Biomedical subjects

Elias R Melhem

Publications and source records attributed to Elias R Melhem.

At least 19 recordsLinked to original sources

PubMed2006

Amyotrophic lateral sclerosis: diffusion-tensor and chemical shift MR imaging at 3.0 T.

PURPOSE: To prospectively determine whether diffusion-tensor magnetic resonance (MR) imaging in conjunction with two-dimensional chemical shift imaging can assist in identifying upper motor neuron involvement and whether disease severity and duration can be predicted based on imaging parameters in patients with amyotrophic lateral sclerosis (ALS). MATERIALS AND METHODS: Institutional review board approval and informed consent were obtained for this HIPAA-compliant study. Fifteen patients with ALS (12 men, three women; mean age, 57.3 years) with clinical evidence of upper motor neuron involvement and 10 healthy control subjects (five men and five women; mean age, 49.4 years) were studied. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) were measured from the corticospinal tracts at the level of the internal capsule. Average N-acetylaspartate (NAA)/creatine-phosphocreatine (Cr) and NAA/choline-containing compounds (Cho) ratios were calculated from the precentral gyrus. Student t test, multiple linear regression analysis, and Spearman correlation coefficients were employed to quantify relationships between imaging and clinical parameters. RESULTS: Patients with ALS exhibited significantly reduced FA values and NAA/Cr and NAA/Cho ratios compared with values in control subjects (P<.05) for both affected and nonaffected sides of the brain. ADC was elevated significantly in the affected side (P<.05) and was an independent predictor of disease duration after adjusting for age; however, FA values and NAA/Cr ratios for the affected side were even stronger predictors of disease duration. Moderate but statistically significant correlation was found between the FA values for the affected side and the ALS Functional Rating Scale Revised (ALSFRS-R) score (r=0.51, P<.05). The NAA/Cr ratio also correlated with both the ALSFRS-R and upper motor neuron scores (r=0.50 and 0.54, respectively; P<.05). CONCLUSION: Diffusion-tensor and two-dimensional chemical shift MR imaging spectroscopy can be used to identify upper motor neuron involvement and predict disease duration in patients with ALS.

Adult↗

PubMed2006

Actinomycotic brain infection: registered diffusion, perfusion MR imaging and MR spectroscopy.

INTRODUCTION: Actinomycotic brain infection is caused by an organism of the Actinomyces genus. We report here one such case. METHODS: The methods used included coregistered diffusion, perfusion and spectroscopic magnetic resonance (MR) imaging. RESULTS: Decreased apparent diffusion coefficient, markedly elevated fractional anisotropy (FA) and reduced cerebral blood flow were observed. MR spectroscopy demonstrated elevated amino acids, acetate and succinate. CONCLUSION: Elevated FA values may be due to the microstructure of this special brain infection.

Actinomycosis↗

PubMed2006

Inverse correlation between cerebral blood flow measured by continuous arterial spin-labeling (CASL) MRI and neurocognitive function in children with sickle cell anemia (SCA).

Overt stroke, clinically "silent" cerebral infarct, and neurocognitive impairment are frequent complications of sickle cell anemia (SCA). Current imaging techniques have limited sensitivity and specificity to identify children at risk for neurocognitive impairment. We prospectively evaluated 24 children with SCA with a neurologic exam, complete blood count, transcranial Doppler ultrasound (TCD), measurement of intelligence quotient (IQ), and magnetic resonance imaging (MRI) with measurement of cerebral blood flow (CBF) using continuous arterial spin-labeling (CASL) MRI. Average CBF to gray matter was 112 +/- 36 mL/100 g/min. We identified a strong inverse relationship between performance IQ and CBF (-1.5 points per 10 mL/100 g/min increase in CBF, P = .013). Elevated steady-state white blood cell count (> or = 14 x 10(9)/L [14,000/microL]) was associated with lower full scale IQ (86 +/- 9 vs 99 +/- 10, P = .005). CASL MRI may identify children with neurocognitive impairment, before damage is evident by structural MRI or TCD.

Anemia, Sickle Cell↗

PubMed2006

Artificial multiple sclerosis lesions on simulated FLAIR brain MR images: echo time and observer performance in detection.

