Brain perfusion measured by flow-sensitive alternating inversion recovery (FAIR) and dynamic susceptibility contrast-enhanced magnetic resonance imaging: comparison with nuclear medicine technique

The aim of this study was to compare cerebral perfusion images and regional cerebral blood flow (rCBF) of SPECT study with the images and regional intensity of relative cerebral blood flow (CBF) images acquired by contrast-enhanced perfusion MR imaging (pMRI) and flow-sensitive alternating inversion recovery (FAIR). Twelve patients with various cerebral diseases were underwent I-123-IMP SPECT, pMRI, and FAIR studies to measure rCBF. A total of 12 regions of interest (ROI) were created over cerebrum and cerebellum to acquire the corresponding rCBF from I-123-IMP study and regional average signal intensity from CBF images of pMRI and FAIR studies. Left-to-right (L/R) and cerebral-to-cerebellar (CCR) ratios were created from the rCBF of I-123-IMP and signal intensity of CBF images of pMRI and FAIR. Image quality of FAIR was the poorest among all; however, CBF images of pMRI and FAIR images show comparatively decreased intensity at the corresponding site of decreased perfusion on I-123-IMP images. Both FAIR and pMRI images showed high intensity along the sinuses, choroid plexus, and large vessels in sulci. No significant correlation was found among all imaging modalities. But L/R ratio of I-123-IMP showed significant correlation with those of pMRI and FAIR, but for CCR, significant correlation was observed only between I-123-IMP and FAIR. Perfusion images of both pMRI and FAIR may produce images comparable to SPECT study. But to calculate absolute CBF more easy-to-apply and accurate algorithms are needed to overcome the artifacts from large vessels. Received: 25 January 2000 Revised: 7 June 2000 Accepted: 8 June 2000     

Quantitative measurement of regional cerebral blood flow with flow-sensitive alternating inversion recovery imaging: comparison with [iodine 123]-iodoamphetamin single photon emission CT

BACKGROUND AND PURPOSE: Flow-sensitive alternating inversion recovery (FAIR) MR imaging is a technique for depicting cerebral perfusion without contrast enhancement. Our purpose was to determine whether quantification at FAIR imaging can be used to assess regional cerebral blood flow (rCBF) in a manner similar to [iodine 123]-iodoamphetamin ((123)I-IMP) single photon emission CT (SPECT). METHODS: Nine patients with internal carotid or major cerebral arterial stenosis underwent (123)I-IMP SPECT and FAIR imaging (single section, different TIs, 1.5 T) at rest and after acetazolamide (Diamox) stress. FAIR and (123)I-IMP rCBF values were compared and correlated. Receiver operating characteristic analysis was conducted to detect hypoperfused segments on FAIR images. RESULTS: rCBF values of normally perfused segments were 41.53 and 51.91 mL/100 g/min for pre- and post-acetazolamide (123)I-IMP studies, respectively. Corresponding values for pre- and post-acetazolamide FAIR images, respectively, were 46.64 and 59.60 mL/100 g/min with a TI of 1200 milliseconds and 53.23 and 68.17 mL/100 g/min with a TI of 1400 milliseconds. (123)I-IMP and FAIR results were significantly correlated, with both pre- and post-acetazolamide images. Sensitivity (86%) in detecting hypoperfused segments was significantly higher with post-acetazolamide images (TI, 1400 milliseconds), and specificity (82-85%) and accuracy (80-82%) were higher with all pre- and post-acetazolamide images (all TIs). CONCLUSIONS: The significant correlation, high specificity and accuracy in detecting hypoperfused segments, similar increases in flow on both post-acetazolamide images, and absence of the need for contrast enhancement suggest that FAIR imaging, like nuclear medicine study, is complementary to routine MR imaging in the assessment of cerebral perfusion.     

Functional assessment of pancreatic parenchyma after secretin administration using serial T2-weighted echo-planar magnetic resonance imaging

Signal intensity (SI) changes of pancreatic parenchyma were evaluated after intravenous administration of secretin using T2-weighted single-shot spin-echo echo-planar imaging (EPI) to assess this method as a magnetic resonance (MR) test of pancreatic exocrine function. Nine volunteers were studied with serial single-shot EPI of the pancreas for 15 minutes after the injection of secretin or saline. The normal pattern of pancreatic SI change was demonstrated after intravenous injection of secretin, a single peak at 3-4 minutes in the head, body, and tail, followed by a gradual decrease in SI. Saline injection did not induce a significant SI change. There was no statistical difference in the peak contrast ratios (first mean, 1.21-1.25, vs. second mean, 1.18-1.22) and peak times (first mean, 3.2-3.7 minutes, vs. second mean, 3.1-3.6) in a repeat study. By evaluating the pattern of time-response curves obtained from serial T2-weighted EPI after secretin injection, pancreatic exocrine function may be directly assessed at the level of the head, body, and tail.     

