CT virtual intravascular endoscopy of abdominal aortic aneurysms treated with suprarenal endovascular stent grafting

Background: We investigated the clinical applications of virtual intravascular endoscopy (VIE) in patients with abdominal aortic aneurysms (AAA) treated by endovascular stent grafting with a suprarenal component. Methods: Thirty-four patients with AAA undergoing endovascular stent grafting were included in the study (28 male, six female; mean age = 76 years). Helical computed tomography (CT) scanning was performed within 1 week after stent graft implantation. All patients received a Zenith/AAA endovascular graft with uncovered suprarenal struts 2.5 cm long placed around the level of the renal arteries. VIE images were created for each patient. The follow-up periods ranged from 3 to 18 months (mean = 8.3 ± 3.7 months). Results: Three of 34 celiac arteries, 22 of 34 superior mesenteric arteries, 32 of 34 right renal arteries, and 30 of 35 left renal arteries were affected by the suprarenal stent struts (wires) to different extents. VIE was able to demonstrate the struts, arterial ostia, and the strut/ostia configuration. Follow-up CT showed that all of these aortic branches were patent. Conclusion: Our preliminary experience has demonstrated that VIE is a novel imaging technique to visualize the three-dimensional intralumenal relationship of the aortic stent struts to the arterial ostia in patients with AAA after suprarenal stent graft placement.     

Use of thin-section,multidetector row helical CT images for coronal oblique reformations for optimal visualization of structures in the hepatoduodenal ligament

Multidetector row computed tomography (CT) can acquire abdominal images of unprecedented thinness in a single breath-hold. This study investigated whether acquiring source axial images at 1.25 mm as opposed to 2.5 mm would result in a perceptible difference in image quality for coronal oblique reformations. Similarly, the hypothesis that a slice pitch of 3:1 would be superior to 6:1 was evaluated. Twenty-nine CT studies were retrospectively evaluated. The images were divided into four groups: 1.25-mm axial images, pitch 3:1; 2.5-mm axial images, pitch 3:1; 1.25-mm axial images, pitch 6:1; and 2.5-mm axial images, pitch 6:1. Three radiologists evaluated by consensus the coronal oblique reformations for overall image quality and image quality of structures in the hepatoduodenal ligament and of nodal groups. Use of 1.25-mm rather than of 2.5-mm source axial images resulted in statistically significant better scores for overall image quality and visualization of the hepatic artery, portal vein, pancreatic duct, and nodal groups. However, a pitch of 3:1 rather than of 6:1 did not result in significant differences in ratings of image quality. Use of 1.25-mm rather than of 2.5-mm source axial images improves image quality when creating coronal oblique reformations for abdominal anatomy.     

PET-CT detection of abdominal recurrence of ovarian cancer: radiologic–surgical correlation

The diagnosis of recurrent ovarian cancer can be difficult on cross-sectional imaging, and variable sensitivities and specificities have been reported for positron emission tomography (PET). Combined functional and anatomic imaging with PET plus computed tomography (CT) potentially allows for improved detection of tumor masses. We investigated the sensitivity, specificity, and accuracy of PET-CT for the diagnosis of recurrent ovarian cancer. Sixteen women with previously treated ovarian cancer underwent imaging on a combined PET-CT scanner followed by surgery to assess for possible recurrent disease. The fused PET-CT images were retrospectively reviewed for recurrent disease, and the results of PET-CT were compared with the operative notes. Eleven of the 16 patients had recurrent disease at surgery. The sensitivity, specificity, and accuracy of PET-CT for disease detection on a per-patient basis were 72.7%, 40%, and 62.5%, respectively. For cases of malignant adenopathy (n = 7), 100% were detected on PET-CT. For peritoneal lesions no larger than 1 cm (n = 23), 13% were detected on PET-CT. For peritoneal lesions larger than 1 cm (n = 8), 50% were detected on PET-CT. The sensitivity of PET-CT for recurrent ovarian cancer is moderate in patients with low volume disease. A trial involving a larger number of patients with a spectrum of disease volumes is necessary to determine the impact of PET-CT in clinical practice.     

Omental torsion: CT features

A 33-year-old male presented to the emergency department complaining of right upper quadrant pain and was initially diagnosed with acute cholecystitis. Abdominal computed tomography showed a whirling pattern of fatty streaks and vessels within the greater omentum, and surgery confirmed infarction of the omentum secondary to torsion. We report a case of surgically and pathologically proven omental torsion that demonstrated the typical whirling appearance on computed tomography.     

Arteriovenous malformation of the pancreas in a patient with gastrointestinal bleeding: helical CT findings

Dynamic computed tomographic (CT) findings of arteriovenous malformation (AVM) of the pancreas include strong enhancement or conglomeration of small hypervascular spots in the pancreas and early contrast filling of the portal vein during the arterial phase. We describe a case with pancreatic AVM in which we identified enlarged arterial feeders and draining veins as supportive findings of the diagnosis and ulceration into the pancreatic duct as a possible cause of gastrointestinal bleeding at contrast-enhanced CT.     

