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.     

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.     

CT differentiation between necrotic and nonnecrotic small bowel in closed loop and strangulating obstruction

Background: The purpose of this study was to evaluate computed tomographic (CT) findings for predicting the presence of intestinal necrosis in patients with closed loop and strangulating obstruction of the small bowel. Methods: Twenty-five patients with surgically confirmed closed loop and strangulating obstruction were divided into two groups with (n= 16) and without (n= 9) intestinal necrosis. By using univariate and multivariate statistical procedures, we evaluated the differences in CT findings between the two groups on the basis of the following six findings: bowel dilatation of strangulated loops (bowel dilatation), wall thickening of strangulated intestines (wall thickening), ascites, vascular dilatation of affected mesenteries (vascular dilatation), elevation of mesenteric attenuation (mesenteric attenuation), and radial distribution of the mesenteric vessels (radial distribution). Results: Of the six findings, ascites, vascular dilatation, mesenteric attenuation, and radial distribution provided significant discriminating findings between the two groups on univariate analysis. On multivariate analysis, mesenteric attenuation was the most important discriminative factor, followed by radial distribution and ascites. Using these three parameters, the CT was correlated with the surgical findings in 15 of the 16 patients in the necrosis group (sensitivity = 93.8%) and in eight of the nine patients in the nonnecrosis group (specificity = 88.9%). The overall accuracy was 92.0%. Conclusions: Mesenteric attenuation, radial distribution, and ascites, depicted on CT differentiate well between necrosis and nonnecrosis of the small bowelin patients with closed loop and strangulating obstruction. Received 5 December 1997/Accepted: 14 January 1998     

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.     

Percutaneous biopsy of periarterial soft tissue cuffs in the diagnosis of pancreatic carcinoma

Pancreatic cancer may present on computed tomography (CT) as an isolated cuff of tumor surrounding the superior mesenteric artery (SMA) or celiac trunk, without an identifiable pancreatic mass. We reviewed our experience with imaging-guided biopsy of the soft tissue cuff in this patient group. A retrospective review of our interventional database identified 163 patients referred for biopsy of suspected pancreatic carcinoma. Of these, eight patients underwent biopsy of an isolated cuff of soft tissue encasing the SMA (n = 6) or celiac trunk (n = 2). None of these eight patients had an identifiable pancreatic mass. The mean width of tissue cuff biopsied was 1.3 cm (range, 0.9â€2.0 cm). Nine imaging-guided biopsies were performed in eight patients. Five biopsies were performed with color Doppler ultrasound and four with CT fluoroscopy. There was a median of two needle passes per procedure (range, 1â€4). In six cases, a diagnosis of pancreatic adenocarcinoma was made at the first biopsy session. In one patient, ultrasound-guided biopsy was negative, but subsequent CT-guided biopsy was positive. In one additional patient with chronic pancreatitis, biopsy revealed benign fibrous tissue. There were no procedure-related complications. In patients with suspected pancreatic cancer (but without a focal parenchymal mass), imaging-guided biopsy of isolated periarterial tissue cuffs of tumor is accurate and safe.     

经胸超声心动图诊断A型主动脉壁间血肿

目的 观察经胸超声心动图诊断A型主动脉壁间血肿的价值。方法 回顾性分析40例经CT血管成像（CTA）确诊的A型主动脉壁间血肿患者的临床资料及超声心动图表现,评价经胸超声心动图诊断A型主动脉壁间血肿的价值。结果 40例A型主动脉壁间血肿患者,男25例（25/40,62.50%）,女15例,发病中位年龄55岁;以胸背部疼痛（36/40,90.00%）为主要症状;其中30例有高血压病史、15例有吸烟史。主动脉壁间血肿超声主要表现为主动脉壁内-中膜与外膜间存在厚薄不均匀低回声;主动脉窦部增宽与年龄、高血压病史相关（r=0.51,P=0.01;r=0.34,P=0.03）。25例（25/40,62.50%）合并主动脉瓣反流,其中21例（21/25,84.00%）为轻度反流;12例合并心包积液,其中10例（10/12,83.33%）为少量积液。结论 经胸超声心动图对诊断A型主动脉壁间血肿有一定价值,并可用于患者随访。     

