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Biomedical subjects

M D Deck

Publications and source records attributed to M D Deck.

At least 37 records · Page 2Linked to original sources
PubMed1993

Magnetic resonance imaging measurements and clinical changes accompanying transtentorial and foramen magnum brain herniation.

Current concepts of brain herniation have depended largely on correlating clinical signs and symptoms with indirect radiographic studies and the results of postmortem neuropathology. This article describes measurements on midsagittal magnetic resonance imaging (MRI) scans that distinctly define normal and abnormal rostral-caudal relationships between the diencephalic-mesencephalic junction and the plane of the tentorial incisura, herein termed the incisural line. We similarly provide quantitative MRI scan measurements relating the cerebellum and the plane of the foramen magnum, termed the foramen magnum line. Measurements from 156 midsagittal and 63 coronal MRI scans performed on 123 normal adults, placed the iter of the aqueduct 0.2 +/- 0.8 mm (mean +/- SD) below the incisural line and the cerebellar tonsils 0.1 +/- 2.1 mm below the foramen magnum line. Defining 2 SD from these norms as abnormal, 23 patients with intracranial mass or obstructive lesions showed 4 distinct patterns of brain herniation, i.e., upward or downward transtentorial shift with or without accompanying cerebellar tonsillar herniation. Five patients with posterior fossa masses demonstrated displacement of the iter above the incisura ranging from 1.6 to 6.3 mm. Eighteen patients with supratentorial masses demonstrated displacement of the iter ranging from 2.0 to 11.0 mm below the incisura. Two-thirds of patients with upward and one-half of those with downward transtentorial shift had concurrent tonsillar herniation. In acute illnesses, MRI scan changes anticipated or confirmed clinical signs of brain herniation. In chronic cases, clinical and MRI scans correlated less well, with MRI sometimes revealing major degrees of anatomical herniation well in advance of clinical abnormalities.

Adolescent↗
PubMed1993

Prenatal growth of the human cerebral cortex: brainprint analysis.

To construct a series of flat maps (brainprints) that document the prenatal growth of human cerebral cortex and help identify sulcal landmarks for division of cortical regions of interest (ROIs) on mapped surfaces, the authors photographed and traced histologic whole-brain slices of 25 normal human fetal brains aged 18-42 weeks gestation. Brainprints of both cerebral hemispheres from each fetus were constructed with semiautomatic brain-mapping software, and each map was divided into five ROIs based on sulcal landmarks: frontal, parietal, insular, occipital, and temporal cortices. Surface areas of cerebral hemispheres and the five ROIs were estimated. Corrected for histologic shrinkage, brainprint estimates of human fetal cortical surface area were approximately twice those of previous estimates. Cortical lobe proportions at 18 weeks appeared to be unchanged to term. Surface area estimates correlated with fetal age, brain weight, and brain volume. This collection of cortical maps may guide future quantitative analyses of cerebral hemispheric growth in premature and term infants who undergo magnetic resonance imaging, which may, in turn, help predict neurobehavioral outcomes of early cortical damage.

Brain Mapping↗
PubMed1993

MRI changes in intracranial hypotension.

We report seven patients with the syndrome of intracranial hypotension who were referred to Memorial Sloan-Kettering, primarily because of suspicion of meningeal tumor or infection raised by the finding of meningeal enhancement on MRI. In three patients, symptoms occurred after lumbar puncture; in four, there was no clear precipitating event. Lumbar puncture after MRI in six patients revealed low CSF pressure (six patients) and pleocytosis or high protein, or both (four patients). Three patients had subdural effusions. Six patients had measurable descent of the brain on midsagittal images. Postural headache resolved in all seven patients, six of whom had follow-up MRIs. Meningeal enhancement resolved or diminished in all six. Subdural effusions resolved spontaneously in two and were evacuated (but were not under pressure) in one. Downward brain displacement improved or resolved in all patients. The clinical syndrome and MRI abnormalities generally resolve on their own. An extensive workup is not helpful and may be misleading. Patients should be treated symptomatically.

Adult↗
PubMed1992

Clinical correlates of cerebral ventricular enlargement in schizophrenia. Further evidence for frontal lobe disease.

Numerous studies have shown evidence of cerebral ventricular enlargement in schizophrenia and its relationship to severity of clinical symptoms and psychosocial dysfunction. In this large prospective study, 88 noninstitutionalized DSM-III-R schizophrenic patients were administered a CT scan and rated for positive and negative symptomatology and premorbid adjustment. The CT scans from 14 healthy controls were used for comparison of cerebral ventricular measures. Patients had an enlarged ventricle to brain ratio of the anterior portion of the lateral ventricles, the frontal horns, compared with controls. Patients with larger frontal horns had more severe negative symptoms and poorer premorbid childhood adjustment. The area of the main body of the cerebral lateral ventricles, though not elevated in patients, was correlated with the total number of prior hospitalizations. These results support the hypothesis of a structural and functional "frontal" deficit in schizophrenia.

