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Bone age is considered an indicator for the diagnosis of precocious or delayed puberty and a predictor of adult height. We aimed to evaluate the performance of a deep neural network model in assessing rapidly advancing bone age during puberty using elbow radiographs. In all, 4437 anteroposterior and lateral pairs of elbow radiographs were obtained from pubertal individuals from two institutions to implement and validate a deep neural network model. The reference standard bone age was established by five trained researchers using the Sauvegrain method, a scoring system based on the shapes of the lateral condyle, trochlea, olecranon apophysis, and proximal radial epiphysis. A test set (n = 141) was obtained from an external institution. The differences between the assessment of the model and that of reviewers were compared. The mean absolute difference (MAD) in bone age estimation between the model and reviewers was 0.15 years on internal validation. In the test set, the MAD between the model and the five experts ranged from 0.19 to 0.30 years. Compared with the reference standard, the MAD was 0.22 years. Interobserver agreement was excellent among reviewers (ICC: 0.99) and between the model and the reviewers (ICC: 0.98). In the subpart analysis, the olecranon apophysis exhibited the highest accuracy (74.5%), followed by the trochlea (73.7%), lateral condyle (73.7%), and radial epiphysis (63.1%). Assessment of rapidly advancing bone age during puberty on elbow radiographs using our deep neural network model was similar to that of experts. • Bone age during puberty is particularly important for patients with scoliosis or limb-length discrepancy to determine the phase of the disease, which influences the timing and method of surgery. • The commonly used hand radiographs–based methods have limitations in assessing bone age during puberty due to the less prominent morphological changes of the hand and wrist bones in this period. • A deep neural network model trained with elbow radiographs exhibited similar performance to human experts on estimating rapidly advancing bone age during puberty.

Background: Merkel cell carcinoma (MCC) is a rare primary cutaneous tumor. The standardized imaging guidelines for the diagnosis of MCC have not been established. We report the multimodality imaging features of MCC, including CT, MRI, and ultrasound with grayscale and color Doppler mode as well as the elastography and even a histopathologic confirmation. Case Report: We report the case of a 76-year old male patient with MCC on the elbow that was treated by excision. On MRI, prominent T2 low signal voiding was noted with branching or chaotic pattern and marked, branching, or chaotic vascularity was also seen on color doppler ultrasound. Those findings corresponded to histology that showed increased vascularity in stromal tissues of the tumor and in between the tumor cells. Conclusion: A mass in the dermal and subcutaneous layer with marked and branching or chaotic vascularity may be the unique characteristic that may contribute to early diagnosis of MCC.

Background A locked thumb metacarpophalangeal joint is a rare condition that presents as restricted joint motions with mild hyperextension deformity, usually after a relatively minor hyperextension injury. Owing to the limitations of radiographs, computed tomography is a useful diagnostic imaging modality for assessing sesamoid displacement. However, despite its convenience, ultrasound findings of the locked thumb have rarely been reported. Here, we report a case of a locked thumb metacarpophalangeal joint diagnosed and followed-up using ultrasound. Case presentation A 15-year-old boy with a locked thumb metacarpophalangeal joint presented to our hospital. On physical examination, the 1st metacarpophalangeal joint was found to be hyperextended, and active and passive flexions were not possible. While radiographs were inconclusive, ultrasound revealed radial sesamoid entrapment at the 1st metacarpophalangeal joint causing locking. After closed manual reduction, metacarpophalangeal motions recovered. Success of the reduction was also confirmable by ultrasound. Conclusions Ultrasound can be a feasible modality to diagnose a locked thumb metacarpophalangeal joint and immediately judge the success or failure of the reduction.

Background Since the diagnosis of post-arthroscopic chondrolysis is very difficult, it can be underdiagnosed and confused with other diseases in clinical practice. Purpose To propose imaging features of post-arthroscopic radiocarpal chondrolysis (PRCC) and to compare these with osteoarthritis associated with scapholunate dissociation which are the most common misdiagnoses of PRCC. Material and Methods To identify missed diagnoses of PRCC, 994 magnetic resonance imaging scans performed in 910 patients were retrospectively reviewed. After the identification of 73 patients who exhibited significant radiocarpal cartilage loss, 11 were diagnosed with PRCC. Since scapholunate advanced collapse was the most common incorrect diagnosis of PRCC (4/11), the imaging findings were compared among the 11 patients with PRCC and 14 patients with osteoarthritis caused by scapholunate dissociation who were diagnosed in the same period. The following imaging features were evaluated: scapholunate dissociation; the center of disease and grade of radiocarpal joint destruction; characteristics of bone marrow edema; the presence of radial styloid and distal scaphoid osteophytes; and the extent of joint effusion and synovitis. Results The imaging diagnosis of PRCC was significantly differentiated from osteoarthritis associated with scapholunate dissociation based on occurrence at a younger age, bone marrow edema crossing the joint, center of disease in the proximal radioscaphoid joint, and absence of radial styloid and scaphoid osteophytes ( P Conclusion The diagnosis of PRCC can be aided if its characteristic imaging findings are differentiated from other disease entities in patients with a history of arthroscopy.