Small bowel obstruction secondary to Crohn disease

We investigated the computed tomographic (CT) findings in patients with small bowel obstruction (SBO) and Crohn disease (CD). Fourteen patients, seven men and seven women (mean age, 41.3 years), were retrospectively reviewed. All presented with clinical symptoms and signs of SBO. Eleven had a history of CD, whereas three experienced the bowel obstruction as the first manifestation of the disease. On CT, features of complete SBO were seen in nine patients, whereas incomplete obstruction was found in the other five. One patient had CT findings of an adhesive obstruction. The other 13 were diagnosed as having CD-related SBO; a markedly stenotic bowel segment caused the obstruction in one patient, and a thickened-wall small bowel segment with luminal narrowing was evident at the transition zone in the other 12. The mural thickening had a target appearance in seven and homogeneous thickening in the other five. Additional thickened bowel segments were found in five patients and mesenteric involvement was found in 10. Five patients were treated conservatively, and the other nine underwent surgery (one with adhesiolysis only). Resection of the stenotic bowel was performed in six patients and stricturoplasty was done in the other two, with associated intestinal biopsy in one of these two patients. Histopathology revealed findings of active on chronic disease in all. CT is frequently performed for suspected SBO, so radiologists should be aware of the diagnosis of CD, because SBO may be its first manifestation. Alternatively, radiologists can accurately diagnose a CD-related obstruction in a patient with known CD and differentiate it from an obstruction due to adhesions. Patient management in these cases, however, is based most often on the clinical condition.     

Isolated dissection of the superior mesenteric artery

Dissection of the superior mesenteric artery (SMA) not associated with aortic dissection is rare. The purpose of this study is to describe the computed tomographic (CT) findings of this condition. We studied the CT findings of six patients with isolated dissection of the SMA. CT demonstrated thrombosis of the false lumen or intramural hematoma (n = 4) and/or intimal flap (n = 4) in all six patients. Other CT findings were enlarged diameter of the SMA (n = 5), increased attenuation of the fat around the SMA (n = 5), and hematoma in the mesentery with hemorrhagic ascites (n = 1). CT is useful for the diagnosis of isolated dissection of the SMA, and increased attenuation of the fat around the artery is considered the key to the diagnosis when no definite findings are evident.     

Radiologic evaluation in planning surgery of renal tumors

The evolution in diagnostic imaging modalities, mainly in computed tomography (CT) and magnetic resonance imaging (MRI), have made it possible to extend the applications of these techniques from diagnosis to staging and surgical planning. Nowadays, the possibility to present images on different planes with an intrinsic resolution close to that of the original axial sections allows presentation of the kidney on sagittal, coronal, and oblique planes. Three-dimensional reconstructions can be obtained with different methods and have attained excellent image quality. Multidetector spiral CT presently is the best technique for planning surgery, but MRI also enables high-quality images to be obtained if state-of-the-art equipment is available. This update reviews the current status and possibilities of diagnostic imaging modalities in planning surgery of renal tumors.     

Proximal small bowel intussusceptions in adults: CT appearance and clinical significance

Background: According to the clinical literature, intestinal intussusception in adults is rare, is associated with a pathologic lead point, and is usually treated surgically. Nonobstructing small bowel intussusception has been reported as a transient finding on computed tomographic (CT) studies.Methods: We evaluated the radiographic and clinical findings in 24 patients who were found to have 26 proximal small bowel intussusceptions on abdominal CT scans performed for a variety of indications.Results: Twenty patients with intussusceptions had no evidence of small bowel obstruction. The transient and clinically insignificant nature of 22 intussusceptions in these 20 patients was proven radiologically (n = 14), surgically (n = 1), or by clinical follow-up (n = 7). These patients demonstrated a bowel-within-bowel pattern on multiple contiguous images and absence of strangulation or intestinal dilatation. No lead points were demonstrated in these patients. Three other patients had symptoms of low-grade small bowel obstruction and were treated conservatively. Extensive follow-up investigations showed no recurrence of intussusception or a lead point. One patient had high-grade obstructive intussusception with intestinal ischemia and required surgical resection of necrotic bowel.Conclusions: Proximal small bowel intussusceptions are likely to be transient and nonobstructive and unlikely to have a significant lead point.     