Adolescent↗
PubMed1989

Magnetic resonance imaging of arachnoid cysts.

A retrospective review of magnetic resonance imaging (MRI)-computed tomography (CT) correlation was performed in 29 patients with arachnoid cysts. Short TR, short TE spin echo (SE) pulse sequences provided the best anatomic definition whereas multiple echo long TR, TE sequences allowed comparison of the signal intensity of the cyst with that of cerebrospinal fluid (CSF). Simple arachnoid cysts were isointense while neoplastic, hemorrhagic or inflammatory cysts were hyperintense relative to CSF. The CT differential diagnosis of an arachnoid cyst (depending upon its location) may include other cystic collections such as craniopharyngioma, epidermoid, astrocytoma, and chronic subdural hematoma. However, on MRI the combination of extra-axial location, morphological features, and signal intensity matching that of CSF allows one to make the diagnosis of an uncomplicated arachnoid cyst with confidence.

Adolescent↗
PubMed1989

Computed tomography versus magnetic resonance imaging of the brain. A collaborative interinstitutional study.

A retrospective study (1983-1984) of magnetic resonance imaging (MRI) and computed tomography (CT) examinations in 471 patients with known pathology in the brain and craniocervical junction was conducted in order to determine the relative efficacy of MRI versus CT. All MRI examinations involved slice thickness greater than 10 mm, and only single-slice single-echo or multislice single-echo imaging techniques were available. These studies were evaluated independently by two neuroradiologists from a panel of six for anatomic abnormalities, lesion contrast, and radiologist's impression. Results, which excluded microadenomas of the pituitary and approximately 9% of studies in which consensus was not achieved by the readers, were as follows: (1) 14% of the studies were positive on MRI but normal on CT; (2) in 55% of the studies, MRI was better than CT; (3) MRI was equal or better than CT in 95% of the studies; and (4) CT was better than MRI in 5% (21/421) of the examinations. There were no patients in this series where CT was positive but MRI missed the abnormality.

Adult↗
PubMed1989

MR imaging of hemorrhagic intracranial neoplasms.

Thirty patients with intracranial tumors containing hemorrhage of varying stages were examined with high-field-strength MR imaging and CT to determine what differences might exist between hemorrhagic tumor and pure hemorrhage. Pathology was obtained in the six patients with primary tumors and in 14 of the 24 patients with metastases. Similar to evolving intraparenchymal hematomas, hemorrhagic neoplasms undergo changes in their appearance that can be categorized into three distinct intensity patterns, or stages. Stage 1 is characterized as iso- or hypointensity on short TR sequences and as hypointensity on long TR sequences; stage 2 as developing hyperintensity on both short and long TR sequences, without evidence of a well-defined black rim; and stage 3 as a hyperintense lesion with a well-defined black rim on long TR sequences. An additional mixed-intensity pattern was identified, which contained areas corresponding to more than one stage. In all of the cases exhibiting this pattern, pathology confirmed that the appearance was due to recurrent bleeding. We found several characteristics on MR that, when present, suggest an underlying neoplasm. These include delay in evolution between stages, central or eccentric hyperintensity in stage 2, and a mixed-intensity pattern. In addition, the presence of a hemosiderin rim does not exclude an underlying neoplasm. We found that the MR patterns that characterize hemorrhagic intracranial neoplasms should help to determine the cause of the hemorrhage.

Adult↗
PubMed1989

Subdural and epidural empyemas: MR imaging.

The MR images of six patients with extraaxial empyemas (five subdural and four epidural) were reviewed and compared with CT scans. MR demonstrated convexity and interhemispheric collections, which were mildly hyperintense relative to CSF and hypointense relative to white matter on short TR pulse sequences and hyperintense relative to CSF and white matter on long TR pulse sequences, allowing distinction from sterile effusions and most chronic hematomas. A hypointense rim, representing displaced dura, was depicted at the interface between the lesion and brain in epidural empyemas, a feature absent in subdural empyemas. Inflammation-induced parenchymal abnormalities, including edema, mass effect, and reversible cortical hyperintensity, were well depicted on MR imaging. MR was superior to CT in demonstrating the presence, nature, and extent of these lesions in all cases. Because early and accurate diagnosis will significantly improve the prognosis of these serious infections, MR is preferred to CT for patients in whom an acute intracranial infection is suspected.

Adolescent↗
PubMed1989

MR imaging of brain abscesses.

