The value of non-enhanced MRI in the evaluation of patients with suspected idiopathic inflammatory myopathy.

INTRODUCTION/AIMS: The performance of magnetic resonance imaging (MRI) for diagnosing suspected idiopathic inflammatory myopathy (IIM) remains controversial. Furthermore, the role of contrast-enhanced magnetic resonance imaging (CE-MRI) sequences is unclear. The aim of this study was to evaluate the sensitivity and specificity of a non-enhanced magnetic resonance imaging (NE-MRI) protocol compared to a CE-MRI protocol in adult patients with confirmed IIM. METHODS: This study retrospectively enrolled patients with suspected IIM who underwent MRI of the upper thigh between 2008 and 2020. The protocol consisted of a T1-weighted (T1w) sequence, a turbo inversion recovery magnitude (TIRM) sequence and a contrast-enhanced T1-weighted sequence (CE-T1w). After randomly stratifying patients into a group with only the T1w and TIRM sequences available and another group with additional availability of CE-T1w, three blinded readers assessed the presence of IIM based on characteristic imaging features. Confirmation of the diagnosis was determined based on the 2017 ACR/EULAR criteria. RESULTS: Of the 80 patients (mean age 49.0 ± 21.1 years; 42 female, 38 male) included, 54 (67.5%) had a positive diagnosis of IIM. Cumulated sensitivity and specificity for MRI to detect IIM was 87.1% and 83.3% in the NE-MRI group versus 87.0% and 63.0% in the CE-MRI group. The group differences for sensitivity and specificity were non-significant for each of the three readers, respectively (p ≥ .081). DISCUSSION: NE-MRI detects suspected IIM with high diagnostic accuracy and performs equivalently to CE-MRI. Therefore, it may be appropriate to omit the use of contrast agents in MRI scans performed for suspected IIM.

Long-term CT follow-up of patients with lumbar spondylolysis reveals low rate of spontaneous bone fusion.

OBJECTIVES: Knowledge about the long-term outcome of patients with lumbar spondylolysis (LS) is limited. This study assessed the frequency of bone fusion in conservatively treated lumbar spondylolysis with photon counting detector computed tomography. METHODS: Patients with lumbar spondylolysis diagnosed with CT or MRI were prospectively enrolled and underwent CT 5-10 years after initial imaging. Image assessment included evaluation of Meyerding grade, listhesis size, measurement of the lysis gap, and disc integrity on the lysis level. Comparisons were made between bone fusion as the primary endpoint and sex, body mass index, age at diagnosis, follow-up interval, size of listhesis, Meyerding grade, size of the lysis gap, sports activity, and presence of pain. RESULTS: A total of 39 patients (26.0 ± 3.1 years, 15 female) with lumbar spondylolysis on 41 levels were included after a mean follow-up period of 9.1 ± 2.2 years. Nine patients (22.0%, four female) showed complete fusion of the lysis gap. Patients with bone fusion of the lysis gap had a significantly lower Meyerding grade (p = 0.01), smaller size of the listhesis (p = 0.019), and smaller anterior and posterior lysis gap size (p = 0.046 and p = 0.011, respectively). Unilateral lyses showed significantly higher fusion rates than bilateral lyses (40.0% vs. 16.1%, p = 0.01). No statistically significant difference was found for pain at follow-up between patients with and without bone fusion (p = 0.253). CONCLUSION: Bone fusion occurred in about a fifth of conservatively treated lumbar spondylolysis after a follow-up period of 9 years. Factors associated with a successful fusion were a lower Meyerding grade, minimal listhesis, and a small lysis gap.

Clinical and radiological outcome of acute quadriceps tendon repair at 2 - year follow-up.

