Rotator Cuff Tendon Assessment in Symptomatic and Control Groups Using Quantitative MRI.

BACKGROUND: Relatively weak correlations between patient symptoms and rotator cuff tendon (RCT) tearing have been reported; however, the relationship between symptoms and tendinosis has been less well-studied. PURPOSE/HYPOTHESIS: To use quantitative MRI to assess the bilateral RCTs in shoulders of both patients with unilateral symptomatic tendinopathy and control subjects. We hypothesized that quantitative MRI measures would differ between symptomatic patients and controls. STUDY TYPE: Prospective imaging study. POPULATION/SUBJECTS: In all, 48 shoulders from 24 subjects (mean age, 32.8 years), including 14 patients with unilateral symptomatic tendinopathy and 10 asymptomatic controls. FIELD STRENGTH/SEQUENCE: 3T/3D ultrashort echo time Cones sequence with magnetization transfer preparation (UTE-Cones-MT) and Carr-Purcell-Meiboom-Gill. ASSESSMENT: Macromolecular fraction (MMF) and T2 relaxation were measured in four regions of the superior RCT, including all-segments, and lateral-third, bursal-sided, and articular-sided segments. The Western Ontario Rotator Cuff (WORC) index and visual analog scale were assessed. STATISTICAL TESTS: Three shoulder groups were evaluated, including symptomatic shoulders, contralateral asymptomatic shoulders in patients, and asymptomatic controls. MMF and T2 values were compared between groups using a bootstrap-based comparison of means. RESULTS: Significant differences were found in both MMF and T2 values between symptomatic and control RCTs when analyzing all-segments (P = 0.027 and P = 0.006, respectively) and articular-sided segments (both P = 0.001). Significant differences between asymptomatic RCTs in patients and control RCTs were also found, including MMF in all four anatomic regions analyzed (P = 0.024-0.044), as well as T2 in all-segments (P = 0.003), bursal-sided segments (P = 0.021), and articular-sided segments (P = 0.002). No significant differences in MMF (P = 0.420-0.950) or T2 (P = 0.380-0.910) were seen between ipsilateral symptomatic and contralateral asymptomatic RCTs in patients. DATA CONCLUSION: Symptomatic RCTs showed significantly lower MMF values and higher T2 values compared with control RCTs. In patients with unilateral symptomatic tendinopathy, the contralateral shoulder can demonstrate asymptomatic tendinopathy, which can be quantified using MMF or T2 . EVIDENCE LEVEL: 2 TECHNICAL EFFICACY: Stage 2. J. Magn. Reson. Imaging 2020;52:864-872.

Assessment of Neuromuscular Function in Patients With Prior Cosmetic Procedures: A Case Report.

Objective: The use of Botulinum toxin type A (Botox) for cosmetic procedures has become so prevalent that many patients do not always consider it to be a past surgical procedure, and it goes excluded from the medical record. Without the knowledge of prior Botox use, interpretation of facial nerve train-of-four testing may be inaccurate. Methods: We describe a 61-year-old woman with a history of multiple cosmetic procedures whose postoperative course was complicated by multiorgan system failure, requiring neuromuscular blockade while on mechanical ventilatory support. Results: Gauged by facial nerve stimulation, adequate neuromuscular blockade was assumed. However, patient-ventilator dyssynchrony motivated the decision to move the peripheral nerve stimulator to the ulnar nerve, where muscle twitches were observed. This indicated inadequate paralysis. Conclusions: This case report highlights the importance of monitoring neuromuscular function with ulnar nerve testing in patients with a history of cosmetic Botox procedures.

Assessment of an in vitro model of rotator cuff degeneration using quantitative magnetic resonance and ultrasound imaging with biochemical and histological correlation.

PURPOSE: Quantitative imaging methods could improve diagnosis of rotator cuff degeneration, but the capability of quantitative MR and US imaging parameters to detect alterations in collagen is unknown. The goal of this study was to assess quantitative MR and US imaging measures for detecting abnormalities in collagen using an in vitro model of tendinosis with biochemical and histological correlation. METHOD: 36 pieces of supraspinatus tendons from 6 cadaveric donors were equally distributed into 3 groups (2 subjected to different concentrations of collagenase and a control group). Ultrashort echo time MR and US imaging measures were performed to assess changes at baseline and after 24 h of enzymatic digestion. Biochemical and histological measures, including brightfield, fluorescence, and polarized microscopy, were used to verify the validity of the model and were compared with quantitative imaging parameters. Correlations between the imaging parameters and biochemically measured digestion were analyzed. RESULTS: Among the imaging parameters, macromolecular fraction (MMF), adiabatic T1ρ, T2*, and backscatter coefficient (BSC) were useful in differentiating between the extent of degeneration among the 3 groups. MMF strongly correlated with collagen loss (r=-0.81; 95% confidence interval [CI]: -0.90,-0.66), while the adiabatic T1ρ (r = 0.66; CI: 0.42,0.81), T2* (r = 0.58; CI: 0.31,0.76), and BSC (r = 0.51; CI: 0.22,0.72) moderately correlated with collagen loss. CONCLUSIONS: MMF, adiabatic T1ρ, and T2* measured and US BSC can detect alterations in collagen. Of the quantitative MR and US imaging measures evaluated, MMF showed the highest correlation with collagen loss and can be used to assess rotator cuff degeneration.

Assessment of WHO criteria for identifying ART treatment failure in Vietnam from 2007 to 2011.

OBJECTIVE: We evaluated the sensitivity and specificity of the WHO immunological criteria for detecting antiretroviral therapy (ART) treatment failure in a cohort of Vietnamese patients. We conducted a stratified analysis to determine the effects of BMI, peer support, adherence to antiretroviral (ARV) drugs, age, and gender on the sensitivity and specificity of the WHO criteria. METHODS: We conducted a retrospective cohort study of 605 HIV-infected patients using data previously collected from a cluster randomized control trial study. We compared the sensitivity and specificity of CD4+ counts to the gold standard of virologic testing as a diagnostic test for ART failure at different time points of 12, 18, and 24 months. RESULTS: The sensitivity [95% confidence interval (CI)] of the WHO immunological criteria based on a viral load ≥ 1000 copies/mL was 12% (5%-23%), 14% (2%-43%), and 12.5% (2%-38%) at 12, 18, and 24 months, respectively. In the same order, the specificity was 93% (90%-96%), 98% (96%-99%), and 98% (96%-100%). The positive predictive values (PPV) at 12, 18, and 24 months were 22% (9%-40%), 20% (3%-56%), and 29% (4%-71%); the negative predictive values (NPV) at the same time points were 87% (84%-90%), 97% (95%-98%), and 96% (93%-98%). The stratified analysis revealed similar sensitivities and specificities. CONCLUSION: The sensitivity of the WHO immunological criteria is poor, but the specificity is high. Although testing costs may increase, we recommend that Vietnam and other similar settings adopt viral load testing as the principal method for determining ART failure.