Tenosynovial Giant Cell Tumor (TSGCT) of the hip: MRI accuracy and results of surgical treatment.

Tenosynovial Giant Cell Tumor (TSGCT) or formerly pigmented villonodular synovitis (PVNS) is a rare nonmalignant tumor of the synovia seldom affecting the hip. MRI and surgical resection are the gold standards in its diagnosis and treatment. However, the accuracy of MRI is unknown, and only few reports on its surgical treatment results exist. The goal of the study was to investigate the MRI accuracy, results after surgical treatment, and natural history of untreated MRI-diagnosed hip TSGCT. Twenty-four consecutive patients with suspected TSGCT on hip MRI, between December 2006 and January 2018, were identified from our medical database. Six refused to participate. About 18 patients with a minimal follow-up of 18 months were enrolled. Charts were reviewed for histopathology results, specific treatment and recurrence. At the last follow-up, all patients had a clinical (Harris Hip Score [HHS]) and radiological examination (x-ray and MRI). Out of 18 patients with suspected TSGCT on MRI, with a mean age of 35y (range 17-52), 14 had surgi- cal resection and 4 refused surgery 1 of whom had a CT-guided biopsy. Out of 15 cases with biopsies, in 10 TSGCT was confirmed. Three surgically-treated patients showed recurrence on MRI after 24, 31 and 43 months. Two non-treated patients showed progression after 18 and 116 months. At the last follow-up (65 m; range 18-159), the mean HHS with or without recurrence was 90 and 80pts (ns). Operative vs. non-operative treatment showed HHS of 86 and 90pts (ns). In the conservatively-treated group, HHS with and without progression was 98 and 82pts (ns), respectively. MRI-suspected TSGCT of the hip was confirmed with biopsy in two-thirds of the cases. Surgical treatment showed recurrence in more than one-third of the patients. Two out of four untreated patients showed progression of the TSGCT-suspected lesion.

Fampridine-induced changes in walking kinetics are associated with clinical improvements in patients with multiple sclerosis.

Gait dysfunction is common in patients with multiple sclerosis (PwMS). Treatment with prolonged-release fampridine (PR-fampridine) improves walking ability in some PwMS. Associated fampridine-induced changes in the walking pattern are still poorly understood but may provide a better understanding of the mechanisms underlying the beneficial drug effects. 61 PwMS were treated with PR-fampridine in a randomized, monocentric, double-blind and placebo-controlled clinical trial with crossover design (FAMPKIN). Drug-induced improvements in walking speed (Timed-25-Foot Walk; T25FW) and endurance (6-Minute Walk Test; 6MWT) were quantified. In this sub-study of the FAMPKIN trial, fampridine-induced changes in kinetic gait patterns were analyzed by pressure-based foot print analysis during treadmill walking. Vertical ground reaction forces were analyzed during different gait phases. Kinetic data of 44 PwMS was eligible for analysis. During double-blind treatment with PR-fampridine, patients performed significantly better in the T25FW and 6MWT than during placebo treatment (p < 0.0001 for both). At the group level (n = 44), there were no significant changes of gait kinetics under PR-fampridine vs. placebo. However, we found relevant changes of walking kinetics regarding forces during loading, single limb and pre-swing phase in a patient sub-group (n = 8). Interestingly, this sub-group demonstrated superior responsiveness to PR-fampridine in the clinical walking tests compared to those patients without any fampridine-induced changes in kinetics (n = 36). Our results demonstrate fampridine-induced changes in gait kinetics in a sub-group of PwMS. These gait pattern changes were accompanied by improved clinical walking performance under PR-fampridine. These results shed some light on the biomechanical changes in walking patterns underlying enhanced fampridine-induced gait performance.

Predicting responsiveness to fampridine in gait-impaired patients with multiple sclerosis.

BACKGROUND AND PURPOSE: Fampridine leads to significant improvements in walking in many people with multiple sclerosis (PwMS). However, a relevant proportion of PwMS does not respond to fampridine and predictors of initial drug responsiveness are unknown. METHODS: Drug response to prolonged-release (PR)-fampridine was assessed in 55 PwMS using the timed 25-foot walk (T25FW), 6-min walk test (6MWT) and 12-item multiple sclerosis walking scale as outcome parameters. Patients were treated with PR-fampridine and placebo for 6 weeks each in a randomized, double-blind, placebo-controlled trial with crossover design (NCT01576354). Possible predictors of drug responsiveness were investigated by multiple correlation analysis and binary logistic regression models. An additional longitudinal analysis followed the drug responses of 32 patients treated with PR-fampridine over 3 years to identify potential predictors of long-term drug responsiveness. RESULTS: Severity of walking disability was positively correlated with enhanced responses to PR-fampridine. The strongest single predictor of drug responsiveness was poor 6MWT performance at baseline, which was positively correlated with enhanced drug response in the 6MWT (R = -0.541; P < 0.001). A multivariable logistic regression model including 6MWT and T25FW baseline performances predicted PR-fampridine responder status with an accuracy of 85.5% (specificity, 90.0%; sensitivity, 73.3%), with a threshold of 211 m in the 6MWT best separating responders from non-responders. Enhanced drug responsiveness after 3 years correlated with decline in walking endurance during this period (R = -0.634; P = 0.001). CONCLUSIONS: Initial walking impairment is a good predictor of therapeutic responsiveness to PR-fampridine. Valid predictors of patients' responsiveness to PR-fampridine are essential for patient stratification and optimization of multiple slcerosis treatment.

