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PubMed1991

Area and volume measurement of posterior fossa structures in MRI.

This study was undertaken to determine the extent to which area measures of posterior fossa structures can be used confidently to represent structure volumes. MRI scans were obtained from three groups: fragile X males, males with other developmental disabilities, and males with normal IQ. The areas of the midbrain, pons, medulla, cerebellar vermis, and fourth ventricle were measured in midsagittal sections. Volumes of midbrain, pons, medulla, cerebellum, fourth ventricle, and third ventricle were obtained by measuring these structures in contiguous axial slices. In addition, the largest axial area for each structure was identified. Analysis revealed that midsagittal area measures for pons, medulla, and fourth ventricle were significantly correlated with structure volumes, and that all of the largest axial area measures were significantly correlated with structure volumes. However, only the midsagittal area measure of fourth ventricle and the largest axial area measures of fourth ventricle and cerebellum were correlated with volume measures with an r of .80 of greater. Results of this study suggest that area measures may not accurately represent three-dimensional structure size.

Adolescent↗

PubMed1992

Gadolinium-DTPA enhancement of dural structures on MRI after surgery.

Gadolinium-DTPA enhanced MRI was examined before and after surgery in 14 patients with particular attention to the enhancement of falx cerebri, tentorium cerebelli and dura mater. A marked enhancement was observed in 2 falx and 2 tentorium before surgery, whereas it was observed in 7 falx, 9 tentorium and 11 dura after surgery. Among 6 falx, 7 tentorium and 12 dura showing increased enhancement after surgery, 2 falx, 3 tentorium and 8 dura showed marked enhancement which was not observed before surgery. A small amount of subdural haemorrhage during surgery is known to heal as subdural neomembrane with capillaries. An increased enhancement of dural structures conceivably derives from the extravasation of Gd-DTPA through capillaries involved in the subdural neomembrane. In the postoperative MRI, the enhancement of dural structures should be taken into consideration.

Adolescent↗

PubMed1991

Cerebral structure on MRI, Part I: Localization of age-related changes.

In this report, earlier findings of age-related changes in brain morphology on magnetic resonance (MR) images are extended to include measurements of individual cerebral grey matter structures and an index of white matter degeneration. Volumes of caudate, lenticular, and diencephalic structures are estimated, as are grey matter volumes in eight separate cortical regions. Results suggest that between 30 and 79 years significant decreases occur in the volume of the caudate nucleus, in anterior diencephalic structures, and in the grey matter of most cortical regions. The data suggest that the volumes of the thalamus and the anterior cingulate cortex may be unchanged. Among those cortical regions found to be affected in aging, some evidence is present for greater change in association cortices and mesial temporal lobe structures. There are also dramatic age-related changes in the white matter, manifest as lengthened T2 values on MR images.

Adult↗

PubMed1991

Cerebral structure on MRI, Part II: Specific changes in Alzheimer's and Huntington's diseases.

Using magnetic resonance (MR) imaging and morphometric techniques, groups of patients with Alzheimer's disease (AD) and Huntington's disease (HD) were compared with a large group of normal control subjects. Measures of volume loss in specific subcortical nuclei and eight cortical regions as well as an index of white matter abnormality were obtained. Results indicated expected widespread cortical volume reductions in AD, which were especially severe in mesial cortices; but comparable reductions were present in subcortical structures, particularly the thalamus. In HD, the greatest reductions were in striatal structures, but significant abnormalities were also detected in the thalamus and inferior cortical areas, especially in mesial temporal lobe structures. Significant degeneration in white matter was present in both groups, but was more dramatic in the HD patients. The significant diencephalic reduction in AD may make an important contribution to early memory deficits in the disorder, which are usually attributed to hippocampal damage. Similarly, damage to both the thalamus and mesial temporal lobe structures may play a role in the memory deficits of HD.

Aged↗

PubMed1990

Cognitive impairment and cerebral structure by MRI in bipolar disorder.

