Predictors of Good Outcome After Stent-Retriever Thrombectomy in Acute Basilar Artery Occlusion.

BACKGROUND AND PURPOSE: Factors related to prognosis after a modern mechanical thrombectomy in patients with acute basilar artery occlusion remain unclear. This study investigated the prognostic factors for patients with acute basilar artery occlusion who underwent a stent-retriever thrombectomy. METHODS: We analyzed clinical and pretreatment diffusion-weighted imaging (DWI) data in 50 consecutive patients with acute basilar artery occlusion treated with stent-retriever thrombectomy. A good outcome was defined as a modified Rankin Scale score of 0 to 2 at 3 months. The association between clinical and DWI parameters and functional outcome was evaluated with logistic regression analysis. RESULTS: In a univariate analysis, the following variables were significantly associated with outcome: age, hypertension, baseline National Institutes of Health Stroke Scale, posterior circulation Acute Stroke Prognosis Early CT Score on a pretreatment DWI, posterior circulation Acute Stroke Prognosis Early CT Score of ≥7 (versus <7), thalamic infarction, and bilateral thalamic infarction. In a multivariate model, only a low initial National Institutes of Health Stroke Scale score (odds ratio, 0.82; 95% confidence interval, 0.709-0.949; P=0.008) and high DWI posterior circulation Acute Stroke Prognosis Early CT Score (odds ratio, 1.854; 95% confidence interval 1.012-3.397; P=0.045) were significant independent predictors of good outcome. In a univariate analysis, bilateral thalamic infarction was associated with a poor outcome (odds ratio, 1.993; 95% confidence interval, 1.187-3.346; P=0.035) but not with a unilateral thalamic infarction (P=0.525). CONCLUSIONS: This study suggested that initial infarction severity and posterior circulation Acute Stroke Prognosis Early CT Score on a pretreatment DWI are independent predictors of clinical outcome after stent-retriever thrombectomy in patients with acute basilar artery occlusion.

Metabolic change in the right dorsolateral prefrontal cortex and its correlation with symptom severity in patients with generalized anxiety disorder: Proton magnetic resonance spectroscopy at 3 Tesla.

AIMS: A few neuroimaging studies have demonstrated the key brain areas associated with generalized anxiety disorder (GAD). However, the brain metabolic changes in the dorsolateral prefrontal cortex (DLPFC) of patients with GAD are unclear. This study utilized 3-Tesla proton magnetic resonance spectroscopy ((1) H-MRS) to assess the DLPFC metabolic change and its correlation with symptom severity in patients with GAD. METHODS: Patients with GAD diagnosed using the DSM-IV-TR and age-matched healthy controls participated in this study. Brain metabolite concentrations were measured from a localized voxel on the DLPFC using 3-Tesla (1) H-MRS. Also, the volumetric composition of the gray matter and white matter volumes was assessed using voxel-based morphometry. RESULTS: The choline/creatine and choline/N-acetylaspartate ratios were significantly lower in patients than in controls. However, there were no significant differences in other metabolite ratios between the two groups. Choline concentrations were negatively correlated with anxiety levels as measured by the Hamilton Anxiety Rating Scale and the Generalized Anxiety Disorder Scale 7. There was no significant difference in the gray matter and white matter volumes in the MRS voxel between the two groups. CONCLUSIONS: The present study demonstrates that GAD is associated with low a level of choline/N-acetylaspartate in the DLPFC, which is closely related with symptom severity and cognitive dysfunction. This finding will be useful for an understanding of the neural mechanism associated with GAD.

Imaging of actinomycosis in various organs: a comprehensive review.

