PubMed HealthSearch

SEARCH · PubMed Health

Results for “Brain imaging”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources

The quest for an image of brain: a brief historical and technical review of brain imaging techniques.

Each of the brain imaging techniques in common clinical use (skull radiography, midline ultrasonography, isotope scan, pneumoencephalography, angiography and computerized tomography) depicts some structural or functional characteristic of the brain. Each produces a correspondingly restricted concept of the status of the brain. Computerized tomography, which defines the radiodensity of head tissues, has a fundamental advantage over the other techniques in that it defines with quite good resolution a characteristic of brain tissue itself (radiodensity), rather than visualizing some anatomic compartment other than brain parenchyma. It provides an explicit image of the brain quite analogous to gross sections of the brain seen at autopsy. Computerized tomography has already substantially reshaped the practice of neurology wherever it has become available and probably will come to play a role as pivotal in clinical neurology as does bone radiography in orthopedics.

Brain

Comparative evaluation of 99mTc GH, 99mTcO4, and 99mTc DTPA as brain imaging agents.

The brain imaging properties of 99mTc glucoheptonate, 99mTc pertechnetate, and 99mTc DPTA are compared. Results demonstrate that optimum images are obtained at 90, 180, and 180 min., for 99mTc GH, 99mTc DTPA, and 99mTc perterchnetate, respectively. The former two images are not affected by prior bone imaging with 99mTc pyrophosphate, while 99mTc pertechnetate images are adversely affected. 99mTc glucoheptonate appears to be the superior agent for brain imaging, followed by 99mTc DTPA and 99mTc pertechnetate.

Brain Diseases

Value of routine cerebral radionuclide angiography in pediatric brain imaging.

In addition to static brain images, cerebral radionuclide angiograms (CRAGs) were performed in 1,051 children to determine the value of routine radionuclide angiography. The CRAG resulted in a statistically significant increase in detection of abnormalities (p less than 0.01), as it provided the only evidence of confirmed abnormalities in 60 children (5.7%). The CRAG helped detect subdural fluid collections, cerebrovascular disease, and cerebral cysts, but it was of little value in detecting hydrocephalus. For maximum diagnostic yield, a CRAG should be performed with all pediatric brain-imaging studies.

Brain Diseases

A quantitative clinical comparison of three 99mTechnetium labeled brain imaging radiopharmaceuticals.

In a comparison study of three commonly employed 99mTc brain imaging pharmaceuticals, 16 patients with proven brain lesions had imaging performed with DTPA, glucoheptonate, and pertechnetate over a short interval of time. Lesion detectability was assessed by a data processing system which evaluated average lesion-to-background activity ratios for each patient examination. Statistical analysis of the resultant data demonstrated a significant improvement (20%) in lesion-to-background ratio in favor of one hour delayed DTPA images versus two hour delayed pertechnetate images. Comparison of one hour delayed DTPA images with one hour delayed glucoheptonate images did not reveal a significant difference in lesion-to-background ratio. The authors conclude that both Tc-DTPA and Tc-glucoheptonate are superior alternatives to pertechnetate when employed in the manner described.

Brain

Critical evaluation of 99mTc glucoheptonate as a brain imaging agent.

99mTc glucoheptonate was used as a brain imaging agent in a consecutive series of 859 patients. Sensitivity was 94% in patients with proved CNS tumors. Static imaging of patients with infarction showed a sensitivity of 62%. When the perfusion study was included, this valve increased to 90%. Overall sensitivity was 83%, specificity 99%, and accuracy 95% without inclusion of perfusion results. When these results were included, overall sensitivity was 93%, specificity 99%, and accuracy 98%.

Brain

Role of the radionuclide brain image in the diagnosis of brainstem gliomas.

The noninvasive detection of brainstem gliomas remains difficult. Eleven of our patients with proven brainstem gliomas had radionuclide brain imaging prior to the initiation of therapy or confirmation of the diagnosis; six studies were positive. Pneumoencephalography remains the most reliable diagnostic test for brainstem glioma, and is invariably required for confirmation. Although angiography is useful in the evaluation of vasocularity it may not detect small infiltrating lesions. Radionuclide brain imaging is useful in the initial workup of patients with suspected brainstem gliomas.