The institutional review board approved the described HIPAA-compliant study, which was performed to prospectively evaluate observer performance in the detection of artificial multiple sclerosis (MS) lesions that were randomly distributed supra- and infratentorially on simulated fluid-attenuated inversion-recovery (FLAIR) magnetic resonance (MR) images obtained at different echo times (TEs). MR parametric maps were derived from mixed multi-echo inversion-recovery images obtained in a 40-year-old healthy male volunteer and in a patient with MS, both of whom gave informed consent. Pseudo-randomly distributed artificial MS lesions of varying size, number, and location were equally represented on the FLAIR images (11 000/100-200/2600 [repetition time msec/TE msec/inversion time msec]). Twelve images obtained in both regions at each of 11 TEs spaced 10 msec apart were rated by seven neuroradiologists by using a four-point scale. Observer performance in the detection of MS lesions on the FLAIR images, as estimated by using areas under the alternative free-response receiver operating characteristic curve, was highest and most consistent at the 100-msec TE, both supratentorially (93.0% +/- 8.6 [standard error of the mean]) and infratentorially (87.4% +/- 10.0).

Adult↗

PubMed2006

Clinically silent cerebral ischemic events after cardiac surgery: their incidence, regional vascular occurrence, and procedural dependence.

BACKGROUND: The reported frequency of stroke after coronary artery bypass grafting varies between 1.5% and 6%, approaches 10% after aortic valve replacement, and may occur in between 40 to 70% in high-risk groups. Clinically silent infarction may be far more frequent and could contribute to long-term cognitive dysfunction in patients after cardiac procedures. Using diffusion-weighted magnetic resonance imaging we document the occurrence, vascular distribution, and procedural dependence of silent infarction after cardiac surgery with cardiopulmonary bypass. We also document the association of preexisting white matter lesions with new postoperative ischemic lesions. METHODS: Thirty-four patients underwent T2-weighted fluid attenuated inversion recovery and diffusion-weighted magnetic resonance imaging before and after cardiac surgery with cardiopulmonary bypass for coronary artery bypass grafting, aortic valve replacement, and mitral valve repair or replacement surgery. Images were evaluated by experienced neuroradiologists for number, size, and vascular distribution of lesions. RESULTS: Mean age of participants was 67 +/- 15 years. Imaging occurred before and 6 +/- 2 days after surgery. New cerebral infarctions were evident in 6 of 34 patients (18%), were often multiple, and in 67% of patients were clinically silent. The occurrence of new infarctions by surgical procedure was as follows: aortic valve replacement (2 of 6), coronary artery bypass grafting and aortic valve replacement (3 of 8), aortic valve replacement with root replacement (1 of 1), coronary artery bypass grafting and mitral valve repair or replacement (0 of 4), mitral valve repair or replacement (0 of 2), and isolated coronary artery bypass grafting (0 of 13). New infarction occurred in 6 of 15 (40%) of all procedures involving aortic valve replacement. The severity of preexisting white matter lesions trended toward predicting the occurrence of new lesions (p = 0.055). CONCLUSIONS: Diffusion-weighted imaging reveals new cerebral infarctions in nearly 40% of patients after aortic valve replacement.

Aged↗

PubMed2006

Detection of simulated multiple sclerosis lesions on T2-weighted and FLAIR images of the brain: observer performance.

PURPOSE: To determine observer performance in the detection of multiple sclerosis (MS) lesions on magnetic resonance (MR) images of the brain and to assess the dependence of observer performance on lesion size, parenchymal location, pulse sequence, and supratentorial versus infratentorial level. MATERIALS AND METHODS: This HIPAA-compliant protocol was approved by the institutional review board, and previously acquired MR data from a healthy volunteer and a patient with MS were used to derive parameter maps, with waiver of informed consent. Parameter maps and image simulator software were used to generate 320 phantom brain images with simulated supratentorial and infratentorial MS lesions. Images were displayed with T2-weighting or fluid-attenuated inversion recovery (FLAIR) contrast. Four readers independently evaluated the images, rating lesions on a five-point certainty scale. Observer performance was measured by using the area under the alternative free-response receiver operating characteristic curve (A(1)), and significance was determined with the z test. RESULTS: Pooled A(1) scores were significantly better for FLAIR imaging (0.96 +/- 0.01 [standard error]) than for T2-weighted MR imaging (0.89 +/- 0.04) supratentorially (P = .05) but were similar for FLAIR imaging (0.90 +/- 0.06) and T2-weighted MR imaging (0.88 +/- 0.05) infratentorially. A(1) scores for cortical, deep white matter, and periventricular lesions were 0.93 +/- 0.05, 0.97 +/- 0.02, and 0.89 +/- 0.04, respectively, for FLAIR imaging and 0.77 +/- 0.06, 0.99 +/- 0.01, and 0.89 +/- 0.05, respectively, for T2-weighted MR imaging. FLAIR scores were significantly higher than T2-weighted scores for cortical lesions. Linear correlation was found between A(1) and lesion size (r = 0.5). CONCLUSION: Supratentorially, performance was better with FLAIR imaging than with T2-weighted MR imaging. Infratentorially, performance was moderate with both modalities. Observers did better with FLAIR imaging in the detection of cortical lesions, and performance improved with increasing lesion size.