PURPOSE: Though previous studies on surgical quadriceps tendon repair reported good to satisfactory results its impact on knee extensor strength and patellofemoral joint is unknown. The purpose of the study was to assess the clinical and functional outcome by quantifying subjective knee related outcome, isokinetic extensor strength complemented by magnetic resonance imaging (MRI). METHODS: For this retrospective clinical trial twenty-one patients with a mean age of 59.1 (±14.9) years were carried out for follow-up evaluation. For clinical outcome numeric rating scale for pain (NRS), Kujala anterior knee pain score, Knee osteoarthritis outcome score (KOOS) with its subscores, Tegener Activity Score (TAS), Isokinetic extensor strength testing (ISO) and the Limb symmetry index (LSI) were utilized. Muscle volume (Vmqf), atrophy and cartilage status were assessed on MRI. Tendon integrity and implant loosening were evaluated. Statistical analysis was carried out using Student´s t-test, Pearson and Spearman correlation coefficient. RESULTS: Mean follow-up was 56.2 (± 17.5) months. Clinical outcomes in mean were as follows: NRS 1.7 (±2.0), Kujala score 75.8 (± 15.8) points; KOOS 62.9 (±30.6) % (Subscores: (KOOSPain 84 (± 18.3)%, KOOSSymptoms 63.4 (± 15.3) %, KOOSADL 79.8% (± 19.4)%, KOOSSports&Rec 61.5 (± 28.8))%, TAS 3.7 (± 1.2). Mean ISO difference was 3.7 (±32.3) %). 41.2% of patients had an LSI < 90% and showed non-significantly (p > 0.05) better outcomes in NRS, Kujala score and KOOS than patients with LSI < 90%. ISO correlated with better subjective outcome (r > 0.5) but not with MRI findings. Vmqf asymmetry > 10% was seen in 41,2% of patients. Degenerative muscle and cartilage changes were few and low grade. One tendon showed partial retear. Patients showed no signs of implant loosening. CONCLUSION: Distal quadriceps tendon repair leads to satisfactory subjective outcome in patients with low to moderate activity levels. Tendon integrity was reliably restored. However, extensor strength deficits remain in more than 40% of patients. Atrophy signs of advanced fatty infiltration were recorded in 15% and patellofemoral cartilage defects in 20% of all patients, indicating that previous assessment tools do not display functional outcome adequately.

Activation patterns of rotator-cuff muscles from quantitative IVIM DWI after physical testing.

BACKGROUND: The diagnostic value of clinical rotator cuff (RC) tests is controversial, with only sparse evidence available about their anatomical specificity. We prospectively assessed regional RC muscle activation patterns by means of intravoxel incoherent motion (IVIM) diffusion-weighted magnetic resonance imaging (MRI) after the execution of common clinical RC tests. METHODS: Ten healthy subjects (five males, five females) underwent three sessions of diffusion-weighted 3-T shoulder MRI before and after testing the supraspinatus (SSP, Jobe test, session 1), subscapularis (SSC, lift-off test, session 2, at least 1 week later), and infraspinatus muscle (ISP, external rotation test, session 3, another week later). IVIM parameters (perfusion fraction, f; pseudo-diffusion coefficient. D*; and their product, fD*) were measured in regions of interest placed in images of the SSP, SSC, ISP, and deltoid muscle. The Wilcoxon signed-rank test was used for group comparisons; p-values were adjusted using the Bonferroni correction. RESULTS: After all tests, fD* was significantly increased in the respective target muscles (SSP, SSC, or ISP; p ≤ 0.001). After SSP testing, an additional significant increase of fD* was observed in the deltoid, the SSC, and the ISP muscle (p < 0.001). After the SSC and ISP tests, no significant concomitant increase of any parameter was observed in the other RC muscles. CONCLUSION: IVIM revealed varying activation patterns of RC muscles for different clinical RC tests. For SSP testing, coactivation of the deltoid and other RC muscles was observed, implying limited anatomical specificity, while the tests for the SSC and ISP specifically activated their respective target muscle. RELEVANCE STATEMENT: Following clinical RC tests, IVIM MRI revealed that SSP testing led to shoulder muscle coactivation, while the SSC and ISP tests specifically activated the target muscles. KEY POINTS: In this study, intravoxel incoherent motion MRI depicted muscle activation following clinical rotator cuff tests. After supraspinatus testing, coactivation of surrounding shoulder girdle muscles was observed. Subscapularis and infraspinatus tests exhibited isolated activation of their respective target muscles.

Assessment of the supraspinatus muscle fiber architecture with diffusion tensor imaging in healthy volunteers.

