Given a passage with a context and an answer, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.

Context: Hypertrophic cardiomyopathy (HCM) is associated with myocardial scarring and ventricular tachycardia (VT). Contrast-enhanced cardiac magnetic resonance imaging (CE-CMR) can quantify myocardial scar, and scar imaging has been documented in patients with HCM. We investigated the assessment of myocardial scar in HCM patients using CE-CMR, and its correlation with proven VT.', 'Twenty-five patients (mean age 54 +/- 8) with HCM who underwent CE-CMR were identified, and clinical data obtained from chart review. Parameters of LV function were calculated from cine imaging, and myocardial scar was assessed using delayed enhancement imaging following gadolinium administration.', 'Myocardial scar was detected in 16 (64%) patients with a mean mass 9 +/- 15 g. Scar was patchy, mid-myocardial and located in the basal anteroseptum, and RV insertion sites. Scar was seen in septal, apical and concentric variants of HCM. Scar mass correlated with both LV Mass (r2 = 0.74) and maximal LV wall thickness (r2 = 0.42). VT occurred in 32% of patients, and was associated with both increased scar mass and wall thickness compared to non-VT patients (21 +/- 22 g vs. 4 +/- 6 g, and 2.4 +/- 0.5 cm vs. 1.8 +/- 0.5 cm, p < 0.05). LV size and function were similar in patients with and without VT. A scar mass of >7 g predicted the presence of VT with a sensitivity of 75% and specificity 82%.
Answer: Myocardial scar imaged by CE-CMR is common in patients with HCM, and is predictive of VT. Scar is seen in all HCM variants, and is associated with maximal wall thickness. There may be a role for CE-CMR in improved risk stratification for individual patients with HCM.
Is myocardial scar detected by contrast-enhanced cardiac magnetic resonance imaging associated with ventricular tachycardia in hypertrophic cardiomyopathy patients?

Context: Sit-to-stand tasks are commonly facilitated by modifying the initial position of the center of mass relative to the feet. It was hypothesized that modifications in the center of mass trajectory during sit-to-stand tasks altered the total body momentum at seat departure and redistributed the lower extremity net joint moments.', 'Between-task within-subject comparison was employed using a robust statistical method to accommodate for small sample size.', 'Six individuals performed four sit-to-stand tasks with systematic modifications in the initial center of mass position by varying the orientation of the lower extremity segments. The momentum of the center of mass and lower extremity net joint moments were quantified and compared.', 'Reducing the horizontal center of mass displacement significantly reduced horizontal total body momentum required at seat departure. Sit-to-stand tasks initiated with more horizontal shank and thigh positions required significantly greater knee and hip extensor net joint moments than those with more vertical shank and thigh positions. Sit-to-stand tasks initiated with vertical shank positions also required significantly greater hip extensor net joint moments as compared to those with more horizontal shank orientations.
Answer: When changes in initial center of mass position are made, alteration in center of mass horizontal momentum and the orientation of the lower extremity segments relative to the reaction force are observed. Consequently, mechanical demand imposed on the ankle, knee, and hip joint is redistributed. The magnitude of the net joint moments is dependent on the segment orientation, the reaction force, and the adjacent net joint moment.
Does modifying center of mass trajectory during sit-to-stand tasks redistribute the mechanical demand across the lower extremity joints?

Context: To identify subgroups of patients with renal stones ≥20 mm that are more suitable for extracorporeal shock wave lithotripsy (ESWL) monotherapy.', 'A total of 376 patients with renal stones ≥20 mm underwent monotherapy with ESWL. The treatment outcome was evaluated after 3 months of follow-up. A stone-free status or fragmentation of stones to 4 mm or smaller was considered efficacious.', 'At 3 months after treatment, the overall stone-free rate was 64.4%, and the efficacy rate was 70.7%. The efficacy rate was 89.4% for patients with a residual stone surface area ≤50% of baseline after the first ESWL, while the efficacy rate was 32.4% for other patients. The efficacy was 92.2% for stones ≤400 mm2 and those with lower radiodensity, as determined by a plain (KUB) film.
Answer: For renal stones with a surface area ≤400 mm2 and a radiodensity equal to or less than that of the 12th rib as determined by a KUB film, ESWL may be considered the first line of treatment, even for stones with a diameter ≥20 mm. For large stones requiring repeat treatments, the surface area of the residual stones after the first ESWL is a predictor of the final treatment result.

Do treatment of Renal Stones ≥20 mm with Extracorporeal Shock Wave Lithotripsy?