Skeletal Radiology最新文献

Objective: The objective of this study is to prospectively compare quantitative and subjective image quality, scanning time, and diagnostic confidence between a new deep learning-based reconstruction(DLR) algorithm and standard MRI protocol of lumbar spine.

Materials and methods: Eighty healthy volunteers underwent 1.5T MRI examination of lumbar spine from September 2021 to May 2023. Protocol acquisition comprised sagittal T1- and T2-weighted fast spin echo and short-tau inversion recovery images and axial multislices T2-weighted fast spin echo images. All sequences were acquired with both DLR algorithm and standard protocols. Two radiologists, blinded to the reconstruction technique, performed quantitative and qualitative image quality analysis in consensus reading; diagnostic confidence was also assessed. Quantitative image quality analysis was assessed by calculating signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). Qualitative image quality analysis and diagnostic confidence were assessed with a five-point Likert scale. Scanning times were also compared.

Results: DLR SNR was higher in all sequences (all p<0.001). CNR of the DLR was superior to conventional dataset only for axial and sagittal T2-weighted fast spin echo images (p<0.001). Qualitative analysis showed DLR had higher overall quality in all sequences (all p<0.001), with an inter-rater agreement of 0.83 (0.78-0.86). DLR total protocol scanning time was lower compared to standard protocol (6:26 vs 12:59 min, p<0.001). Diagnostic confidence for DLR algorithm was not inferior to standard protocol.

Conclusion: DLR applied to 1.5T MRI is a feasible method for lumbar spine imaging providing morphologic sequences with higher image quality and similar diagnostic confidence compared with standard protocol, enabling a remarkable time saving (up to 50%).

Objective: To determine the age-related prevalence and imaging characteristics of the superior acetabular roof notch (SARN) on hip MRI and radiographs in a young study population.

Materials and methods: Retrospective analysis of 304 MRI examinations and corresponding available radiographs of patients between the ages of 4 and 24 years. Two observers classified SARN with fluid-like findings on MRI as type-1, whereas SARN with fat-like findings on MRI were classified as type-2. Sensitivity and specificity of radiographic SARN findings were determined using MRI as the reference standard. Logistic regression models were used to assess the age-related prevalence on MRI.

Results: Twelve patients (3.9%) had fluid-like SARN type-1, 27 patients (8.9%) had fat-like SARN type-2, while 265 patients (87.2%) had no SARN on MRI. The odds ratio (OR) for age (years) with respect to the presence of a fluid-like SARN type-1 on MRI was 0.79 (95% CI: 0.70-0.89), meaning that with each year, the likelihood for SARN type-1 decreased by 21% (p < 0.001). The OR for age with respect to the presence of a fat-like SARN type-2 on MRI was 1.14 (95% CI: 1.02-1.27) (p = 0.017). The diagnostic sensitivity for detecting a SARN on radiographs compared to MRI as the reference standard was between 0.75 and 0.83 and the corresponding specificity was between 0.85 and 0.89 for both observers.

Conclusion: SARN is a common finding on MRI and radiographs. The present data suggest that SARN undergoes an age-related imaging characteristic from a fluid-like appearance to a fat-like appearance on MRI during adolescence.

The following White Paper will discuss the appropriateness of gadolinium administration in MRI for musculoskeletal indications. Musculoskeletal radiologists should consider the potential risks involved and practice the judicious use of intravenous contrast, restricting administration to cases where there is demonstrable added value. Specific nuances of when contrast is or is not recommended are discussed in detail and listed in table format. Briefly, contrast is recommended for bone and soft tissue lesions. For infection, contrast is reserved for chronic or complex cases. In rheumatology, contrast is recommended for early detection but not for advanced arthritis. Contrast is not recommended for sports injuries, routine MRI neurography, implants/hardware, or spine imaging, but is helpful in complex and post-operative cases.

Objective: To utilize hip MRI 3D models for demonstration of location and frequency of impingement during simulated range-of-motion in ischiofemoral impingement (IFI) compared to non-IFI hips.

