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Background Tin filter-based spectral shaping has been used for low-dose and ultra-low-dose computed tomography (CT) in several body parts. However, studies of shoulder CT arthrography with spectral shaping are limited. Purpose To investigate image quality and radiation dose of shoulder CT arthrography with tin filter-based spectral shaping at 100 kV (Sn 100 kV) and 140 kV (Sn 140 kV) in comparison with the conventional protocol. Material and Methods Ninety-nine shoulder CT arthrographies with protocols of Sn 100 kV (n = 32), Sn 140 kV (n = 25), and conventional 120 kV (n = 42) were retrospectively evaluated. Qualitative image quality, CT attenuations of intra-articular contrast mixture and tissues, background noise, contrast-to-noise ratios (CNRs), and figures of merit were assessed. Radiation doses were compared. Results CT arthrographies with Sn 100 kV and Sn 140 kV yielded approximately 70% and 60% radiation dose reduction, respectively, compared with the conventional 120 kV ( P Conclusion Shoulder CT arthrography with Sn 100 kV substantially reduced radiation dose and image noise and maintained image contrast, compared with the conventional protocol.

Background Although time-of-flight magnetic resonance angiography (TOF-MRA) is widely used, it has limited usefulness for follow-up after stent-assisted coil embolization. Contrast-enhanced MRA (CE-MRA) and ultrashort echo time MRA have been suggested as alternative methods for visualization after this procedure. Purpose To compare efficacy and usefulness of pointwise encoding time reduction with radial acquisition (PETRA) sequence in subtraction-based MRA (qMRA), TOF-MRA, and CE-MRA during the follow-up after Neuroform Atlas stent-assisted coil embolization for intracranial aneurysms. Material and Methods This retrospective study included 23 patients with 24 aneurysms who underwent Neuroform Atlas stent-assisted coil embolization for intracranial aneurysms. All patients were evaluated with PETRA qMRA, TOF-MRA, and CE-MRA at the same follow-up session. The flow within stents, occlusion status, and presence of pseudo-stenosis were evaluated; inter-observer and intermodality agreements for the three methods were also graded. Results The mean score for flow visualization within the stents was significantly higher for PETRA qMRA and CE-MRA than for TOF-MRA (although no significant difference was found between PETRA qMRA and CE-MRA). Good inter-observer agreement was observed for each modality. PETRA qMRA and CE-MRA were more consistent with digital subtraction angiography (DSA) than TOF-MRA for aneurysm occlusion status. The intermodality agreement was better between PETRA qMRA and DSA, and between CE-MRA and DSA, than between DSA and TOF-MRA. Pseudo-stenosis was most frequently observed in TOF-MRA, followed by CE-MRA and PETRA qMRA. Conclusion PETRA qMRA is useful for evaluating the parent artery patency and occlusion status of aneurysms after Neuroform Atlas stent-assisted coil embolization.

Background The distally extended muscle belly of the flexor digitorum (MB-FD) within the carpal tunnel has been suggested as a plausible cause for carpal tunnel syndrome (CTS) based on cadaveric studies. Purpose To evaluate whether MB-FD within the carpal tunnel is a risk factor for CTS by comparing asymptomatic volunteers and patients with CTS. Material and Methods Presence, length, and cross-sectional area of MB-FD within the carpal tunnel were evaluated in 63 wrists of 32 asymptomatic volunteers and 52 wrists of 33 patients with CTS using ultrasonography. Length of MB-FD within the carpal tunnel was measured as the distance between the distal end of MB-FD and the palmar margin of the distal radius longitudinally. On a transverse scan, the cross-sectional area of MB-FD at the proximal limit of the carpal tunnel was measured. Results MB-FD in the carpal tunnel was found in 39 (62%) asymptomatic volunteers and 35 (67%) patients with CTS ( P = 0.549). There was a female preponderancy of MB-FD within the carpal tunnel in asymptomatic volunteers ( P = 0.044), but not in patients. Length and cross-sectional area of MB-FD within the carpal tunnel were significantly greater in male-CTS patients than in male volunteers ( P = 0.022 and 0.012, respectively). These qualities were risk factors for CTS in men, though not in women. Conclusion The presence of distally extended MB-FD within the carpal tunnel was not a risk factor for CTS. In men, a longer and thicker MB-FD within the carpal tunnel increased the risk for CTS.

Purpose No previous study using follow-up ultrasonography for evaluating the factors associated with the successful regression of congenital muscular torticollis in young infants has been published. This study aimed to assess clinical factors and sonographic features potentially influencing regression in patients with congenital muscular torticollis. Methods From January 2010 to December 2012, 80 infants underwent neck ultrasonography because of clinical suspicion of congenital muscular torticollis. We statistically analysed the correlation between complete resolution and clinicosonographic findings when complete resolution was defined as no visible lesion on follow-up ultrasonography. Results Of the 80 infants, 61 had congenital muscular torticollis and all were followed up by ultrasonography: 1) 34 underwent physiotherapy, and 27 of them (79.4%) revealed complete resolution in follow-up; 2) 27 did not undergo physiotherapy, and 15 of them (55.6%) showed complete resolution. A statistically significant correlation was found between physiotherapy and complete resolution, but not between complete resolution and patient sex; size, volume, and echogenicity of the lesion; and thickness ratio. Conclusions Physiotherapy was the only factor influencing complete resolution in young infants with congenital muscular torticollis.