Pericaval fat collection mimicking an intracaval lesion on CT in patients with chronic liver disease

Background: Localized fat collections, which mimic fat-containing lesions of the inferior vena cava (IVC) on computed tomographic (CT) images, have been reported as rare incidental findings. Our goal was to evaluate the association of this CT finding with chronic liver disease. Methods: Sixty-one patients with chronic liver disease were prospectively studied with contrast-enhanced abdominal CT. The prevalence, attenuation, location, shape, and size of the pericaval fat collections were assessed. Multidirectional reformatted CT images were obtained from helical CT data to identify origins of the pericaval fat collections. Sixty-one patients without chronic liver disease were studied as control subjects. Results: Pericaval fat collections were seen on abdominal CT in 16 (26.2%) of the 61 patients. On the reformatted images, the fat collections were contiguous to the fat tissue around the subdiaphragmatic esophagus in all 16 patients. The fat collections were located at the posterior aspect of the IVC in 12 patients. In the control group, pericaval fat collection mimicking an intracaval lesion was not seen. Conclusion: In patients with chronic liver disease, pericaval fat collections are not rare CT findings and their characteristic location is considered to be posterior to the IVC. It is important not to misinterpret such CT findings as abnormalities of the IVC, such as thrombus or tumors. Received: 18 October 2000/Accepted: 15 November 2000     

Perforations of the rectosigmoid colon induced by cleansing enema: CT findings in 14 patients

Background: We report the computed tomographic (CT) features of colorectal perforations caused by cleansing enema. Methods: We reviewed the medical records and CT studies of all patients with colorectal perforations caused by a cleansing enema. Results: Fourteen patients (10 men, four women; average age = 80 years) were included in the study. The most common presenting symptoms were severe abdominal pain and fever. CT was performed within 48 h after the event in most patients. Extraluminal air in the perirectal fat was the most frequent finding on CT and was present in all patients. Additional findings were extraperitoneal (n = 9), intraperitoneal (n = 3) and /or subcutaneous (n = 3) air, free fluid (n = 9), extraluminal feces (n = 8), and focal bowel wall thickening (n = 4). No leak of contrast from the rectum was observed in any patient including the one patient in whom contrast was administered rectally. Ten patients were treated by surgery; five recovered and the other five died. The other four patients were treated conservatively and all four died. Conclusion: The diagnosis of colorectal perforation can be made on CT. Because the diagnosis is not always suspected by the clinician, the radiologist may be the first to suggest it. Therefore, the radiologist should be familiar with the CT features of a potentially lethal, rectally induced perforation. Received: 19 April 2001/Revision accepted: 4 July 2001     

肺黏液表皮样癌的CT表现

目的探讨肺黏液表皮样癌的CT表现特点。方法回顾性分析11例经手术病理证实的肺黏液表皮样癌的CT表现。结果 10例为中央型,1例为周围型;形态分别为椭圆形(7例)、分叶状(2例)及不规则形(2例)。9例边界清楚,2例边缘毛糙。10例为实性病灶,1例为囊实性病灶。增强CT显示7例肿瘤实质部分密度较均匀,4例密度不均匀;其中5例密度明显高于胸壁肌肉,4例密度与胸壁肌肉相仿,2例密度明显低于胸壁肌肉。3例支气管腔内结节周围见环形低密度液体影,2例见周围新月形或环形气体影。所有病例在CT上均可见支气管狭窄或阻塞(8例见阻塞性肺炎,5例见远端支气管扩张伴黏液栓塞,5例见肺不张)。5例可见纵隔、肺门或支气管周围淋巴结肿大,1例见同侧肋骨转移。结论大部分肺黏液表皮样癌的CT表现具有一定特点,有助于术前诊断。     