Background: Understanding the axial lumbar spine anatomy, including knowledge of the relationship between the lumbar spine level and other paraspinal structures, is important in diagnosing and treating disease. The purpose of this study was to validate the accuracy of a convolutional neural network (CNN) model in lumbar spine level numbering on axial MR images and to find the appropriate anatomic landmarks for numbering using a class activation map (CAM).Methods: A total of 6055 axial MR images of the lumbar spine from L1–2 to L5–S1 disc levels were obtained to train and validate the CNN model. The MR images were acquired using three 3-Tesla machines. The algorithm was developed with three models, and the best-performing model was selected. The external validation set (n = 493) was obtained from other institutions using various machines. The accuracy of the numbering was analyzed using a confusion matrix and receiver operating characteristic curves. The CAMs were reviewed, and the identified anatomic structures were investigated. A reader study was performed by three radiologists, and their accuracy was compared with that of the model.Results: The overall accuracy of the best-performing model for lumbar spine numbering was 0.98 on internal validation and 0.95 on external validation. For the CAM review, mappings concentrated on both paraspinal areas, including the kidney, back muscles, and ilium according to the level. Top-1 and top-2 accuracies of the reviewers ranged between 0.56–0.75, and 0.84–0.93, respectively. After reviewing the CAMs, the accuracy increased to 0.75–0.78 and 0.93–0.98, respectively.Conclusion: A CNN model can accurately determine the level of the lumbar spine on axial MR images, and the configuration of muscles can be used to determine the lumbar level.

Radiology plays a key role in the diagnosis of arthritis. We herein suggest an algorithmic approach to diagnosing arthritis. First, the number of joint involvements is reviewed. Monoarticular arthritis includes septic arthritis, pigmented villonodular synovitis, and synovial chondromatosis. Second, polyarticular arthritis can be categorized by its characteristics: erosive, productive, and mixed. Erosive disease includes rheumatoid arthritis, hemophilia, and amyloidosis, while productive disease includes osteoarthritis and hemochromatosis. Third, mixed diseases are subcategorized by symmetricity. Ankylosing spondylitis and inflammatory bowel disease related arthritis affect joints symmetrically, while psoriatic arthritis, reactive arthritis, and crystalline arthropathy are asymmetric. Adjacent soft tissue density, periostitis, and bone density are ancillary findings that can be used as additional differential diagnostic clues. The final step in identifying the type of arthritis is to check whether the location is a site frequently affected by one particular disease over another. This systematic approach would be helpful for radiologists in diagnosing arthritis.

Objectives To assess the diagnostic performance of dual-energy CT (DECT) with electron-density (ED) image reconstruction compared with standard CT (SC) and virtual non-calcium (VNCa) image CT reconstruction for detecting cervical disc herniation. Methods This cross-sectional study was approved by the IRB. We enrolled 64 patients (336 intervertebral discs from C2/3 to C7/T1; mean age, 55 years; 17 women and 47 men) who underwent DECT with spectral reconstruction and 3-T MRI within 2 weeks between January 2018 and June 2020. Four radiologists independently evaluated the first image set of randomized SC, VNCa, and ED images to detect cervical disc herniation. After 8 weeks, the readers re-evaluated the second and the last image sets with an 8-week interval. MRI evaluations performed by two other experienced served as the reference standard. Comparing diagnostic performance between each images set was evaluated by a generalized estimating equation. Results A total of 233 cervical disc herniations were noted on MRI. For detecting cervical disc herniation, electron-density images showed higher sensitivity (94% [219/233; 95% CI, 90–97] vs. 76% [177/233; 70–81] vs. 69% [160/233; 62–76]) (p 0.05) as SC and VNCa images, respectively. Inter-reader agreement for cervical disc herniation calculated among the four readers was moderate for all image sets (κ = 0.558 for ED, κ = 0.422 for SC, and κ = 0.449 for VNCa). Conclusion DECT with ED reconstruction can improve cervical disc herniation detection and diagnostic confidence compared with SC and VNCa images. Key Points • Intervertebral discs with high material density are well visualized on electron-density images obtained from dual-energy CT. • Electron-density images showed much higher sensitivity and diagnostic accuracy than standard CT and virtual non-calcium images for the detection of cervical disc herniation. • Electron-density images can have false-negative results, especially for disc herniation with high signal intensity on T2W images and can show pseudo-disc extrusion at the lower cervical spine. Supplementary Information The online version contains supplementary material available at 10.1007/s00330-021-08374-y.

