Prevalence Of MRI Abnormalities Research Articles

Magnetic Resonance Imaging Findings in Preterm Infants With Bilirubin Encephalopathy Beyond Three Years Corrected Age

BackgroundMagnetic resonance imaging (MRI) abnormalities in preterm infants with bilirubin encephalopathy (BE) become less clear as the infants age. We assessed MRI findings in children with preterm BE older than 36 months corrected age (CA). MethodsIn a previous questionnaire survey, hospitals were asked to provide head MRI data of patients older than 36 months CA. MRI findings were reviewed by three pediatric neurology specialists and classified as no abnormalities, partial globus pallidus (GP) lesions, or diffuse GP lesions. ResultsIn total, 33 MRI scans were available from 28 patients. The median gestational age and birth weight were 26 weeks and 824 g, respectively. The prevalence of MRI abnormalities was 100% in patients at 37 to 48 months CA, 71% in those at 49 to 60 months CA, 50% in those at 61 to 72 months CA, 67% in those at 73 to 84 months CA, and 38% in those at 85 months CA or older. Partial GP lesions were more common than diffuse GP lesions at all ages. No significant differences in sex, gestational age, birth weight, or gross motor function impairment were observed among lesion groups. ConclusionsGP lesions were detected on MRI in most children with preterm BE when studied after 36 months CA, although MRI abnormalities became less apparent along with age. Partial GP lesions may be a characteristic of older children with preterm BE.

Prevalence of MRI abnormalities in people with epilepsy in rural China.

To assess the prevalence of brain MRI abnormalities in people with epilepsy in rural China and to compare it with that of individuals in the United Kingdom. Brain MRI scans were obtained in people with epilepsy who participated in a rural community-based program in China between July 2010 and December 2012. Individual epileptogenic lesion types were reviewed and their associations with seizure control examined. The MRI findings were compared with 2 previous similar studies in the United Kingdom. Among the 597 individuals (58% male, median age 38 years) with MRI scans analyzed, 488 (82%) had active epilepsy. The MRI was abnormal in 389 individuals (65%), with potentially epileptogenic lesion in 224 (38%) and nonspecific abnormalities in 165 (28%), and 108 (18%) were potentially resectable. The potentially epileptogenic lesions were less frequently detected in children (<18 years old, 12 of 68, 18%) than in adults (212 of 529, 40%; p < 0.001). In people with potentially epileptogenic lesions, 67% (150 of 224) had failed ≥2 antiseizure medications. They had higher risk of uncontrolled epilepsy than those with normal MRI (risk ratio [RR] 1.25; p < 0.001) and those with nonspecific abnormality (RR 1.15; p = 0.002) after adjustment for age and sex. The diagnostic yield of MRI was similar to that reported in community- and hospital-based studies in the United Kingdom. More than one-third of people with chronic epilepsy in rural China have potentially epileptogenic lesions identifiable on brain MRI, with two-thirds fulfilling the definition of pharmacoresistance. These findings highlight the magnitude of the unmet needs for epilepsy surgery in China.

Spectrum of phenotype and genotype of congenital isolated hypogonadotropic hypogonadism in Asian Indians.

Congenital isolated hypogonadotropic hypogonadism (IHH) is caused due to defect in GnRH neuronal development, migration and action. Although genetic aetiology of IHH is increasingly being studied, Asian Indian data on phenotypic spectrum and genetic basis are scarce. To investigate the phenotypic and genotypic spectrum of IHH in Asian Indian subjects. A cohort of 135 IHH probands were characterized phenotypically for reproductive and nonreproductive features and screened for rare sequence variations (RSVs) in five genes KAL1, FGFR1, FGF8, GNRHR and KISS1R. Of 135 probands [56 normosmic IHH (nIHH) and 79 Kallmann syndrome (KS)], 20 were familial cases. KS group had more male dominance (M:F ratio of 8:1) as compared to nIHH group (M:F ratio of 1·5:1). Complete absence of puberty was more prevalent in KS probands (81% in KS vs 46% in nIHH). The prevalence of MRI abnormalities was more in anosmic group (92·8%) as compared to hyposmic (37·5%) and normosmic groups (15·4%). No particular nonreproductive phenotypic predominance was seen in any group. Genotyping revealed rare sequence variation (RSV) detection rate of 15·5% in five genes studied: (KAL1 - 4·4%, FGFR1 - 4·4%, GNRHR - 6·7%, oligogenicity - 1·5%). Prevalence of RSV was more common in familial cases (35%) as compared to sporadic (12·2%). GNRHR RSV p.C279Y (not reported in patients of ethnicities other than south Asians) was recurring in four unrelated patients. In our cohort, 60% were KS with majority of males and a severe reproductive phenotype as against nIHH. Contribution of the genetic burden for the five genes studied was 15·5%. RSV p.C279Y in GNRHR may have a founder effect originating from south Asia. This study provides a model for molecular and phenotypic representation of Asian Indian subjects with IHH.