Association of HER-2 overexpression with prognosis in nonsmall cell lung carcinoma: a metaanalysis

BACKGROUND: Prognostic implications of overexpression of the HER-2 gene in nonsmall cell lung carcinoma (NSCLC) are a matter of controversy. Many conflicting results have been reported from different laboratories. METHODS: A metaanalysis of published studies was performed for this quantitative review of the effects of HER-2 overexpression on survival among patients with NSCLC. Of 44 articles initially selected, 20 articles fulfilled eligibility criteria. DerSimonian-Laird random effects analysis was used to estimate the effects of HER-2 overexpression on survival differences (the survival rate among patients without HER-2 overexpression minus the survival rate among patients with HER-2 overexpression) at endpoints of 1 years, 3 years, and 5 years after resection of NSCLC. RESULTS: In total, 2579 patients were included in the final analysis. Overall, HER-2 positivity differed according to histologic type and included 38% of patients with adenocarcinoma, 16% of patients with squamous cell carcinoma, and 18% of patients with large cell carcinoma (P < 0.0001). The combined survival differences in patients with NSCLC at 1 year, 3 years, and 5 years, respectively, were 2.7% (95% confidence interval [95% CI], 1.3-6.7%; P = 0.1787), 15.2% (95% CI, 5.8-24.5%; P = 0.0015), and 16.4% (95% CI, 7.9-14.8%; P = 0.0001), suggesting significant poorer survival at 3 years and 5 years among patients with HER-2 overexpression. In patients with adenocarcinoma, the combined survival difference at 5 years was 26.0% (95% CI, 16.0-36.1%; P < 0.0001), suggesting a particularly strong survival impact for HER-2 overexpression. CONCLUSIONS: A significant, unfavorable prognostic effect of HER-2 overexpression in NSCLC was evident from the metaanalysis. However, because several studies that found no significant difference were excluded by the current eligibility criteria, caution is needed in interpreting the results.     

Zinc intake from daily meals in preschool children and its influence on their physical growth

OBJECTIVE: The aims of this study were to investigate the influence of dietary zinc intake on physical growth and to clarify effects of dietary factors in preschool children. METHODS: Food consumption of 30 children aged 5-6 years (15 boys and 15 girls) was surveyed using a weighing dietary method for three consecutive days each in spring and autumn. Daily nutrient intakes were calculated using the Standard Tables of Food Composition in Japan Fifth Revised Edition, 2000. The heights and weights were also measured in each season. They were classified into low, middle and high zinc intake groups, and their physical growth and dietary factors were compared. RESULTS: The average zinc intake was 6.4 +/- 1.1 mg/day in all children, which met the demands of the Japanese RDA (6.0 mg/day). Classification was a low zinc intake group (5.4 +/- 0.5 mg/day), a middle group (6.2 +/- 0.3 mg/day), and a high group (7.7 +/- 0.6 mg/day). The lower zinc intake group showed lower heights and weights, but all children who participated demonstrated increase during the 5 months from spring to autumn. In particular, increase in height in the low zinc intake group was the highest among the three groups. Regarding each food item contribution for the zinc intake, rice (20.53%), meat (16.28%), milk (15.57%), eggs (7.45%), and soybeans (6.87%) were the highest 5 of 19 items, accounting for 66.7% of the total. Zinc intake from vegetable foods (55%) was more than that from animal foods (45%). Intake of total energy, nutrients, and some food groups positively associated with average zinc intake. However, energy intake from confectionery in the lowest zinc intake group was highest among the three groups. CONCLUSION: Estimation of zinc intake of Japanese children using a weighing dietary method has suggested that even a relatively low dietary value might not significantly affect the physical growth of children. Rice is the main source and reduction of zinc intake from regular meals might be related to high consumption of confectionery.     

Diffusion tensor imaging in patients with major cerebral artery occlusive disease

Diffusion tensor (DT) imaging provides quantitative information about the magnitude and the directionality (anisotropy) of water diffusion in vivo and can detect pathologic changes in brain ischemia. This study tried to detect ischemic brain damage using DT imaging in patients with symptomatic chronic major cerebral artery occlusive disease. DT imaging was performed using a 3.0 Tesla magnetic resonance (MR) scanner in 50 patients with unilateral internal carotid artery or middle cerebral artery stenosis or occlusion, who had no obvious infarct lesions on conventional MR imaging. Thirty-three patients underwent DT imaging before and after vascular reconstruction surgery. Fractional anisotropy (FA) was calculated in the middle cerebral artery territory. Preoperative FA values in the ipsilateral side were significantly lower than those in the contralateral side. After surgery, the FA value was significantly increased. DT imaging may indicate ischemic brain damage, not visualized by conventional MR imaging, in patients with major cerebral artery occlusive disease.