The degree of height loss varies among individuals, and excessive height loss can be a vertebral fracture or bone loss manifestation. The objective of this study was to examine the relationships between height loss and bone mineral density (BMD) and to assess the prevalence of osteoporosis according to the height loss quartiles. Data from the Korea National Health and Nutrition Examination Survey were analyzed. A total of 2799 participants more than 60 years old were included and subdivided into quartiles according to height loss (Q1–Q4). Height loss was calculated with the difference between the self-reported maximum adult height and the actual measured height. BMD was measured by dual-energy X-ray absorptiometry at the total femur (TF), femoral neck, and lumbar spine. Multivariable linear and logistic regression analyses were conducted to study the height loss-BMD and the height loss-osteoporosis prevalence relationships, respectively. After adjustments for all covariates, height loss was negatively associated with BMD at all the 3 sites (TF and lumbar spine, p 0.001; femoral neck, p = 0.002) in men, but only at TF ( p = 0.008) in women. Men with Q4 height loss had an increased prevalence of osteoporosis compared with those with Q1 (odds ratio = 2.092 and 95% confidence interval = 1.076–4.068). In women, the prevalence of osteoporosis was not associated with height loss. In conclusion, Q4 height loss in elderly men was associated with the increased prevalence of osteoporosis in Korea.

Background: Bone age assessments (BAAs) is an important clinical modality to investigate endocrine, genetic and growth disorders in children. It is generally performed by radiological examination of the left hand by using either the Greulich-Pyle (GP) or the Tanner-Whitehouse (TW) method. However, both clinical procedures show several limitations, from significant intra- and inter-operator variability to examination effort of clinicians. To address these problems, several automated approaches have been proposed; nevertheless, some disparity still exists between automated BAAs and manual BAAs to be employed in clinical practice. To overcome this disparity, deep learning-based bone age assess software using GP and TW3 hybrid method has been developed. In this study, we evaluate the accuracy and efficiency of the new automated hybrid software system for bone age assessment and validate its feasibility in clinical practice. Materials and Methods: Greulich-Pyle (GP) and Tanner-Whitehouse (TW3) hybrid method-based deep-learning technique was used to develop the automated software system for bone age assessment. Total 102 radiographs from children with the chronological age of 4.9-17.0 years (mean age 10.9±2.3, 51 cases for females and 51 cases for males) were selected and bone age was estimated with this software. For validation of the automated software system, three human experts have manually performed BAAs at expert’s discretion based on GP method for accuracy estimation and one naïve radiologist performed BAAs with automated software system assist and BAAs reading time was recorded in each session for efficiency evaluation. The performance of automated software system was assessed by comparing mean absolute difference (MAD) between the system estimates and the experts manual BAAs.Results: The results of bone age assessment by human experts and automated software system showed no significant difference between the two groups. Each assessed average of bone age were 11.39 ± 2.74 and 11.35 ± 2.76, respectively. MAD was 0.39 years between automated software system BAAs and experts manual BAAs. The 95% confidence interval of the MAD was 0.33 years and 0.45 years. BAAs reading time was reduced from 56.81 sec (95% confidence interval 52.81 - 60.81 sec) in naïve manual BAAs to 31.72 sec (95% confidence interval 29.74 - 33.69 sec) in automated software system assisted BAAs and statistically significant (p < 0.001). MAD showed 0.42 years between naïve manual BAAs and the software-assisted BAAs (95% confidence interval 0.31-0.47 years).Conclusion: The newly developed GP and TW3 hybrid automated software system were reliable for bone age assessments with equivalent accuracy to human experts. Also, the automated system appeared to enhance efficiency by reducing reading times without compromising diagnostic accuracy.