The distinction between bipolar disorder and schizophrenia customarily follows examination of the clinical symptomatology and course of illness. The presence of cognitive impairment has been held to be uncommon in bipolar disorder and more likely in schizophrenia. This study explored neuropsychological function in 30 ambulatory outpatients with a DSM-III-R diagnosis of bipolar affective disorder (all of whom had been psychotic during manic episodes), comparing their performance with that of controls. These bipolar patients proved to have significant levels of diffusely represented cognitive impairment when compared with controls. Further, the degree of impairment was significantly correlated with reduction in midsagittal areas of brain structures measured on magnetic resonance imaging scans. The implications of these findings in relation to bipolar disorder are discussed.

Adult↗

PubMed2026

Complexity in disguise: a systematic review of fractal analysis in psychiatric neuroimaging.

OBJECTIVES: Psychiatric diagnosis and fractal studies are complex processes that extend beyond clinical evaluation and require careful methodological considerations in neuroimaging. Over the years, fractals have helped reduce these complexities in research, but they still cannot grant clinical diagnoses. Thus, the main objective was a systematic review exploring the potential applications of fractal analysis in characterizing psychiatric conditions through neuroimaging techniques-including both functional and structural MRI. MATERIALS AND METHODS: A systematic literature review was conducted on PubMed, identifying thirty-nine original studies that met the inclusion criteria. Areas showing statistical significance (p < 0.05) were reported. These studies were categorized according to DSM-V classification and examined for the description of psychiatric conditions through the fractal analysis. RESULTS: The review primarily focuses on young adults with psychiatric conditions compared to control groups. Schizophrenia and Autism Spectrum Disorder are major areas of investigation, and fractal dimension (FD) is the primary analysis method used to reflect brain patterns. Studies that calculated whole-brain FD may have underestimated local abnormalities due to the inclusion of a high percentage of tissue, potentially resulting in overlooked findings. Notably, abnormalities in the frontal cortex represent a common neurobiological feature across several psychiatric conditions. CONCLUSIONS: The findings from this systematic review shed light on the use of fractal analysis to quantify complex brain patterns in both psychiatric patients and healthy individuals. However, it is essential to recognize the need for further research to elucidate a fractal analysis protocol that allows for optimal extraction of psychiatric insights. KEY POINTS: Question Fractal analysis applied to structural and functional MRI help characterize brain alterations across psychiatric conditions. Findings This review shows consistent fractal patterns across multiple psychiatric disorders, especially in frontal regions. Despite heterogeneous methodologies, results highlight shared structural and functional abnormalities. Clinical relevance Fractal analysis may offer complementary characterization of subtle brain organization across psychiatric disorders. Its potential clinical utility-such as improving diagnostic characterization, earlier detection, among others-remains limited by the current absence of a standardized protocol.

Humans↗

PubMed1989

Special diagnostic procedures in sports medicine.

In summary, there are a number of imaging procedures available to support the physician in his or her evaluation of sports injuries. Conventional radiographs remain the primary imaging examination. Specialized radiographic projections will often provide additional pertinent information. A fluoroscopic examination or conventional tomography may provide a cost-effective method of clarifying subtle post-traumatic changes. The use of the more sophisticated and costly imaging procedures should be reserved for those cases in which a diagnosis cannot be made with simpler technology. CT scanning, by virtue of its ability to image in the axial plane, has proved to be an effective method of documenting injuries particularly in complex bony anatomy such as the spine, wrist, elbow, and hips. CT arthrography provides diagnostic information about intra-articular structures. MRI is emerging as an excellent method of noninvasively imaging injuries to soft-tissue structures such as tendons, ligaments, and cartilage. The advancements in MRI technology that are projected for the future may expand the range of usefulness of this modality and decrease the current high cost of these procedures. Radionuclide scanning with Tc99m diphosphonate compounds has proved to be an efficient method of localizing subtle bone pathology and providing a "road map" for further analysis with additional imaging techniques. The cost-effective use of all of these imaging procedures is predicated on an understanding of their usefulness in the diagnosis of each clinical problem and the judicious use of each procedure to fit the needs of the individual patient.

Athletic Injuries↗

PubMed1989

[The value of nuclear magnetic resonance tomography in staging of bone and soft tissue sarcomas].

