Ultrasound localization of lacerated flexor tendon ends in the hand: a cadaveric study In the results section of the abstract, it states “99.0% (n = 05/96 tendons)” when it should state “99.0% (n = 95/96 tendons)”.

Camptodactyly resulting from anatomical variation of lumbrical muscles: imaging findings Abstract We report three cases of camptodactyly in adolescent patients, presenting with a passive flexion deformity of the fifth finger. Ultrasound findings include aberrant lumbrical insertion and decreased lumbrical size, confirmed with magnetic resonance imaging, and aberrant dynamics. Surgery confirmed these findings in one patient. To the best of our knowledge, these imaging findings have not been reported previously.

Comparison of PSMA-PET/CT, choline-PET/CT, NaF-PET/CT, MRI, and bone scintigraphy in the diagnosis of bone metastases in patients with prostate cancer: a systematic review and meta-analysis Abstract Objective A systematic review and meta-analysis to compare the diagnostic performance of prostate-specific membrane antigen (PSMA)-PET/CT, choline-PET/CT, Sodium Fluoride (NaF) PET/CT, MRI, and bone scintigraphy (BS) in detecting bone metastases in patients with prostate cancer. Methods We searched PubMed and Embase for articles published between January 1990 and September 2018. Two evaluators independently extracted the sensitivity, specificity, the numbers of true and false positives, and true and false negatives. We calculated the pooled sensitivity, specificity, and 95% confidence intervals (CI) for each method. We calculated the tests’ diagnostic odds ratios (DOR); drew the summary receiver operating characteristic (SROC) curves; and obtained the areas under the curves (AUC), Q* values, and 95% CIs. Results The per-patient pooled sensitivities of PSMA-PET/CT, choline-PET/CT, NaF-PET/CT, MRI, and BS were 0.97, 0.87, 0.96, 0.91, and 0.86, respectively. The pooled specificities were 1.00, 0.99, 0.97, 0.96, and 0.95, respectively. The pooled DOR values were 504.16, 673.67, 242.63, and 114.44, respectively. The AUC were 1.00, 0.99, 0.99, 0.98, and 0.95, respectively. The per-lesion pooled sensitivities of PSMA-PET/CT, choline-PET/CT, NaF-PET/CT, MRI, and bone imaging were 0.88, 0.80, 0.97, 0.81 and 0.68, respectively. Conclusions According to the meta-analysis, PSMA-PET/CT had the highest per-patient sensitivity and specificity in detecting bone metastases with prostate cancer. The sensitivities of NaF-PET/CT and MRI were better than those for choline-PET/CT and BS. The specificity of PSMA-PET/CT was significantly better than BS. Others were similar. For per-lesion, NaF-PET/CT had the highest sensitivity, PSMA-PET/CT had higher sensitivity than choline-PET/CT and MRI, and BS had the lowest sensitivity.

Radiographic signs of hook of hamate fracture: evaluation of diagnostic utility Abstract Objective Hook of hamate fracture, the most common swing-related wrist fracture, is commonly seen in high-level athletes. The fracture is rarely diagnosed on routine wrist radiographs, thus generally requiring CT or MR for diagnosis. Surgical excision has a high success rate, however diagnostic delay contributes to a high complication rate. Radiographic signs of hook of hamate fracture have been published, but uncertainty of the diagnostic accuracy limits application. The purpose of this study is to determine accuracy and interobserver reliability of radiographic signs of hook of hamate. Materials and methods This retrospective case-control study evaluated wrist radiographs of 50 patients, including 24 positive and 26 negative, for hook of hamate fracture, each proven by CT or MR. Five reviewers performed blinded, randomized evaluation of radiographs documenting whether the hook of hamate was normal or fractured, and if fractured, the radiographic signs present (ring sign, ghostly shadow, and diffuse sclerosis) and views that contributed to diagnosis. Results Radiographic signs demonstrated high sensitivity (85%; 95% CI: 77–91), specificity (92%; 95% CI: 86–96), and accuracy (89%; 95% CI: 84–92) with substantial interobserver reliability (k = 0.652). The ring sign was the most sensitive radiographic sign. Diagnosis was most often supported by the oblique view (38%) and rarely the lateral view (15%). Conclusions Radiographic signs of hook of hamate fracture on routine radiographs can accurately and reliably diagnose hook of hamate fractures. Evaluation for discontinuity of the cortical ring will optimize sensitivity, allowing for timely diagnosis and treatment, and a reduction of complications.

