MR imaging of abdominal aortic aneurysm.

Eight patients with abdominal aortic aneurysms were evaluated with magnetic resonance imaging (MRI). The MRI findings were verified by surgery in five, compared with ultrasonography in eight, with computed tomography in four and with angiography in eight patients. The size and extent of aneurysm, presence of thrombus, size of the residual lumen and involvement of branch vessels were readily demonstrated by MRI. Whilst sonography should remain the screening procedure of choice in patients with suspected abdominal aortic aneurysms, this early experience suggests that MRI may prove to be a noninvasive and adequate means of evaluating patients prior to surgery.     

CT of inflammatory abdominal aortic aneurysm: development from an uncomplicated atherosclerotic aneurysm.

The etiology and natural history of inflammatory abdominal aortic aneurysm are poorly understood. We report a case of inflammatory abdominal aortic aneurysm that developed from an uncomplicated aneurysm over a period of 6 1/2 months.     

Detection of an abdominal aneurysm by indium-111 platelet imaging

The authors report a case in which In-111 platelet imaging provided uniquely useful information in the discovery of an abdominal aortic aneurysm. This case illustrates the potential usefulness of this procedure in the detection of unsuspected sites of thrombogenic vascular disease.     

Indium-111 leukocyte imaging in appendicitis

Indium-111-labeled leukocyte scintigraphy was applied to the diagnosis of acute appendicitis. Thirty-two patients observed in the hospital for possible appendicitis were prospectively studied. Scanning was done 2 hr after radiopharmaceutical injection. Thirteen scans were positive for acute appendicitis, and all but one were confirmed at laparotomy. In addition, two cases of colitis and two cases of peritonitis were detected. Of 15 negative studies, 11 had a benign course. Four patients with negative studies had laparotomy; two were found to have appendicitis and two had a normal appendix. Of 14 proven cases of appendicitis, 12 scans were positive for appendicitis with one false-positive scan, providing a sensitivity of 86%. Specificity was 93%: all negative cases except one had negative scans. Overall accuracy was 91% (29 of 32), comparing favorably with the accepted false-positive laparotomy rate of 25%. Use of In-111-labeled leukocyte scintigraphy serves to reduce the false-positive laparotomy rate and to shorten the clinical observation time in patients with acute appendicitis.     

Indium-111 leukocyte imaging. The skeletal photopenic lesion

Photon-deficient lesions in the skeleton occasionally are seen in In-111 leukocyte imaging. Although the findings usually indicate past surgery, previous infections, or radiation therapy effect, they may be due to metastatic disease or active or partially treated infection.     

Indium-111 chloride imaging with ununited fractures

Twenty patients with ununited fractures and a suspicion of infection had In-111 chloride imaging. Surgically obtained cultures were positive for infection in 12 and negative in eight patients. In-111 chloride images were positive in all 12 patients with infection but also were positive in six of the patients with negative cultures. It is not possible to differentiate infected from noninfected ununited fractures by In-111 chloride imaging.     

The role of gadolinium-enhanced MR imaging in the preoperative evaluation of inflammatory abdominal aortic aneurysm

Inflammatory abdominal aortic aneurysm is an uncommon variant of abdominal aortic aneurysms. Thorough preoperative imaging of the extent of the aneurysm and inflammation and the associated complications are crucial in the management of this condition. We report a case of inflammatory abdominal aortic aneurysm where, after the initial contrast-enhanced CT, gadolinium-enhanced MR imaging was used to define the true extent of the inflammation and differentiate inflammation from mural thrombus at the iliac extension of the aneurysm. The imaging appearances are presented and the impact of MR imaging on further surgical management options including endovascular repair are discussed.     

The role of gadolinium-enhanced MR imaging in the preoperative evaluation of inflammatory abdominal aortic aneurysm

European Radiology - Inflammatory abdominal aortic aneurysm is an uncommon variant of abdominal aortic aneurysms. Thorough preoperative imaging of the extent of the aneurysm and inflammation and...     

Indium-111 autologous leukocyte imaging in pancreatitis

Thirty-nine patients with acute pancreatitis have been assessed using a prognostic factor grading system, abdominal ultrasound, and autologous leukocyte imaging. Both prognostic factor grading and leukocyte imaging can accurately assess the severity of the disease early in its course. All patients with a negative indium-labeled leukocyte image recovered without sequelae, whereas five of the 12 patients with a positive image developed complications, including two deaths. Abdominal ultrasound is of no value in assessing severity, but is a useful method of detecting those patients with gallstone-associated disease. In patients with suspected abscess formation following acute pancreatitis, indium leukocyte imaging does not differentiate between fat necrosis and abscess formation. In this situation, computerized tomography should be carried out before laparotomy is undertaken.     

Complications of endovascular repair for thoracic and abdominal aortic aneurysm: an imaging spectrum.