The prognosis of survival in bone and soft-tissue sarcomas is definitely correlated with compartmental tumor extension at the time of surgery and with the surgical margins achieved by resection. Preoperative planning and selection of an adequate surgical treatment procedure require a maximum of information on the tumor size, compartmental extension, proximity to the physis, skin layers, and the vessels and nerves. This information is indispensable and can only be obtained by a combination of several diagnostic investigations, MRI being of utmost importance. Whereas CT is superior in illustrating the bone structure, MRI outclasses CT in outlining the intraosseous tumor extension and the extraosseous tumor components. The latter aspects are especially important in planning and performing tumor resection. With the combined use of gradient echo sequences and Gadolinium DTPA with MRI, appreciation of the tumor margin and response to polychemotherapy may be possible in the future.

Bone Neoplasms↗

PubMed1991

[MRI of normal pituitary glands and their surrounding structures].

Normal MRI appearances of the pituitary glands and their surrounding structures were evaluated in 332 patients without sellar and parasellar diseases. The height of the pituitary gland was maximum at 10-19 years of age reflecting hormonal activity. The width of the pituitary gland decreased, while that of the cavernous sinus increased with aging. This is probably due to atherosclerotic change of the internal carotid artery. Females younger than 30 years of age tended to show a convex upper surface of the pituitary gland and the displacement of the pituitary stalk was common after 50 years of age. Almost all of the anterior lobe of the pituitary gland showed isointensity relative to the pons or cerebral cortex and the majority (85.1%) of the posterior lobe showed hyperintensity. However, the anterior lobe in 2 newborns showed hyperintensity similar to the normal posterior lobe in adults. The posterior lobe was located off the midline in 19.1% of the subjects. One case of pars intermedia cyst was discovered among 14 subjects who were administered Gd-DTPA. The dural membrane between the pituitary gland and cavernous sinus was recognizable only in 8.6% on the right side and 7.5% on the left side. Primary empty sella was identified in 4.5%. A knowledge of the above normal ranges and variations of the pituitary gland and its surrounding structures is important in diagnosing sellar and parasellar lesions.

Adolescent↗

PubMed1987

Magnetic resonance imaging versus computed tomography in the evaluation of soft tissue tumors of the extremities.

Twenty patients with extremity soft tissue tumors were prospectively evaluated with magnetic resonance imaging (MRI) and computed tomography (CT) scans with subsequent anatomic correlation of surgical findings. MRI and CT had a similar percentage of accuracy in assessing tumor relationship with major neurovascular (80% and 70%, respectively) and skeletal (80% and 75%, respectively) structures. MRI was significantly better than CT in displaying contrast between tumor and muscle when using the T2 weighted spin echo (SE) (p2 less than 0.002) and inversion recovery (IR) (p2 less than 0.005) pulse sequences. MRI and CT were comparable in demonstrating contrast between tumor and fat. The contrast between tumor and vessel was better displayed by MRI compared with CT when using the T1 weighted SE (p2 less than 0.001) and T2 weighted SE (p2 less than 0.001) pulse sequences. T1 and T2 values were measured on fresh tumor and normal tissue samples and were used to predict relative contrast on different MRI pulse sequences using isosignal contour plots. MRI appears to offer several advantages over CT in the evaluation of extremity soft tissue tumors.

Arm↗

PubMed1990

[Preoperative staging of central bronchopulmonary cancer. X-ray CT-MRI-pulmonary digital subtraction angiography and surgery].

In order to evaluate the reliability of medical imaging methods in the assessment of mediastinal invasion by lung cancers, a prospective study was conducted in 30 patients undergoing preoperative computed tomography (CT), magnetic resonance imaging (MRI) and pulmonary digital subtraction angiography. MRI improved the sensitivity of detection of surgically confirmed mediastinal lymphadenopathy, but its specificity in relation to histological results was poor and identical to that of CT. In terms of extension to vascular structures, MRI and CT gave comparable results for the pulmonary artery and vein with two false positives for the pulmonary veins and left atrium with the two methods. MRI was found to be superior to CT for the detection of invasion of the aortic arch. Digital subtraction angiography is not as reliable as the other two modalities, particularly for extension to the pulmonary vein for which it was found to be technically inappropriate. By means of sagittal and frontal scans, MRI was therefore found to be more effective than CT for examination of the subcarinal region and aorto-pulmonary window. In contrast, the persistence of false positives with the two methods and the impossibility of distinguishing between inflammatory lymph nodes and neoplastic lymph nodes means that thoracotomy can never be contraindicated on the basis of the results of imaging alone.

