Skeletal Radiology最新文献

Objective: Real-time imaging is useful for the evaluation of wrist instability. However, currently available real-time magnetic resonance imaging (MRI) methods are limited due to their 2D nature or provide insufficient temporal resolution and image quality for quantitative kinematic analysis. This work introduces a novel approach for volumetric dynamic MRI of the wrist joint during active motion and demonstrates the feasibility of tracking carpal bone motion.

Materials and methods: A flexible 8-element 3 T wrist receive coil and 3D-printed support platform for guiding motion were designed for dynamic wrist imaging. 2D real-time images were acquired using a fat-saturated FLASH sequence with radial sampling and reconstructed with the GRASP algorithm. Corresponding volumetric dynamic wrist images were obtained by assembling 2D real-time images into 3D snapshots using autodetected MRI-visible markers for slice alignment. The proposed method was demonstrated for radial-ulnar deviation on five healthy volunteers.

Results: The flexible wrist coil provided high SNR while allowing a wide range of wrist movements. 2D real-time wrist images were acquired with a temporal resolution of 48 ms/frame with negligible streaking artifacts. Carpal bones and metacarpal bones were properly aligned in the assembled dynamic volumes for all five subjects. The excellent bone-to-tissue contrast enabled accurate segmentation of the individual carpal bones on the assembled dynamic volumes.

Conclusion: This work introduces a novel wrist coil and demonstrates that real-time volumetric dynamic examination of the moving wrist is feasible. The achieved image quality and high temporal resolution could enable automatic segmentation of carpal bones and quantitative kinematic assessment for evaluating wrist instability.

Periphyseal stress injuries (PPSIs) in young rock climbers are gaining recognition due to the surge in popularity of the sport. These injuries, occurring near the growth plates of fingers, pose diagnostic challenges due to their subtle presentation and potential long-term complications if left untreated. This review emphasizes the importance of radiologists' awareness of PPSIs, covering their anatomy, biomechanics, and imaging findings. Techniques like the "crimp-grip" in climbing exacerbate the vulnerability of the physis, leading to repetitive stress injuries. Imaging modalities such as radiography, MRI, CT, and ultrasound play crucial roles in diagnosis, each with its advantages and limitations. While radiographs remain a cost-effective initial choice, MRI offers detailed soft tissue evaluation and can detect occult injuries. Understanding the pathophysiology and imaging characteristics of PPSIs is essential for early detection and appropriate management to prevent long-term skeletal deformities and growth disturbances in young climbers.

Objective: To examine how different photon-counting detector (PCD) CT scanning and reconstruction methods affect the volume of metal artifacts and image quality for a hip prosthesis phantom.

Methods: A titanium and cobalt-chromium-molybdenum-alloy total hip prosthesis phantom was scanned using a clinical PCD-CT with a constant tube potential (140 kV) and Computed-Tomography-Dose- Index (7 mGy). Different scan settings were used: with/without tin-filter (Sn), with/without ultra-high resolution (UHR), both individually and combined, resulting in four modes: Quantumplus (Standard), UHR Quantumplus (HighRes), QuantumSn (Standard-Tin) and UHR QuantumSn (HighRes-Tin). Reconstructions included virtual monoenergetic images (VMI) spanning 40-190 keV and polychromatic images, with/without iterative metal artifact reduction (MAR). Artifact volumes rendered in a 3D-printing software were quantified in milliliters (ml), and image quality was evaluated using a Likert score.

Results: Polychromatic reconstruction: Tin-filter reduced artifact volumes (298 (Standard-Tin) vs. 347 ml (Standard) and 310 (HighRes-Tin) vs. 360 ml (HighRes)). The smallest artifact volume was measured in HighRes MAR (150 ml). VMI reconstruction: The smallest artifact volume was measured in Standard 130 keV (150 ml) and HighRes 130 keV (164 ml) and in Standard-Tin 120 keV (169 ml) and HighRes-Tin 120 keV (172 ml). MAR further reduced the artifact volumes to 130 ml (Standard 150 keV MAR) and 140 ml (HighRes 160 keV MAR). Image quality was rated best for Standard 65 keV MAR, polychromatic HighRes MAR, Standard 100 keV MAR, polychromatic Standard-tin MAR, HighRes-tin 100 keV and polychromatic HighRes-tin.

Conclusion: Combining tin-filter, UHR and MAR in VMI or polychromatic images achieve the strongest artifact reduction.

Objective: To determine an optimal region of interest (ROI) for opportunistic screening of osteoporosis in terms of short-term in vivo diagnostic precision.

Materials and methods: We included patients who underwent two CT scans and one dual-energy X-ray absorptiometry scan within a month in 2022. Deep-learning software automatically measured the attenuation in L1 using 54 ROIs (three slice thicknesses × six shapes × three intravertebral levels). To identify factors associated with a lower attenuation difference between the two CT scans, mixed-effect model analysis was performed with ROI-level (slice thickness, shape, intravertebral levels) and patient-level (age, sex, patient diameter, change in CT machine) factors. The root-mean-square standard deviation (RMSSD) and area under the receiver-operating-characteristic curve (AUROC) were calculated.

