AIFRS showed frequent extra-sinonasal involvement and variable MR enhancement patterns. An enhancement pattern of LoCE was seen in about half of the cases and was a unique prognostic factor among the various clinico-radiologic factors.

564S everal studies have demonstrated that arterial spin labeling (ASL)-perfusion-weighted imaging (PWI) can detect hypoperfusion and perfusion-diffusion mismatch in the setting of acute stroke, with good to modest correlation to dynamic susceptibility contrast perfusion MRI. [1][2][3][4] Recently, ASL-PWI has been incorporated as a part of the acute ischemic stroke evaluation in our institution, and with its increasing use, we have encountered patients with acute ischemic stroke in whom a characteristic bright intravascular signal (which we termed bright vessel appearance) is found within an occluded arterial segment. To our knowledge, the usefulness of ASL bright vessel appearance in patients with acute ischemic stroke has not been elucidated yet. The purpose of our study was, therefore, to evaluate whether the bright vessel appearance on ASL-PWI can help localize sites of arterial occlusion in patients with acute ischemic stroke. MethodsThis retrospective study was approved by our institutional review board, and informed consent was waived. PatientsOur radiology database from January 2014 to April 2014 was searched for patients who underwent MRI for suspected acute ischemic stroke. Among 171 patients, those whose MR images showed infarctions, as identified by areas of restricted diffusion, were included. Fifty-four patients were excluded for the following reasons: (1) no ASL images, (2) ASL images of poor image quality because of inadequate acquisition times or artifacts, or (3) occlusions at the extracranial carotid arteries (in which arterial labeling was insufficient). As a result, 117 consecutive patients were included in this study. MRI ProtocolAll patients underwent MRI at a 1.5T (Signa HDxt; GE Medical Systems, Milwaukee, WI [n=70]) or 3.0T (Verio; Siemens, Erlangen, Germany [n=47]) MR scanner using a 16-channel head coil. Our MRI Background and Purpose-The purpose of this study was to evaluate whether bright vessel appearance on arterial spin labeling (ASL) MRI can help localize arterial occlusion sites in patients with acute ischemic stroke. Methods-Patients who underwent MRI for suspected acute ischemic stroke, as identified by an area of restricted diffusion, were included. All images were visually analyzed for the presence or absence of (1) arterial occlusion on time-of-flight MR angiography, (2) bright vessel appearance on ASL images, and (3) susceptibility vessel sign. McNemar 2-tailed test was used to compare the sensitivities of ASL and susceptibility-weighted imaging for the detection of arterial occlusion, using MR angiography as the reference standard. Results-ASL bright vessel appearance was significantly more common in the group with occlusion than in the group without occlusion (94% protocol for acute stroke evaluation included diffusion-weighted imaging, fluid-attenuated inversion recovery, susceptibility-weighted imaging (SWI), ASL-PWI, and 3-dimensional time-of-flight MR angiography. ASL-PWI scans were performed using a pseudocontinuous ASL pulse sequence. The signal intensity chan...

Desmoid-type fibromatosis in the head and neck of adults frequently involves perivertebral space. Along with various common imaging features, desmoid-type fibromatosis shows characteristic nonenhancing low signal intensity bands on MR images.

Proper management of lymph nodes (LNs) with ultrasonographic (US) indeterminate features in thyroid cancer patients remains elusive. We aimed to evaluate the malignancy risk and US findings predictive of malignancy for US indeterminate LNs in preoperative thyroid cancer patients through node-by-node correlation. Materials and Methods: A total of 348 LNs in 284 thyroid cancer patients, who underwent fine-needle aspiration or coreneedle biopsy between December 2006 and June 2015, were included. We determined the malignancy risks for US probably benign, indeterminate, and suspicious categories. For US indeterminate LNs, which had neither echogenic hilum nor hilar vascularity in the absence of any suspicious finding, US findings were compared between benign and metastatic LNs using Mann-Whitney U test and Fisher's exact test. Results: US imaging diagnoses were probably benign in 20.7% (n = 72) cases, indeterminate in 23.6% (n = 82), and suspicious in 55.7% (n = 194). Malignancy risk of US indeterminate LNs (19.5% [16/82]) differed from those of the US probably benign (2.8% [2/72]) (p = 0.002) and US suspicious LNs (78.4% [152/194]) (p < 0.001). Among US indeterminate LNs, there were no significant differences in short, long, and long-to-short diameter (L/S) ratios between benign and metastatic LNs (3.9 vs. 3.8 mm, p = 0.619; 7.3 vs. 7.3 mm, p = 0.590; 1.9 vs. 1.9, p = 0.652). Conclusion: US indeterminate LNs were frequently encountered during preoperative evaluation and had intermediate malignancy risk. Given the lack of discriminative power of size criteria and L/S ratio, clinical factors such as surgical strategy and node size should be considered for proper triage of US indeterminate LNs in thyroid cancer.

Background: Although there is a standard guideline for performing revascularization surgery in patients with Moyamoya diseases (MMD), more objective and easily obtainable predictors are still needed. Objectives: In this study, we aimed to evaluate the relationship between an ipsilateral ivy sign and ischemic stroke recurrence in adult MMD patients without revascularization surgery. Methods: We included consecutive MMD patients without revascularization surgery between 2006 and 2014. The ivy sign was defined as a linear or focal high-signal intensity on fluid-attenuated inversion recovery images, and the burdens of ivy sign were rated in each hemisphere. The ischemic stroke recurrence was defined as a new clinical event that accompanied a new brain lesion on magnetic resonance imaging. Results: Overall, 84 patients with 154 hemispheres were analyzed. We found recurrent ischemic stroke in 9 (6%) hemispheres within 3 years. In multivariate analysis, an ipsilateral ivy sign remained an independent predictor of 3-year ischemic recurrence (adjusted hazard ratio [aHR] 10.15, 95% CI 2.10–49.14, p = 0.004). An initial presentation as infarction was also significant (aHR 7.15, 95% CI 1.36–36.78, p = 0.019). The burdens of ivy sign showed a dose-response tendency with the 3-year ischemic recurrence rate (p < 0.001). When comparing the ischemic recurrence rate among 4 groups with and without ivy sign and perfusion defect, the “Ivy sign (+) Perfusion defect (+) group” showed a significantly higher risk in both observed (p = 0.005) and estimated (p = 0.003) 3-year ischemic recurrence than did the other group. Additionally, the “Ivy sign (+) Perfusion defect (–) group” showed a higher recurrence rate than did the “Ivy sign (–) Perfusion defect (+) group”. Conclusions: The ivy sign is associated with ischemic recurrence in adult MMD patients in a dose-response manner. It would be helpful for selecting high-risk patients who need revascularization surgery.