE KIDNEYS

ADRENAL METS

PHEOCHROMOCYTOMA Phaeochromocytoma is a tumor of the adrenal gland that causes excess release of epinephrine and norepinephrine, hormones that regulate heart rate and blood pressure.

BLADDER CANCER

ABDOMINAL AORTIC ANEURYSM (AAA)

AAA Contrast coronal CT scan demonstrating a ruptured saccular aneurysm of the infrarenal aorta with surrounding thrombus/hematoma and a focus of active extravasation inferiorly (arrow). Abdominal Aortic Aneurysm

Renal Artery Stenosis

Image shows significant disease at aortic bifurcation and iliac artery aneurysm. Type I atherosclerosis with occlusive disease limited to infrarenal aorta and common iliac arteries.

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