Given a passage, 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.

[EX Q]: Diastolic runoff in the abdominal aorta, with subsequent circulatory mesenteric insufficiency, has been postulated as a cause of necrotizing enterocolitis in term infants with congenital heart disease. With this study we sought to determine whether Doppler-flow characteristics in the abdominal aorta can predict which infants are at specific risk, independent of gestational age and type of congenital heart disease.', 'We conducted a case-control study of term infants with congenital heart disease and proven necrotizing enterocolitis (n = 18) compared with gestational age-matched and diagnosis-matched control subjects (n = 20). Abdominal aortic Doppler velocities, time intervals, and reversals were analyzed. Groups were compared, and independent risk factors for necrotizing enterocolitis were determined.', 'The groups were similar with regard to weight, pulse pressure, use of prostaglandins or inotropes, presence of a patent ductus arteriosus, and systolic function. However, 47% of the case subjects with necrotizing enterocolitis had persistent retrograde diastolic flow in the abdominal aorta compared with 15% of the control subjects. When adjusting for multiple risk factors, persistent diastolic flow reversal remained the only factor significantly associated with necrotizing enterocolitis.
[EX A]: Is persistent diastolic flow reversal in abdominal aortic Doppler-flow profiles associated with an increased risk of necrotizing enterocolitis in term infants with congenital heart disease?

[EX Q]: Freezing of gait (FOG) is a major concern for Parkinson's disease (PD) patients because it is a leading cause of falls and is associated with poor quality of life. The pathophysiology is unknown but it is hypothesized that it relates to cognitive abnormalities; particularly executive and visuospatial dysfunction. However, prior results have been discrepant. Pharmacologic subtypes of FOG include those that are responsive and unresponsive to levodopa.", 'To determine whether executive and visuospatial dysfunction are associated specifically with the levodopa unresponsive subtype of FOG.', '135 PD subjects completed a single assessment included FOG questionnaire, UPDRS motor scale, comprehensive cognitive battery and measure of hallucinations. Analyses compared unresponsive (n=16), responsive (n=20) and no FOG (n=99) subtypes.', 'The unresponsive subtype had a significantly older age of onset of PD than the responsive group (p=.03) and had worse motor scores (p=.003) than the no FOG group. Longer disease duration was associated with the responsive group compared to the no FOG group (p=.002). The unresponsive FOG group had significantly poorer visuospatial ability (p=.001) and executive functioning (p=.02) than both the no and responsive FOG subgroups. These latter groups were not significantly different. The responsive FOG group was associated with the presence of hallucinations.
[EX A]: Do freezing of gait subtypes have different cognitive correlates in Parkinson 's disease?

[EX Q]: The critical issue related to breast-conserving therapy (BCT) is that cosmetic outcomes deteriorate with long-term follow-up. There is little research for breast density as a predictor of cosmetic outcomes at the late stage after BCT. To improve the long-term quality of life after BCT of breast cancer patients, the correlation of volumetric breast density (VBD) and cosmetic outcome at the late stage after BCT was evaluated.', 'Breast volume, fibroglandular tissue volume, adipose tissue volume, and VBD were calculated on mammography using image analysis software (Volpara(®️)) in 151 patients with BCT. Furthermore, the correlation of breast density and the change of breast volume over time was analyzed on mammography in 99 patients who were followed-up long-term after BCT.', 'On multivariate analysis, VBD was a predictor of cosmetic outcome after BCT with percent breast volume excised (PBVE). Decreased adipose tissue volume and increased fibrosis were more common in patients with VBD < 15%. Furthermore, remnant breast volume continued to decrease over time in low breast density patients during long-term follow-up. 93% of patients with VBD 15% and PBVE < 10% had a better cosmetic outcome, while 60% of patients with VBD < 15% and PBVE 10% had a worse cosmetic outcome after BCT.
[EX A]:
Is volumetric breast density essential for predicting cosmetic outcome at the late stage after breast-conserving surgery?