Whole-Body Diffusion Imaging Applying Simultaneous Multi-Slice Excitation.

PURPOSE: The purpose of this study was to examine the feasibility of a fast protocol for whole-body diffusion-weighted imaging (WB-DWI) using a slice-accelerated echo-planar sequence, which, when using comparable image acquisition parameters, noticeably reduces measurement time compared to a conventional WB-DWI protocol. MATERIALS AND METHODS: A single-shot echo-planar imaging sequence capable of simultaneous slice excitation and acquisition was optimized for WB-DWI on a 3 T MR scanner, with a comparable conventional WB-DWI protocol serving as the reference standard. Eight healthy individuals and one oncologic patient underwent WB-DWI. Quantitative analysis was carried out by measuring the apparent diffusion coefficient (ADC) and its coefficient of variation (CV) in different organs. Image quality was assessed qualitatively by two independent radiologists using a 4-point Likert scale. RESULTS: Using our proposed protocol, the scan time of the WB-DWI measurement was reduced by up to 25.9 %. Both protocols, the slice-accelerated protocol and the conventional protocol, showed comparable image quality without statistically significant differences in the reader scores. Similarly, no significant differences of the ADC values of parenchymal organs were found, whereas ADC values of brain tissue were slightly higher in the slice-accelerated protocol. CONCLUSION: It was demonstrated that slice-accelerated DWI can be applied to WB-DWI protocols with the potential to greatly reduce the required measurement time, thereby substantially increasing clinical applicability. KEY POINTS: •Whole-body diffusion-weighted imaging (WB-DWI) using simultaneous multi-slice and blipped-CAIPIRINHA reduces the measurement time strongly without having a significant impact on image quality. •The reduction in measurement time might strongly contribute to the clinical applicability of WB-DWI. •However, further refinement of the slice-accelerated EPI sequence, and the WB-DWI protocol applying this sequence type seems necessary; and the value of such WB-DWI protocols for assessment of systemic oncological diseases needs to be investigated in further clinical studies.

Age- and Level-Dependence of Fatty Infiltration in Lumbar Paravertebral Muscles of Healthy Volunteers.

BACKGROUND AND PURPOSE: Normative age-related decline in paravertebral muscle quality is important for reference to disease and risk identification in patients. We aimed to establish age- and vertebral level-dependence of paravertebral (multifidus and erector spinae) muscle volume and fat content in healthy adult volunteers. MATERIALS AND METHODS: In this prospective study multifidus and erector spinae fat signal fraction and volume at lumbar levels L1-L5 were measured in 80 healthy volunteers (10 women and men per decade, 20-62 years of age) by 2-point Dixon 3T MR imaging. ANOVA with post hoc Bonferroni correction compared fat signal fraction and volume among subgroups. Pearson and Spearman analysis were used for correlations (P < .05). RESULTS: Fat signal fraction was higher in women (17.8% ± 10.7%) than men (14.7% ± 7.8%; P < .001) and increased with age. Multifidus and erector spinae volume was lower in women (565.4 ± 83.8 cm(3)) than in men (811.6 ± 98.9 cm(3); P < .001) and was age-independent. No differences in fat signal fraction were shown between the right and left paravertebral muscles or among the L1, L2, and L3 lumbar levels. The fat signal fraction was highest at L5 (women, 31.9% ± 9.3%; men, 25.7% ± 8.0%; P < .001). The fat signal fraction at L4 correlated best with total lumbar fat signal fraction (women, r = 0.95; men, r = 0.92, P < .001). Total fat signal fraction was higher in the multifidus compared with erector spinae muscles at L1-L4 for both sexes (P < .001). CONCLUSIONS: Lumbar paravertebral muscle fat content increases with aging, independent of volume, in healthy volunteers 20-62 years of age. Women, low lumbar levels, and the multifidus muscle are most affected. Further study examining younger and older subjects and the functional impact of fatty infiltrated paravertebral muscles are warranted.