Aged↗

PubMed1989

'Benign thoracic pain' syndrome: role of magnetic resonance imaging in the detection and localization of thoracic disc disease.

The syndrome of 'benign thoracic pain' is seen in young women who have pain and tenderness in the mid-thoracic spine radiating around the chest and aggravated by spinal movement. Ten consecutive patients with this syndrome and 15 controls were evaluated with magnetic resonance imaging (MRI). This showed thoracic intervertebral disc dehydration with no associated prolapse in 90% of the patients and 13% of the controls. We postulate that the clinical features are due to impaired shock absorption of these degenerate discs rather than direct compression of surrounding structures. MRI is non-invasive and does not use ionizing radiation; it allows direct visualization of the entire thoracic spine and cord, and accurate detection of early disc degeneration. Thus, it is the imaging modality of choice for defining the subtle intervertebral disc abnormalities that characterize the 'benign thoracic pain' syndrome.

Adult↗

PubMed2026

Neurocorrelates of nocturnal enuresis in pre-adolescent children.

INTRODUCTION: Nocturnal enuresis (NE) is a common neurodevelopmental condition, yet its underlying neural mechanisms remain unclear. This study leverages the large-scale Adolescent Brain Cognitive Development (ABCD) dataset to identify structural and functional brain correlates associated with active symptoms and the resolution of bedwetting. METHODS: Using cross-sectional data from 3472 participants aged 9-10 years, children were categorized into three groups: active nocturnal enuresis (ANE, n = 225), history of nocturnal enuresis (HNE, n = 1171), and healthy control groups (CG, n = 2076). Multimodal neuroimaging protocol evaluated macrostructural properties via structural MRI (sMRI), microstructural white matter integrity via diffusion MRI (dMRI), and functional connectivity via resting-state fMRI (fMRI). Group differences were evaluated using linear models within an ANCOVA framework, adjusting for intracranial volume and handedness with False Discovery Rate (FDR) correction. RESULTS: Compared to controls, the ANE group exhibited a significant volume deficit in the right caudate, decreased sulcal depth in the left insula, and lower internal correlation within the Cingulo-Opercular Network (CON). Conversely, the dry HNE group demonstrated significant structural adaptations, including bilaterally larger putamen volumes and increased right caudate volume compared to the ANE group. The HNE group also showed increased microstructural density (decreased mean diffusivity) in the bilateral hippocampus and an increased cortical surface area in the left insula. Both NE groups demonstrated persistently reduced functional coupling within the CON. CONCLUSIONS: Nocturnal enuresis appears to be associated with a potential complex central signaling deficits. Reduced internal correlation within the CON across both active and former bedwetters indicates a potential for impairment in processing internal homeostatic bladder signals during sleep.

Humans↗

PubMed2026

Ultra-high-field 7T MRI reveals neural abnormalities of attention networks in relation to cognitive impairment in hypertension.

Hypertension is a significant risk factor for cognitive impairment (CI), yet the corresponding neural network abnormalities remain underexplored. In this study, we examined the associations among global and domain-specific cognitive dysfunction, neuroimaging measures, and blood pressure in a subgroup of hypertensive patients with CI (N = 41) from a randomized controlled trial who underwent ultra-high-field 7 T MRI. Structural atrophy related to CI was localized to regions overlapping the attention networks. Both whole-brain and within-network dysfunction of the attention networks were associated with worse global cognitive performance. Notably, hyperconnectivity within key attention network hubs, including the right anterior insula and posterior intraparietal sulcus, was associated with declined processing speed in hypertensive patients, mediating the association between pulse pressure and processing speed. These findings provide new insights into the neural pathophysiology of hypertension-related CI and suggest potential network-based targets for intervention.

Magnetic Resonance Imaging↗

PubMed2026

Longitudinal functional network connectivity changes across the clinical stages of C9orf72 hexanucleotide repeat expansion carriers.