Materials and methods: Sixteen hips (N = 7 IFI, 9 non-IFI) from 8 females were examined with high-resolution MRI. We performed image segmentation and generated 3D bone models and simulated hip range-of-motion and impingement. We examined the frequency and location of bone contact in early external rotation and early extension (0-20°), isolated maximum external rotation, and isolated maximum extension. Frequency and location of impingement at varied combinations of external rotation and extension and areas of simulated bone impingement at early external rotation and extension were compared between IFI and non-IFI.

Results: Higher frequency of bony impingement occurred more often in IFI hips at each simulated range-of-motion combination (P < 0.05). Impingement involved the lesser trochanter more often in IFI hips (P < 0.001) and occurred at early degrees of external rotation and extension. In isolated maximum external rotation, only the greater trochanter, intertrochanteric area, or both combined were involved, in 14%, 57%, and 29% in IFI hips. In isolated maximum extension, the lesser trochanter, intertrochanteric area, or both combined were involved in 71%, 14%, and 14% in IFI hips. The simulated area of bone impingement was significantly higher in IFI hips (P = 0.02).

Conclusion: Hip MRI 3D models are feasible for simulated range-of-motion and show a higher frequency of extra-articular impingement at early stages of external rotation and extension in IFI compared to non-IFI hips.

Objective: This study aims to compare the relative reliability and accuracy of TT-TG measurements in EOS with that of MRI in a paediatric population.

Methods: Patients were included if they underwent both an MRI and EOS scans and were under the age of 16. Two authors recorded the TT-TG distances on each modality at two separate time points. In the EOS images, the distance between the two points was measured in the horizontal 2D plane. In the MRI images, it was done in the plane referenced by posterior femoral condylar axis. The intra- and inter-rater reliability was assessed in each modality and between modalities.

Results: Twenty-seven patients (30 knees), 14 males, and 13 females with an average age of 13 years (range: 7-16 years) were included in the study. The mean TT-TG distance on EOS scan and MRI scan was 14 mm. On inter- and intra-observer analysis, both imaging modalities had excellent reliability (0.97 ICC for EOS and 0.98 ICC for MRI inter-observer) and repeatability (0.98-0.99 ICC for EOS and 0.99 ICC for MRI for intra-observer). However, on comparing the two imaging modalities (EOS vs MRI), the ICC was fair (0.56 ICC for rater 1 and 0.65 ICC for rater 2).

Conclusion: While the EOS TT-TG measurements were precise and reproducible, they were only moderately comparable to MRI TT-TG measurements. Consequently, EOS TT-TG measurements should not be used for decision-making without the development of EOS-specific TT-TG values that indicate the need for distal realignment surgery.

Level of evidence: Level II.

Objective: CT imaging precisely and quantitatively analyzes the kinematics of the carpal bones to evaluate the etiology of related osteoarthritis. Previous studies have investigated the kinematics of the trapeziometacarpal joint using static CT scans of various postures including the pinch position. This study analyzed the in-vivo kinematics of the trapeziometacarpal joint during dynamic pinch motion in young healthy volunteers using four-dimensional CT.

Materials and methods: Twelve healthy young volunteers participated in this study. Each participant held the pinch meter between their thumb and index finger and pinched it with maximum force for a period of 6 s. This series of movement was recorded using a four-dimensional CT. The surface data of the trapezium and first metacarpal of all frames were reconstructed, and bone movement at the trapeziometacarpal joint was calculated using sequential three-dimensional registration. The instantaneous pinch force of each frame was measured using a pointer on a pinch meter that was reconstructed from the CT data.

Results: The first metacarpal was abducted (15.9 ± 8.3°) and flexed (12.2 ± 7.1°) relative to the trapezium, and significantly translated to the volar　(0.8 ± 0.6 mm) and ulnar directions (0.9 ± 0.8 mm) with maximum pinch force. This movement consistently increased with the pinch force.

Conclusion: This study successfully employed 4D-CT to precisely demonstrate changes in rotation and translation at the trapeziometacarpal joint during pinch motion for various instantaneous forces.

