Evaluation of cerebral aneurysms with helical CT: correlation with conventional angiography and MR angiography.

PURPOSE: To evaluate detection of intracranial aneurysms with helical computed tomography (CT) and compare the results with those of conventional angiography and magnetic resonance (MR) angiography. MATERIALS AND METHODS: Twenty-one patients with 30 intracranial aneurysms were studied with helical CT and conventional angiography; 17 of the patients (24 aneurysms) also underwent MR angiography. RESULTS: All aneurysms 3 mm or larger in greatest dimension were seen with helical CT and MR angiography; no aneurysms smaller than 3 mm were apparent with either modality. Of the 21 aneurysms demonstrated with both helical CT and MR angiography, 11 were seen equally well with both techniques; six were seen better with helical CT owing to flow-related or motion artifact at MR angiography, and four were seen better with MR angiography because calcium partially obscured them at helical CT. CONCLUSION: Helical CT is a promising noninvasive method of imaging the intracranial vasculature and is comparable with standard MR angiographic techniques in demonstrating aneurysms.

Detection of intracranial abnormalities in patients with chronic fatigue syndrome: comparison of MR imaging and SPECT.

OBJECTIVE: Chronic fatigue syndrome is a recently characterized condition of unknown origin that is manifested by fatigue, flulike complaints, and neurologic signs and symptoms, including persistent headache, impaired cognitive abilities, mood disorders, and sensorimotor disturbances. This syndrome can be difficult to diagnose clinically or by standard neuroradiologic tests. We performed MR imaging and single-photon emission computed tomography (SPECT) in patients with chronic fatigue syndrome to compare the usefulness of functional and anatomic imaging in the detection of intracranial abnormalities. SUBJECTS AND METHODS: Sixteen patients who fulfilled the Centers for Disease Control, British, and/or Australian criteria for chronic fatigue syndrome had MR and SPECT examinations within a 10-week period. Axial MR and SPECT scans were analyzed as to the number and location of focal abnormalities by using analysis of variance with the Student-Newman-Keuls option. MR imaging findings in patients with chronic fatigue syndrome were compared with those in 15 age-matched control subjects, and SPECT findings in the patients with chronic fatigue syndrome were compared with those in 14 age-matched control subjects by using Fisher's exact test. The findings on MR and SPECT scans in the same patients were compared by using the Wilcoxon matched-pairs signed-ranks test. RESULTS: MR abnormalities consisted of foci of T2-bright signal in the periventricular and subcortical white matter and in the centrum semiovale; there were 2.06 foci per patient, vs 0.80 foci per control subject. MR abnormalities were present in eight (50%) of 16 patients, compared with three (20%) of 15 age-matched control subjects. Neither of these differences reached significance, although the power of the study to detect differences between groups was small. Patients with chronic fatigue syndrome had significantly more defects throughout the cerebral cortex on SPECT scans than did normal subjects (7.31 vs 0.43 defects per subject, p < .001). SPECT abnormalities were present in 13 (81%) of 16 patients, vs three (21%) of 14 control subjects (p < .01). SPECT scans showed significantly more abnormalities than did MR scans in patients with chronic fatigue syndrome (p < .025). In the few patients who had repeat SPECT and MR studies, the number of SPECT abnormalities appeared to correlate with clinical status, whereas MR changes were irreversible. CONCLUSION: SPECT abnormalities occur more frequently and in greater numbers than MR abnormalities do in patients with chronic fatigue syndrome. SPECT may prove to be useful in following the clinical progress of patients with this syndrome.

Fast spin-echo imaging of intracranial neoplasms.