In the pubertal period, bone age advances rapidly in conjunction with growth spurts. Precise bone-age assessments in this period are important, but results from the hand and elbow can be different. We aimed to compare the bone age between the hand and elbow around puberty onset and to elucidate the chronological age confirming puberty onset according to elbow-based bone age. A total of 211 peripubertal subjects (127 boys and 84 girls) who underwent hand and elbow radiographs within 2 months was enrolled. Two radiologists and a pediatric orthopedic surgeon assessed bone age. Hand bone age was graded using the Greulich–Pyle (GP) method, and elbow bone age was determined using the Sauvegrain method. The correlation of 2 methods was evaluated by Demining regression analysis, and the mean absolute difference (MAD) with chronological age was compared between pre-pubertal and pubertal subjects. Receiver-operating characteristic curve analysis was performed to determine the chronological age confirming puberty onset. There was a statistically significant difference in bone age revealed by the GP and Sauvegrain methods in the pubertal group. In the pubertal group, the MAD was 1.26 ± 0.90 years with the GP method and 0.61 ± 0.47 years with the Sauvegrain method in boys (P

Purpose To use multiparametric magnetic resonance (MR) imaging to assess for and establish age-related differences in healthy thigh muscles. Materials and Methods Ninety-five subjects (47 men, 48 women; median age, 47 years) with healthy body mass index were grouped according to age: 30-39 years (n = 25), 40-49 years (n = 25), 50-59 years (n = 25), and 60-69 years (n = 20). Multiparametric MR imaging (intravoxel incoherent motion diffusion-weighted, diffusion-tensor, multiecho Dixon, and dynamic contrast material-enhanced MR imaging) was performed at 3.0 T. Two radiologists independently evaluated parametric maps of the anterior, medial, and posterior compartments. Welch-modified one-way analysis of variance and post hoc Dunnet T3 test were used to evaluate differences in apparent diffusion, true diffusion, and pseudodiffusion coefficients; perfusion fraction; fractional anisotropy (FA); fat percentage; volume transfer constant; constant efflux rate from the extravascular-extracellular space to plasma; volume fraction of the extravascular-extracellular space (V

The aim of this study was to assess the concordance between magnetic resonance imaging (MRI) grading for cervical neural foraminal stenosis (CNFS) based on axial and oblique sagittal images and evaluate the reliability of each grading plane. CNFS was graded at C2-3 to C7-T1 levels based on axial and oblique sagittal images separately by three radiologists. The concordance between CNFS grading based on axial and oblique sagittal images was strong for all three observers (Kendall's W=0.80, 0.79, and 0.82), despite the tendency of higher grading with oblique sagittal images. Both imaging planes supported strong interobserver reliability.

Ultrasonography is an imaging modality widely used to evaluate venous diseases of the lower extremities. It is important to understand the normal venous anatomy of the lower extremities, which has deep, superficial, and perforating venous components, in order to determine the pathophysiology of venous disease. This review provides a basic description of the anatomy of the lower extremity veins and useful techniques for approaching each vein via ultrasonography.

OBJECTIVES The purpose of this study was to investigate and compare the serial changes of morphology and strain in the early process of Achilles tendinopathy in a rabbit model. METHODS A total of 10 New Zealand white rabbits underwent ligation of one of their Achilles tendons to induce ischemic injury. Both inflamed and contralateral Achilles tendons were serially evaluated with 3 follow-ups: the first on days 3 to 5, the second on days 9 to 13, and the third and last follow-up on days 15 to 20 after surgery. During each examination, tendon thickness was measured and red, green, and blue pixel intensities of the elastogram were analyzed using color histogram analysis software. Differences between the inflamed and control group were compared. RESULTS The mean thickness of the inflamed tendons increased during consecutive follow-ups and was significantly larger than that of control tendons (P

Background High cumulative radiation dose in cancer patients warrants systemic examination of possible changes in bone marrow. Purpose To assess retrospectively changes in vertebral bone marrow diffusion and perfusion using intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) in hepatocellular carcinoma (HCC) patients after exposure to radiation from diagnostic imaging and interventional procedures. Material and Methods A total of 21 IVIM-DWI sets in 20 HCC patients, consisting of baseline and follow-up liver magnetic resonance imaging (MRI) with an interval less than 100 days, were reviewed after varying levels of radiation exposure from transarterial chemoembolization (TACE), multiphase liver CT, and abdominal radiography. IVIM parameters (apparent diffusion coefficient [ADC], true diffusion coefficient [D], pseudodiffusion coefficient [D*], and perfusion fraction [PF]) of vertebral bone marrow were analyzed for significant differences between baseline and follow-up MRI using Wilcoxon signed-rank test, and for correlations with cumulative effective dose, as well as time interval between last radiation exposure and follow-up MRI using Spearman’s correlation. Results Compared to baseline MRI, ADC, D*, and PF significantly decreased on follow-up MRI (ADC: median [interquartile range], 0.405 × 103 mm2/s [0.364–0.477] versus 0.390 [0.348–0.461]; D*: 24.011 [18.141–29.584] versus 20.815 [15.022–28.347]; PF: 10.960% [8.828–12.985] versus 9.125 [8.606–12.803]) ( P Conclusion Vertebral bone marrow diffusion and perfusion parameters were significantly changed after exposure to medical radiation.