Afferent loop obstruction after gastric cancer surgery: helical CT findings

Background: We reviewed the computed tomographic (CT) findings of afferent loop obstruction and assessed the value of helical CT in determining the underlying cause.Methods: Helical CT scans of 18 patients (12 men and six women; age range = 35–67, mean age = 50 years) with afferent loop obstruction were reviewed. All patients had gastric cancer. Ten patients had undergone radical subtotal gastrectomy with Billroth II gastrojejunostomy, and eight had undergone total gastrectomy with Roux-en-Y esophagojejunostomy. CT images were analyzed retrospectively, and the presumed cause of obstruction on CT was compared with surgical findings (n = 8) and clinical courses (n = 10).Results: Local recurrence (n = 15), peritoneal seeding (n = 1), internal hernia (n = 1), and adhesion (n = 1) were the presumed causes of obstruction on CT. In all eight patients who underwent a second operation, the cause of afferent loop obstruction was correctly suggested on CT (local recurrence in six patients and adhesion and internal hernia in one patient). In 10 patients who were not re-explored, the clinical findings or biopsy indicated recurrent tumor as suggested on CT.Conclusion: Recurrent tumors and other potential causes of afferent loop obstruction can be correctly predicted with CT in most cases.     

Acute adrenal hemorrhage after blunt trauma

Objective To determine the appropriate management of adrenal hemorrhage in patients with severe chest and upper abdominal blunt trauma. Materials and Methods We reviewed 7 patients who suffered from severe traumatic adrenal hemorrhage after a traffic accident (n = 4) or fall (n = 3). Contrast-enhanced CT images were analyzed for multi-organ traumatic injury, hematoma size, extravasation, and pseudoaneurysm formation. We also report their management including transarterial embolization (TAE) and follow-up findings. Results All 7 patients manifested multi-organ traumatic injury and hemothorax; 5 also had rib fractures, 5 had abdominal organ injuries (liver, n = 3; kidneys, n = 2; pancreas, n = 1); 2 had dorsal fractures, and 1 had a traumatic aortic aneurysm. On CT images, unilateral right adrenal hematomas ranging from 20 to 50 mm (mean 26 mm) in length and from 15 to 50 mm (mean 23 mm) in width were seen. In 6 patients these were localized, and they were followed without any intervention. The other patient had a massive hematoma with pseudoaneurysm and extravasation, who subsequently received TAE. At 3-month follow-up all patients were doing well. Conclusion Information regarding the size of the hematoma and the presence of extravasation helps to select the appropriate management of patients with traumatic adrenal hemorrhage. TAE appears to be useful for treating patients with massive adrenal hemorrhage.     

Preoperative evaluation of Klatskin tumor: accuracy of spiral CT in determining vascular invasion as a sign of unresectability

Background: To assess the accuracy of spiral computed tomography (CT) in predicting the resectability of Klatskin tumor as determined by vascular invasion. Methods: Twenty-one consecutive patients with Klatskin tumor who had undergone laparotomy were included in this study. The preoperative thin-section (5-mm-thick) spiral CT scans of these patients were assessed for the surgical resectability of tumor by evaluating the vascular invasion. The criterion for vascular invasion indicating unresectability was the tumoral invasion of the proper hepatic artery or main portal vein or simultaneous invasion of one side of the hepatic artery and the other side of the portal vein. Results: All nine patients with tumors thought to be unresectable on the basis of CT findings had tumors that were unresectable at surgery (positive predictive value, 100%). Of 12 patients with tumors thought to be resectable, six had resectable tumors (negative predictive value, 50%). Spiral CT failed to detect small hepatic metastasis (n= 1), lymph node metastasis (n= 1), extensive tumor (n= 2) and variation of bile duct (n= 2), which precluded surgical resection. Conclusion: Spiral CT is a reliable method for detecting vascular invasion and unresectable tumors. However, it has limitations in detecting variations of the bile duct or the intraductal extent of tumor. Received: 24 November 1999/Accepted: 26 January 2000     

The ratio of superior mesenteric artery diameter to superior mesenteric vein diameter based on non-enhanced computed tomography in the early diagnosis of spontaneous isolated superior mesenteric artery dissection