Adult↗

PubMed2006

Advanced MR imaging techniques in the diagnosis of intraaxial brain tumors in adults.

Intraaxial brain masses are a significant health problem and present several imaging challenges. The role of imaging is no longer limited to merely providing anatomic details. Sophisticated magnetic resonance (MR) imaging techniques allow insight into such processes as the freedom of water molecule movement, the microvascular integrity and hemodynamic characteristics, and the chemical makeup of certain compounds of masses. The role of the most commonly used advanced MR imaging techniques-perfusion imaging, diffusion-weighted imaging, and MR spectroscopy-in the diagnosis and classification of the most common intraaxial brain tumors in adults is explored. These lesions include primary neoplasms (high- and low-grade), secondary (meta-static) neoplasms, lymphoma, tumefactive demyelinating lesions, abscesses, and encephalitis. Application of a diagnostic algorithm that integrates advanced MR imaging features with conventional MR imaging findings may help the practicing radiologist make a more specific diagnosis for an intraaxial tumor.

Algorithms↗

PubMed2006

Demonstration of an anterior diffusional pathway for solutes in the normal human eye with high spatial resolution contrast-enhanced dynamic MR imaging.

PURPOSE: The present studies were conducted to determine whether a diffusional pathway for solutes exists from the ciliary body stroma to the anterior chamber of the human eye. The existence of such a pathway has been demonstrated in rabbits and monkeys, but such a pathway in humans would necessitate a shift in the physiological paradigm of the blood-aqueous barrier. METHODS: Seven normal human volunteers (five men, two women; age range, 27 to 59 years) underwent nine dynamic T1-weighted, spin-echo MR imaging studies, using intravenous, gadolinium-based contrast agents. RESULTS: In all cases, signal intensity rose rapidly in the ciliary body. In all subjects, there was a measurable latent rise in signal strength (enhancement) in the anterior chamber. Signal enhancement typically occurred in the angle of the anterior chamber earlier, and to a greater degree, than within the center of the chamber. Increased signal within the posterior chamber was significantly less than in the anterior chamber, with measured increases probably attributable to volume averaging. CONCLUSIONS: These findings are consistent with the existence of an anterior diffusional pathway in the human eye. The model warrants further testing.

Adult↗

PubMed2005

Leftward asymmetry in relative fiber density of the arcuate fasciculus.

Left hemispheric language dominance is well established, but the structural substrate for this functional asymmetry is uncertain. We report a strong asymmetry in the relative fiber density of the arcuate fasciculus, a white matter pathway associated with language that connects the frontal, temporal, and parietal lobes. Measured with diffusion tensor tractography, nearly all study participants demonstrated greater relative fiber density in the left arcuate fasciculus than in the right arcuate fasciculus. In comparison, we found no asymmetry in the corticospinal tract, an important white matter pathway with no known role in language. Combined with data on volumetric and activation asymmetry, greater connectivity may provide the elements of a neural system model for language lateralization.

Adult↗

PubMed2005

Follow-up of 89 asymptomatic patients with adrenoleukodystrophy treated with Lorenzo's oil.