To assess whether a proximal ligamentous component (PLC) of the triangular fibrocartilage complex (TFCC) with a distally prolapsing morphology is associated with the presence of a TFCC foveal tear on arthroscopy. One-hundred thirty-two patients (134 wrists) who underwent MR arthrography and subsequent wrist arthroscopy between September 2014 and March 2018 were retrospectively evaluated. The degree of distal PLC prolapse was measured on coronal MR arthrography using the height-to-length ratio (HLR). Subjects’ demographics, ulnar variance, presence of a degenerative TFCC tear, and ulnar styloid nonunion were assessed. The association between specific variables and the presence of a foveal tear was investigated. A TFCC foveal tear was identified in a total of 101 of 134 wrists examined by arthroscopy. Univariable analysis showed that the HLR of the PLC was significantly greater in the foveal tear group compared with the intact fovea group (44.6 vs. 38.9%, respectively, p

Background The purpose of this study was to examine the reliability of plain radiographic methods of determining the lunate type and its compatibility with magnetic resonance arthrography (MRA) findings. Methods Plain radiographs of a total of 150 wrists were reviewed by three observers. Lunate types were evaluated using both conventional posteroanterior (PA) radiographic analysis and the capitate-triquetrum distance (CTD) analysis. Cohen kappa and Fleiss kappa statistics were used to estimate intra- and inter-observer reliabilities. Compatibility with the MRA findings, as assessed by each observer, was investigated. Results The overall intra-observer reliability was 0.517 for the analysis and 0.589 for the CTD analysis. The overall inter-observer agreement was 0.448 for the PA radiographic analysis and 0.581 for the CTD analysis. The PA radiographic analysis and MRA findings for the detection of medial lunate facets were compatible in 119 of the 150 patients (79.3%). Twenty-eight (90.3%) of the 31 incompatible wrists had a medial facet on MRA (Type II), which was not detected in the PA radiographic analysis. In the CTD analysis, the results for 27 of 29 Type II lunates (93.1%) and 39 of 45 Type I lunates (86.7%) were compatible with the MRA. Conclusions This study suggests that predicting the lunate type by plain radiographs alone is insufficient, as both radiographic analyses showed moderate intra- and inter-observer reliabilities. Although both radiographic analyses showed good compatibility with the MRA for Type II lunates, clinicians should be alert to undetected medial facets in Type I lunates on PA radiographic analysis.

Objective To evaluate the accuracy and clinical efficacy of a hybrid Greulich-Pyle (GP) and modified Tanner-Whitehouse (TW) artificial intelligence (AI) model for bone age assessment. Materials and Methods A deep learning-based model was trained on an open dataset of multiple ethnicities. A total of 102 hand radiographs (51 male and 51 female; mean age ± standard deviation = 10.95 ± 2.37 years) from a single institution were selected for external validation. Three human experts performed bone age assessments based on the GP atlas to develop a reference standard. Two study radiologists performed bone age assessments with and without AI model assistance in two separate sessions, for which the reading time was recorded. The performance of the AI software was assessed by comparing the mean absolute difference between the AI-calculated bone age and the reference standard. The reading time was compared between reading with and without AI using a paired t test. Furthermore, the reliability between the two study radiologists' bone age assessments was assessed using intraclass correlation coefficients (ICCs), and the results were compared between reading with and without AI. Results The bone ages assessed by the experts and the AI model were not significantly different (11.39 ± 2.74 years and 11.35 ± 2.76 years, respectively, p = 0.31). The mean absolute difference was 0.39 years (95% confidence interval, 0.33–0.45 years) between the automated AI assessment and the reference standard. The mean reading time of the two study radiologists was reduced from 54.29 to 35.37 seconds with AI model assistance (p < 0.001). The ICC of the two study radiologists slightly increased with AI model assistance (from 0.945 to 0.990). Conclusion The proposed AI model was accurate for assessing bone age. Furthermore, this model appeared to enhance the clinical efficacy by reducing the reading time and improving the inter-observer reliability.

