Hemorrhage within pituitary adenomas: how often associated with pituitary apoplexy syndrome?

To determine the clinical significance and specificity of suspected intratumoral hemorrhage in pituitary adenomas, we reviewed the clinical presentations, CT results, and findings at surgery in 12 patients who had hyperintense signal within intrasellar and suprasellar masses on short TR/TE spin-echo MR pulse sequences. Eight of the cases were confirmed at surgery. In seven of the operated cases, hemorrhage was found within pituitary adenomas and in the eight case there was hemorrhage but no identifiable adenomatous tissue. Nine of the 12 patients had CT scans; three had focal areas of increased attenuation, four had focal areas of decreased attenuation, and two had uniform hypoattenuation. All nine of these CT abnormalities correlated with areas of hemorrhage on MR. Three patients had clinical apoplexy; in two there was increased attenuation on CT and in one it was decreased. We found that intratumoral hemorrhage may be seen without clinical evidence of pituitary apoplexy, and that the areas of hemorrhage can appear as low attenuation on CT. CT may be better for visualizing intratumoral hemorrhage within the first few days, but MR is more sensitive in detecting and following the hemorrhage in the subacute stage.

Xenon-CT cerebral blood flow evaluation of cerebral ischemia in children and young adults

Xenon-CT cerebral blood flow determinations in 20 children and young adults (age less than 40) who presented with cerebral ischemia were retrospectively reviewed for evidence of unifocal or multifocal ischemic disease. These results were compared with the findings of conventional CT and magnetic resonance (MR) examinations in the same patients. Xenon-CT revealed additional lesions or added significant pathophysiological information in 80% of patients scanned by noncontrast CT, 89% scanned by postcontrast CT, and 58% scanned by MR. Xenon-CT is a useful adjunct to MR and conventional CT in the evaluation of cerebral ischemia in children and young adults.

The temporomandibular joint

MRI is the procedure of choice for diagnosing most internal derangements. MRI provides images that not only demonstrate bony detail but show excellent representation of soft tissues in both anatomic and semifunctional relationships. MRI does not use ionizing radiation and has no known adverse effects. Multiplanar imaging allows a three-dimensional analysis of the TMJ, providing a more complete assessment of the condyle, articular disc, fossa relationships. Whenever capsular adhesions or disc perforations are suspected and are not demonstrated with MRI, then arthrography should be performed.

Imaging modalities for the study of the temporal bone

During the past 30 years, rapid and extensive progress has been made in diagnostic imaging of the petrous temporal bone, especially in the techniques of complex motion (pluridirectional) tomography, computed tomography, and magnetic resonance imaging. Because there are a variety of imaging techniques for evaluation of the petrous temporal bone, it is essential to utilize the optimal examinations. Economic factors and the need to reduce unnecessary radiation exposure for the patient are both important considerations.

Traumatic injuries of the temporal bone

The most common serious consequences of trauma to the temporal bone are hearing loss and facial nerve paralysis. In order to prevent these sequelae, radiologic evaluation is often necessary. CT offers specific information about the extent of injury, including the presence of bony fragments that need removal in order to free the facial nerve.

CT and angiographic correlation of severe neurological disease in toxemia of pregnancy

Two patients with severe cerebral symptoms of toxemia of pregnancy were examined using computed tomography (CT) and angiography. CT disclosed extensive areas of low attenuation within the cerebral hemispheres. Angiography revealed constriction and narrowing of proximal and peripheral vessels suggesting vasculitis with extensive areas of impaired regional cerebral blood flow. A review of the known pathology and the theories regarding the pathophysiology of the cerebral effects of toxemia is presented.