Multislice CT angiography of mesenteric vessels

Due to several distinct advantages over conventional angiography (including minimal invasiveness, lower cost, and lower ionizing radiation exposure for patients and staff), computed tomography (CT) angiography has replaced diagnostic conventional angiography in several clinical situations. The recent introduction of multislice CT (MSCT) scanners has significantly improved CT angiographic applications, especially in the evaluation of the mesenteric vasculature. Thin-slice collimation protocols associated with powerful postprocessing procedures allow the display of mesenteric circulation with excellent detail. The purposes of this presentation are (a) to illustrate the imaging technique that can be used to obtain state-of-the-art MSCT angiographic images of the mesenteric vasculature, (b) to review the normal anatomy and anatomic variants of mesenteric vessels, and (c) to illustrate some of the potential clinical applications of MSCT angiography of the mesenteric vessels.     

Virtual CT cholangiography in patients with choledocholithiasis

Background: We evaluated the feasibility and accuracy of virtual computed tomographic cholangiography (VCTC) in detecting choledocholithiasis and imaging anatomic variations of the biliary tree. Methods: Thirty-three consecutive patients with clinical and biological signs of choledocholithiasis underwent spiral CT after intravenous infusion of iotroxindimeglumine. Patients with total serum bilirubin levels above 3 mg/dL were not included in this study. Spiral data sets were used to construct intralumenal images of the biliary tree. The images were reviewed by two abdominal radiologists. The biliary ducts were divided into three segments, so the analysis was based on 99 segments. The diagnosis obtained by VCTC was compared with the final diagnosis established by endoscopic retrograde cholangiography or intraoperative cholangiography. Results: VCTC correctly depicted biliary stones in nine of 10 patients and anatomic variations in all five patients, and no false-positive cases were observed. VCTC showed excellent endolumenal visualization of 87 of 99 segments of the biliary tree. The processing time (9.3 ± 2.1 min) was particularly short. Conclusion: VCTC with intravenous infusion of iotroxindimeglumine may be a feasible clinical tool, with acceptable accuracy in selected cases.     

Preoperative assessment of pancreatic malignancy using endoscopic ultrasound

Background: Endoscopic ultrasound (EUS) has been regarded as the most accurate modality for locoregional staging of pancreatic malignancy. However, several recent studies have questioned this. The current study assessed the accuracy of EUS in determining preoperative resectability of pancreatic neoplasia. Methods: A retrospective review was performed of patients with pancreatic malignancy who had preoperative EUS and underwent surgery. EUS-predicted resectability was compared with surgical resectability. Where available, accuracies of vascular and nodal staging were also assessed. Results: Forty-five patients were identified (mean age = 60 years, age range = 36–79 years). All patients underwent surgical exploration; vascular staging was available in 32 cases and 17 cases underwent surgical resection. The sensitivity, specificity, and accuracy of EUS in determining unresectability were 66%, 100%, and 78% respectively. Overall EUS stage concurred with surgical stage in 56%, greater than surgical stage in 4%, and less than surgical stage in 40%. Vascular staging on EUS had a sensitivity of 69% and a specificity of 100%. Accuracy of nodal staging was 71%. Conclusion: EUS had a high specificity for assessing unresectable pancreatic malignancy. This technique should be used to avoid unnecessary surgical exploration of incurable lesions. However, EUS had only a moderate sensitivity, and a proportion of patients staged preoperatively as having resectable disease will not be surgically resectable.     

Hyperattenuating insulinoma at unenhanced CT

We report a case with insulinoma that showed higher attenuation than normal pancreatic parenchyma on precontrast CT. Pathology of the surgical specimen revealed the presence of psammoma bodies, which were responsible for hyperattenuation. It is worthwhile to obtain precontrast CT in patients suspected of having insulinoma. Received: 22 December 1994/Accepted: 4 February 1995     

Fatal,complete splenic infarction and hepatic infection due to disseminated <Emphasis Type="Italic">Trichosporon beigelii</Emphasis> infection

We report on a 56-year-old woman with acute lymphocytic leukemia who presented with right upper quadrant pain, fever, nausea, and vomiting. Laboratory studies confirmed fungemia with Trichosporum beigelii, and contrast-enhanced computed tomography of the abdomen demonstrated numerous low-attenuation liver lesions and a hypodense spleen with capsular enhancement suggestive of complete splenic infarction. Subsequent splenectomy confirmed that the spleen was completely infarcted and infiltrated with Trichosporum. The patient had a difficult postoperative course and died despite aggressive antifungal therapy.     

