Diagnostic performance of CT findings for bowel ischemia and necrosis in closed-loop small-bowel obstruction.

PURPOSE: The aim of this study was to investigate the diagnostic performance of contrast-enhanced CT (CECT) findings for bowel ischemia and necrosis in closed-loop small-bowel obstruction (CL-SBO). MATERIALS AND METHODS: Thirty-five patients with CL-SBO confirmed by laparotomy (n = 34) or multiplanar reconstruction of thin slice CT images (n = 1) were included. Based on the surgical and clinical findings, these patients were classified into three groups: necrosis group (n = 16), ischemia without necrosis group (n = 11), and no-ischemia group (n = 8). Two blinded radiologists retrospectively reviewed CECT including multiplanar reconstruction images and evaluated 12 CT findings. The sensitivity and specificity of each finding were compared among the three groups, and logistic regression analysis was performed. RESULTS: High attenuation of the bowel wall, intraperitoneal air, reduced enhancement of the mesenteric arteries, and small-bowel feces signs showed high specificities of 100%, 100%, 89%, and 89% but low sensitivities of 31%, 25%, 44%, and 31%, respectively, for the prediction of bowel necrosis in CL-SBO. According to multivariate logistic regression analysis, reduced bowel-wall enhancement, reduced enhancement of the mesenteric veins, and a lack of engorgement of the mesenteric veins were significant for predicting bowel ischemia or necrosis (P < 0.05). CONCLUSIONS: Reduced enhancements of bowel wall and mesenteric veins were good indicators of bowel ischemia or necrosis. On the contrary, engorgement of the mesenteric veins was a predictor of a viable bowel.

Local recurrence after chemoembolization of hepatocellular carcinoma: uptake of gadoxetic acid as a new prognostic factor.

OBJECTIVE: The purpose of this article is to investigate whether there is a difference in susceptibility to transcatheter arterial chemoembolization between hepatocellular carcinomas (HCCs) showing high uptake and those showing low uptake of gadoxetic acid in the hepatobiliary phase of MRI. MATERIALS AND METHODS: One hundred HCCs that achieved optimal chemoembolization, as assessed by immediate CT in 60 patients, were classified as having high (n = 19) or low (n = 81) uptake of gadoxetic acid on MRI performed before chemoembolization. The local recurrence rates were estimated using the Kaplan-Meier method, and differences between the groups were compared using the log-rank test. The following factors were also correlated with the local recurrence rate using the Cox proportional hazards model for a univariate analysis: high uptake of gadoxetic acid, number of feeding arteries, extrahepatic arterial supply, Child-Pugh class, clinical tumor stage, size, location, and iodized oil accumulation in the noncancerous tissue surrounding the lesion. Parameters that were significant at p < 0.05 were entered into a multivariate model. RESULTS: The 1- and 3-year local recurrence-free rates were 95% in high-uptake HCCs and 66% and 54%, respectively, in low-uptake HCCs (log-rank test, p < 0.01). The low uptake of gadoxetic acid was the only significant predictor of early local recurrence (hazard ratio = 9.24; p = 0.03) by multivariate analysis. CONCLUSION: HCCs showing high uptake of gadoxetic acid appear to be susceptible to chemoembolization.

Peri-stent aneurysm formation following a stent implant for stenotic intracranial vertebral artery dissection: a technical report of two cases successfully treated with coil embolization.