INTRODUCTION: Intrinsic functional connectivity network abnormalities in C9orf72 hexanucleotide repeat expansion carriers emerge during the asymptomatic phase, yet longitudinal studies remain limited. We examined cross-sectional abnormalities and longitudinal connectivity changes across clinical stages. METHODS: We analyzed task-free functional magnetic resonance imaging (fMRI) and structural MRI data in 36 asymptomatic (aSxC9), 17 prodromal (proC9), and 29 symptomatic (SxC9) carriers, and 107 healthy controls (HCs). Functional networks previously found altered in C9orf72, including salience, sensorimotor, default mode, and medial pulvinar thalamic networks, were examined. Associations between longitudinal connectivity and gray matter decline with baseline neurofilament light chain (NfL) concentrations and symptom severity were assessed. RESULTS: aSxC9 and SxC9 showed longitudinal connectivity changes within specific networks. In aSxC9, connectivity changes correlated with baseline NfL. In proC9 and SxC9, changes in connectivity and gray matter were associated with baseline NfL and symptom severity. DISCUSSION: C9orf72 expansion carriers demonstrate stage-specific network connectivity changes.

Humans↗

PubMed1989

Very-low-birth-weight, preterm infants with or without intracranial hemorrhage. Neurologic, cognitive and cranial MRI correlations at 4-8-year follow-up.

Fourteen very-low-birth-weight (VLBW) preterm infants with and without intracranial hemorrhage (ICH) were prospectively followed from birth to 4 to 8 years for the purpose of determining neurologic and cognitive sequelae associated with ICH severity and to correlate outcomes with brain morphology as determined by Magnetic Resonance Imaging (MRI). Intracranial hemorrhage was documented by cranial ultrasonography performed in early life. Follow-up assessments included neurologic and psychometric examinations and cranial MRI scans. Of six children with no ICH, five had normal results on all three follow-up measures. Three children with Grade I-II ICH had mild to moderate neurologic and cognitive sequelae with focal white matter MRI abnormalities. Five children with Grade III-IV ICH had severe neurologic, cognitive, and MRI deficits, including MRI regional and diffuse white matter abnormalities and/or cortical atrophy. Focal and diffuse neurologic deficits correlated with the extent of MRI morphologic abnormalities. Results of this study indicate that ICH severity correlated with outcomes in children at follow-up; the more severe the ICH, the more adverse the neurologic, cognitive, and MRI results. MRI white matter abnormalities were present in all children with any degree ICH, while ventriculomegaly was seen only in severe ICH (Grade III-IV ICH). Neurologic deficits correlated with MRI structural abnormalities.

Brain↗

PubMed1988

Neck pain.

Six conditions cause most of the neck pain complaints seen by primary care physicians: cervical muscle strain or sprain, torticollis, acceleration injury, myofascial pain dysfunction syndrome, and cervical osteoarthritis or rheumatoid arthritis. Most of them can be diagnosed and treated by the primary care physician. Of the more unusual causes, one should not miss a clinical fracture; a herniated cervical disc, spinal cord compression from a disc, or epidural tumor; infection of the disc or the vertebral body; subluxation of the vertebral bodies; or pain referred from the chest or mediastinal structures. MRI offers new opportunity for early diagnosis of myelopathy owing to OA or RA, vertebral osteomyelitis, and metastatic involvement of cervical vertebrae.

Humans↗

PubMedDate not supplied

Assessment of posterior fossa structures with midsagittal MRI: the effects of age.

Midsagittal magnetic resonance (MR) images of 36 normal volunteers, ranging in age from 26 to 79 years, were used to evaluate the effects of age on the size of posterior fossa structures (cerebellar vermis, midbrain, pons, medulla and fourth ventricle). Our results demonstrate a highly statistically significant age-related decline in the cross-sectional area of the midbrain (r = -.44, p less than 0.007), a less prominent decline in the area of the anterior cerebellar vermis (r = -.33, p less than 0.05) and striking intercorrelations between the dimensions of the pons, medulla and cerebellar vermis. To the best of our knowledge, this is the first MRI demonstration of midbrain atrophy during aging in normal adults.

Adult↗