BACKGROUND:Spontaneous isolated superior mesenteric artery (SMA) dissection (SISMAD) is a rare cause of abdominal pain. The aim of the study is to investigate the role of a new parameter, the ratio of the SMA diameter to the superior mesenteric vein (SMV) diameter (SMA/SMV) based on non-enhanced computed tomography (CT), in the early diagnosis of SISMAD.METHODS:In a registry study from December 2013 to June 2021, 97 abdominal pain SISMAD patients (SISMAD group) admitted to our hospital were enrolled. Meanwhile, the matched sex and age abdominal pain non-SISMAD patients at 1:2 were collected in reverse chronological order as the control group. Student’s t-test, Wilcoxon rank-sum test, and Chi-square test were used to compare differences between the SISMAD and control groups. MedCalc was used to generate receiver operating characteristic (ROC) curve.RESULTS:A total of 291 abdominal pain patients, including 97 SISMAD patients and 194 non-SISMAD patients, were included in the current study. The maximum SMA diameter, perivascular exudation, and SMA/SMV based on non-enhanced CT were significant between the two groups (all P<0.05). ROC curves showed that for the maximum SMA diameter, the area under the curve (AUC), cut-off, sensitivity, and specificity were 0.926, 9.80, 93.8%, and 79.4%, respectively. For SMA/SMV, its AUC, cut-off, sensitivity, and specificity were 0.956, 0.83, 88.7%, and 92.3%, respectively. The diagnostic efficiency of SMA/SMV was better than that of the maximum SMA diameter (P<0.05). The combined parameters of SMA/SMV and maximum SMA diameter had the best diagnostic efficiency (AUC=0.970).CONCLUSION:SMA/SMV may be a potential marker for SISMAD.     

Superior mesenteric artery syndrome: spectrum of CT findings with multiplanar reconstructions and 3-D imaging

Objective

This article reviews the causes, clinical presentation, and CT diagnosis of superior mesenteric artery (SMA) syndrome.

Conclusion

In conjunction with an appropriate clinical history, several CT findings can suggest the diagnosis of SMA syndrome. These findings include narrowing of the aortomesenteric angle and distance, distension of the stomach and duodenum, and dilatation of the left renal vein with left-sided venous collaterals.     

Hepatic artery embolization for postoperative hemorrhage in upper abdominal surgery

Background: The purpose of this study was to evaluate angiographic findings and radiologic and clinical results of transcatheter arterial embolization (TAE) of the hepatic artery for hemorrhage after upper abdominal surgery. Methods: Ten patients (nine male, one female, mean age = 63.5 years) with postoperative hemorrhage underwent emergency hepatic artery embolization. We retrospectively analyzed the angiographic findings and the effectiveness of TAE. Results: Angiography demonstrated pseudoaneurysms (n = 6) and extravasation (n = 5). Portal veins were not compromised in any patient. The bleeding points were at the gastroduodenal artery (n = 3), proper hepatic artery (n = 3), right hepatic artery (n = 2), left hepatic artery (n = 1), and intrahepatic artery (n = 2). Embolization was performed at the extrahepatic site (n = 6) and intrahepatic site (n = 4). TAE was successful in eight patients. Hemostasis was achieved in eight patients. Two patients in whom TAE was not successful died of bleeding after TAE. In six patients whose collateral arteries were visualized at TAE, hypoxic hepatic failure was avoided and the patients had a favorable clinical course. Conclusion: TAE is a useful treatment for postoperative hemorrhage, but the presence of collateral arteries at the time of TAE can affect the patients' prognoses.     

Segmental high intensity on T1-weighted hepatic MR images

Background We investigated the diagnostic importance of segmental high-intensity (SHI) areas not corresponding to mass lesions on T1-weighted magnetic resonance (MR) images. Methods We conducted a retrospective investigation of hepatic MR images obtained from 634 patients during a 4-year period at our institution. Images were compared with findings reported in the patients’ medical records. There were 16 patients (2.5%) with SHI areas not corresponding to a mass lesion. We compared MR images with plain computed tomographic (CT) scans (n = 16), angiograms (n = 12), and histologic findings (n = 10). Results The segments with intrahepatic bile duct dilatation showed hyperintensity on T1-weighted images. In six of 16 patients, the biliary duct was more dilated in the area of hyperintensity than in areas without hyperintensity. The SHI areas appeared as areas of low attenuation (n = 13), high attenuation (n = 1), or isoattenuation (n = 2) on plain CT scans. Histologically, these areas showed ductular proliferation and deposition of bile pigment within the hepatocytes. Conclusion Segmental areas of increased signal intensity on T1-weighted images were probably due to intrahepatic cholestasis.     