Brain Magnetic Resonance Imaging Abnormalities in Adult Patients With Sickle Cell Disease

Brain imaging abnormalities were reported in up to 44% of children with sickle cell disease (SCD). The prevalence of neuroimaging abnormalities in adult patients with SCD and their relationship to transcranial Doppler is still unclear. Our objectives were to study the frequency of MRI and MR angiography abnormalities in adults with SCD and to define what transcranial Doppler velocities are associated with intracranial stenoses detected by MR angiography. We examined all adult patients (>16 years) with SCD followed in the hematology outpatient clinic at our university hospital with MRI, MR angiography, and transcranial Doppler. We evaluated 50 patients. The overall prevalence of MRI abnormalities was 60%. Abnormal MRI findings were more frequent when vessel tortuosity or stenoses were present on MR angiography (P<0.01). Patients with intracranial stenoses had significantly higher time-averaged maximum mean velocities (P=0.01). A time-averaged maximum mean velocity of 123.5 cm/s allowed the diagnosis of middle cerebral artery or internal carotid artery intracranial stenosis with sensitivity of 100% and specificity of 73% with an area under the receiver operator characteristic curve of 0.91 (CI, 0.79 to 1.00). The frequency of brain imaging abnormalities detected by MRI/MR angiography in adults with SCD was higher than that described for children. Transcranial Doppler velocities in adult patients with intracranial stenoses were lower than those described for the pediatric population with SCD.

Neuropsychological (NP) Dysfunction and Neuroimaging Abnormalities in Neurologically Intact Adult Patients with Sickle Cell Disease (SCD).

Background. Brain dysfunction may be the most important and least studied problem afflicting the aging SCD population. 25% of neurologically intact pediatric SCD patients have NP dysfunction and silent CNS infarction. In children, age is associated with progressive decline in NP scores suggesting adults are at risk for progressive brain injury and NP decline.Objective. To determine the extent of NP impairment, the prevalence of MRI abnormalities, and their relationship in neurologically asymptomatic adult SCD patients compared to national norms and matched controls.Methods. Patients (21–55 yrs) with HbSS, normal neurologic exams and no history of stroke or abnormal neuroimaging, were recruited from 11 centers and screened for mental status and depression. The patient to control ratio goal was 3:1. After consenting, participants completed NP tests that assessed verbal and nonverbal intelligence, academic achievement, executive functioning, processing speed (PS), attention, and memory. Tests included the Wechsler Adult Intelligence Scale (WAIS-III), the Wechsler Memory Scales (WMS-III), the Woodcock-Johnson Tests of Achievement (WJ III), the Test of Everyday Attention (TEA), and others. Participants underwent standardized brain MRI read for atrophy and lesions. Volumetric analysis (vMRI) quantitated white and grey matter.Results. This is a report of 138 of the 150 planned SCD subjects and 37 controls: 62% female, 21–29 yrs, with mean hemoglobin (Hb) 8.2g/dl. 32% and 39% of patients scored one standard deviation (below 86) on the WAIS-III Performance IQ (PIQ) and PS index (PSI) scores compared to 16% in national norms. 26% and 22% of patients scored below 86 on the WMS-III visual immediate and immediate memory scales compared to 16% in national norms. Controlling for age, gender, and education, patients and controls differed significantly on the WAIS-III PSI Score, −14.1 (95% CI of −19.2 to −9.0) and the WJ-III including reading, math and following directions. Subtests of attention and flexibility of thought of the TEA significantly decreased with age in patients but not controls. In 82 patients with MRIs, 63% had an abnormal MRI or NP dysfunction, 38% had atrophy and/or ischemic lesions, and 18% had ischemic lesions only. Low PIQ and PSI were significantly associated with ischemic lesions. In vMRI, adjusting for age and gender, hippocampal volume in patients was 541.1 μL < controls (95% CI of 212.0, 870.3) and CSF volume in patients was 16 mL > controls (95% CI of 1.7, 31.5). These dfferences were significant. Patient Hb was a significant independent predictor of verbal IQ, PIQ, PSI, math, and executive function (Pearson r = .20 –.28).Conclusion. NP dysfunction and/or undetected brain injury affect the majority of neurologically intact adults with SCD, especially in areas of executive functioning, reading and math fluency. Patients with lower Hb have lower IQ scores. Ischemic lesions, alone, do not account for the extent of the NP impairment observed. Hb, age, and hippocampal volume were predictive of NP dysfunction, suggesting a link between reduced oxygenation, neuronal loss, and cognitive impairment. This supports the importance of a transfusion trial to improve NP function.

MR features of osteoarthritis of the knee

A group of patients with idiopathic osteoarthritis (OA) of the knee was surveyed using weight-bearing radiographs and MR imaging to compare the relative value of these methods in disease evaluation. Fifty-two patients with a clinical and radiological diagnosis of OA of the knee of relatively short duration (87%: ≤4 yr) were compared to a reference group of 40 age- and sex-comparable subjects with no knee symptoms. All patients had a complete history, physical examination, standard anterior-posterior and lateral weight-bearing radiographs, T 1-weighted, and FLASH MR images in both knees. The prevalence of MRI abnormalities was significantly greater in patients with OA of the knee in all radiographic grades (Kellgren and Lawrence) compared to the reference subjects. Significant differences were encountered for synovial thickening (OA, 73%; reference, 0%), synovial fluid (60%; 7%), meniscal degeneration (52%; 7%), osteophytes (67%; 12%), and subchondral bone involvement (65%; 7%), even in the patients at the mild end of the osteoarthritic spectrum, indicating the exquisite sensitivity of MRI compared with weight-bearing radiographs.