The bright choroid plexus on MR: CT and pathologic correlation

Fourteen patients studied with MR imaging were found, incidentally, to have unusually bright, large choroid plexus glomera on T2-weighted sequences. A group of 167 patients was then examined retrospectively for size and intensity of the choroid plexus glomera on T2-weighted images. In the latter group of 167 patients, 66 (39.5%) had bright choroid plexus glomera. Of those who had bright choroid plexus glomera, eight of the 14 initial group and 11 of the 66 patients studied retrospectively had previous CT scans. The typical CT appearance of these bright glomera consisted of nonenhancing central regions of low (but not negative) attenuation with peripheral calcifications in the majority. The remainder showed noncalcified glomera. Fifty-two glomera were obtained at autopsy and examined retrospectively. Eight showed small, variably sized masses with lipid deposits, neuroepithelial microcysts, and peripheral psammoma body calcifications. One patient who died had a bright choroid plexus glomus on MR, and his glomera showed the same pathologic findings. The autopsy findings were believed to be typical pathologically for early xanthogranulomata formation. These early xanthogranulomatous changes appear to be of little clinical significance but must be differentiated from other lesions that can produce bright or enlarged choroid plexus glomera on MR.

Computed tomography of the normal temporomandibular joint

A study was made in two parts, retrospective (I) and prospective (II), on two samples of 36 and 17 individuals, respectively, who had temporal bone CT studies for reasons unrelated to TMJ pain and dysfunction. Groups I and II had no radiographic signs of TMJ disease and Group II had neither radiographic nor clinical signs of TMJ disease. Both groups were considered to have normal joints. Joint morphometrics for the two groups (I/II) were as follows; transverse condylar dimensions were 18.5/18.1 mm. Condylar angulation averaged 24 degrees/25 degrees and intercondylar distance averaged 83/83 mm while extra condylar distance averaged 118/118 mm. The condyle in the sagittal plane showed a smooth and rounded form with anterior-superior joint space averaging 1.9/1.7 mm while the central-superior joint space averaged 2.3/2.2 mm. The medial-horizontal joint space averaged 3.9/3.7 mm. The slope of the central portion of the articular eminence averaged 60 degrees/60 degrees in the sagittal plane.

Computed tomography of condylar and articular disk positions within the temporomandibular joint

The computed tomograms of temporomandibular joints in 25 patients (41 joints) were retrospectively evaluated for condylar position and joint space with General Electric computer software. Computed tomography scans of the temporomandibular joint were made in the axial plane with the teeth in centric occlusion, and measurements were made from vertically reformatted images. Interarticular joint spaces were measured anterosuperiorly, superiorly, posterosuperiorly, and posteriorly from the condylar surfaces. This was repeated in five equidistant (3.1 mm) serial sagittal planes across the condyle, beginning and ending, on average, 2.5 mm from the lateral and medial condylar poles. Articular disk positions (anterolateral, anterior, anteromedial, medial, and normal) were correlated with condylar position. Significant differences between disk positions and joint spaces were found most frequently in the anterosuperior and the superior joint interval. When the disk was positioned normally, the anterosuperior joint space was consistent (1.5 to 2.0 mm) across the joint (standard deviation, 0.3 to 0.8 mm). The superior, the posterosuperior, and the posterior joint spaces in the normal joint were greater than the anterosuperior joint space. When the disk was anterior to the condyle, the anterosuperior joint interval was widened. When the disk was medial, the superior joint space was significantly wider than normal across the breadth of the condyle. In those joints in which the disk was anteromedial, there was an absence (0.2 mm) of joint space, and this occurred in all areas of the condyle except in its medial one fourth. In the internally deranged joint, joint space narrowing may be focal in nature.

CT evaluation of trauma to the temporomandibular joint

The computed tomograms of 43 patients who had suffered craniofacial trauma and who were referred for evaluation of complaints of temporomandibular joint (TMJ) pain and dysfunction were reviewed. Fifteen of the 43 patients (34%) had sustained fractures, 16 (37%) had documented articular disc derangements without associated fractures, and 32 patients (74%) had degenerative joint changes. Computed tomography (CT) showed fractures, degenerative joint changes, and articular disc displacements not seen on conventional radiographs indicating that CT is particularly useful when patients' symptoms are not adequately explained by conventional radiographs or tomograms.