Adult

Is impulsivity simply a failure of self-control? Evidence based on multi-omics analyses of genomics, metabolomics and brain imaging.

High impulsivity-a hallmark of various adverse life outcomes such as substance abuse, impulsive buying, violence, and crime-has typically been considered as a failure of self-control. However, is impulsivity simply a failure of self-control? To address this issue, we employed multi-omics combined with brain imaging approach in a large-scale sample (Nbrain imaging=1524, Ngenomics=835, Nmetabolomics=946) to elucidate the relationship between impulsivity and self-control. Mendelian randomization showed a bidirectional association between impulsivity and self-control, suggesting that they influenced each other. Partial least squares analysis highlighted that self-control primarily implicates the frontal lobe regions (e.g., superior frontal gyrus), whereas impulsivity involves the amygdala, insula, and basal ganglia. The cerebellum, superior frontal gyrus, and middle frontal gyrus were identified as shared areas in impulsivity and self-control. Furthermore, gene-based association analysis identified heterochromatin protein 1 binding protein 3 as specifically related to impulsivity, while pathway enrichment analysis demonstrated that arginine and proline metabolism was a common metabolic pathway associated with both impulsivity and self-control. Overall findings demonstrate that impulsivity and self-control involve both shared and distinct brain regions, genetic and metabolic foundations. The brain imaging results suggest that impulsivity is related not only to self-control-related processes but also to the motivation to pursue rewards. Together, this large-scale integrative study firstly provides a side-by-side map of genomic, metabolic, and limbic-network signatures of impulsivity distinct from self-control, offering a foundation for mechanism-driven biomarker and intervention research in maladaptive impulsivity.

Impulsive Behavior

Optimal utilization of computerized cranial tomography and radionuclide brain imaging.

The results of computerized cranial tomography and radionuclide brain imaging in 490 patients were compared in relationship to the patients' clinical presentation. In 195 patients with focal neurologic abnormalities, both tests detected most lesions, but computerized cranial tomography was slightly more accurate overall. Results of both studies were normal in 69 percent of 295 patients with nonfocal neurologic presentations, and radionuclide imaging failed to detect lesions in only five patients with nonfocal presentations. These results suggest that radionuclide imaging can be used to accurately screen most patients with nonfocal neurologic presentations. An exception is the patient presenting with dementia, in whom computerized cranial tomography provides details of the anatomy of the ventricular cavities and cerebral cortex. This study demonstrates a continuing role of importance for radionuclide imaging in the evaluation of patients with neurologic disease and provides data to allow a rational approach to the optimum use of both techniques.

Atrophy

Radionuclide brain imaging--its role and relation to CT scanning.

Separate CNS disease entities are discussed with either the complementary or exclusive indications for radionuclide brain imaging and computerized cranial tomography. Either modality alone has a potential overall precision somewhat in excess of 90% in the localization of cerebral lesions with the effectiveness of each modality differing according to the histology and anatomic location of the lesion. Most investigators agree that the combined application of the two procedures is far superior to their separate use. Routine dynamic isotope studies are essential and in addition, new radiopharmaceuticals and technological advances may improve the radionuclide evaluation of CNS disease. Areas discussed include: primary and secondary CNS neoplasms; acute cerebrovascular accidents; arteriovenous malformations; traumatic cerebrovascular disease; hydrocephalus and dementia; and intracranial inflammatory processes.

Adult

Genetic Correlation Between Brain Imaging Phenotypes and Externalizing Behavior: A Large-Scale LDSC Analysis of UK Biobank IDPs.