The MR images and CT scans of 14 patients with surgically verified pyogenic cerebral abscesses were reviewed. The MR findings correlated well with those seen on CT and were believed to be sufficiently characteristic to allow early and accurate diagnosis with MR alone. These features include (1) peripheral edema producing mild hypointensity on short TR/short TE and marked hyperintensity on long TR/intermediate to long TE scans; (2) central necrosis with abscess fluid hypointense relative to white matter and hyperintense relative to CSF on short TR/short TE scans and hyperintense relative to gray matter on long TR/intermediate to long TE scans (the fluid had concentric zones of varying intensity in seven cases, a finding not previously identified in other lesions); (3) extraparenchymal spread (intraventricular or subarachnoid), which was detected more easily on MR than on CT and was manifested by increased intensity relative to normal CSF on both short TR/short TE and long TR/intermediate TE scans; and (4) visualization of the abscess capsule, which was iso- to mildly hyperintense relative to brain on short TR/short TE scans and iso- to hypointense relative to white matter on long TR/intermediate to long TE scans. On the long TR scans, the relative hypointensity of the rim allowed for visualization of the typical morphologic features of the capsule, which in turn aided in differentiation of abscesses from other lesions (as it does on CT). To investigate the cause of the capsular intensity, pathologic studies of the capsules were reviewed when available (10 cases). Fibrosis was identified in all mature abscess capsules, but the combination of the intensities seen on short TR/short TE and long TR/intermediate to long TE scans as well as the temporal changes in intensity were believed to be incompatible with fibrosis as a cause of the capsular changes. Intensity patterns were suggestive of hemorrhage, but neither acute nor chronic hemorrhage was identified on routine H and E stains, while iron stain revealed scant hemorrhage in only two of the eight patients in whom these stains were used. We believe the capsular intensity (in particular the hypointense rims on long TR scans) may reflect paramagnetic T1, and to a greater extent T2, shortening, possibly due to the presence of heterogeneously distributed free radicals that are products of the respiratory burst produced by actively phagocytosing macrophages in the capsule wall. Distinctive MR features of pyogenic abscesses should afford early and accurate diagnosis.

Brain↗
PubMed1988

Malignant extradural spinal tumors: MR imaging with Gd-DTPA.

Magnetic resonance (MR) imaging with gadolinium diethylenetriaminepentaacetic acid (DTPA) was performed in 12 patients with neoplasia of the spine and epidural space. Postcontrast images were compared with precontrast images. Gd-DTPA MR images did not improve the detection of tumors affecting the epidural space of the spine. In fact, many lesions were isointense when compared with the intensity of the surrounding bone marrow and were difficult to see. Because of this, contrast material-enhanced images were not sufficient; however, when they were combined with precontrast images, the use of Gd-DTPA improved the delineation and characterization of certain lesions. Gd-DTPA MR images were helpful in differentiating disk herniation from epidural tumors, indicating regions of more active tumor for biopsy, outlining areas of spinal cord compression, and demonstrating tumor response to therapy. Therefore, while it may be unlikely that Gd-DTPA will be used routinely in every case of suspected neoplasia of the epidural space, contrast-enhanced images will undoubtedly have an adjunctive role in certain clinical applications.

Adult↗
PubMed1988

Intraparenchymal brain metastases: MR imaging versus contrast-enhanced CT.

Prospective and retrospective studies of 75 patients were performed to assess the sensitivities of magnetic resonance (MR) imaging and computed tomography (CT) in the evaluation of suspected intraparenchymal brain metastases. The findings on MR images were equivalent to those on CT scans in 49 of the 75 patients; the remaining findings were discordant in 26 patients, and neither MR imaging nor CT was consistently superior. MR imaging demonstrated more metastases in nine of these 26 patients. However, contrast material-enhanced CT scans were superior in lesion depiction in eight of the 26 patients. Large enhanced lesions that were nearly isointense on MR images were seen well on CT scans. In several cases in which results were discordant, gadolinium-diethylenetriaminepentaacetic acid (DTPA)-enhanced MR images were obtained, and this agent behaved similarly to iodinated contrast agents. If indicated clinically, such as before surgery for a single metastasis, the authors perform both MR imaging and contrast-enhanced CT. Gd-DTPA-enhanced MR imaging may prove to be the method of choice for depiction of intraparenchymal metastases.

Adolescent↗
PubMed1988

Acute intracranial hemorrhage: intensity changes on sequential MR scans at 0.5 T.