OBJECTIVES: To identify asymptomatic boys with X-linked adrenoleukodystrophy who have a normal magnetic resonance image (MRI), and to assess the effect of 4:1 glyceryl trioleate-glyceryl trierucate (Lorenzo's oil) on disease progression. METHOD: Eighty-nine boys (mean +/- SD baseline age, 4.7 +/- 4.1 years; range, 0.2-15 years) were identified by a plasma very long-chain fatty acids assay used to screen at-risk boys. All were treated with Lorenzo's oil and moderate fat restriction. Plasma fatty acids and clinical status were followed for 6.9 +/- 2.7 years. Changes in plasma hexacosanoic acid levels were assessed by measuring the length-adjusted area under the curve, and a proportional hazards model was used to evaluate association with the development of abnormal MRI results and neurological abnormalities. RESULTS: Of the 89 boys, 24% developed MRI abnormalities and 11% developed both neurological and MRI abnormalities. Abnormalities occurred only in the 64 patients who were aged 7 years or younger at the time therapy was started. There was significant association between the development of MRI abnormalities and a plasma hexacosanoic acid increase. (For a 0.1-microg/mL increase in the length-adjusted area under the curve for the hexacosanoic acid level, the hazard ratio for incident MRI abnormalities in the whole group was 1.36; P = .01; 95% confidence interval, 1.07-1.72.) Results for patients aged 7 years or younger were similar (P = .04). CONCLUSIONS: In this single-arm study, hexacosanoic acid reduction by Lorenzo's oil was associated with reduced risk of developing MRI abnormalities. We recommend Lorenzo's oil therapy in asymptomatic boys with X-linked adrenoleukodystophy who have normal brain MRI results.

Adrenoleukodystrophy↗

PubMed2005

Grading of CNS neoplasms using continuous arterial spin labeled perfusion MR imaging at 3 Tesla.

PURPOSE: To differentiate glioma grade based on blood flow measured using continuous arterial spin labeled (CASL) perfusion MRI, implemented at 3 Tesla for improved signal-to-noise ratio (SNR) and spin labeling effect. MATERIALS AND METHODS: CASL perfusion images were obtained preoperatively in 26 patients with brain neoplasms (19 high-grade gliomas (HGGs; WHO grades 3 and 4) and seven low-grade gliomas (LGGs; WHO grades 1 and 2)). The mean and maximum tumor blood flow (TBF and TBFmax) were calculated in the neoplasm, including surrounding infiltrating tumor vs. edema. Measures normalized to global CBF (nTBF and nTBFmax) were also obtained. RESULTS: Normalized measures of TBFmax provided the best distinction between HGG and LGG groups (Wilcoxon rank sum test, P = 0.01). Seventeen of 19 HGGs showed nTBFmax > 1.0, and 15 of 19 showed nTBFmax > 1.3. Four of seven LGGs showed nTBFmax < 1.0, and six of seven showed nTBFmax < 1.3. Absolute TBFmax also differed significantly between the HGG and LGG groups (P = 0.04). TBFmax in 11 of 17 HGGs was >50 mL/100 g/min (mean +/- SD = 94.9 +/- 71.7 mL/100 g/min). All but one LGGs showed TBFmax < or = 50 mL/100 g/min (mean +/- SD = 42.8 +/- 22.0 mL/100 g/min). CONCLUSION: CASL perfusion MRI provides a quantitative, noninvasive alternative to dynamic susceptibility contrast perfusion MR methods for evaluating gliomas.

Adult↗

PubMed2005

Middle cerebral artery spasm after subarachnoid hemorrhage: detection with transcranial color-coded duplex US.

PURPOSE: To prospectively determine the accuracy of transcranial color-coded duplex ultrasonography (US) used alone and in conjunction with carotid artery US for diagnosis of middle cerebral artery (MCA) spasm, with intraarterial digital subtraction angiography (DSA) used as the reference standard. MATERIALS AND METHODS: The institutional ethics committee approved the study. Each patient, or members of the patient's family, gave informed consent. One hundred twenty consecutive patients (64 women, 56 men; mean age, 45.5 years +/- 13.6 [standard deviation]) were routinely referred for DSA after subarachnoid hemorrhage. Vasospasm was graded as mild (< or =25% reduction in vessel diameter), moderate (>25% to 50% reduction), or severe (>50% reduction). US was performed 2 hours or less before angiography. The ratio of flow velocity in the middle cerebral artery (V(MCA)) to flow velocity in the ipsilateral extracranial internal carotid artery (V(ICA)) was calculated. Diagnostic accuracy was evaluated by calculating the area under the receiver operating characteristic curve (Az). The significance of the difference between the two Az values (for US vs DSA) was determined by using the z test with correction for correlated data. RESULTS: Nine of 120 patients were excluded because of inadequacy of acoustic windows in the squama of temporal bones. Spasm was mild in 17, moderate in 16, and severe in only nine of 222 arteries studied. Arteries with moderate or severe vasospasm were combined in one group. The best-performing parameters were peak systolic velocity and V(MCA)/V(ICA) ratio. Az values for these two parameters in diagnosis of moderate-to-severe vasospasm were 0.93 and 0.95, and in diagnosis of mild vasospasm, 0.90 and 0.91. Accuracy of the V(MCA)/V(ICA) ratio calculated on the basis of end-diastolic velocity for diagnosis of mild MCA narrowing was significantly better than that of end-diastolic MCA velocity alone (Az = 0.88 vs 0.84, P < .05). The stepwise approach with use of the V(MCA)/V(ICA) ratio after flow velocity measurements in the MCA resulted in a decreased number of false-negative findings in both vasospasm subgroups. The thresholds of highest efficiency were at a mean velocity of 94 and 108 cm/sec and a peak systolic V(MCA)/V(ICA) ratio of 3.6 and 3.9 for diagnosis of mild and moderate-to-severe vasospasm, respectively. CONCLUSION: Transcranial color-coded duplex US alone or in conjunction with carotid artery US has excellent accuracy for angiographic detection of vasospasm. Use of MCA velocity measurements and V(MCA)/V(ICA) ratio can increase the accuracy of Doppler US.

