Automated Detection and Segmentation of Bone Metastases on Spine MRI Using U-Net:A Multicenter Study

Objective@#To develop and evaluate a deep learning model for automated segmentation and detection of bone metastasis on spinal MRI. @*Materials and Methods@#We included whole spine MRI scans of adult patients with bone metastasis: 662 MRI series from 302 patients (63.5 ± 11.5 years; male:female, 151:151) from three study centers obtained between January 2015 and August 2021 for training and internal testing (random split into 536 and 126 series, respectively) and 49 MRI series from 20 patients (65.9 ± 11.5 years; male:female, 11:9) from another center obtained between January 2018 and August 2020 for external testing. Three sagittal MRI sequences, including non-contrast T1-weighted image (T1), contrast-enhanced T1-weighted Dixon fat-only image (FO), and contrast-enhanced fat-suppressed T1-weighted image (CE), were used. Seven models trained using the 2D and 3D U-Nets were developed with different combinations (T1, FO, CE, T1 + FO, T1 + CE, FO + CE, and T1 + FO + CE). The segmentation performance was evaluated using Dice coefficient, pixel-wise recall, and pixel-wise precision. The detection performance was analyzed using per-lesion sensitivity and a free-response receiver operating characteristic curve. The performance of the model was compared with that of five radiologists using the external test set. @*Results@#The 2D U-Net T1 + CE model exhibited superior segmentation performance in the external test compared to the other models, with a Dice coefficient of 0.699 and pixel-wise recall of 0.653. The T1 + CE model achieved per-lesion sensitivities of 0.828 (497/600) and 0.857 (150/175) for metastases in the internal and external tests, respectively. The radiologists demonstrated a mean per-lesion sensitivity of 0.746 and a mean per-lesion positive predictive value of 0.701 in the external test. @*Conclusion@#The deep learning models proposed for automated segmentation and detection of bone metastases on spinal MRI demonstrated high diagnostic performance.

Magnetic Resonance Imaging Grading Systems for Central Canal and Neural Foraminal Stenoses of the Lumbar and Cervical Spines With a Focus on the Lee Grading System

Magnetic resonance imaging (MRI) is a standard imaging modality for diagnosing spinal stenosis, which is a common degenerative disorder in the elderly population. Standardized interpretation of spinal MRI for diagnosing and grading the severity of spinal stenosis is necessary to ensure correct communication with clinicians and to conduct clinical research. In this review, we revisit the Lee grading system for central canal and neural foraminal stenosis of the cervical and lumbar spine, which are based on the pathophysiology and radiologic findings of spinal stenosis.

A problem-based approach in musculoskeletal ultrasonography: heel pain in adults

Musculoskeletal ultrasonography (US) has unique advantages, such as excellent spatial resolution for superficial structures, the capability for dynamic imaging, and the ability for direct correlation and provocation of symptoms. For these reasons, US is increasingly used to evaluate problems in small joints, such as the foot and ankle. However, it is almost impossible to evaluate every anatomic structure within a limited time. Therefore, US examinations can be faster and more efficient if radiologists know where to look and image patients with typical symptoms. In this review, common etiologies of heel pain are discussed in a problem-based manner. Knowing the common pain sources and being familiar with their US findings will help radiologists to perform accurate and effective US examinations.

Florid Reactive Periostitis of the Clavicle: A Case Report

Florid reactive periostitis (FRP) is a rare benign fibro-osseous proliferation, occurring mostly in the short tubular bones of hands and rarely in the long tubular bones. We report a surgically confirmed case of FRP involving the clavicle in a 26-year-old male. On MRI scans, a soft tissue mass with T2 high signal intensity was found that originated from the periosteum of the clavicle and included surrounding a periosteal elevation and perilesional soft tissue edema. Strong contrast enhancement was noted inside the mass and along the periosteum involving more than half of the circumference of the clavicle. Serial radiographs revealed a soft tissue mass without mineralization that turned into an ossified mass with a solid periosteal reaction within a month.