OBJECTIVES: This study presents a framework for the calculation of supraspinatus (SSP) muscle pennation angles (PAs) from diffusion tensor imaging (DTI). MATERIALS AND METHODS: Ten healthy individuals (five females and five males; age 32.0 ± 4.7 years) underwent three sessions of 3-T MRI, including a stimulated echo acquisition mode DTI sequence. The imaging plane of the DTI sequence was angled along the intramuscular part of the SSP tendon. A custom-built software was developed and implemented to compute DTI-based PAs of the anterior and posterior SSP in relation to the orientation of the tendon. Subsequently, three readers measured PAs from the post-processed images. Test-retest reliability, inter-reader agreement, and intra-reader agreement of PA measurements were evaluated with intraclass correlation coefficients (ICCs). RESULTS: The mean PA in the anterior SSP was 15.6 ± 2.1° and 10.7 ± 0.9° in the posterior SSP. MRI-derived PAs showed good to excellent test-retest reliability (ICC: 0.856-0.945), inter-reader agreement (ICC: 0.863-0.955), and intra-reader agreement (ICC: 0.804-0.955). CONCLUSION: PAs derived from DTI demonstrated good to excellent test-retest reliability, inter-reader agreement, and intra-reader agreement. We successfully implemented a highly standardized technique for evaluating PAs of the SSP muscle. CRITICAL RELEVANCE STATEMENT: This proposed low-complex method might facilitate the increased use of the PA as a biomarker for pathological conditions of the rotator cuff. KEY POINTS: A low-complex method for measuring PAs of the SSP might help identify pathology early. The mean PA was 15.6 ± 2.1° and 10.7 ± 0.9° in the anterior and posterior SSP, respectively. ICCs were ≥ 0.856 for test-retest reliability, ≥ 0.863 for inter-reader agreement, and ≥ 0.804 for intra-reader agreement.

Accelerated High-Resolution Deep Learning Reconstruction Turbo Spin Echo MRI of the Knee at 7 T.

OBJECTIVES: The aim of this study was to compare the image quality of 7 T turbo spin echo (TSE) knee images acquired with varying factors of parallel-imaging acceleration reconstructed with deep learning (DL)-based and conventional algorithms. MATERIALS AND METHODS: This was a prospective single-center study. Twenty-three healthy volunteers underwent 7 T knee magnetic resonance imaging. Two-, 3-, and 4-fold accelerated high-resolution fat-signal-suppressing proton density (PD-fs) and T1-weighted coronal 2D TSE acquisitions with an encoded voxel volume of 0.31 × 0.31 × 1.5 mm3 were acquired. Each set of raw data was reconstructed with a DL-based and a conventional Generalized Autocalibrating Partially Parallel Acquisition (GRAPPA) algorithm. Three readers rated image contrast, sharpness, artifacts, noise, and overall quality. Friedman analysis of variance and the Wilcoxon signed rank test were used for comparison of image quality criteria. RESULTS: The mean age of the participants was 32.0 ± 8.1 years (15 male, 8 female). Acquisition times at 4-fold acceleration were 4 minutes 15 seconds (PD-fs, Supplemental Video is available at http://links.lww.com/RLI/A938) and 3 minutes 9 seconds (T1, Supplemental Video available at http://links.lww.com/RLI/A939). At 4-fold acceleration, image contrast, sharpness, noise, and overall quality of images reconstructed with the DL-based algorithm were significantly better rated than the corresponding GRAPPA reconstructions (P < 0.001). Four-fold accelerated DL-reconstructed images scored significantly better than 2- to 3-fold GRAPPA-reconstructed images with regards to image contrast, sharpness, noise, and overall quality (P ≤ 0.031). Image contrast of PD-fs images at 2-fold acceleration (P = 0.087), image noise of T1-weighted images at 2-fold acceleration (P = 0.180), and image artifacts for both sequences at 2- and 3-fold acceleration (P ≥ 0.102) of GRAPPA reconstructions were not rated differently than those of 4-fold accelerated DL-reconstructed images. Furthermore, no significant difference was observed for all image quality measures among 2-fold, 3-fold, and 4-fold accelerated DL reconstructions (P ≥ 0.082). CONCLUSIONS: This study explored the technical potential of DL-based image reconstruction in accelerated 2D TSE acquisitions of the knee at 7 T. DL reconstruction significantly improved a variety of image quality measures of high-resolution TSE images acquired with a 4-fold parallel-imaging acceleration compared with a conventional reconstruction algorithm.

Beyond body mass index: Body composition profiling for perioperative risk stratification in intrahepatic cholangiocarcinoma patients.

