The occurrence of transient severe motion during arterial phase MRI with gadoxetate disodium is 12.9% and is poorly predicted on the basis of risk factors.

A markedly distended gallbladder associated with decreased wall enhancement is highly specific for gangrenous cholecystitis.

Objective:To evaluate the efficacy of computer tomography (CT)-guided core needle biopsy (CNB) in the diagnosis of deep suprahyoid lesions in patients with treated head and neck cancers. Materials and Methods: Between December, 2003 and May, 2011, 28 CT-guided CNBs were performed in 28 patients with deep suprahyoid head and neck lesions. All patients had undergone treatment for head and neck cancers. Subzygomatic, paramaxillary, and retromandibular approaches were used. The surgical results, response to treatment, and clinical follow-up were used as the diagnostic reference standards. Results: All biopsies yielded adequate specimens for definitive histological diagnoses. A specimen from a right parapharyngeal lesion showed atypia, which was deemed a false negative diagnosis. Diagnostic accuracy was 27/28 (96.4%). Two minor complications were encountered: a local hematoma and transient facial palsy. Between the 18 or 20 gauge biopsy needles, there was no statistical difference in the diagnostic results. Conclusion: CT-guided core needle biopsy, with infrequent and minor complications, is an accurate and efficient method for the histological diagnosis of deep suprahyoid lesions in post-treated head and neck cancer patients. This procedure can preclude an unnecessary surgical intervention, especially in patients with head and neck cancers.

Previous studies have shown that single or multiple treatments by focused ultrasound are effective and safe. However, most include focused ultrasound only and not radio-frequency treatment. There is paucity of magnetic resonance imaging (MRI) measurements and pictures in the literature. This study aimed to assess the efficacy, safety, and pain and satisfaction levels of the combination therapy of focused ultrasound and radio-frequency for improving body contours. Thirty-two Asian patients received 3 sequential treatments every 2 weeks in the abdominal region. Safety parameters and adverse events were recorded. The subjects' pain and satisfaction levels were evaluated using a five-point Likert scale. Two patients underwent MRI study randomly. There was a mean reduction in circumference of 3.91 ± 1.8 cm (p ≤ 0.001). In MRI measurement, the average in fat thickness reduction was 21.4 and 25% on the upper and lower abdomen, respectively. There were three mild and self-limited localized adverse events. The satisfaction survey showed that 71.9% was satisfied with the results, while pain level evaluation showed that 90.5% felt no pain. Combination therapy of focused ultrasound and radio-frequency for noninvasive body contouring is an effective, safe, and painless procedure in Asians. Although the change is minor compared to traditional surgical procedure, it is real, definite, and effective.

This study aimed to evaluate the efficacy of CT-guided core needle biopsy (CNB) in the diagnosis of deep head and neck tumors in untreated patients. We retrospectively reviewed the records of ten consecutive CT-guided CNB procedures from ten patients without a related history from March 2004 to February 2012. The surgical results, treatment response and clinical follow-up were used as the diagnostic standards. All specimens were considered adequate. Nine out of ten cases matched the final diagnosis. Biopsy failed to diagnose the infratemporal meningioma en plaque in a particular case. Three cases were carcinomas. No complication was encountered. CT-guided core needle biopsy is an efficient and safe technique for histological diagnosis of skull base lesions in patients without a related history. This technique can offer a definite tissue diagnosis and avoid unnecessary surgical interventions for such patients.

Acute surgical abdomen is commonly encountered in the ED and CT is widely used as an informative diagnostic tool to evaluate potential surgical indications. However, the adverse effects of contrast material used in CTscanning have been documented. We sought to delineate the role of noncontrast CT in the evaluation of patients with acute surgical abdomen. Between August 2015 and December 2015, patients with nontraumatic surgical abdomen who underwent preoperative CT were enrolled in the current study. The patients for whom the CT results permitted surgical decision-making were the focus of this study. The disease entities included acute appendicitis, acute cholecystitis, hollow organ perforation, mechanical bowel obstruction, intra-abdominal abscess that could not be drained percutaneously, and ischemic bowel disease. The results of contrast-enhanced and noncontrast CT were compared and analyzed. The surgical conditions identifiable by noncontrast CT were recorded. In total, 227 patients were enrolled in the study. In 90.7 per cent of patients overall, the findings indicating the need for surgical treatment were visualized on both the noncontrast and contrast-enhanced images (acute appendicitis: 89.3%, acute cholecystitis: 89.7%, hollow organ perforation: 97.4%, bowel obstruction: 100%, intra-abdominal abscess: 100%, and ischemic bowel disease: 55.6%). Noncontrast CT provides benefit for critical decision-making. Body mass index may affect the accuracy of noncontrast imaging in the evaluation of patients with surgical abdomen. In some specific situations, contrast enhancement remains necessary.

OBJECTIVE The purpose of this study is to describe the appearance and frequency of gas interface artifacts in the jejunum that may mimic severe bowel disease on iodine-density images generated from rapid-voltage-switching dual-energy CT (DECT) scans. MATERIALS AND METHODS Two readers retrospectively reviewed 108 consecutive abdominal rapid-voltage-switching DECT scans to record the presence of image artifacts in jejunal segments with different degrees of gaseous luminal filling, classified as full, partial, or absent. Readers viewed iodine-density images and corresponding 140-kVp and 65-keV virtual monochromatic images and classified the jejunal artifacts on iodine-density images as pseudostratified appearance of the bowel wall, pseudopneumatosis, pseudohyperenhancement, or pseudohypoenhancement. We correlated the presence of the artifacts with clinical features suggesting bowel disease. RESULTS Image artifacts were found in 91 of 108 scans (84.3%), appeared in 148 of 265 jejunal segments (55.8%), and included each type except for pseudohypoenhancement. Artifacts occurred exclusively when gas was present in the bowel lumen and were seen in 59 of 59 (100%) fully gas-distended segments, 89 of 98 (90.8%) partially gas-distended segments, and none of 108 gas-absent segments (p < 0.0001). In fully and partially gas-distended jejunal segments (n = 157), 148 (94.3%) segments had two or more artifacts. None of the patients was found to have clinical bowel-related injury on follow-up of medical records. CONCLUSION Pseudostratified appearance, pseudopneumatosis, and pseudohyperenhancement, but not pseudohypoenhancement, artifacts are common in gas-filled jejunal segments on iodine-density images generated from rapid-voltage-switching DECT scans and are not seen in the corresponding 140-kVp or 65-keV images. Knowledge of the appearance of such iodine-density image artifacts will avoid potential examination interpretation pitfalls.

Background: Salivary gland masses constitute a diagnostic challenge in daily clinical practice and tissue sampling is required to establish a diagnosis. We aimed to evaluate the efficacy of ultrasonography-guided fine needle aspiration biopsy (UGFNAB) in the diagnosis of salivary gland lesions. Methods: From January 2007 to September 2010, a total of 158 patients who underwent both UGFNAB and surgical excision for salivary gland mass lesions were included in this study. Patients with insufficient sampling or inconclusive cytology diagnosis were excluded from the analysis of diagnostic accuracy of UGFNAB. Results: UGFNAB yielded sufficient sampling for analysis in 137 patients, leading to a diagnostic yield of 86.7%. Among these 137 patients, 24 patients were confirmed to have malignant tumors. The sensitivity, specificity and accuracy of UGFNAB for malignancy were 66.7%, 98.2%, and 92.7%, respectively. No UGFNAB-related complications were encountered. Conclusions: UGFNAB of salivary gland masses is a safe technique that offers high specificity and accuracy but moderate diagnostic yield and sensitivity.