Rationale and Objectives The study aimed to evaluate the usefulness of dual-energy computed tomography (DECT) before and after calcium subtraction in the diagnosis of spinal bone bruise. Materials and Methods Among the patients who visited our emergency department between January 2013 and July 2014 who underwent both spinal DECT and magnetic resonance imaging, 38 patients (men:women = 25:13; mean age: 55.6 years, range: 28–82) were included. The patients were divided into two groups, those with and without acute spinal compression fracture, based on magnetic resonance imaging findings. In the fracture group (n = 22), the ratio of Hounsfield unit (HU) values was calculated between the fracture level and the next normal inferior vertebra in the DECT before and after calcium subtraction. In the non-fracture group (n = 16), the ratios of HU values were calculated between two normal adjacent vertebrae. The mean HU ratios were compared between the two groups. Results The mean HU ratio was higher in the fracture group (calcium subtraction: before: 1.57 and 1.59; after: 1.74 and 1.76) than the non-fracture group (before: 1.07 and 1.08; after: 1.07 and 1.07) (P Conclusion The HU ratio between the fractured and next normal vertebra was diagnostic for spinal bone bruise on DECT images both before and after calcium subtraction.

Purpose To assess regional variations of T1rho (T1ρ) and T2 rates within lumbar intervertebral discs and to evaluate the correlation of T1ρ and T2 rates in different disc regions with Pfirrmann grades of degeneration and morphologic changes. Materials and methods We retrospectively evaluated 105 lumbar discs in 22 subjects who were examined at 3.0-T MRI. T1ρ and T2 relaxation rates (1/T1ρ and 1/T2) were measured in five segmented regions of discs: anterior annulus fibrosus (AF), anterior junction, nucleus pulposus (NP), posterior junction, and posterior AF. Disc degeneration was graded using 5-level Pfirrmann grading system and morphologic change was categorized into five groups (normal, bulging, annular fissure, protrusion, and extrusion). Regional differences of T1ρ and T2 rates and correlation with degeneration and morphologic changes were statistically analyzed. Results Most of the five segmented regions showed statistically different T1ρ and T2 rates from each other. T1ρ and T2 relaxation rates were positively associated with Pfirrmann grades of degeneration and morphologic changes, with different strength of relation in each region. T2 rates in the posterior junction showed the strongest correlation with degeneration (r = 0.810) and T2 rates in the anterior junction showed the highest association with morphologic changes (r = 0.621). Conclusions Regional variations of T1ρ and T2 rates within discs and different strength of relation with degeneration and morphologic changes should be taken into account when evaluating lumbar discs.

Objective To compare the diagnostic performance of contrast-enhanced (CE) magnetic resonance imaging (MRI) and non-CE MRI for adhesive capsulitis (AC). Methods CE MRI of 50 AC and 53 non-AC patients were reviewed by two radiologists independently. Results Axillary capsular thickening and T2 hyperintensity (sensitivity=92–94%; specificity=53–64%) and enhancement of the axillary capsule and rotator interval (sensitivity=92–98%; specificity=38–64%) were helpful in diagnosing AC. Interobserver reliability was highest with axillary joint capsule enhancement (κ=0.92). Conclusion Non-CE and CE MRI are helpful in confirming the clinical diagnosis of AC. CE-MRI may improve assessment of the rotator interval and diagnostic confidence in patients with AC.

Hoffmann's syndrome is a hypothyroid myopathy presenting as muscle stiffness and hypertrophy. It is a rare complication of hypothyroidism. MRI features of this syndrome have seldom been described in the literature. We present a case of Hoffmann's syndrome in a 34-year-old man who underwent lower extremity contrast-enhanced MRI. MRI can demonstrate the hypertrophic configuration, T2 hyperintensity, and enhancement of the involved muscles in Hoffmann's syndrome. Along with clinical, laboratory, and electromyography findings, MRI may be helpful in distinguishing between inflammatory myopathy, myonecrosis, subacute muscle denervation, and infectious myositis.

Background: Imaging findings of adhesive capsulitis (AC) have been reported widely with the use of magnetic resonance imaging (MRI) and ultrasonography (US), although diagnosing AC is still based on clinical finding. However, the use of contrast-enhanced ultrasonography (CEUS) has not yet been reported in patients with AC. Objectives: To validate the application of CEUS in patients with AC, and to compare CEUS findings with those of MRI. Patients and Methods: Both shoulders of five patients with unilateral AC, who underwent MRI on the affected shoulder, were examined using CEUS (2 men, 3 women; mean age, 54.2 ± 8 years). CEUS was performed after bolus administration of the contrast agent, SonoVue (Bracco, Milan, Italy), followed by a saline flush. Enhancement of the rotator interval was evaluated using a visual enhancement score (0 to 2) and compared with the contrast-enhanced MRI findings. For quantitative analysis, an region of interest was established for each rotator interval, and time-intensity curves were analyzed with parameters including time-to-peak and peak intensity. The difference of peak intensity between the affected and unaffected shoulders was compared. Results: Contrast enhancement of the rotator interval was notable in all CEUS of affected shoulders, whereas no evident enhancement was detected in all asymptomatic shoulders. The mean visual enhancement score of affected shoulders was 1.4 in CEUS and 2.0 in contrast-enhanced MRI. In quantitative analysis, the mean peak intensity was 5.45 ± 2.80 dB (mean time to peak, 30.6 ± 5.39 seconds) in affected shoulders, and 0.72 ± 0.91 dB in unaffected shoulders (P < 0.05). Conclusion: CEUS was capable of demonstrating capsular inflammation in patients with AC, and this was comparable to MRI. CEUS could be a feasible imaging tool for evaluating patients with AC.