BACKGROUND AND AIMS: Intrahepatic cholangiocarcinoma (iCC) is an aggressive tumor, usually detected at an advanced stage. Our aim was to investigate the potential of body composition analysis (BCA) derived from presurgical staging computed tomography (CT) in predicting perisurgical complications. METHODS: In this retrospective cohort study, we enrolled 86 patients who underwent CT imaging prior to liver surgery. Cox and logistic regression were performed to assess risk factors for prolonged hospital and intensive care unit (ICU) stays, as well as the occurrence of various complications. BCA parameters served as covariates besides conventional risk factors. RESULTS: Postoperative complications after resection of iCC significantly prolonged the overall length of hospitalization (p < .001). Presence of sarcopenia was associated with longer ICU stays. Complications were common, with 62.5% classified as Clavien-Dindo grade IIIa or lower and 37.5% as more severe. Subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) were identified as risk factors for complications, including bile leakage (in 24 cases, p = .025), pleural effusions (in 26 cases, p = .025), and intra-abdominal abscess formation (in 24 cases, p = .043). SAT was associated with severe complications requiring interventional therapy, whereas VAT was correlated with abscess formation. Despite normal prevalence of obesity (22%), body mass index (BMI) did not have an impact on the development of perioperative complications. CONCLUSION: BCA is a useful tool for preoperative risk stratification in patients with iCC and is superior to BMI assessment. Increased SAT and VAT were associated with the risk of perisurgical complications, prolonging hospitalization. Therefore, BCA derived from routine staging CT should be considered in the preoperative assessment of patients with iCC.

Advanced muscle imaging in adolescent elite rowers utilizing diffusion tensor imaging: Association of imaging findings with stroke typology.

PURPOSE: Muscular overuse injuries are a common health issue in elite athletes. Changes in the muscular microenvironment can be depicted by Diffusion Tensor Imaging (DTI). We hypothesize that the biomechanics of different stroke typologies plays a role in muscle injury and tested our hypothesis by magnetic resonance imaging (MRI) examination of the lumbar spine muscles of adolescent rowers utilizing DTI. METHODS AND MATERIALS: Twenty-two male elite rowers (12 sweep, 10 scull rowers) with a mean age of 15.8 ± 1.2 years underwent 3-Tesla MRI of the lumbar spine 6 hours after cessation of training. Apparent diffusion coefficient (ADC) and fractional anisotropy (FA) were calculated for the erector spinae and multifidus muscle. Student's t-test was used to test differences of DTI parameters between sweep and scull rowers and a Pearson correlation was utilized to correlate the parameters to training volume. RESULTS: ADC values in the erector spinae and multifidus muscle were significantly higher (p = 0.039) and FA values significantly lower (p < 0.001) in sweep rowers compared to scull rowers. There was no significant association between DTI parameters and training volume (r ≤ -0.459, p ≥ 0.074). CONCLUSIONS: Our DTI results show that lumbar spine muscle diffusivity is higher in sweep rowers than in scull rowers. Altered muscle diffusivity is suggestive of microscopic tissue disruption and might be attributable to biomechanical differences between stroke typologies.

Prediction of regional lymph node metastasis in intrahepatic cholangiocarcinoma: it's not all about size.

OBJECTIVES: Lymph node metastases (LNM) are frequent in patients with intrahepatic cholangiocarcinoma (iCC) and worsen their prognosis even after surgery. Our aim was to investigate the predictive value of lymph node (LN) short axis, the most common discriminator for identifying LNM in tumor-imaging and to develop a predictive model for regional LNM in iCC taking computed tomography (CT) features of extranodal disease into account. MATERIALS AND METHODS: We enrolled 102 patients with pathologically proven iCC who underwent CT prior to hepatic resection and hilar lymph node dissection (LND) from 2005 to 2021. Two blinded radiologists assessed various imaging characteristics and LN diameters, which were analyzed by bivariate and multivariate logistic regression to develop a prediction model for LNM. RESULTS: Prevalence of LNM was high (42.4 %) and estimated survival was shorter in LN-positive patients (p = 0.07). An LN short axis diameter of ≥ 9 mm demonstrated the highest predictive power for LNM. Three additional, statistically significant imaging features, presence of intrahepatic metastasis (p = 0.003), hilar tumor infiltration (p = 0.003), and tumor growth along the liver capsule (p = 0.004), were integrated into a prediction model, which substantially outperformed use of LN axis alone in ROC analysis (AUC 0.856 vs 0.701). CONCLUSIONS: LN diameter alone proved to be a relevant but unreliable imaging-marker for LNM prediction in iCC. Our proposed prognostic model, which additionally considers intrahepatic metastases and hilar and capsular infiltration, significantly improves discriminatory power. Hilar and capsular involvement might indicate direct tumor extension to lymphatic liver structures.