Externalizing has been associated with differences in brain structure and function; however, it remains unclear whether these associations reflect shared common-variant genetic influences. Cross-trait linkage disequilibrium score regression was used to estimate genome-wide genetic correlations between externalizing genome-wide association study (GWAS) results and 3,935 brain imaging-derived phenotypes from the UK Biobank BIG40 resource. The imaging phenotypes covered structural magnetic resonance imaging (MRI), diffusion MRI, susceptibility-weighted imaging, resting-state functional MRI, and task-based functional MRI. Results were included in the primary analysis when the imaging phenotype had positive single-nucleotide polymorphism (SNP) heritability, a heritability Z statistic of at least 1.96, a mean GWAS chi-square statistic of at least 1.02, at least 200,000 regression SNPs, and a complete LDSC result without a fatal error. Technical imaging quality-control phenotypes were excluded from biological inference. Individual results were corrected using the Benjamini-Hochberg false discovery rate procedure. Aggregated Cauchy association tests (ACATs) were used to evaluate evidence across all imaging phenotypes and within predefined imaging categories. Statistical power, simultaneous confidence bounds, and alternative quality-control definitions were examined in sensitivity analyses. Of the 3,935 imaging phenotypes, 3,716 produced estimable genetic correlations, 2,980 met the primary LDSC quality-control criteria, and 2,967 were classified as biological imaging phenotypes. No individual phenotype survived false discovery rate correction. The smallest unadjusted P value was 0.0005, and the minimum adjusted q value was 0.486. The distribution of genetic correlations was centered near zero, with a median genetic correlation of 0.0014 and a median absolute genetic correlation of 0.0338. ACAT provided no evidence of an aggregate association across all biological imaging phenotypes (P = 0.302), and no predefined imaging category survived multiple-testing correction. The median minimum detectable genetic correlation at 80% power was 0.216. Bonferroni-adjusted simultaneous confidence intervals were fully contained within the interval [-0.30, 0.30] for 80.0% of phenotypes in the primary analysis and 88.0% under the stringent heritability quality-control definition. Broad and stringent sensitivity analyses produced the same overall conclusions. In this study, no statistically robust evidence of genome-wide genetic correlations between externalizing and individual UK Biobank brain imaging phenotypes was found. Nevertheless, small, localized, mixed-direction, or developmentally specific genetic effects remain possible.

Journal Article

Sensitivity of radionuclide brain imaging and computerized transaxial tomography in detecting tumors of the posterior fossa: concise communication.

In a series of 25 patients with histologically proven mass lesions of the posterior fossa, computerized transaxial tomography (CTT) and radionuclide (RN) brain imaging detected 23 (92%) and 22 (88%) of the 25 tumors, respectively. In this small group of patients, the difference is not statistically significant. When the results of both techniques were combined, the detection rate was 100%, which emphasizes the complementary value of the two procedures. The two lesions not detected by CTT were metastatic carcinomas, and contrast enhancement was not employed. The three lesions not detected by RN imaging were cystic. The results may represent underestimates of the true sensitivity of both techniques since the use of contrast enhancement with CTT and of posterior flow studies and magnified static RN images of the posterior fossa would probably improve the sensitivity of both tests.

Adolescent

An iodinated catecholamine congener for brain imaging and metabolic studies.

The iodinated O-methylated catecholamine congener, 4-iodo-2,5-dimethoxyphenylisopropylamine (4-I-DPIA), has potential as a new agent for imaging and metabolic studies of the brain and lung. The organ distribution and brain uptake of radioiodine-labeled 4-I-DPIA were studied in the dog and monkey by whole-body scanning, gamma-camera scintigraphy, and organ assay. The brain takes up 2% of the injected dose, with a half-time of 8 sec in the monkey, and the lung takes up 11.8%. An unusual finding was a concentration in the retina, five times that in any other CNS tissue. 4-I-DPIA may have potential in the imaging of normal brain tissues and thereby delineating nonfunctional areas damaged by infarction, trauma, or malignancy, and may also be useful in metabolic studies of catecholamine function. Adequate radioactivity can theoretically be administered with a quantity of 4-I-DPIA 1/10,000 of the pharmacologically active levels. The agent may also find application in lung imaging because of the high pulmonary uptake.

Amphetamines