Adolescent↗

PubMed2005

Amyotrophic lateral sclerosis and primary lateral sclerosis: The role of diffusion tensor imaging and other advanced MR-based techniques as objective upper motor neuron markers.

Amyotrophic lateral sclerosis (ALS), also called Lou Gehrig's disease, is a motor neuron disease characterized by progressive degeneration of upper motor neuron (UMN) and lower motor neuron (LMN), while primary lateral sclerosis (PLS) is defined by pure UMN involvement. A reliable objective marker of UMN involvement is critical for the early diagnosis and monitoring of disease progression in patients with ALS and PLS. Diffusion tensor imaging (DTI), magnetization transfer imaging (MTI), and magnetic resonance spectroscopy (MRS), which provide insight into the pathophysiological process of ALS and PLS, show great promise in this regard. Further investigation is needed to determine and to compare the utility of various neuroimaging markers.

Amyotrophic Lateral Sclerosis↗

PubMed2005

Age and sex variability and normal reference values for the V(MCA)/V(ICA) index.

BACKGROUND AND PURPOSE: The index of mean blood flow velocity (V) in the middle cerebral artery (MCA) divided by respective velocity in the ipsilateral internal carotid artery (ICA), or V(MCA)/V(ICA) index, is commonly used as a marker of vasospasm, although reference values are not established. We sought to provide reference data for these velocities and index. METHODS: Transcranial color-coded duplex and carotid duplex sonography was performed in 335 healthy volunteers (211 women, 124 men; mean age +/- SD, 42 +/- 18 years; range, 18-86 years). Age analyses were based on three groups: I, <40; II, 40-60; and III, >60 years. The V(MCA)/V(ICA) index was calculated based on angle-corrected blood flow velocities determined in the MCA and extracranial ICA. RESULTS: Mean flow velocities in the MCA and ICA diminished with increasing age, most pronounced in those subjects >40 years. The V(MCA)/V(ICA) index increased significantly (1.67 + 0.005 [age]; P < .05) with age in women, but not in men. In women, reference values and ranges for the V(MCA)/V(ICA) index were as follows, by group: I, 1.82 (range, 0.88-2.68); II, 1.91 (range, 0.94-2.88); and III, 2.06 (range, 0.59-3.53). Respective values for men were as follows, by group: I, 2.10 (range, 0.96-3.24); II, 2.04 (range, 0.71-3.37); and III, 1.78 (range, 0.81-2.75). In subjects <40 years, the V(MCA)/V(ICA) index was significantly higher in men than in women. CONCLUSION: The V(MCA)/V(ICA) index significantly varies with age and sex. Sonographic diagnosis of cerebral vasospasm should be based on age- and sex-adjusted reference values of the V(MCA)/V(ICA) index.

Adolescent↗

PubMed2004

Influence of 17-beta-estradiol on cerebrovascular impedance during menstrual cycle in women.

