Avascular Necrosis of the Capitate: MRI and Surgical Decision-Making of Two Case Reports

Avascular necrosis (AVN) is a rare disease occurring in the capitate of the wrist which is the third most common site of AVN among carpal bones. There are few reports on the MRI findings of AVN in the capitate bone. Besides, there is a paucity of reports showing the benefits of imaging for the choice of the treatment modality. We report two rare cases of capitate AVN requiring surgery.

Clinical Validation of a Deep Learning-Based Hybrid (Greulich-Pyle and Modified Tanner-Whitehouse) Method for Bone Age Assessment

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.

Stress Fracture of the Capitate

Most capitate fractures occur in association with additional carpal injuries, particularly scaphoid fractures. Isolated fractures of the capitate account for only 0.3% of carpal injuries, and stress fractures are one form of this fracture. We report the case of a 20-year-old male who had a stress fracture of the capitate after serving as an honor guard in the military. Conventional radiographs and computed tomography of the right wrist revealed a minimally displaced fracture line located at the midcarpal aspect of the right capitate. A magnetic resonance imaging scan demonstrates a subarticular capitate fracture with diffuse bone marrow edema, small osteophytes, and irregularity of the midcarpal articular cartilage. We also review the carpal kinematics which possibly caused the stress fracture. Although stress fractures of the capitate are rare, they should also be accounted for with patients who perform repetitive motions of the wrist to a considerable extent.

An Unusual Cause of Knee Pain: Periosteal Glomus Tumor of the Distal Femur

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.

Ultrasonography of the lower extremity veins: anatomy and basic approach

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.

Detecting Peripheral Nerves in the Elbow using Three-Dimensional Diffusion-Weighted PSIF Sequences: a Feasibility Pilot Study

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.

Xanthoma Simulating Plantar Fibromatosis on Sonography

Xanthomas are local collections of lipid-laden macrophages and collagen, which are usually associated with impaired lipoprotein metabolism. Xanthomas occur frequently in the skin, subcutis, or tendon, and occasionally in the plantar fascia. Small numbers of xanthomas have been surgically confirmed in the plantar fascia and their sonographic appearance has not been described in the literature. We present sonographic findings of a pathologically proven plantar fascia xanthoma, which was initially mistaken as plantar fibromatosis.

Female External Genitalia and Urethra on MR Imaging: Optimal Pulse Sequence and Comparison of Anatomy in Premenopausal and Postmenopausal Women

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 < 0.05). The vestibular bulb, clitoris and labium minor were more clearly visualized on FSCE-T1WI in premenopausal subjects rather than in postmenopausal subjects (p < 0.05). The urethra had a target-like appearance with three layers in premenopausal and postmenopausal subjects. Postmenopausal subjects were observed to have significantly smaller vaginal wall thickness, urethral wall thickness and vestibular bulb width than premenopausal subjects (p < 0.05). CONCLUSION: The anatomy and morphologic changes of female external genital organs and urethra were well discernible on FSCE-T1WI.

Spontaneously Migrated Tip of an Implantable Port Catheter into the Axillary Vein in a Patient with Severe Cough and the Subsequent Intervention to Reposition It

Migration of an implantable port catheter tip is one of the well-known complications of this procedure, but the etiology of this problem is not clear. We describe here a case of migration of the tip of a port catheter from the right atrium to the right axillary vein in a patient with severe cough. Coughing was suggested for this case as the cause of the catheter tip migration. We corrected the position of the catheter tip via transfemoral snaring.

Nodular Fasciitis on the Nasolabial Fold in a 5-month-old Infant: A Case Report

We report the case of a 5-month-old infant with a rapidly growing mass on the right nasolabial fold; to our knowledge, this is the youngest infant diagnosed with nodular fasciitis in the literature. Based on the anatomic location, this was a subcutaneous type of nodular fasciitis and it had a mixed cellular and fibrous histologic composition, which is rare in infancy. Here we present periodic ultrasonographic images and MR images, as well as a detailed comparison of the pathologic and radiologic findings.

TREATMENT OF BURN DEFORMITIES USING FREE FLAPS

No abstract available.