INTRODUCTION: Although stenting for stenotic vertebral artery dissection (VAD) improves compromised blood flow, subsequent peri-stent aneurysm (PSA) formation is not well-known. We report two cases with PSA successfully treated with coil embolization. METHODS: Three patients with stenotic intracranial VAD underwent endovascular angioplasty at our institution because they had acute infarction in posterior circulation territory and clinical evidence of hemodynamic insufficiency. In two of three patients balloon angioplasty at first session failed to relieve the stenosis, and a coronary stent was implanted. Angiography immediately after stenting showed no abnormality in case 1 and minimal slit-like projection at proximal portion of the stent in case 2. RESULTS: Angiography obtained 16 months after the stenting revealed PSA in case 1. In case 2, angiography performed 3 months later showed that the projection at proximal portion enlarged and formed an aneurysm outside the stent. Because follow-up angiographies showed growth of the aneurysm in both cases, endovascular aneurysmal embolization was performed. We advanced a microcatheter into the aneurysm through the strut of existing stent and delivered detachable coils into the aneurysm lumen successfully in both cases. The post-procedural course was uneventful, and complete obliteration of aneurysm was confirmed on angiography in both cases. CONCLUSION: Stenting for stenotic intracranial VAD may result in delayed PSA; therefore, follow-up angiographies would be necessary after stenting for stenotic intracranial arterial dissection. Coil embolization through the stent strut would be a solution for enlarging PSA.

Fatal paradoxical air embolism diagnosed by postmortem imaging and autopsy.

The recognition and visualization of an arterial gas embolism are difficult. We report a case of sudden death caused by paradoxical air embolism of coronary and cerebral arteries, diagnosed by the pre autopsy computed tomography (CT) scanning. A 54-year-old woman suddenly died after the self-removal of the jugular vein catheter. Postmortem imaging examination using CT scanning showed multiple gas embolisms in the cerebral arteries, pulmonary artery, right atrium and ventricle, left ventricle, aorta, and coronary arteries. These findings suggested that the occurrence of acute ischemia of the brain and heart caused by massive air inflow to the artery. Conventional autopsy revealed a patent foramen ovale of the heart. These results indicated that the patient died of paradoxical air embolization of the coronary and cerebral arteries through a patent foramen ovale because of right-to-left shunting. The use of postmortem imaging as an aid for conventional autopsy has proved to be of advantage in the case of gas embolism.

Contrast-fluid level in the inferior vena cava (IVC niveau sign) in patients with acute type A aortic dissection: computed tomography findings during acute cardiac tamponade.

PURPOSE: The purpose of this study was to report a new computed tomography (CT) finding in acute cardiac tamponade: a contrast-fluid level in the hepatic inferior vena cava (IVC) during an arterial dominant phase CT study (IVC niveau sign) in patients with acute type A aortic dissection. MATERIALS AND METHODS: We retrospectively reviewed CT studies with the diagnosis of proximal aortic dissection (Stanford type A) with acute cardiac tamponade. There were 12 patients enrolled in the study (6 women, 6 men; mean age 66 years). A total of 62 patients were selected as a control chronic pericardial effusion group to compare with the acute cardiac tamponade group. RESULTS: Among the 12 patients with acute cardiac tamponade, the IVC niveau sign was seen in 7 (58%). In the control chronic pericardial effusion group (n = 62), we identified the IVC niveau sign in only one patient (1.6%). There was a significant difference in the presence of the IVC niveau sign between the acute cardiac tamponade and chronic pericardial effusion groups (P < 0.0001). CONCLUSION: The presence of the IVC niveau sign suggests acute cardiac tamponade in patients with acute type A aortic dissection.

CT and clinical features of hemorrhage extending along the pulmonary artery due to ruptured aortic dissection.

The purpose was to evaluate CT findings of hemorrhage extending along the pulmonary artery (PA) due to ruptured aortic dissection (AD) and its prognostic factors. In 232 patients with Stanford type A AD, 21 patients (9.1%; 11 women; mean 70.3 years) were diagnosed. Twelve patients had double-barreled (classic) AD, and nine patients had intramural hematoma (IMH; closed false lumen) of the aorta. Based on CT findings, hemorrhage was classified into three categories as follows: category 1 (IMH of the PA or blood localized around the PA), category 2 (extending into the interlobular septa), and category 3 (extending into the alveoli). The factors influencing prognosis, including CT features and patient characteristics, were evaluated. Fourteen (66.7%) of the 21 patients underwent emergency surgery, and 8 (38.1%) patients died within 72 h of onset. Twelve cases (57.1%) were classified into category 1, 2 cases (9.5%) into category 2, and 7 cases (33.3%) into category 3. Double-barreled AD and category 3 hemorrhage were significant risk factors for death in univariate analyses. In multivariate analyses, the presence of category 3 hemorrhage was the only significant risk factor for death. CT findings indicative of a poor prognosis include double-barreled type AD and category 3 hemorrhage.