Actinomycosis is a chronic suppurative bacterial infection caused by Actinomyces species. Actinomyces israelii is the organism most commonly found in human disease. Actinomycosis usually manifests with abscess formation, dense fibrosis, and draining sinuses. The disease is further characterized by the tendency to extensively spread beyond normal fascial and connective tissue planes. Actinomycosis occurs most commonly in the cervicofacial region (50%-65%), followed by the thoracic (15%-30%) and abdominopelvic (20%) regions, but rarely involves the central nervous system. Most cases of cervicofacial actinomycosis are odontogenic in origin. In the acute form, cervicofacial disease can manifest with soft-tissue swelling, a painful pyogenic abscess, or a mass lesion. In the subacute to chronic form, a painless indurated mass can spread to the skin, leading to draining sinus tracts. Thoracic manifestations include parenchymal, bronchiectatic, and endobronchial actinomycosis. At computed tomography, pulmonary actinomycosis usually appears as chronic segmental airspace consolidation containing necrotic low-attenuation areas with peripheral enhancement. Abdominopelvic actinomycosis preferentially involves the ileocecal region, ovary, and fallopian tube. The imaging findings favoring abdominopelvic actinomycosis include strong enhancement in the solid portion of the mass after contrast material administration, small rim-enhancing abscesses within the mass, and extensive inflammatory extensions. Actinomycosis in the central nervous system may produce brain abscess, meningitis, subdural empyema, actinomycetoma, and spinal and cranial epidural abscess. In general, actinomycosis responds well to antibiotic therapy, but long-term follow-up after treatment is needed because of frequent relapses.

Review of ovarian tumors in children and adolescents: radiologic-pathologic correlation.

The incidence, histologic distribution, and clinical manifestations of ovarian tumors in the pediatric population are distinct from those in adults. Although ovarian neoplasms in childhood and adolescence are rare, the diagnosis should be considered in young girls with abdominal pain and a palpable mass. Differential diagnosis in children and adolescents with ovarian tumors should be conducted on the basis of unique clinical manifestations, elevated serum tumor marker levels, and distinctive imaging findings. Although the clinical manifestations are nonspecific and may overlap, they may assist in diagnosis of some types of ovarian tumors. Children who present with a palpable mass or symptoms of precocious puberty have a high likelihood of malignancy. Many ovarian tumors are associated with abnormal hormonal activity and/or abnormal sexual development. Elevated levels of serum tumor markers, including α-fetoprotein, the beta subunit of human chorionic gonadotropin, and CA-125, raise concern for ovarian malignancies. However, negative tumor markers do not exclude the possibility of malignancy. Identification of imaging features at ultrasonography, computed tomography, and magnetic resonance imaging can help differentiate benign from malignant ovarian tumors and, in turn, plays a crucial role in determining treatment options. At imaging, malignant ovarian tumors usually appear predominantly solid or heterogeneous and are larger than benign tumors. Because surgery is the primary treatment for ovarian tumors, ovarian salvage with fertility preservation and use of a minimally invasive surgical technique are important in children and adolescents.

Subarachnoid hemorrhage in a multimodal approach heavily weighted toward mechanical thrombectomy with solitaire stent in acute stroke.

BACKGROUND AND PURPOSE: Subarachnoid hemorrhage (SAH) may appear on computerized tomography scans after mechanical thrombectomy for acute ischemic stroke. The incidence and prognosis of this observation remain unknown. We investigated the frequency and clinical consequences of SAH after treating acute ischemic stroke with a multimodal approach heavily weighted toward mechanical thrombectomy with Solitaire stent. METHODS: Seventy-four consecutive patients with acute ischemic stroke underwent mechanical thrombectomy with a Solitaire stent as a first-line treatment. Nonenhanced computerized tomography scans were performed before, immediately after, and 24 hours after treatment to detect SAH. Clinical outcome was assessed after treatment, on day 1, at discharge, and at 3 months. Clinical and radiological data were compared between patients with and without SAH. RESULTS: Twelve patients (16.2%) exhibited SAH associated with pure SAH (n=4) or mixed SAH and contrast extravasation (n=8). The SAH was located in the ipsilateral Sylvian fissure (n=11) or bilateral parietooccipital sulci (n=1). Patients with SAH had no periprocedural vessel perforations or arterial dissections and no postprocedural neurological deteriorations. Rescue angioplasty was performed more frequently in SAH group than in control group (33.3% vs 9.7%; P=0.05). Patients with SAH and those without had similar recanalization rates and clinical outcomes. CONCLUSIONS: SAH on post-therapeutic computerized tomography scans were not uncommon after primary mechanical thrombectomy with a Solitaire stent, but they seemed to be benign. Rescue angioplasty and unidentified, small vessel ruptures due to mechanical stretch during stent retrieval might give rise to these lesions.

