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To evaluate the diagnostic performance, image quality, artifacts, and radiation doses of virtual non-contrast (VNC) images, relative to true non-contrast (TNC) images, in patients with surgically clipped aneurysms. Seventy-six patients who underwent unenhanced computed tomography (CT) and dual-energy (DE)-CT angiography after surgical clipping of 85 intracranial aneurysms were included in the study. Diagnostic performances of VNC and TNC images were compared with respect to sensitivity, specificity, and positive and negative predictive values. The results of quantitative and qualitative analyses were compared between VNC and TNC images. Radiation doses were also compared between VNC and TNC images. Diagnostic performance of VNC images was lower than that of TNC images; however, addition of contrast-enhanced images improved diagnostic performance. Image noise and mean attenuation of VNC images were significantly higher than those of TNC images in the centrum semiovale, cerebellum, and pons. The quality of VNC images was excellent or sufficient (85.5% for observer 1, 85.5% for observer 2), and complete acceptance of VNC images was achieved in 64.5% for observer 1 and in 71.0% for observer 2; however, the addition of contrast-enhanced images increased the level of acceptance (92.0% for observer 1, 90.9% for observer 2). Clip artifacts were significantly lower in VNC images than in TNC images. CT dose index, dose-length product, and effective dose were significantly lower without TNC images. VNC images showed lower diagnostic performance and image quality, and higher image noise than TNC images; however, VNC images could reduce clip artifacts and radiation doses.

To evaluate the normal location of the peroneus longus tendon (PL) in the cuboid groove in various ankle–foot positions by ultrasonography in asymptomatic volunteers. Ultrasonographic assessment of the PL in the cuboid groove was performed in 20 feet of ten healthy volunteers. Each PL was examined in five ankle–foot positions (i.e., neutral, dorsiflexion, plantar-flexion, supination, and pronation). The PL location was qualitatively categorized as “inside” when the PL was entirely within the cuboid groove, as “overlying” when some part of the PL was perched on the cuboid tuberosity, and as “outside” when the PL was entirely on the cuboid tuberosity. For quantitative evaluation of the PL location, the distance between the PL and the cuboid groove was measured. The width of the cuboid groove was measured in the neutral position. The PL location did not significantly change with changes in the ankle–foot position. Qualitatively, an “overlying” PL was the most common type, regardless of the ankle–foot position. “Inside” PLs were found in only 35, 20, 30, 25, and 35% of feet in neutral, dorsiflexion, plantar-flexion, supination, and pronation positions, respectively. The quantitative PL location was also not significantly different among all ankle–foot positions and it was significantly negatively correlated with the cuboid groove width. In healthy volunteers, 65% or more of the PLs were partially or completely located outside of the cuboid groove, regardless of the ankle–foot position. The PL location relative to the cuboid groove was related to the cuboid groove width.

Persistent trigeminal artery (PTA) is a rare cerebrovascular variation of remnant fetal carotid-vertebrobasilar anastomoses. The PTA variant terminates in the cerebellar artery with no direct connection to the basilar artery. We present a rare case of a PTA variant that terminated directly into the ipsilateral posterior inferior cerebellar artery.

No study has so far investigated the relationship between aspirate color or degree of aspiration on the success of ethanol ablation (EA) of cystic thyroid nodules. We aimed to evaluate the efficacy of EA of benign cystic thyroid nodules and assess the relevant factors influencing the outcome. Over a 2-year period, 64 benign cystic thyroid nodules in 62 patients were treated with EA. Several factors related to EA efficacy were evaluated, including the cystic component volume, volume and color of aspirates, degree of aspiration, and volume of injected ethanol. In all cases, we performed ultrasound follow-up for at least 12 months after the last EA session to evaluate the collapsed cystic component. The 64 treated nodules had aspirate colors that were red bloody (n = 3), dark bloody (n = 31), brownish (n = 15), greenish-yellow (n = 13), and colorless (n = 2). The degrees of aspiration were scant (n = 8), mild (n = 3), moderate (n = 8), and complete (n = 45). There was successful collapse of the cystic component after initial EA in 52 cases, but a repeat EA was employed in 12 failed cases. Statistical analysis showed that the degree of aspiration and color of aspirates correlated significantly with the success of EA. The results of this study suggest that complete aspiration of cystic contents was the most important factor in the efficacy of EA of benign cystic thyroid nodules, and greenish-yellow contents were closely related to scant or mild aspiration.

Lateral ankle pain is common with overuse and sports-related injuries and may cause considerable morbidity. The differential diagnosis of lateral ankle pain is extensive. Disorders of the peroneal tendons should be an important consideration during interpretation of a routine ankle magnetic resonance imaging (MRI) or ultrasound (US). This article presents a review of the common causes of peroneal tendon pathology with particular reference to anatomy, US, and MRI features. The importance of dynamic evaluation with ultrasound is also emphasized.

Background To date, appropriate management for Bethesda IV thyroid nodules is controversial, and no specific features of follicular neoplasm and nodular hyperplasia on ultrasonography, computed tomography (CT), or other imaging modalities have been reported. This study aimed to compare CT features of follicular neoplasm and nodular hyperplasia and to determine the specific CT features that could be used to distinguish follicular neoplasm from nodular hyperplasia. Methods In 122 patients who underwent preoperative CT of the neck and thyroid surgery, 59 follicular neoplasms and 65 nodular hyperplasias were included. In each case, non-enhanced and contrast-enhanced CT images were obtained, and a single radiologist retrospectively analyzed CT images, including degree and pattern of attenuation, nodular configuration, margin, shape, pattern of calcification, degree and pattern of nodular enhancement, and CT halo sign. A univariate and multivariate logistic regression analyses were used to evaluate the predictive power of each variable and CT features with a high predictive power, respectively. Results According to the univariate analysis, iso-attenuation, intraglandular configuration, smooth margin, ovoid shape, decreased enhancement, and absence of CT halo sign were more frequently observed in nodular hyperplasia (p

The purpose of this study was to analyze statistically significant diagnostic factors for pilomatricoma on the basis of ultrasonographic features. Sonographic images were retrospectively reviewed from 44 pilomatricomas, and from 43 control subjects with other subcutaneous tumors. Two radiologists determined the tumoral shape, margin, echotexture, echogenicity, posterior shadowing, posterior enhancement, hypoechoic rim, internal calcification, and vascularity. The reliable diagnostic factors for pilomatricoma were hypoechogenicity (P