Results: In total, 73 consecutive patients (mean age ± standard deviation, 69 ± 9 years, 38 women) were included. A lower attenuation difference was observed in ROIs in images with slice thicknesses of 1 and 3 mm than that in images with a slice thickness of 5 mm (p < .001), in large elliptical ROIs (p = .007 or < .001, respectively), and in mid- or cranial-level ROIs than that in caudal-level ROIs (p < .001). No patient-level factors were significantly associated with the attenuation difference. Large, elliptical ROIs placed at the mid-level of L1 on images with 1- or 3-mm slice thicknesses yielded RMSSDs of 12.4-12.5 HU and AUROCs of 0.90.

Conclusion: The largest possible regions of interest drawn in the mid-level trabecular portion of the L1 vertebra on thin-slice images may yield improvements in the precision of opportunistic screening for osteoporosis via CT.

The sacroiliac joints (SIJ) play a pivotal role in pelvic stability and load transmission. SIJ-related disorders can pose a diagnostic challenge because of complex anatomy, non-specific imaging findings, and overlapping symptomatology with other lower back conditions. Broadly, SIJ pathology can be divided into the following categories: infectious, inflammatory, degenerative, mechanical, traumatic, and neoplastic. On the spectrum of mechanical disorders is the entity of SIJ dysfunction, defined as pain localized to the SIJ due to non-inflammatory causes. This paper aims to enhance the understanding of SIJ dysfunction by exploring SIJ anatomy, pathophysiology, and differential diagnosis for SIJ pain. Etiologies, associations, and diagnostic physical examination maneuvers for SIJ dysfunction are reviewed. We will discuss the role of diagnostic imaging in SIJ dysfunction and propose imaging findings which may indicate the diagnosis. Finally, we will discuss therapeutic strategies to treat SIJ dysfunction. By delving into the complexities of SIJ anatomy and pathophysiology, this paper provides valuable discernment for the diagnosis and management of SIJ-related disorders.

Objective: This study is to investigate the three-dimensional (3D) kinematic changes in the knee joint in patients with recurrent patellar dislocation using four-dimensional computed tomography (4DCT) imaging and the 3D-3D surface registration technique.

Materials and methods: Ten knees from nine patients with recurrent patellar dislocation and seven knees from seven controls (unaffected side of patients with unilateral anterior cruciate ligament injury) were analyzed using 4DCT. The patients were asked to extend their knees from 60° of flexion to full extension for 10 s in the CT gantry. We used the 3D-3D registration technique, and the 3D angles of the patella and tibia relative to the femur were evaluated.

Results: In the dislocation group, the patellar lateral tilt increased as the knee extended. Significant differences were found between the two groups at 0°-20° of knee flexion. The tibia rotated externally as the knee extended in the dislocation group. Significant differences between the two groups were found at 0°-10° of knee flexion.

Conclusion: This study demonstrated significant differences in the timing and magnitude of tibial external rotation between patients with recurrent patellar dislocation and controls. Specifically, the tibia began to externally rotate during the early phase of knee extension in the dislocation group. These findings provide new insights into knee kinematics that may inform future treatment strategies for patellar dislocation.

Osteoarthritis can be treated with hyaluronic acid derivatives, such as Durolane manufactured by Bioventus (Hill, 2017), particularly when conventional treatments prove ineffective. In osteoarthritic joints, the synovial fluid has a lower concentration of hyaluronic acid compared to healthy joints. Intra-articular therapy with exogenous hyaluronic acid can improve viscoelastic properties, enhance chondrocyte synthesis, reduce cartilage degradation, and alleviate pain associated with osteoarthritis (Migliore and Procopio in Clin Cases Miner Bone Metab. 12:31-3, 2015). This report describes a unique case where a patient, following Durolane administration, presented with an intraosseous foreign body giant cell reaction. A 2.5-cm lesion was identified on MRI, initially raising concerns for metastatic disease or multiple myeloma. Subsequent IR CT-guided biopsy confirmed a diagnosis of "foreign body giant cell reaction to gel," linked to the Durolane injection. This case presents a contribution to the literature due to the scarcity of documented instances where Durolane injection leads to an intraosseous foreign body giant cell reaction resembling metastatic disease. While a solitary intraosseous pseudotumor, reportedly due to viscosupplement injection, has been published, it differs in both location (hip vs. knee) and imaging characteristics from the presented case. The manifestation of a foreign body giant cell reaction after Durolane injection, mimicking malignant osseous lesions, merits attention among practitioners. This case underscores the necessity for further research into potential adverse reactions associated with hyaluronic acid derivatives.

Chronic refractory pain poses a significant challenge in knee joint pathologies, especially after exhaustion of conservative, arthroscopic, and endoprosthetic therapy options. This case report illustrates an innovative approach using MRI-assisted chemical neurolysis of a genicular nerve to manage persistent knee pain after arthroscopy. A 62-year-old male patient with chronic refractory knee pain, primarily localized at the inferomedial part of the knee, underwent high-resolution MRI to visualize the genicular nerves. This allowed for targeted ethanol-based neurolysis of the inferomedial genicular nerve. Following the procedure, the patient experienced substantial pain reduction for the follow-up duration of 4 months. The successful use of MRI-assisted chemical neurolysis offers a promising alternative treatment for patients with refractory knee pain, providing long-lasting pain relief without major side effects. This technique has the potential to improve the quality of life for patients suffering from chronic knee pain While these initial results are encouraging, it is important to note that further research, including both short-term and long-term studies, as well as randomized controlled trials, is warranted to establish the efficacy and safety of this treatment method in broader populations before it can be considered for routine incorporation into pain management practices.