The study aimed to evaluate the usefulness of dual-energy computed tomography (DECT) before and after calcium subtraction in the diagnosis of spinal bone bruise.Among the patients who visited our emergency department between January 2013 and July 2014 who underwent both spinal DECT and magnetic resonance imaging, 38 patients (men:women = 25:13; mean age: 55.6 years, range: 28-82) were included. The patients were divided into two groups, those with and without acute spinal compression fracture, based on magnetic resonance imaging findings. In the fracture group (n = 22), the ratio of Hounsfield unit (HU) values was calculated between the fracture level and the next normal inferior vertebra in the DECT before and after calcium subtraction. In the non-fracture group (n = 16), the ratios of HU values were calculated between two normal adjacent vertebrae. The mean HU ratios were compared between the two groups.The mean HU ratio was higher in the fracture group (calcium subtraction: before: 1.57 and 1.59; after: 1.74 and 1.76) than the non-fracture group (before: 1.07 and 1.08; after: 1.07 and 1.07) (P 0.001). The mean HU ratio between before and after calcium subtraction images was different only in the fracture group (P 0.05). There was no significant difference in the area under the curve, sensitivity, specificity, positive and negative predictive values, and accuracy (before: 0.846, 87.5%, 81.2%, 87.5%, 81.2%, 85%; after: 0.865, 91.7%, 81.2%, 88%, 86.7%, 87.5% in high energy) between the images before and after calcium subtraction.The HU ratio between the fractured and next normal vertebra was diagnostic for spinal bone bruise on DECT images both before and after calcium subtraction.

To determine the relationship between clinical impairment and MRI findings in patients with adhesive capsulitis. Contrast-enhanced MRI of 97 patients with a clinical diagnosis of adhesive capsulitis (AC) were retrospectively reviewed. Specific MRI criteria, including thickness and gadolinium enhancement of the joint capsule in the axillary recess and subcoracoid fat obliteration in the rotator interval, were correlated with limited range of motion (ROM) and pain. Other variables considered in this study were rotator cuff pathology, arm dominance, diabetes mellitus, age, and gender. Statistical analysis was performed using logistic and linear regression analysis. Thickening of the joint capsule in the axillary recess correlated with limited external rotation (p

Glomus tumors are rare neoplasms that characteristically occur in subungual regions, but may also be found in other regions of the body. The clinical diagnosis of this tumor may be difficult if the tumor is located in an extradigital site. Most extradigital glomus tumors form in superficial locations. Herein, we present the case of a 34-year-old woman who experienced chronic knee pain with pinpoint tenderness resulting from a deep-seated periosteal glomus tumor of the distal femur. Extradigital glomus tumors should be considered in the differential diagnosis when characteristic clinical features and imaging findings indicative of glomus tumors are present, even if the tumor is located within deep tissues.

Calcifying aponeurotic fibroma (CAF) is a rare, benign fibroblastic tumor that typically occurs in the palms of the hands and soles of the feet, in children and adolescents. Due to its infiltrative nature, this tumor can mimic malignancy on preoperative magnetic resonance imaging (MRI) and has a predilection for local recurrence. There are very few reports in the literature that describe features of CAF on MRI, especially those arising in the foot. We present an unusual case of a CAF affecting the dorsum of the foot in a four-year-old boy.