Our goal was to compare dual echo fast SE (FSE) T2-weighted MRI of intracranial neoplasms with conventional SE (CSE) images. In phase 1 of the study, CSE and FSE dual echo MR studies of 33 patients with intracranial neoplasms and 26 normal controls were separately interpreted by three neuroradiologists blinded to clinical history to ascertain differences in lesion conspicuity. The CSE and FSE images were read independently, in random order, with at least a 3 week interval between readings. In phase 2 of the study, CSE and FSE sequences were compared side by side by three neuroradiologists independently to evaluate lesion conspicuity and artifacts and to determine whether FSE would be an acceptable replacement for CSE imaging. Lesion detection was equivalent in 111 of 117 interpretations (94.9%). The CSE and FSE sequences were equivalent in detecting lesion-associated abnormalities (hemorrhage, calcium, mass effect, edema, and hydrocephalus) and in characterizing lesion size, margins, and signal intensity. Nonspecific T2 white matter hyperintensities were detected more often with CSE, while susceptibility artifacts were less conspicuous on FSE. Ventricular catheters, postoperative soft tissue and bony changes, and postradiation therapy changes were detected equally well on both sequences. In phase 2 of the study, lesion conspicuity and presence of artifacts were felt to be equivalent with the two sequences. The FSE sequences can serve as a rapid, feasible alternative to conventional CSE sequences for intracranial tumor detection.

Imaging of neurologic complications associated with pregnancy.

The occurrence of a neurologic event during pregnancy or the puerperium may have devastating consequences for mother and child. It is imperative that the radiologist be familiar with the entities likely to be encountered in pregnancy so that these patients can be examined rapidly and efficiently. The importance of early and accurate diagnostic imaging is underscored by the fact that most patients are otherwise young and healthy, and prompt institution of appropriate therapy can result in complete recovery. In this report, we illustrate some of the more common neurologic complications that occur during pregnancy and the immediate postpartum period.

Common carotid artery bifurcation: evaluation with spiral CT. Work in progress.

To determine the utility of spiral computed tomography (CT) in evaluation of carotid artery stenosis, spiral CT images of 20 patients were compared with images obtained with conventional angiography (20 patients), ultrasound (US) (15 patients), and magnetic resonance (MR) angiography (six patients). The category of stenosis was determined for each internal carotid artery on the basis of the percentage of narrowing: mild = less than 30%, moderate = 30%-69%, and severe = 70%-99%. Occlusions were also noted. The degree of carotid stenosis determined with spiral CT correlated with that determined with conventional angiography in 92% of cases, with that determined with US in 97% of cases, and with that determined with MR angiography in 100% of cases. Calcifications and large ulcers were also well delineated. Spiral CT provided an accurate anatomic depiction of the carotid bifurcation, which could be helpful in preoperative evaluation. The major disadvantage of the technique was the need to postprocess data to remove veins, calcifications, and bone structures from the images.

Ovarian volumes measured by US: bigger than we think.

Authors have disputed the classic normal ovarian volume measurement of 6 cm3 without reference to a study with a large number of patients. To determine normal sonographic measurements, 762 consecutive female patients were examined. Satisfactory measurements of 1,157 ovaries in 725 of these patients were obtained. Average ovarian volumes of 9.8, 5.8, and 3.0 cm3 were obtained for the menstruating, postmenopausal, and premenarchal groups, respectively. These volumes were significantly different for these three menstrual groups (P less than .0001). Significant volume differences were noted when measurements were grouped by decade of life. Volumes peaked in the 3rd decade and declined over the subsequent four decade groups. A significant average volume difference was noted between pregnant (11.1 cm3) and non-pregnant (9.4 cm3) menstruating patients (P less than .0001). No significant differences in volume were noted between right and left ovaries or when the variables of weight, presence of a leiomyomatous uterus, or phase of the menstrual cycle were evaluated.

Studies on the alpha-subunit of bovine brain S-100 protein.

A method is described for the rapid purification of both S-100 protein and calmodulin from crude bovine brain extracts by the use of a fluphenazine-Sepharose affinity column eluted stepwise with decreasing concentrations of free Ca2+. Protein containing only alpha-subunit was purified from preparations of S-100 protein by anion-exchange chromatography. This protein co-migrated with the alpha-subunit of S-100 protein on sodium dodecyl sulphate/urea/polyacrylamide-gel electrophoresis and had an amino acid composition identical with that previously reported for this subunit. The results of u.v.-absorption and fluorescence-emission spectroscopy indicate that the tryptophan residue of the purified alpha-subunit of S-100 protein undergoes a Ca2+-induced change in environment. Measurements of changes in tryptophan fluorescence with increasing Ca2+ concentrations suggest an apparent dissociation constant of the alpha-subunit for Ca2+ of 7 X 10(-5)M in the absence of K+. In the presence of 90mM-K+ this value is increased to 3.4 X 10(-4)M.