Background Acute ischemic stroke (AIS) more frequently develops in patients with intracranial vertebral artery dissection (VAD) than extracranial VAD, and is associated with possible poor clinical outcomes. The aim of this study is to compare high-resolution magnetic resonance imaging (HR-MRI) findings and clinical features of VAD with and without AIS. Methods Twenty-nine lesions from 27 patients (15 male and 12 female patients; age range = 28–73 years) who underwent diffusion MRI and 3T HR-MRI within seven days were included. We classified VAD according to the presence of AIS lesions on diffusion MRI. Clinical features and HR-MRI findings (angiographic patterns, presence of double lumen sign, dissecting flap, posterior inferior cerebellar artery involvement, remodeling index, length of affected vessels, T1-signal intensity, area of intramural hematoma, and grades and patterns of vessel wall enhancement) were evaluated. Results Thirteen VADs with AIS and 16 without AIS were included. There were no significant differences in the clinical parameters (sex, age, risk factors, symptoms). More VADs with AIS presented as a steno-occlusive pattern than VADs without AIS. More VADs without AIS presented with aneurysmal dilation, larger mean remodeling index and longer mean length than VADs with AIS. Presence of intramural hematoma, T1-iso-signal intensity of intramural hematoma and contrast enhancement were significantly more common in VADs with AIS than without AIS. Conclusions Our study showed some differences in HR-MRI comparing intracranial VAD patients with and without AIS. Differing findings may facilitate a better understanding of intracranial VAD and risk assessment of AIS in these patients.

BackgroundThe rotator cable is an important structure providing stress shield to the rotator cuff, similar to the mechanism of suspension bridge.PurposeTo evaluate the visibility and appearance of the rotator cable in various conditions of the rotator cuff, using indirect magnetic resonance (MR) arthrography.Material and MethodsIndirect MR arthrography images from 27 patients (age range, 20–63 years) with normal rotator cuffs, and 47 (age range, 20–73 years) with tendinosis, 32 (age range, 49–71 years) with partial-thickness tears, and 55 (age range, 44–75 years) with full-thickness tears in the supraspinatus and infraspinatus tendons (SST-ISTs) were included in this study. In these various rotator cuff conditions, the visibility and appearance (thickness and width) of the rotator cable and the relationships between the rotator cable appearance, rotator cuff tear size, rotator cuff thickness, and patient’s age were assessed.ResultsOn the sagittal MR images, all rotator cables were visible in the normal rotator cuffs and tendinosis/partial-thickness tears of SST-ISTs. In the order of normal cuff, tendinosis, partial-thickness tear, and full-thickness tear of SST-ISTs, the rotator cable tended to become thicker (1.07, 1.27, 1.32, and 1.59 mm, respectively) and narrower (12.1, 10.68, 10.90, and 8.55 mm, respectively). The thickness of the rotator cable was significantly positively correlated with the rotator cuff thickness in the normal rotator cuffs (coefficient, 0.49; P = 0.010) and tendinosis of SST-ISTs (coefficient, 0.53; P ConclusionOn sagittal plane of indirect MR arthrography, most rotator cables were visible. The appearance of the rotator cable changed according to the rotator cuff condition.

Introduction Our purpose was to evaluate whether plain abdominal radiography (PAR) could accurately differentiate between small bowel obstruction (SBO) and small bowel ileus (SBI) in an emergency setting. We also evaluated the value of known classic signs on the PAR for differentiating between SBO and SBI. Methods This retrospective study included 216 emergency room patients who had small bowel distension (maximal small bowel diameter ≥2.5 cm) on the PAR and who underwent successive abdominal computed tomography. One radiologist and one emergency physician retrospectively reviewed PAR in consensus, unaware of the patients' clinical data; they divided the patients into an SBO group and an SBI group according to the radiographic findings. Presence or numeric values of 10 radiographic signs were also recorded. Final diagnoses of SBO and SBI were established by a combined analysis of medical charts, surgical records, radiographic findings on abdominal computed tomography, and small bowel studies. The differential diagnoses based on PAR and the final diagnoses were compared, and the sensitivity and specificity of PAR were calculated. We also evaluated the differences among 10 radiographic signs between the final SBO and SBI groups. Results Sensitivity and specificity of PAR for SBO were 82.0% and 92.4%, respectively. Among the 10 radiographic signs, all except maximal colon diameter were statistically significant predictors on the final diagnosis. Conclusions PAR is an accurate and effective initial imaging modality for differentiating between SBO and SBI in an emergency setting, and most of the classic radiographic signs have a diagnostic value.