Endovascular stent-graft implantation is an alternative to conventional open surgery for the treatment of aortic aneurysm. Forty-nine consecutive patients with aortic aneurysm (thoracic, n = 17; infrarenal, n = 32) were treated with endovascular stent-graft implantation. Complications occurred in 25 patients (two patients had two complications): endoleak (n = 13), graft thrombosis (n = 5), graft kinking (n = 2), pseudoaneurysm caused by graft infection (n = 1), graft occlusion (n = 1), shower embolism (n = 1), perforation of mural thrombus by means of inadvertent penetration of delivery system (n = 1), colon necrosis (n = 1), aortic dissection (n = 1), and hematoma at the arteriotomy site (n = 1). Imaging findings were analyzed for spiral computed tomography, plain abdominal radiography, transesophageal echocardiography, and digital subtraction angiography. Since some of these complications are fatal, radiologists need to instantly and accurately recognize them. Awareness and understanding of possible complications should help ensure a safe, successful procedure.     

Indium-111 chloride imaging in chronic osteomyelitis

Sixty-eight patients with clinically suspected chronic osteomyelitis were studied with [111In]chloride. Fifty-four images were categorized as true positive; seven were categorized as true negative. There were four false-positive studies, two of which were associated with healing cancellous bone grafts. There were three false-negative studies in patients previously treated with long-term antibiotic therapy. Images in eight noninfected healing fractures 3 to 8 mo old were normal. Three patients with infected total hip prostheses had positive images. Two patients with loose prostheses had negative images. This study shows that [111In]chloride imaging is an accurate way to localize chronic osteomyelitis and may overcome some of the disadvantages of [67Ga]citrate such as localization in noninfected healing fractures and in some loose [67Ga]citrate such as localization in noninfected healing fractures and in some loose prostheses.     

Indium-111-leukocyte imaging in acute cholecystitis

Eleven patients with suspected acute cholecystitis underwent sequential 99mTc-iminodiacetic derivative (IDA) and 111In-white blood cell (WBC) imaging to determine if 111In-WBCs accumulate within an acutely inflamed hemorrhagic gallbladder wall and, thus, could be employed as a reasonable alternative to 99mTc-IDA scintigraphy in detecting acute cholecystitis. Seven patients had surgically confirmed acute cholecystitis. Of these cases, five had a true-positive 99mTc-IDA and 111In-WBC, one an indeterminate 111In-WBC and true-positive 99mTc-IDA, and one a true-positive 111In-WBC and false-negative 99mTc-IDA scan. The remaining four patients did not have acute cholecystitis. All visualized their gallbladder within 1 hr after 99mTc-IDA administration and none had 111In-WBC gallbladder wall uptake. Both 111In-WBC and 99mTc-IDA scintigraphy accurately detected acute cholecystitis: hepatobiliary scintigraphy demonstrated a cystic duct obstruction and 111In-WBC imaging detected the inflammatory infiltrate within the gallbladder wall. The sensitivity and specificity of each was 86% and 100%, respectively.     

Indium-111 labeled leukocyte imaging following hepatic artery embolization

The use of In-111 labeled leukocytes for abscess localization is becoming well established. The first report of In-111 imaging following hepatic embolization is presented. A 45-year-old man with adenocarcinoma of the colon and metastatic liver disease was treated for intractable pain using particulate embolization of the hepatic artery. In-111 leukocyte imaging was performed to rule out abscess formation. The distribution of the labeled leukocytes demonstrated hepatic uptake commensurate with Tc-99m sulfur colloid (SC) images. Areas of embolization did not accumulate tracer. Pathologic examination at autopsy correlated with the distribution of the labeled leukocytes. Thus, therapeutic embolization did not alter the normal distribution of this tracer in functional hepatic tissue.     

Indium-111 leukocyte imaging in patients with rheumatoid arthritis

This study evaluates the usefulness of labeled leukocyte imaging in patients with rheumatoid arthritis. In 33 patients, the incidence of pain and swelling in 66 wrist joints and 66 knee joints was compared with the accumulation of [111In]leukocytes. No accumulation of [111In]leukocytes was seen in any of the patients' wrists (0/12) or knee joints (0/14) when both pain and swelling were absent. In contrast, 93% (25/27) of wrist joints and 80% (24/30) of knee joints with both pain and swelling were positive by [111In]leukocyte scintigraphy. There was little correlation between the stage of the disease, as determined by radiography, and [111In]leukocyte accumulation. This study suggests that [111In]leukocyte imaging may be a reliable procedure for monitoring the activity of rheumatoid arthritis, especially for confirming the lack of an ongoing inflammatory response.     

Indium-111 chloride imaging in the detection of infected prostheses

Thirty-three patients with painful joint prostheses and a suspicion of infection were imaged with [111In]chloride. A final diagnosis was established by culture in 19. Of these, 12 were categorized as true positives and three as true negatives. There were two false-positive studies, occurring in patients with knee prostheses. In both, the culture was obtained by aspiration. Two false negatives were in patients with hip prostheses, one of whom had been on long-term antibiotic suppressive therapy. The sensitivity was 86%, specificity 60%, and accuracy 79%. Seventeen of the proven cases had bone imaging prior to [111In]chloride imaging. All 17 static images were positive and were not helpful in differentiating loosening from infection. Using increased uptake on the blood-pool image as a criteria for infection, the sensitivity was 89%, but the specificity was 0. Adding flow studies made little difference in interpreting the blood-pool images. This study shows that [111In]chloride accurate in evaluating infection in prosthesis than bone imaging.