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.

Ex Input:
Context: Blood oxygenation level-dependent (BOLD)-weighted and vessel-encoded arterial spin labeling (VE-ASL) MRI provide complementary information and can be used in sequence to gauge hemodynamic contributions to cerebrovascular reactivity. Here, cerebrovascular reactivity is assessed using dual echo VE-ASL MRI to understand how VE labeling preparations influence BOLD and ASL contrast in flow-limited and healthy perfusion territories.', 'Patients (n\u2009=\u200912; age\u2009=\u200955 +/- 14 years; 6F/6M) presenting with ischemic steno-occlusive cerebrovascular disease underwent 3.0T angiographic imaging, T1 -weighted structural, and planning-free dual echo hypercarbic hyperoxic (i.e., carbogen) VE-ASL MRI. Vasculopathy extent, timecourses, and cerebrovascular reactivity (signal change and Z-statistic) for different VE-ASL images were contrasted across flow territories and Bonferroni-corrected P-values reported.', 'BOLD cerebrovascular reactivity (i.e., long-TE VE-ASL) Z-statistics were similarly sensitive to asymmetric disease (P\u2009≤\u20090.002) regardless of labeling scenario. Cerebral blood flow reactivity correlated significantly with BOLD reactivity (Z-statistic). However, BOLD signal changes did not differ significantly between labeling scenarios (P\u2009>\u20090.003) or across territories (P\u2009>\u20090.002), indicating BOLD signal changes in response to carbogen offer low sensitivity to lateralizing disease.
Answer: Dual echo VE-ASL can provide simultaneous cerebral blood flow and qualitative BOLD contrast consistent with lateralizing disease severity in patients with asymmetric steno-occlusive disease. The methodological strengths and limitations of composite BOLD and VE-ASL measurements in the clinic are discussed.

Ex Output:
Do dual echo vessel-encoded ASL for simultaneous BOLD and CBF reactivity assessment in patients with ischemic cerebrovascular disease?


Ex Input:
Context: This study evaluated risk factors for acute wheeze in preschool children and investigated whether subnormal levels of vitamin D were associated with increased risk for acute wheeze, atopy or viral/bacterial respiratory infections.', 'We recruited 130 children with acute wheeze, aged 6\xa0months to 4\xa0years, from paediatric emergency departments in Stockholm, Sweden, and 101 age-matched controls with no history of wheeze or sensitisation to airborne allergens. Parents answered standardised questionnaires, and blood samples were analysed for specific IgE to airborne and food allergens and levels of 25 hydroxyvitamin D (25(OH)D). Nasopharyngeal virus samples were collected during the emergency department visit in the group of children with wheeze, and a subset were also tested for bacteria.', 'Vitamin D insufficiency (25(OH)D\xa0<\xa075\xa0nmol/L (30\xa0ng/mL)) was associated with an odds ratio of 2.7 (95% confidence interval 1.1-6.2) for acute wheeze. However, no association was found between vitamin D insufficiency and atopy, presence of virus or bacteria or recurrent infections. Children older than 24\xa0months were particularly at risk of subnormal vitamin D levels, irrespective of wheezing history.
Answer: Our findings support the hypothesis that subnormal levels of vitamin D are associated with acute wheeze in young children.

Ex Output:
Are subnormal levels of vitamin D associated with acute wheeze in young children?


Ex Input:
Context: To compare the efficacy of two surgical techniques for controllong nasal width after Le Fort I osteotomy.', "Fifty-five patients who received the Le Fort I osteotomy have been included in this study. They were randomly divided into 2 groups. The experimental group received extraoral ABS, and the control group received traditional intraoral ABS. 3D photos of the patient's face were taken before operation and at postoperative 3 months. Alar width was measured on the 3D photos. Data was reported as means and standard deviations, and statistic analysis was done by using student t test.", 'Compared with presurgical data, G. lat-G. lat increased by (2.66 +/- 1.47) mm, Al-Al increased by (2.20 +/- 1.22) mm and Sbal-Sbal increased by (1.30 +/- 1.33) mm in experimental group. G. lat-G. lat increased by (1.38 +/- 1.29) mm, Al-Al increased by (1.06 +/- 0.95) mm and Sbal-Sbal increased by (0.36 +/- 1.33) mm in the control group. There was significant difference between two groups.
Answer: The surgical technique of ABS is the most important factor for determining the postoperative alar width. Both techniques have better effect on the Sbal-Sbal width control than the G. lat-G. lat and Al-Al width control. Traditional intraoral ABS can more effectively control the alar width. Both techniques cannot completely control the alar base widening after Le Fort I osteotomy.

Ex Output:

Do [ Comparative analysis of two surgical techniques for controlling nasal width after Le Fort I osteotomy ]?