Longitudinal MRI structural findings observed in accelerated knee osteoarthritis: data from the Osteoarthritis Initiative Abstract Objective To analyze structural, longitudinal MRI findings during the development of accelerated knee osteoarthritis (AKOA) over 4 years. Materials and methods From the Osteoarthritis Initiative (OAI), knees with no radiographic osteoarthritis (KL 0/1) developing advanced-stage osteoarthritis (KL 3/4; AKOA) within a 4-year (y) timeframe were selected. MRIs were graded using the modified Whole-Organ Magnetic Resonance Imaging Score (WORMS) at the beginning of the 4-year timeframe (index visit), at 2-year, and 4-year follow-up. Morphological and clinical findings associated with KL 3/4 onset within 2 years compared to 4 years were assessed using generalized estimating equations. Results AKOA was found in 162 knees of 149 subjects (age 63.25 ± 8.3; 103 females; BMI 29.4 ± 3.9). Moderate to severe meniscal lesions WORMS ≥ 3 were present in 25% (41/162) at the index visit, 64% (104/162) at 2-year and 93% (151/162) at 4-year follow-up. Meniscal extrusion was the most prevalent finding (ranging from 18% at the index visit, 45% at 2-year and 94% at 4-year follow-up) and root tears were the most common types of tears (9% at the index visit; 22% at 2 years and 38% at 4 years). Risk factors associated with KL 3/4 onset within 2 years included root tears at the index visit (adjusted OR, 2.82; 95% CI: 1.33, 6.00; p = 0.007) and incident knee injury (42%, 49/116 vs. 24%, 11/46, p = 0.032). Conclusions Meniscal abnormalities, in particular extrusion and root tears, were the most prevalent morphological features found in subjects with AKOA. These results suggest that meniscal abnormalities have a significant role in accelerated progression of OA.

Subchondral insufficiency fracture of the knee: grading, risk factors, and outcome Abstract Objective To propose an magnetic resonance imaging (MRI) grading system for subchondral insufficiency fracture of the knee (SIFK) to predict outcome and assess risk factors. Materials and methods A total of 50 SIFK patients were retrospectively reviewed utilizing two MRI examinations approximately a year apart and compared them with 51 control subjects. A grading system was introduced that classifies lesions as low- vs high-grade. Lesion location 3D dimensions, extent of bone marrow edema (BME), location of meniscal tears and associated extrusion, degree of chondrosis and among other parameters were stratified according to lesion grade and compared with follow-up examinations. Statistical analyses were performed (Pearson’s correlation, binary logistic regression, and Chi-squared analysis). Results The majority of SIFK lesions were low-grade (LG; 78%) and most of them (70%) were observed in the medial femoral condyle. Predictor variables comparing low-grade and high-grade SIFK lesions included meniscal tear (p = 0.01), degree of extrusion (p < 0.003), chondrosis (p = 0.01), medial chondrosis grade (p = 0.001), medial femoral condyle (p = 0.01), surface collapse (p < 0.0001), marrow edema improvement (p < 0.0001), first MRI anteroposterior dimension (p = 0.001), transverse dimension (p < 0.001), and ellipsoid volume (p = 0.02). Predictor variables found to be significantly different between controls and patients were meniscal tear (p = 0.024), location of the medial meniscal tear (p < 0.0001), degree of extrusion (p < 0.0001), chondrosis (p < 0.0001), joint effusion (p < 0.0001), Baker’s cyst (p < 0.0001), knee lock (p = 0.03) and buckle (p = 0.01), and history of trauma (p = 0.01). Conclusion A SIFK grading system for MRI is introduced. Surrogate markers of high-grade lesions include medial meniscus posterior root tears with associated moderate to severe extrusion, high-grade chondrosis, larger lesion sizes (anteroposterior/transverse), and articular surface collapse. Improvement of BME on follow-up was highly predictive of low-grade disease.