Thirty-seven patients underwent MR imaging at 0.5 T within 7 days of a CT-documented intracranial hemorrhage. A total of 57 hematomas were evaluated. Twelve patients underwent serial scanning and 12 patients had multiple hemorrhages into different intracranial compartments. The appearances of the hematomas on spin-echo (SE) images with a short repetition time (TR) of 500 msec and short echo time (TE) of 32 msec (SE 500/32), long TR/intermediate TE (SE 2000/60), and long TR/long TE (SE 2000/120) were carefully evaluated with specific attention to the precise time after ictus. Hematomas showed heterogeneous, complex, rapidly changing intensities. There was a significant amount of variation among patients, especially between the third and seventh days. Hematomas studied between 12 and 24 hr after hemorrhage were mildly hyperintense on short TR scans and markedly hyperintense on long TR (intermediate and long TE) scans (stage I). These findings in acute hemorrhage have received little prior attention. Over the next 1-2 days, hematomas became iso- to mildly hypointense on short TR scans and markedly hypointense on long TR scans (stage II). Hypointensity on long TR scans has previously been described at high field strengths; our communication demonstrates that this phenomenon is seen routinely at intermediate field strengths as well. Hematomas became markedly hyperintense on short TR scans beginning on approximately the fourth day postictus and redeveloped hyperintensity on long TR scans approximately 5-6 days after ictus (stage III). By the end of the first week they were hyperintense on all pulse sequences (stage IV). MR findings on the first day after intracranial hemorrhage (in particular, subtle hyperintensity on short TR scans) probably allow for a specific diagnosis, while the variable, hetergeneous, and rapidly changing intensities noted between days 2 and 7 are often less specific.

Acute Disease↗
PubMed1988

Gadolinium-DTPA in the evaluation of intradural extramedullary spinal disease.

Gadolinium-DTPA was used in MR imaging of the spine to determine the ability of a contrast agent to increase the detection and characterization of disease in the intradural extramedullary space. Although MR imaging, especially with recent technological improvements, has been shown to be at least competitive with, and often superior to, myelography and postmyelography CT in the study of intramedullary and extradural disease, its use in the assessment of intradural extramedullary disease has been questioned. We selected 12 patients with intradural extramedullary disease as demonstrated by positive CSF cytology and/or myelographic findings and performed MR examinations on them before and after administering gadolinium-DTPA (0.1 mmol/kg). Gadolinium-DTPA was extremely effective in depicting intradural extramedullary disease of the spine. Small nodules of 3 mm, virtually invisible on noncontrast MR scans, enhanced strongly and were easily detected. In addition, leptomeningeal spread of tumor along nerve roots was also visualized, sometimes more readily than by myelography and postmyelography CT. The remarkable sensitivity of gadolinium-DTPA to intradural extramedullary disease assures its role in future MR examinations of the spine.

Adult↗
PubMed1988

Intramedullary disease of the spine: diagnosis using gadolinium-DTPA-enhanced MR imaging.

Twenty-six patients with suspected lesions of the spinal cord were studied before and after administration of gadolinium-DTPA to assess whether contrast enhancement was useful in the MR evaluation of intramedullary disease. Nine patients had primary tumors, six had benign syringes, three had multiple sclerosis with cord involvement, three had thrombosed vascular malformations, three had probable intramedullary metastasis, and two were normal. Although all lesions were detected on noncontrast MR scans, gadolinium-DTPA was of great help in their delineation and characterization. Specifically, contrast material may be able (1) to localize tumor nidus and separate it from edema, in cases of hemangioblastomas and metastases; (2) to suggest regions of more active tumors, in cases of glioma, for surgical biopsy or removal; (3) to differentiate benign or reactive processes from neoplastic lesions, such as reactive cyst from tumor cyst or hematoma due to thrombosed malformation from tumor hemorrhage; and (4) possibly to differentiate active from inactive lesions, for example, in multiple sclerosis. Because of these advantages, gadolinium-DTPA probably will often be used routinely when intramedullary lesions are detected on noncontrast MR scans.

Adult↗
PubMed1987

Hemorrhagic neoplasms: MR mimics of occult vascular malformations.

The MR scans of 24 patients who had findings previously reported to be characteristic of occult cerebral vascular malformations were reviewed to demonstrate that such findings may also occur in primary or secondary neoplasms. Eighteen of the 24 patients were found to have hemorrhagic neoplasms. Additional criteria, such as multiplicity of lesions and the presence of edema, were of some help in differentiating between occult vascular malformation and hemorrhagic neoplasm. In certain cases, CT was necessary to provide further information, such as the presence of calcification; however, an absolute and accurate diagnosis was impossible in several cases. The striking similarity on MR between cryptic vascular malformation and some hemorrhagic neoplasms is most likely due to the unifying mechanisms that underlie the evolution of extravascular intracerebral blood. Although the preponderance of neoplastic etiologies in our series may be partly due to the strong bias in our sample population toward patients with tumors, it seems clear that when an MR scan discloses findings "typical" of an occult vascular malformation, consideration must also be given to the generally more serious possibility of underlying neoplasm.

Adolescent↗