Operative balloon angioplasty in the treatment of internal carotid artery fibromuscular dysplasia

Seven patients with symptomatic fibromuscular dysplasia have had eight internal carotid arteries treated by operative balloon dilatation. This technique is described in detail and provides three distinct advantages over conventional graduated intraluminal dilatation--atraumatic passage of the catheter through the affected vessel with fluoroscopic guidance; precise dilatation of the involved segment of the internal carotid artery; and the application of a radial force against the arterial wall rather than a longitudinal shear force, thereby making intimal damage less likely. There were no treatment complications in this group of patients. This technique of balloon angioplasty is compared with the results of treatment in eight patients with fibromuscular dysplasia of the internal carotid artery, who had percutaneous transfemoral angioplasty. Long-term follow-up revealed the resolution of symptoms in all patients.

Pericerebellar fluid collections in infancy, sequelae of birth injury? A retrospective CT study

Retrospective analysis of axial CT scans from 600 consecutive pediatric patients revealed 37 patients (6%) with abnormal low density pericerebellar spaces. Fourteen of these 37 patients (38%) were diagnosed as cerebellar atrophy, whereas 23 of the 37 patients (62%) were diagnosed as mass-like pericerebellar fluid collections. Detailed analysis of the morphology of these spaces suggests that the CT criteria proposed in this paper distinguish between (a) those low attenuation pericerebellar spaces that represent cisternal dilatation caused by cerebellar atrophy (Group I - Atrophy) and (b) those low attenuation pericerebellar spaces that represent low density mass-like collections of fluid which distort a relatively normal cerebellum (Group II - Collections). Analysis of the medical records of the patients in Group II - Collections reveal a high incidence of prematurity, developmental delay, difficult birth and head trauma, possibly indicating that such collections represent sequelae of birth.

Cerebral vasoconstriction in toxemia

Three patients with toxemia developed acute neurologic deterioration postpartum. In all, cerebral angiography revealed widespread arterial vasoconstriction. Cerebral vasoconstriction may be an important cause of neurologic complications in toxemia.

Computed tomography of children and adolescents with suspected spinal stenosis

Spinal stenosis in children and adolescents is a rare condition that should be considered in patients with appropriate clinical signs and symptoms. We describe and discuss four cases of spinal stenosis in children and adolescents diagnosed by CT. In all these cases, CT was beneficial at demonstrating and defining the nature and location of suspected spinal stenosis.

CT number characteristics of malpositioned TMJ menisci. Diagnosis with CT number highlighting (blinkmode)

The use of computed tomography (CT) number highlighting ("blinkmode") for diagnosing malpositioned temporomandibular joint menisci was investigated. By determining the average CT number, standard deviation, and range for specific periarticular tissues, it is possible to tell how much their attenuation values overlap and, therefore, whether there is a sound basis for distinguishing the disc from adjacent tissues. Fresh and fresh-frozen cadaver specimens, were scanned in axial and direct sagittal planes with 1.5-mm thick overlapping soft-tissue sections. CT number measurements were made for tendon, muscle, fat, and meniscus. Patients also were scanned with overlapping 1.5-mm thick axial soft-tissue sections in order to compare the range of CT numbers in cadavers with that in living subjects. Cadaver joints were cryosectioned at 0.5-mm intervals in the same planes as their CT sections, and the tissue sections were compared with their respective CT highlighted sections. For patients the average CT numbers in Hounsfield units were 88 for tendon, 67 for muscle, -25 for fat, and 100 for meniscus. Fresh unembalmed cadavers showed a higher CT average number for tendon and a lower average CT number for fat. The anatomic sections confirmed the meniscal position seen in the highlighted sections in nine of ten joints (90%) and was equivocal in one. Misshapen and malpositioned discs are seen readily with the blinker function; thinned and normal discs are not. The tendinous insertion of the lateral pterygoid muscle may be confused for meniscus in the medial aspect of the TMJ.(ABSTRACT TRUNCATED AT 250 WORDS)

Magnetic resonance imaging of the normal carotid bifurcation

A Siemens 0.5 Tesla Magnetic Resonance Imaging (MRI) system was used with the saddle head coil and transverse scout localization for imaging 10 normal cervical carotid artery bifurcations in the sagittal plane. Good to excellent visualization of the flow voids and vessel contours was accomplished in all cases. Careful technique and patient cooperation are required.