Iliopsoas muscle abscess secondary to sacral pressure ulcer treated with computed tomography-guided aspiration and continuous irrigation: a case report.

Iliopsoas abscess is an aggressive infection usually associated with Crohn's disease, spinal tuberculosis, a septic hip joint (including hip replacement), and spinal cord injury. It rarely occurs secondary to sacral pressure ulcer. The infection requires immediate surgical debridement or drainage. The case of a 78-year-old woman with high fever and severe inflammation caused by iliopsoas abscess secondary to a sacral pressure ulcer is reported. The patient was treated with a computed tomography-guided aspiration; Escherichia coli was isolated from the pus of the ulcer and abscess sites. The abscess completely resolved within 2 weeks but another abscess developed. Following surgery and daily cleansing, the drainage tube was removed after 1 week. Once granulation tissue formation was sufficient, the sacral wound was covered with gluteal fasciocutaneous rotation flaps 6 weeks after admission. The wounds closed and the patient made a full recovery within 2 months. Early recognition followed by immediate drainage of pus and appropriate antibiotic therapy are essential to the treatment of these wounds. Experience confirms that computed tomography-guided aspiration is useful and may be less damaging than surgical debridement.

Primary pericardial malignant fibrous histiocytoma causing cardiac tamponade.

We describe herein an extremely rare case of a large primary pericardial malignant fibrous histiocytoma causing a cardiac tamponade that occurred in a 72-year-old woman. The clinical, radiographic, and pathologic features are reported here together with a brief review of the literature.

Percutaneous radiofrequency ablation and transcatheter arterial chemoembolization for hypervascular hepatocellular carcinoma: rate and risk factors for local recurrence.

PURPOSE: To analyze local recurrence-free rates and risk factors for recurrence following percutaneous radiofrequency ablation (RFA) or transcatheter arterial chemoembolization (TACE) for hypervascular hepatocellular carcinoma (HCC). METHODS: One hundred and nine nodules treated by RFA and 173 nodules treated by TACE were included. Hypovascular nodules were excluded from this study. Overall local recurrence-free rates of each treatment group were calculated using the Kaplan-Meier method. The independent risk factors of local recurrence and the hazard ratios were analyzed using Cox's proportional-hazards regression model. Based on the results of multivariate analyses, we classified HCC nodules into four subgroups: central nodules < or =2 cm or >2 cm and peripheral nodules < or =2 cm or >2 cm. The local recurrence-free rates of these subgroups for each treatment were also calculated. RESULTS: The overall local recurrence-free rate was significantly higher in the RFA group than in the TACE group (p = 0.013). The 24-month local recurrence-free rates in the RFA and TACE groups were 60.0% and 48.9%, respectively. In the RFA group, the only significant risk factor for recurrence was tumor size >2 cm in greatest dimension. In the TACE group, a central location was the only significant risk factor for recurrence. In central nodules that were < or =2 cm, the local recurrence-free rate was significantly higher in the RFA group than in the TACE group (p < 0.001). In the remaining three groups, there was no significant difference in local recurrence-free rate between the two treatment methods. CONCLUSION: A tumor diameter of >2 cm was the only independent risk factor for local recurrence in RFA treatment, and a central location was the only independent risk factor in TACE treatment. Central lesions measuring < or =2 cm should be treated by RFA.

Two cases of hepatopulmonary syndrome with improved liver function following long-term oxygen therapy.