Assessment of brain metabolites change during visual sexual stimulation in healthy women using functional MR spectroscopy.

INTRODUCTION: Numerous functional magnetic resonance imaging (fMRI) studies demonstrated the key brain areas associated with visual sexual arousal. However, the changes in brain metabolites involved in sexual stimuli have not been reported. AIM: This study utilized functional MR spectroscopy (fMRS) to evaluate the changes in brain metabolites associated with sexual arousal induced by stimulation with erotic video clips in healthy women. METHODS: Twenty-three healthy, right-handed women (38.4 ± 10.0 years) participated in (1) H-fMRS and fMRI studies. T1 and T2 MR images were used for voxel localization of the anterior cingulate gyrus, which is one of the most important key centers associated with sexual arousal. MAIN OUTCOME MEASURES: The changes of brain metabolites were measured using (1) H-fMRS during time-course activation: "before," "during," and "after" visual sexual stimulation. The time-course variation of the brain metabolites was analyzed by the repeated-measures analysis of variance. RESULTS: The CVmean of all the metabolites had <30% (range, 9-29%). The ICCs of α-glutamine-glutamate (Glx), choline (Cho), ߷γ-Glx, N-acetylaspartate (NAA) and lactate (Lac) all exceeded 0.6. However, myo-inositol (mI) and lipid (Lip) were <0.6. The concentration of brain metabolites including α-Glx, ߷γ-Glx, Cho, and Lac comparatively increased significantly during visual sexual stimulation. CONCLUSIONS: (1) H-fMRS, for the first time, was applied to assess the brain metabolic changes during visually-evoked sexual arousal. The fMRS outcomes in relation to functional MRI data will be useful to understand the neural mechanism associated with sexual arousal.

Outcome of mechanical thrombectomy with Solitaire stent as first-line intra-arterial treatment in intracranial internal carotid artery occlusion.

INTRODUCTION: Acute stroke from occlusion of the intracranial internal carotid artery (ICA) is associated with a poor clinical outcome despite a thrombolytic treatment. The purpose of this study was to evaluate the outcome of mechanical thrombectomy using the Solitaire stent for the treatment of acute stroke patients with intracranial ICA occlusion. METHODS: A total of 104 consecutive patients with acute stroke were treated with mechanical thrombectomy using the Solitaire stent as a first-line intra-arterial treatment. We retrospectively reviewed data from 26 of these patients who presented with acute stroke attributable to intracranial ICA occlusion. Rescue treatments in cases of failed Solitaire thrombectomy included intra-arterial urokinase, angioplasty, and forced suction thrombectomy. Successful recanalization was defined as thrombolysis in cerebral ischemia grades 2b to 3. Outcome measure was the modified Rankin Scale (mRS) score of 0-2 at 3 months. RESULTS: Successful recanalization was achieved in 77% (20/26) of patients. Recanalization was achieved with the Solitaire stent alone in 69% (18/26) of patients. Ten patients (39%) had a good clinical outcome (mRS score of 0-2) at 3 months. There was a good outcome in 50% of patients (10/20) with recanalization and no good outcome in patients (0/6) without recanalization (P = 0.027). None of eight patients who received rescue treatments showed a good outcome. No symptomatic intracerebral hemorrhage occurred. Mortality was 8% (2/26) at 3 months. CONCLUSION: Mechanical thrombectomy using the Solitaire stent can achieve a high rate of successful recanalization and a very low rate of symptomatic hemorrhage and thus improve a clinical outcome in patients with acute intracranial ICA occlusion.