Radiation dose in radiography, CT, and arthrography of the temporomandibular joint

Thermoluminescent dosimetry studies were performed on a Rando Humanoid head phantom to compare radiation dosages used in temporomandibular joint examinations. Studies included transaxial and direct sagittal high-resolution CT, reduced milliamperage dynamic CT, tomoarthrography, pluridirectional and linear tomography, pantomography, transcranial plain films, and fluoroscopy. Radiation doses were determined for the brain, lens, pituitary gland, condylar marrow, and thyroid gland. Condylar marrow received doses of 64 and 52 mGy, respectively, for the GE 9800 and 8800 high-resolution scans; 21 and 17 mGy, respectively, for the dynamically sequenced scans; and 26 mGy for the GE 9800 direct sagittal sections. Tomoarthrography yielded 31 mGy and fluoroscopy 12 mGy. Other lower doses showed 5 mGy for polytomography, 3 mGy for ipsilateral joint linear tomography, 1.9 mGy for the GE 9800 slow ScoutView, 1.8 mGy for xeroradiography, 0.9 mGy for contralateral joint linear tomography, 0.3-0.4 mGy for transcranial plain films and pantomography, and 0.2 mGy for the GE 8800 ScoutView. The estimated error in this study was calculated to be +/- 15%. On a relative scale, the radiation doses from high-resolution CT and tomoarthrography are high, dynamic CT yields a medium dose, and all other tomographic and plain-film techniques yield low doses.

Correlative thin section temporomandibular joint anatomy and computed tomography

The author believes that multiplanar CT imaging serves to distinguish the articular disc from other tissues of similar density and is necessary for a detailed temporomandibular joint survey.

Fibromuscular dysplasia of the internal carotid artery treated by operative transluminal balloon angioplasty

Operative treatment of critical stenoses of the internal carotid artery secondary to fibromuscular dysplasia has been performed for nearly 2 decades using graduated metal dilators. While percutaneous transluminal balloon angioplasty of the internal carotid via the femoral artery has several advantages over the operative metal dilator method, cerebral embolization is a matter for concern. The authors have performed operative transluminal balloon angioplasty in such cases, permitting backbleeding with removal of any thrombi or debris. This technique combines the advantages of dilatation by a Grüntzig balloon with post-dilatation carotid backbleeding. Five patients have been successfully treated thus far using this technique.

Computed tomography of local complications of temporal bone cholesteatomas

The preoperative temporal bone CT scans of 13 patients with surgically proven acquired cholesteatoma were retrospectively reviewed for bony erosions and for extension beyond the temporal bone. A correlation with the clinical and surgical findings was also carried out. The CT findings are discussed and illustrated as well as some pitfalls in the evaluation of bony erosions. The appearance of "autoantrectomy" caused by a dry, self-cleaning, well ventilated cholesteatoma is also discussed and illustrated.

Normal frontal lobe gray matter-white matter CT volume ratio in children

We attempted to establish a computed tomographic value representing the normal volume ratio of gray matter to white matter (G/W) in children in order to have a baseline for studying various developmental disorders such as white matter hypoplasia. The records of 150 children 16 years of age or younger who had normal cranial computed tomography were reviewed. From these a group of 119 were excluded for various reasons. The remaining 31 were presumed to have normal brains. Using the region of interest function for tracing gray and white matter boundaries, superior and ventral to the foramen of Munro area, measurements were determined for consecutive adjacent frontal slices. Volumes were then calculated for both gray and white matter. A volume ratio of 2.010 (sigma = 0.349), G/W, was then derived from each of 31 children. The clinical value of this ratio will be determined by future investigation.