Multidetector-row CT findings of colonic perforation: direct visualization of ruptured colonic wall

Background: We examined the findings of contrast-enhanced multidetector-row computed tomography (MD-CT) in patients with colonic perforation.Methods: Abdominal contrast-enhanced MD-CT findings in six patients with colonic perforation were reviewed retrospectively. Patients (three men and three women) were 74 to 88 years old (mean age = 78 years). Colonic perforation was confirmed by surgery. CT findings were correlated with surgical and pathologic findings.Result: The site of colonic perforation was suggested by the following combination of CT findings: free air, dirty mass, dirty fat sign, extraluminal fluid collection, bowel wall thickening, and interruption of colonic wall. The ruptured colonic wall was directly visualized in four cases (67%).Conclusion: Abdominal contrast-enhanced MD-CT may improve the accuracy of diagnosis and localization of colonic perforation.     

Ultrasound in abdominal tuberculosis

Background: The present study was done to emphasize the importance of ultrasound (US) and US-guided fine-needle aspiration biopsy (FNAB) in the diagnosis of abdominal tuberculosis. Methods: Sixty-six proven cases of abdominal tuberculosis were selected for this study. The diagnosis was based on clinical features, US observations, FNAB, operative findings, and responses to appropriate antitubercular treatment. The US findings were interpreted with regard to the involvement of lymph nodes, intestine, peritoneum, solid viscera, and abdominal abscesses. Patients with disease limited to the musculoskeletal and genitourinary systems were not included in the study. Results: Peritoneal tuberculosis was the most common form, of the wet ascitic type. Ascites was clear in 19 patients and complex in 17. Tuberculous lymphadenopathy was seen in 37 patients. There was a predilection of periportal, peripancreatic, and mesenteric locations compared with the degree of retroperitoneal involvement. Calcification and heterogeneous echotexture were seen in seven cases. FNAB confirmed the diagnosis of tubercular lymphadenopathy in 19 patients. Intestinal disease was seen in 14 patients. Hepatic or splenic involvement was seen as diffuse organomegaly; less commonly, focal lesions were seen. Conclusion: This combination of US findings in proper clinical settings are diagnostic of tuberculosis. FNAB confirms the diagnosis in lymphadenopathy, abscesses, and focal lesions of the viscera.     

Whole Body MR Angiography Screening

Lack of side effects, diagnostic accuracy and recent improvements in technology qualify magnetic resonance imaging for preventive cardiovascular imaging. The purpose of this study was to assess the feasibility of a comprehensive contrast-enhanced three-dimensional whole-body MR (magnetic resonance) angiography examination technique using a rolling table platform system with a 1.5-T MR system. The examination yielded diagnostic image quality in 5312 out of 5400 (98.3%) evaluated vascular segments in 180 consecutive patients with peripheral vascular disease. Besides the proved peripheral vascular disease, additional relevant vascular disease was found in 65 vessel segments in 42 patients: carotid artery stenosis (n = 21), subclavian artery stenosis (n = 5), renal artery stenosis (n = 27) abdominal aortic aneurysm (n = 7), aortic dissection (n = 5). In 20 patients additional imaging studies confirmed the results of whole-body MRA without false positive or false negative findings. The described whole-body MR angiography protocol appears well suited for comprehensive evaluation of the arterial system beyond the peripheral vasculature.     

Isolated, spontaneous superior mesenteric and celiac artery dissection: case report and review of literature

Spontaneous, isolated dissection of the superior mesenteric artery (SMA) and celiac artery (CA) is rare. Although there are known risk factors, there is no particular mechanism that is common to vascular dissections. The objectives of this study were to review the current literature on diagnosis and treatment of isolated SMA and CA dissection, and to review aortic complications in giant cell arteritis, Takayasu arteritis, and polyarteritis nodosa. Giant cell arteritis, Takayasu arteritis, and polyarterteritis nodosa are vasculitides that are associated with SMA and CA dissection. An interesting aspect of this case is that the patient was a healthy person before presentation, and ultimately, did not have an underlying etiology to explain the dissection. In addition, the patient was successfully managed without operative intervention. Although there are known risk factors in patients who present with isolated, spontaneous SMA and CA dissection, the pathogenesis is still unclear. The prognosis has improved significantly with the early use of computed tomography angiography to diagnosis this entity. Although most cases require surgical intervention, there are some, as in this case, that are managed non-operatively.