Predicting response to neoadjuvant chemoradiation therapy in locally advanced rectal cancer: diffusion-weighted 3 Tesla MR imaging.

PURPOSE: To evaluate the efficacy of diffusion-weighted imaging (DWI) on 3 Tesla (T) MR imaging to predict the tumor response to neoadjuvant chemoradiation therapy (CRT) in patients with locally advanced rectal cancer. MATERIALS AND METHODS: Thirty-five patients who underwent neoadjuvant CRT and subsequent surgical resection were included. Tumor volume was measured on T2-weighted MR images before and after neoadjuvant CRT and the percentage of tumor volume reduction was calculated. The apparent diffusion coefficient (ADC) value was measured on the DWI before and after neoadjuvant CRT, and the change of ADC (Δ ADC) was calculated. The histopathologic response was categorized either as a responder to CRT or as a nonresponder. The relationship between the ADC parameters and the percentage of tumor volume reduction or histopathologic response was then evaluated. RESULTS: There was a significant correlation between tumor volume reduction and pre-CRT ADC and Δ ADC, respectively (r = -0.352, r = 0.615). Pre-CRT ADC of the histopathologic responders was significantly lower than that of the histopathologic nonresponders (P = 0.034). Δ ADC of the histopathologic responders was significantly higher than that of the histopathologic nonresponders (P < 0.005). CONCLUSION: DWI on 3T MR imaging may be a promising technique for helping to predict and monitor the treatment response to neoadjuvant CRT in patients with locally advanced rectal cancer.

Diagnostic performance of 64-section CT using CT gastrography in preoperative T staging of gastric cancer according to 7th edition of AJCC cancer staging manual.

OBJECTIVES: To evaluate the accuracy of 64-section multidetector CT with CT gastrography for determining the depth of mural invasion in patients with gastric cancer according to the 7th edition of the AJCC cancer staging manual. METHODS: A total of 127 patients with gastric cancer and who had undergone both esophago-gastro-duodenoscopy and 64-section CT were included in this study. Two radiologists independently reviewed the preoperative CT images with respect to the detectability and T-staging of the gastric cancers. The sensitivity, specificity, accuracy and overall accuracy of each reviewer for the T staging of gastric cancer were calculated. RESULTS: Overall, gastric cancer was detected in 123 (96.9%) of the 127 cancers on the CT images. Reviewer 1 correctly staged 98 gastric cancers, and reviewer 2 correctly classified 105 gastric cancers. The overall diagnostic accuracy of the T staging was 77.2% (98/127) for reviewer 1 and 82.7% (105/127) for reviewer 2. CONCLUSION: 64-section CT using CT gastrography showed a reasonable diagnostic performance for determining the T staging in patients with gastric cancer according to the 7th edition of the AJCC cancer staging manual. KEY POINTS: 64-section CT is useful for determining the T staging of gastric cancer Virtual gastroscopy is helpful for detecting early gastric cancer New CT criteria may be applicable to the T staging The normal gastric wall frequently shows a multilayered pattern.

Medullary carcinoma of the breast: MRI findings.

OBJECTIVE: The objective of our study was to describe the MRI findings of medullary carcinoma of the breast and to correlate those findings with the histopathologic findings. MATERIALS AND METHODS: From January 2005 to June 2010, MR images of 15 patients (age range, 32-73 years; mean age, 50 years) with pathologically confirmed medullary carcinoma of the breast were retrospectively evaluated according to BI-RADS. MR images were reviewed for the following: enhancement type (mass vs nonmass), size, shape, margins, contrast enhancement, signal intensity, and time-intensity curve pattern on a dynamic study. These MR features were correlated with the histopathologic features. RESULTS: All 15 tumors were seen as a mass on MRI. The median size of the masses was 2.7 cm (range, 1.5-6.3 cm) and the most common features were an oval or lobular shape (13/15, 86.7%) and a circumscribed margin (13/15, 86.7%). Rim enhancement with enhancing internal septations was seen in seven masses (46.7%), and rim enhancement was seen in six masses (40%). A hypointense rim on T2-weighted images was seen in nine tumors (9/15, 60%). Last, the kinetics curve showed a rapid initial increase in enhancement and a washout or plateau pattern on delayed phase imaging in all 15 tumors. CONCLUSION: On MRI, medullary carcinomas of the breast appeared as masses with an oval or lobular shape and circumscribed margins. Rim enhancement with or without enhancing internal septations was frequently seen on contrast enhancement.