The Dixon technique for MRI of the bone marrow Abstract Dixon sequences are established as a reliable MRI technique that can be used for problem-solving in the assessment of bone marrow lesions. Unlike other fat suppression methods, Dixon techniques rely on the difference in resonance frequency between fat and water and in a single acquisition, fat only, water only, in-phase and out-of-phase images are acquired. This gives Dixon techniques the unique ability to quantify the amount of fat within a bone lesion, allowing discrimination between marrow-infiltrating and non-marrow-infiltrating lesions such as focal nodular marrow hyperplasia. Dixon can be used with gradient echo and spin echo techniques, both two-dimensional and three-dimensional imaging. Another advantage is its rapid acquisition time, especially when using traditional two-point Dixon gradient echo sequences. Overall, Dixon is a robust fat suppression method that can also be used with intravenous contrast agents. After reviewing the available literature, we would like to advocate the implementation of additional Dixon sequences as a problem-solving tool during the assessment of bone marrow pathology.

Dual-layer spectral computerized tomography for metal artifact reduction: small versus large orthopedic devices Abstract Introduction Metal artifacts limit the diagnostic utility of computerized tomography (CT) for implant-related complications. Dual-layer spectral detector CT imaging has been suggested for artifact reduction. Our objective was to evaluate the utility of spectral CT in artifact reduction in patients with small and large metal implants. Methods In this prospective study, patients with metallic orthopedic implants underwent CT imaging using a prototype spectral detector CT scanner. Conventional images were generated with iterative reconstruction at 120 kVp, and virtual monochromatic images were generated at 20-keV intervals between 40 to 200 keV. Conventional and monochromatic images were compared quantitatively using signal-to-noise ratio (SNR) and artifact improvement. Qualitative analysis was performed independently by two musculoskeletal radiologists and included six image quality indicators. Results A total of 12 patients were scanned. In monochromatic images, as the energy level increased, the artifact size decreased progressively (p < 0.01). When conventional and monochromatic images were compared, maximum reduction was seen at 200 keV. Using qualitative assessments, 160 and 180 keV levels had the best overall diagnostic image quality. With increased energy level, there was improvement in qualitative ratings of bone-metal interface conspicuity (p = 0.002), degree of streak artifact (p = 0.010) and trabecular bone definition at 1 cm from implant (p = 0.023), and a trend towards significance for bone definition at 5 cm, soft tissue detail and overall diagnostic quality. Subgroup analysis revealed superior artifact reduction in small implants compared to large hardware. Discussion Our results support the utility of dual-layer spectral CT in metal artifact reduction. Virtual monochromatic images were diagnostically superior, especially for smaller implants. Virtual monoenergetic images at 160–180 keV are ideal for reducing artifacts.

Change in MRI findings of medial collateral ligament injury in adolescent baseball players with no clinical symptoms over time Abstract Objective Elbow screening of adolescent baseball players began in 2014 using ultrasound, palpation, and dedicated magnetic resonance imaging (MRI). We frequently encountered subjects showing MCL injury on MRI but no clinical symptoms. We assessed variations in asymptomatic MCL injury findings at follow-up MRI, and clarified the pathogenesis of these findings. Materials and methods Using a 0.2-T-dedicated MRI, 30 subjects with asymptomatic MCL injury at initial MRI who agreed to follow-up MRI were included. We classified the findings at repeat MRI as follows: (a) disappeared, (b) better, and (c) worse. Results There were 6, 16, and 8 subjects in groups a, b, and c, respectively. The average age at follow-up was 14.0, 12.1, and 12.4 years in groups a, b, and c, respectively. There were significant differences between groups a and b and between groups a and c. Average height at follow-up of groups a, b, and c was 1.64, 1.52, and 1.57 cm, respectively, with a statistically significant difference between groups a and b. The average size of the short axis of the MCL of subjects in group a was 2.0 cm on the dominant side and 1.5 cm on the contradominant side (P < 0.04). Conclusion Players with asymptomatic MCL injury can continue to play baseball with no limitations, as these findings usually disappear around the age of 14.0 years, when the growth spurt occurs. This finding may be a precursor of ‘adaptation’, which is generally observed in high school baseball players, suggesting that the MCL adapts as growth occurs.

Clinical utility of virtual noncalcium dual-energy CT in imaging of the pelvis and hip Abstract Dual-energy virtual noncalcium images are increasingly used to identify marrow edema which accompanies bony pelvic injuries and marrow pathology obscured by cancellous bone. We present a clinical perspective of our experience using virtual noncalcium images in the work up of pelvic osseous pathology.