Hepatopulmonary syndrome (HPS) is a complication of liver disease that is characterized by hypoxemia and intrapulmonary vascular dilatations. The only established therapy for this disorder is liver transplantation. Here, we report two patients (a 63-year-old woman and a 72-year-old man) with HPS associated with hepatitis C virus-related cirrhosis. We gave the patients low-dose oxygen supplementation to improve their respiratory symptoms. Surprisingly, their liver function improved from Child Pugh class C to class A, and ascites disappeared after a year of oxygen supplementation. We believe that long-term oxygen therapy contributed to the improvement of liver function in these two cases. Long-term oxygen therapy might offer a new therapeutic approach to improve liver function in patients with cirrhosis with hypoxemia.

New development of an ulcerlike projection in aortic intramural hematoma: CT evaluation.

PURPOSE: To investigate the natural history and predictors of progression of a newly developed ulcerlike projection in patients with an aortic intramural hematoma. MATERIALS AND METHODS: Serial computed tomographic (CT) findings in 52 patients with intramural hematoma were reviewed. Sixteen patients had Stanford type A intramural hematoma, and 36 had Stanford type B. Diagnosis of intramural hematoma was established with CT. Regular follow-up studies were performed every week during the 1st month and two or three times a year after the 2nd month. The presence or absence of an ulcerlike projection, diameter and progression of the projection, and aortic diameter were evaluated. Relationships among ulcerlike projections, clinical data, and CT findings were analyzed. RESULTS: In 17 (33%) of the 52 patients, 17 ulcerlike projections were newly identified during the follow-up period. Patients with type A intramural hematoma had a significantly higher frequency of new development of ulcerlike projection than that of patients with type B intramural hematoma (P =.002). In 17 patients with new development of ulcerlike projection, 12 (70%) of 17 projections progressed to complications such as enlargement (n = 10) or progression to overt aortic dissection (n = 2). One of 10 enlarged projections progressed to rupture. A significant predictor of progression of ulcerlike projection was based on location from the ascending aorta to the aortic arch with the use of univariate (P =.009) and multivariate Cox (P =.018) regression analyses. CONCLUSION: The location of ulcerlike projections is the principal predictor of progression, and careful follow-up study is needed for patients with an ulcerlike projection located from the ascending aorta to the aortic arch.

Analysis of predictive factors for progression of type B aortic intramural hematoma with computed tomography.

PURPOSE: For patients with Stanford type B aortic intramural hematoma (IMH), medical treatment is usually selected. However, the outcomes of patients with type B IMH are not completely understood, and some cases can have fatal complications develop or surgical treatment necessitated. The purpose of this study was to investigate predictors of progression of the affected aorta in patients with type B IMH with initial computed tomography (CT) images. METHODS: Thirty-five patients with type B IMH were studied with serial CT images. Initially, medical therapy was selected for all patients. CT findings of the affected aorta were evaluated on admission and at follow-up. We divided the patients into two groups (progression group or regression group) on the basis of CT findings and investigated predictors of progression of the affected aorta with initial CT images. RESULTS: We defined 15 patients who showed increased maximum aortic diameter (n = 14), increased maximum aortic wall thickness (n = 3), progression to overt dissection (n = 4), or rupture of the aortic wall (n = 2) during the follow-up period as the progression group. The other 20 patients, who all showed decreased maximum aortic wall and aortic wall thickness, were defined as the regression group. In the maximum aortic diameter, an optimal cutoff value of 40 mm resulted in positive predictive and negative predictive values of 86.7% and 90.0%, respectively. Both a maximum aortic diameter of 40 mm or more (P =.0011) and a maximum aortic wall thickness of 10 mm or more (P =.0009) were shown to be significantly predictive of the progression with Cox regression analysis. CONCLUSION: Maximum aortic diameter and maximum aortic wall thickness on initial CT images are predictive for progression of the affected aorta in patients with type B IMH. For type B IMH with a maximum aortic diameter of 40 mm or more or a maximum aortic wall thickness of 10 mm or more, careful follow-up studies must be required.