Evaluation of early gastric cancer at multidetector CT with multiplanar reformation and virtual endoscopy.

Early gastric cancer (EGC) is defined as a carcinoma in which invasion is limited to the mucosa and submucosa, regardless of lymph node status and distant metastasis. Recent advances in multidetector computed tomography (CT) with multiplanar reformation (MPR) provide a powerful tool for identifying gastric wall invasion and the perigastric extent of gastric cancer. In addition, MPR images confer advantages in the assessment of both intra- and extraluminal processes of the gastric wall and the evaluation of more distant regions, such as the paraaortic lymph nodes and other abdominal organs. Virtual endoscopy performed after air distention of the stomach can aid in the evaluation of gastric endoluminal morphologic features and the extent of EGC. Moreover, virtual endoscopy helps in detecting subtle mucosal changes and differentiating them from submucosal lesions in the same way as conventional endoscopy. Virtual endoscopy can depict abnormal endoluminal lesions within a wider field of view than can conventional endoscopy, and there are no "blind spots" because retrospective image reformation is available, which provides useful information for preoperative mapping. Multidetector CT with MPR and virtual endoscopy is a powerful, noninvasive tool for the early detection and accurate preoperative staging of EGC.

Paget disease of the breast: mammographic, US, and MR imaging findings with pathologic correlation.

Paget disease is a rare malignancy of the breast characterized by infiltration of the nipple epidermis by adenocarcinoma cells. The clinical features of Paget disease are characteristic and should increase the likelihood of the diagnosis being made. An important point is that more than 90% of cases of Paget disease are associated with an additional underlying breast malignancy. Paget disease is frequently associated with ductal carcinoma in situ (DCIS) in the underlying lactiferous ducts of the nipple-areolar complex; it may even be associated with DCIS or invasive breast cancer elsewhere in the breast, at least 2 cm from the nipple-areolar complex. Nevertheless, mammographic findings may be negative in up to 50% of cases. Magnetic resonance (MR) imaging can be useful in patients with Paget disease for evaluation of the nipple-areolar complex and identification of an additional underlying malignancy in the breast. The appropriate surgical treatment must be carefully selected and individualized on the basis of radiologic findings, especially those obtained with breast MR imaging.

Diagnosis of acute gastrointestinal bleeding: comparison of the arterial, the portal, and the combined set using 64-section computed tomography.

OBJECTIVES: To compare the respective capabilities of the arterial, the portal, and the combined set in the detection and localization of acute gastrointestinal (GI) bleeding with 64-section computed tomography (CT). METHODS: A total of 46 patients with acute GI bleeding and who had undergone both 64-section CT and digital subtraction angiography were included in this study. The results of angiography were used as a reference standard. Two radiologists independently reviewed the 3 sets of CT images (arterial set, the unenhanced and arterial-phase images; portal set, the unenhanced and portal venous-phase images; combined set, the unenhanced and arterial-phase and portal venous-phase images). The diagnostic accuracy was assessed by a receiver operating characteristic analysis. RESULTS: For each observer, the Az values were 0.915 and 0.931 for the arterial set, 0.903 and 0.933 for the portal set, and 0.919 and 0.911 for the combined set, respectively. The differences were not statistically significant among the 3 data sets for each observer (P > 0.05). Both observers correctly detected the bleeding site in 81.3% and 84.4% on the arterial set, in 81.3% and 84.4% on the portal set, and in 84.4% and 84.4% on the combined set, respectively. CONCLUSIONS: Using 64-section CT, the diagnostic performance was not different among the arterial, the portal, and the combined set for the detection and localization of acute GI bleeding.