This study aimed to examine average height loss and the relationship between height loss and socioeconomic status (SES) among the elderly in South Korea.Data were obtained from the Korean National Health and Nutrition Examination Survey 2008–2010. A total of 5265 subjects (2818 men and 2447

The objective of our study was to investigate the clinical feasibility of ultrasound elastography for assessing patients with lateral epicondylosis and to establish an objective and quantitative method of elastographic measurement in the affected tendon.A total of 97 symptomatic and 89 asymptomatic common extensor tendons from both elbows of 79 consecutive patients with lateral epicondylosis and 14 healthy participants were prospectively examined by gray-scale sonography, color Doppler sonography, and compression-based elastography. Real-time color-coded elastography was performed and quantified with two regions of interest: the adjacent subcutis (S1) for a reference area and the common extensor tendon (S2) for the target area. The mean strain ratio (S1/S2) was used for quantitative comparisons. The difference in the mean strain ratio between symptomatic and asymptomatic tendons was assessed with conditional regression analysis.In symptomatic elbows, 87 of 97 tendons (89.7%) showed intratendinous hypoechogenicity, 86 of 97 (88.7%) showed swelling, and 70 of 97 tendons (72.2%) showed intratendinous hyperemia. Color-coded elastography revealed a soft area on 73 of 97 tendons (75.3%). The mean strain ratio was 1.45 (SD, 0.45) for symptomatic tendons and 2.07 (SD, 0.70) for asymptomatic tendons. The mean strain ratio of the symptomatic tendons was significantly lower than that of asymptomatic tendons (p0.001), indicating that the symptomatic tendons were softer.Our results revealed that patients with lateral epicondylosis had significantly lower strain ratios in their common extensor tendon origins. Ultrasound elastography using quantitative strain ratio measurements could be a promising supplementary method to evaluate tendon abnormalities in lateral epicondylosis.

Purpose: To analyze the feasibility of three-dimensional (3D) diffusion-weighted (DW) PSIF (reversed FISP [fast imaging with steady-state free precession]) sequence in order to evaluate peripheral nerves in the elbow. Materials and Methods: Ten normal, asymptomatic volunteers were enrolled (6 men, 4 women, mean age 27.9 years). The following sequences of magnetic resonance images (MRI) of the elbow were obtained using a 3.0-T machine: 3D DW PSIF, 3D T2 SPACE (sampling perfection with application optimized contrasts using different flip angle evolution) with SPAIR (spectral adiabatic inversion recovery) and 2D T2 TSE (turbo spin echo) with modified Dixon (m-Dixon) sequence. Two observers used a 5-point grading system to analyze the image quality of the ulnar, median, and radial nerves. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of each nerve were measured. We compared 3D DW PSIF images with other sequences using the Wilcoxon-signed rank test and Friedman test. Inter-observer agreement was measured using intraclass correlation coefficient (ICC) analysis. Results: The mean 5-point scores of radial, median, and ulnar nerves in 3D DW PSIF (3.9/4.2/4.5, respectively) were higher than those in 3D T2 SPACE SPAIR (1.9/2.8/2.8) and 2D T2 TSE m-Dixon (1.7/2.8/2.9) sequences (P < 0.05). The mean SNR in 3D DW PSIF was lower than 3D T2 SPACE SPAIR, but there was no difference between 3D DW PSIF and 2D T2 TSE m-Dixon in all of the three nerves. The mean CNR in 3D DW PSIF was lower than 3D T2 SPACE SPAIR and 2D T2 TSE m-Dixon in the median and ulnar nerves, but no difference among the three sequences in the radial nerve. Conclusion: The three-dimensional DW PSIF sequence may be feasible to evaluate the peripheral nerves around the elbow in MR imaging. However, further optimization of the image quality (SNR, CNR) is required.

We present a rare case of right circumflex retro-oesophageal aortic arch with coarctation of a high-positioned right arch. A 7-month-old boy presented with a cardiac murmur. Cardiac situs was normal and there was no evidence of an intracardiac shunt or patent ductus arteriosus. MR aortography revealed a right aortic arch that was high-positioned, tortuous and narrowed. This right aortic arch crossed the midline behind the oesophagus and continued as a left-sided descending aorta. The left common carotid and subclavian arteries arose from a large branching vascular structure that derived from the top of the left-sided descending aorta. The right common carotid artery arose from the ascending aorta. The proximal portion of the right common carotid artery showed very severe stenosis and poststenotic dilatation. The right subclavian artery originated distal to the narrowed and tortuous segment of the aortic arch.

Purpose : To describe normal anatomy and compare the differences of external genital organs and urethra on MR imaging in pre- and postmenopausal women. Materials and Methods : A total of 19 pre- and 18 postmenopausal healthy women underwent pelvis MR imaging at 1.5 T. Two radiologists retrospectively scored and compared the image quality of female external genitalia and urethra on axial T2-weighted images (T2WI) and axial fat-suppressed contrast-enhanced T1-weighted images (FSCE-T1WI) by using Wilcoxon signed ranks test. The radiologists compared the wall thickness or size of external genital organs and urethra on FSCE-T1WI between two groups by using Student t test. Results : Image quality was better with FSCE-T1WI than with T2WI in all subjects (p