Numerous experimental studies showed that estrogen alters diameters of cerebral arteries by modifying production of vasoactive substances. In this study, we address a question whether increased concentration of 17-beta-estradiol (E2) during a typical menstrual cycle of young, healthy women influences cerebrovascular impedance, as measured with Doppler pulsatility index (PI) in the common (CCA), internal (ICA), and external (ECA) carotid arteries using duplex Doppler sonography. PI was determined and correlated with plasma E2 concentration in 14 women (ages 23-25) throughout their menstrual cycle. The concentration of E2 increased in the follicular phase of the cycle and reached a peak of 140-300 pg/ml on days 13 and 14, whereas concentration of progesterone remained low (<1 ng/ml). Along with an increase in E2 concentration, the ICA PI decreased from its initial level on average by 11% on day 13 and by 7% on day 14 (r=-0.41, P<0.05). In contrast, the value of the ECA PI showed an increasing trend during the peak of E2 concentration. There were no significant changes in the CCA PI as well as in the systolic blood pressure, heart rate, hematocrit, and hemoglobin concentration during the menstrual cycle. Cerebral vascular impedance in young women is modulated by concentration of E2 throughout the menstrual cycle. The decrease in the ICA PI during the late follicular phase seems to be attributed to a decrease in cerebrovascular resistance.

Adult↗

PubMed2004

Diffusion-weighted MRI in Lhermitte-Duclos disease: report of two cases.

Lhermitte-Duclos disease is a rare benign lesion of uncertain pathogenesis characterized by distortion of the normal cerebellar laminar cytoarchitecture. There is a characteristic MR imaging appearance of a nonenhancing mass in the cerebellar hemisphere with a striated pattern. We report two cases of Lhermitte-Duclos disease and describe findings on diffusion-weighted MR imaging.

Cerebellar Neoplasms↗

PubMed2004

Intracranial dural arteriovenous fistulas: evaluation with combined 3D time-of-flight MR angiography and MR digital subtraction angiography.

OBJECTIVE: The purpose of this study was to compare the diagnostic utility of 3D time-of-flight (TOF) MR angiography and MR digital subtraction angiography in patients with angiographically proven moderate- to high-flow intracranial dural arteriovenous fistula. MATERIALS AND METHODS: Two neuroradiologists, unaware of patients' histories and angiographic findings, retrospectively reviewed 17 MR angiograms with 3D TOF MR angiography and MR digital subtraction angiography in 15 patients with dural arteriovenous fistula and also reviewed 35 MR angiograms in control patients without findings of dural arteriovenous fistula on angiography. Disagreements were resolved by consensus. RESULTS: In patients with dural arteriovenous fistula, source images of 3D TOF MR angiography showed two abnormal findings: multiple high-intensity curvilinear or nodular structures adjacent to the sinus wall and high-intensity areas in the venous sinus. Findings of multiple high-intensity structures adjacent to the sinus wall were observed in all cases of dural arteriovenous fistula. Findings of high-intensity areas in the venous sinus were observed in 13 of 17 cases of dural arteriovenous fistula. Findings of multiple high-intensity structures adjacent to the sinus wall were not observed in any control subjects. Findings of high-intensity areas within the venous sinus were observed in five of 35 control subjects. Findings of MR digital subtraction angiography showed early filling of the venous sinus, suggestive of dural arteriovenous fistula, in 13 of 15 patients with dural arteriovenous fistula. Sensitivity and specificity of multiple high-intensity structures adjacent to the sinus wall, high-intensity areas in the venous sinus, and early filling of the venous sinus were 100% and 100%, 76% and 86%, and 87% and 100%, respectively. Although 3D TOF MR angiography failed to show the findings of retrograde cortical venous drainage and venous sinus occlusion, MR digital subtraction angiography clearly showed both findings in all five subjects. CONCLUSION: A protocol including both 3D TOF MR angiography (source images) and MR digital subtraction angiography allowed the diagnosis of moderate- to high-flow dural arteriovenous fistula. In addition, cortical venous drainage was reliably noted in a small subset of patients.

Adult↗

PubMed2003

Sickle cell disease: continuous arterial spin-labeling perfusion MR imaging in children.

Cerebral blood flow (CBF) was measured with continuous arterial spin-labeling perfusion magnetic resonance (MR) imaging in 14 children with sickle cell disease and seven control subjects. Mean CBF values were higher in patients (P <.005) than in control subjects in all cerebral artery territories. Three patients had decreased CBF in right anterior and middle cerebral artery territories compared with CBF on the left, and one patient had a profound decrease in CBF in all three territories in the right hemisphere. Baseline CBF was significantly decreased in territories seen as unaffected on conventional MR images and MR angiograms in four children with sickle cell disease.

Anemia, Sickle Cell↗