The accuracy of 64-slice MDCT for determining the perforation site of the gastrointestinal tract: ROC analysis.

PURPOSE: This study was performed to evaluate the diagnostic performance of 64-slice multidetector-row computed tomography (MDCT) for preoperatively detecting the perforation site in patients with gastrointestinal (GI) tract perforations. MATERIALS AND METHODS: A total of 49 patients with pathologically proven GI tract perforations, who had undergone MDCT were included in this study. The contrast-enhanced axial images (3 mm thick) and multiplanar reformation (MPR) images (3 mm thick) were generated for all the patients. Two radiologists independently reviewed the two sets of MDCT images (axial set: the axial images alone, and combined set: the axial and MPR images) for the detection of the perforation site. The perforation site was considered to be positive according to the direct and indirect findings. The diagnostic accuracy was assessed with a receiver operating characteristic (ROC) analysis. Weighted kappa statistics were used to evaluate the interobserver agreement. RESULTS: The corresponding values in respect of the first and the second observers for the areas under the ROC curve were 0.984 and 0.966 for the axial set; and 0.998 and 0.973 for the combined set. The differences were not statistically significant between the two data sets for each observer (P > 0.05). Both the observers detected the perforation site in 43 (87.8%) and 40 (81.6%) patients on the axial set, and in 46 (93.9%) and 41 (83.7%) patients on the combined set, respectively. The kappa values between the two observers showed excellent agreement with the two data sets. CONCLUSION: 64-slice MDCT showed a consistently excellent diagnostic performance for preoperatively determining the perforation site in patients with GI tract perforations, irrespective of the availability of the MPR images.

Sonographic findings of invasive cribriform carcinoma of the breast.

The purpose of this series was to evaluate the sonographic features of invasive cribriform carcinoma of the breast. Between 2004 and 2010, 3 patients had confirmed invasive cribriform carcinoma of the breast in our institution, and all of them underwent sonography. Sonograms showed masses with an oval (n = 2) or irregular (n = 1) shape, partially microlobulated (n = 2) or well-circumscribed (n = 1) margins, and a hypoechoic (n = 2) or an isoechoic (n = 1) internal echo texture. Sonographic assessments were classified as Breast Imaging Reporting and Data System category 4 in all 3 cases. Although invasive cribriform carcinoma is a rare breast malignancy, awareness of its sonographic features will be helpful for the diagnosis.

Gastrointestinal tract perforation: MDCT findings according to the perforation sites.

Our objective is to describe the characteristic CT findings of gastrointestinal (GI) tract perforations at various levels of the gastrointestinal system. It is beneficial to localize the perforation site as well as to diagnose the presence of bowel perforation for planning the correct surgery. CT has been established as the most valuable imaging technique for identifying the presence, site and cause of the GI tract perforation. The amount and location of extraluminal free air usually differ among various perforation sites. Further, CT findings such as discontinuity of the bowel wall and concentrated free air bubbles in close proximity to the bowel wall can help predict the perforation site. Multidetector CT with the multiplanar reformation images has improved the accuracy of CT for predicting the perforation sites.

Assessment of cerebrocortical areas associated with sexual arousal in depressive women using functional MR imaging.