Subclinical Coronary Atherosclerosis: Implication of Coronary Computed Tomography Angiography Findings among Statin Candidates according to the 2013 ACC/AHA Cholesterol Management Guidelines

OBJECTIVE: To analyze the cardiovascular outcome of statin medication in individuals retrospectively categorized on the basis of the 2013 American College of Cardiology and American Heart Association (ACC/AHA) guidelines risk assessment and to determine the additional prognostic value of coronary computed tomography angiography (CCTA) in assessing cardiovascular disease (CVD) risk in this group. MATERIALS AND METHODS: This retrospective study reviewed 4255 asymptomatic individuals who had undergone self-referred CCTA with a median follow-up period of 87 months. The primary endpoint was major adverse cardiac events (MACEs); these included cardiac death, nonfatal myocardial infarction, and unstable angina. Individuals recommended for statins according to the ACC/AHA guidelines were analyzed by their assessed risk. RESULTS: MACE occurrence was significantly higher in the statin-recommended (SR) group with significant coronary artery disease (CAD) than in those with insignificant CAD (p < 0.001). In individuals with a normal coronary artery on CCTA, MACEs did not occur regardless of statin medication. In the SR group with significant CAD, there was no significant difference between statin users and non-users (p = 0.810). However, in cases with insignificant CAD, the event-free survival was significantly lower among statin users (p = 0.034). In patients recommended for moderate-intensity statins, the segment involvement score on CCTA was significantly associated with a higher risk of MACEs (hazard ratio 2.558; p = 0.001). CONCLUSION: CCTA might have a potential role in CVD risk stratification among asymptomatic statin candidates.

A New MRI Grading System for Cervical Foraminal Stenosis Based on Axial T2-Weighted Images

OBJECTIVE: The purpose of this study was to evaluate the reliability of a new magnetic resonance imaging (MRI) grading system for cervical neural foraminal stenosis (NFS). MATERIALS AND METHODS: Cervical NFS at bilateral C4/5, C5/6, and C6/7 was classified into the following three grades based on the T2-weighted axial images: Grade 0 = absence of NFS, with the narrowest width of the neural foramen greater than the width of the extraforaminal nerve root (EFNR); Grade 1 = the narrowest width of the neural foramen the same or less than (but more than 50% of) the width of the EFNR; Grade 2 = the width of the neural foramen the same or less than 50% of the width of the EFNR. The MRIs of 96 patients who were over 60 years old (M:F = 50:46; mean age 68.4 years; range 61-86 years) were independently analyzed by seven radiologists. Interobserver and intraobserver agreements were analyzed using the percentage agreement, kappa statistics, and intraclass correlation coefficient (ICC). RESULTS: For the distinction among the three individual grades at all six neural foramina, the ICC ranged from 0.68 to 0.73, indicating fair to good reproducibility. The percentage agreement ranged from 60.2% to 70.6%, and the kappa values (κ = 0.50-0.58) indicated fair to moderate agreement. The percentages of intraobserver agreement ranged from 85.4% to 93.8% (κ = 0.80-0.92), indicating near perfect agreement. CONCLUSION: The new MRI grading system shows sufficient interobserver and intraobserver agreement to reliably assess cervical NFS.

The Value of Additional Cervicothoracic Spine Sagittal T2-weighted Images Included in Routine Lumbar Spine MR Imaging

PURPOSE: To evaluate the usefulness of cervicothoracic spine sagittal T2-weighted images (CT SAG T2WIs) included in routine lumbar spine MRI. MATERIALS AND METHODS: Institutional review board approval was obtained and informed consents were waived for this retrospective study. The study group comprised 2,113 patients who underwent lumbar spine MRI from January 2005 to December 2005. CT SAG T2WIs were added in the routine lumbar spine MRIs. Radiologic reports were reviewed retrospectively for pathologic lesions on CT SAG T2WIs by one radiologist. Information of additional cervical or thoracic spine MRI and/or CT for further evaluation of positive findings on CT SAG T2WIs and their treatment were collected by retrospectively reviewing medical records. RESULTS: The CT SAG T2WIs revealed 142 pathologic lesions in 139 (6.58%) of the 2,113 patients. They were easily obtained without positional change in a scan time of less than 2 minutes. Additional cervical or thoracic spine MRI and/or CT for positive findings on CT SAG T2WIs were performed in 13 patients. Seven patients underwent surgical treatment. CONCLUSION: CT SAG T2WIs included in routine lumbar spine MRI were useful in finding the pathologic lesions in cervicothoracic spine for the patients who assumed to have lesions in lumbar spine.