Hepatic involvement in hereditary hemorrhagic telangiectasia:

Hereditary hemorrhagic telangiectasia (HHT), also known as Rendu-Osler-Weber disease, is an autosomal-dominant vascular disease characterized by mucocutaneous or visceral angiodysplastic lesions (telangiectases and arteriovenous malformations) that may be widely distributed throughout the cardiovascular system. The recognition of mucocutaneous telangiectases, the occurrence of spontaneous and recurrent episodes of epistaxis, the presence of visceral involvement, and a family history of this disease are the clinical criteria that allow diagnosis. In comparison with skin, lungs, gastrointestinal tract, and brain involvement, hepatic involvement defined by clinical criteria alone has long been considered uncommon. Our experience with a large group of HHT patients, even those asymptomatic for liver involvement, demonstrates that it is more frequent than reported and is characterized by the presence of intrahepatic shunts, disseminated intraparenchymal telangiectases, and other vascular lesions. Congestive cardiac failure, portal hypertension, portosystemic encephalopathy, cholangitis, and atypical cirrhosis have been reported as possible serious complications related to this condition. Thus, a correct diagnosis is important, and diagnostic imaging has a fundamental role in detecting alterations involving the liver. The possibilities to perform a multiphasic study and to provide high-quality multiplanar and angiographic reconstructions, gives multidetector row helical computed tomography the ability to detect and characterize the complex anatomopathologic alterations typical of this disease.     

Imaging of the liver: a survey update of prevailing techniques for conventional CT scanning

Background A survey of the Society of Computed Body Tomography/Magnetic Resonance (SCBT/MR) was performed to assess current techniques in liver CT scanning.Methods The study was designed as an update to a study performed in 1987. The survey was distributed to 67 members of the SCBT/MR at 35 institutions.Results Twenty-six institutions responded. As in 1987, none relied solely on noncontrast scans. In 1987, only 54% (12/22) of institutions performed contrast-enhanced scans as their primary technique compared with 73% (19/26) in 1993. Ionic contrast was used exclusively in the earlier study, whereas in the present study 58% used nonionic contrast in the majority of cases and 38% used nonionic contrast routinely. In 1987, 41% performed scans with a power injector compared with 85% in the present study. Enhanced scans were performed during the contrast bolus in 36% of institutions in 1987 compared with 76% in this study. No institution relied on noncontrast scans alone. In the previous study the delay between injection and scanning was variable (0–60 s), whereas in the present study 83% specified a delay of 21–45s.Conclusion Significant refinements in CT technique, wider use of power injectors, utilization of nonionic contrast, and a more critical approach to optimize liver imaging have created a significant impact on the practice of liver CT.Dr. Silverman is supported in part by a Senior Research and Development Award from General Electric Medical Systems. Additional grant support provided by NY COMED Inc., Mallinckrodt Medical and Medrad Inc.     

Peritoneal metastases from transitional cell carcinoma of the urinary tract: CT and MR imaging

We present three patients with peritoneal metastases from transitional cell carcinoma of the urinary tract. CT scan in one patient showed massive ascites with subtle peritoneal thickening and infiltration of omental fat. We had the opportunity to study the other patients with both CT and MR. Both examinations showed numerous large and small peritoneal implants in the abdomen and pelvis, mostly in the greater omentum. Received: 6/10/96/Accepted: 7/12/96     

Complications after laparoscopic gynecologic procedures: CT findings

Laparoscopic gynecologic surgery has gained worldwide popularity in the past few years, but complications of this new technique do occur. We encountered three patients who developed major complications after laparoscopic gynecologic procedures including perforation of the sigmoid colon, urinary bladder, and ureter. We report the computed tomographic findings of these cases and the diagnostic dilemmas they posed. Received: 9 November 1999/Accepted: 15 December 1999     

Peritoneal serous papillary carcinoma: a reappraisal of CT imaging features and literature review

We evaluated the imaging features of primary serous peritoneal carcinoma (PSPC) on computed tomography (CT) and reviewed the literature. Preoperative CT images of 11 women with PSPC were retrospectively reviewed. The clinical presentations and serum levels of CA-125 were recorded. Special attention was paid to the operative and histopathologic findings of the ovaries. Imaging features were correlated with those in the literature. An elevation of serum CA-125 was found in 91% of cases. The CT findings included ascites (82%), peritoneal nodules or masses (73%), and omental nodules or omental caking (64%). Absence of an overt ovarian mass was observed in 64% of cases. The clinical manifestations and imaging features in our patients were consistent with those in the literature. Eighty-five percent of the ovaries in our study were superficially involved by PSPC in histopathologic examination. In none of our cases could the ovarian size be clearly assessed in the CT images. In conclusion, the presence of diffuse peritoneal disease and the absence of an ovarian mass on CT and an elevation of serum CA-125 level is suggestive of PSPC. However, in our experience, the evaluation of ovarian morphology and size by CT alone may not be as reliable.     

Vascular invasion in pancreatic cancer

The evaluation of resectability in patients with pancreatic cancer remains a diagnostic challenge, especially regarding the preoperative assessment of vascular invasion. Thin-slice multiplanar reconstructions obtained with multislice helical computed tomography provide an exact depiction of the spatial relation between the tumor and the potentially invaded vessels and thus have the capability to improve the assessment of local resectability.