Painful os peroneum syndrome encompasses a spectrum of disorders associated with lateral foot and ankle pain. In the setting of an os peroneum fracture or diastasis of a partitioned os peroneum, marked displacement of the proximal fragment on radiographs is often used as an imaging surrogate for detection of a complete peroneus longus tendon tear. We present a case of a displaced proximal fragment of the os peroneum above the level of the ankle joint on radiographs and MRI associated with incomplete tear of the peroneus longus tendon. We hypothesize that such an injury pattern results from an anatomic prerequisite where the os peroneum occupies a portion of the cross-sectional diameter of the tendon. We suggest that the retracted proximal moiety of the sesamoid bone is the result of elastic recoil of delaminated fibers of the peroneus longus directly inserting on the os, whereas eccentric bundles of the tendon draping over the os remain in continuity. Although treatment implications are debatable, the case questions the assumption of a complete peroneus longus tear based on a retracted os peroneum on radiography and highlights the role of MRI in providing a full description.

Purpose: To evaluate the results of total-body (TB) MRI used as a screening tool for assessment or exclusion of malignant transformation in patients with hereditary multiple osteochondromas (HMO).

Patients and methods: In a single-institute cohort of MO patients, 366 TB-MRI examinations, including T1-weighted and STIR images, were performed for screening and follow-up purposes to rule out the malignant transformation, and retrospectively analyzed. In each patient, the presence and location of osteochondromas in the axial and appendicular bones were recorded. Forty-seven patients underwent a second TB surveillance in this period. STIR sequences were used to identify sites of increased signal intensity that could represent suspicious thickened cartilage caps or indeterminate reactive changes related to osteochondromas.

Results: In 82% of patients, one or more OC locations were determined in one or more flat bones. In 366 exams, nine OC (2,5 %) with suspicious imaging features were identified. These proved to be peripheral chondrosarcomas after targeted MRI and resection were performed. All nine malignant lesions were in flat bones (pelvis 5, ribs 3, scapula 1). Three of these patients were 19 years of age. In 12 patients who had peripheral or intraosseous low-grade chondrosarcoma in their history, before their first TB-MRI, no new lesions were identified. Twenty-three additional TB-MRI exams, demonstrating focal high T2 signal intensity, also gave rise to performing additional targeted MRI. One OC of the distal femur was excised and appeared benign. No suspicious cartilage caps were depicted on the remaining 22 targeted MRI exams but instead increased T2 signal was clarified by reactive changes (frictional bursitis, soft tissue edema) in close relation with benign osteochondromas. No malignant lesions were found in 47 patients who had a second TB surveillance (mean interval between exams 3.2 years, range 2-5 years).

Conclusion: TB-MRI can identify malignant transformation of osteochondromas in HMO patients. All peripheral chondrosarcomas occurred in flat bones (ribs, scapula, pelvis) in our study. TB-MRI might assist in triage between higher risk patients with a high burden of OC, including the location of OC in main flat bones vs lower risk patients without OC of the flat bones.

Objective: Enchondromas (EC) of the shoulder joint are benign intraosseous cartilage neoplasms, with atypical cartilaginous tumours (ACT) representing their intermediate counterpart. They are usually found incidentally on clinical imaging performed for other reasons. Thus far the prevalence of ECs of the shoulder has been analysed in only one study reaching a figure of 2.1%.

Materials and methods: The aim of the current study was to validate this number via retrospective analysis of a 45 times larger, uniform cohort consisting of 21.550 patients who had received an MRI of the shoulder at a single radiologic centre over a time span of 13.2 years.

Results: Ninety-three of 21.550 patients presented with at least one cartilaginous tumour. Four patients showed two lesions at the same time resulting in a total number of 97 cartilage tumours (89 ECs [91.8%], 8 ACTs [8.2%]). Based on the 93 patients, the overall prevalence was 0.39% for ECs and 0.04% for ACTs. Mean size of the 97 ECs/ACTs was 2.3 ± 1.5 cm; most neoplasms were located in the proximal humerus (96.9%), in the metaphysis (60.8%) and peripherally (56.7%). Of all lesions, 94 tumours (96.9%) were located in the humerus and 3 (3.1%) in the scapula.

Conclusion: Frequency of EC/ACT of the shoulder joint appears to have been overestimated, with the current study revealing a prevalence of 0.43%.