INTRODUCTION: Mental illness is closely related with sexual dysfunction. A number of investigators have reported that depressive women have difficulties in sexual arousal. AIM: The purpose of this study was to compare the cerebrocortical regions associated with sexual arousal between the healthy and depressive women using functional magnetic resonance imaging (fMRI) based on the blood-oxygenation-level-dependent (BOLD) technique. METHODS: Together with nine healthy women (mean age: 40.3), seven depressive women (mean age: 41.7 years, mean Beck Depression Inventory: 35.6, mean Hamilton Rating Scale Depression-17: 34.9) underwent fMRI examinations using a 1.5T MR scanner (Signa Horizon; GE Medical Systems, Milwaukee, WI, USA). The fMRI data were obtained from seven oblique planes using gradient-echo EPI. Sexual stimulation paradigm began with a 1-minute rest and then 4-minute stimulation using an erotic video film. The brain activation maps and their resulting quantification were analyzed by the statistical parametric mapping (SPM99) program. The number of pixels activated by each task was used as brain activity, where the significance of the differences was evaluated by using independent t-test. MAIN OUTCOME MEASURES: We measured brain activation areas using BOLD-based fMRI with visual sexual stimulation in healthy volunteers and depressive patients. RESULTS: Healthy women were significantly (P < 0.05) activated in the regions of middle occipital gyrus, middle temporal gyrus, inferior frontal gyrus, insula, hypothalamus, septal area, anterior cingulate gyrus, parahippocampal gyrus, thalamus, and amygdala by erotic visual stimulation. In comparison with the healthy women, the depressive women gave lower activity, especially in the brain regions of hypothalamus (55.5:3.0), septal area (49.6:8.6), anterior cingulate gyrus (23.5:11.0), and parahippocampal gyrus (18.2:5.8). CONCLUSIONS: This preliminary study performed by fMRI gives valuable information on differentiation of the activated cerebral regions associated with visually evoked sexual arousal between healthy and depressive women. In addition, these findings might be useful to understand neural mechanisms for female sexual dysfunction in depressive women.

Preoperative staging of colorectal cancer: CT vs. integrated FDG PET/CT.

Accurate preoperative staging is essential in determining the optimal therapeutic planning for individual patients. The computed tomography (CT) in the preoperative staging of colorectal cancer, even if controversial, may be useful for planning surgery and/or neoadjuvant therapy, particularly when local tumor extension into adjacent organs or distant metastases are detected. There have been significant changes in the CT technology with the advent of multi-detector row CT (MDCT) scanner. Advances in CT technology have raised interest in the potential role of CT for detection and staging of colorectal cancer. In recent studies, MDCT with MPR images has shown promising accuracy in the evaluation of local extent and nodal involvement of colorectal cancer. Combined PET/CT images have significant advantages over either alone because it provides both functional and anatomical data. Therefore, it is natural to expect that PET/CT would improve the accuracy of preoperative staging of colorectal cancer. The most significant additional information provided by PET/CT relates to the accurate detection of distant metastases. For the evaluation of patients with colorectal cancer, CT has relative advantages over PET/CT in regard to the depth of tumor invasion through the wall, extramural extension, and regional lymph node metastases. PET/CT should be performed on selected patients with suggestive but inconclusive metastatic lesions with CT. In addition, PET/CT with dedicated CT protocols, such as contrast-enhanced PET/CT and PET/CT colonography, may replace the diagnostic CT for the preoperative staging of colorectal cancer.

Myxoid solitary fibrous tumor of the retroperitoneum: MRI findings with the pathologic correlation.

We report here on a case of solitary fibrous tumor of the retroperitoneum, and the tumor displayed a predominantly myxoid histology. A 56-year-old man presented with an incidentally detected retroperitoneal mass. On the MR images, the mass was observed as having iso-signal intensity on the T1-weighted images and high signal intensity on the fat-saturated T2-weighted images. The mass showed intense enhancement on the Gd-DTPA enhanced T1-weighted images. At surgery, a well-defined solid mass was found in the left retroperitoneum. The histological diagnosis was made as solitary fibrous tumor with a predominantly myxoid histology.

Transcatheter coil embolization of an Arc of Buhler aneurysm.

We report the findings of a patient with an asymptomatic Arc of Buhler (AOB) aneurysm, which was successfully treated by transcatheter coil embolization. An abdominal CT and angiography revealed an intact pancreaticoduodenal artery arcade (PDAA) and an anomalous communication between the SMA and celiac axis, termed an AOB. An aneurysm was observed at the origin of the AOB and treated with a transcatheter embolization using coils. A follow-up CT imaging confirmed the total occlusion of the aneurysm with a patent PDAA. The successful results of this treatment suggest that the endovascular therapy of an AOB aneurysm with a celiac axis occlusion and an intact PDAA is feasible and safe.