Trygve O. Gabrielsen

MR imaging of primary epidermoid tumors

The magnetic resonance (MR) imaging characteristics of five primary intradural epidermoid tumors are described. At 0.35 T, the most consistent finding on spin echo imaging was a tumor signal intensity that differed from brain and CSF. On T1-weighted images [repetition time (TR) 0.5 s, echo time (TE) 30–40 ms] all tumors exhibited a signal intensity intermediate between brain and CSF. On moderately T2-weighted images (TR 2.0 ms, TE 60–80 ms) the tumor signal intensity was greater than brain and CSF in all cases. The tumor signal consistency was mixed in four of five lesions and homogeneous in one. The tumor margins were well defined in all cases; in three cases the tumor margins were irregular, in one case smooth, and in the last case, one margin was irregular and the remaining margins were smooth. These findings are contrasted with the MR appearance of arachnoid cysts. Using identical imaging factors, four arachnoid cysts were studied and exhibited a homogeneous signal intensity that was identical to CSF on all pulse sequences; their margins were smooth and well defined in each case. These MR findings contribute to the characterization of extraaxial lesions.

Premature Closure of the Frontosphenoidal Suture in Synostosis of the Coronal Suture

Fourteen cases of premature coronal synostosis are reviewed. Thirteen of these showed extension into the base of the skull involving the Irontosphenoidal suture. Recognition of this fact is of importance if surgical correction is attempted. Pertinent radiographic findings include narrowing or absence of the coronal suture, shortened frontal bone and anterior fossa, outward and upward sweep of the sphenoid wing and orbital roof, and shallowness of the orbit on the involved side. Because of the basal involvement, simple craniectomy may not be sufficient for correction in infants over two months of age and additional cuts may be necessary.

Gas as a mass: A symptomatic spinal canalicular collection

A symptomatic collection of spinal canalicular gas of degenerative origin was observed by computed tomography. Relief of symptoms followed gas aspiration. The collection involved the lateral recess. Such gas collections do not appear to represent benign, transient entities in all patients.

Cerebral Manifestations of Alveolar Soft-Part Sarcoma

Clinical, pathological, and radiological features of metastatic cerebral lesions resulting from alveolar soft-part sarcoma are presented. Angioarchitecture, scintiscans, and radiotherapeutic findings are discussed. The morphologically indolent nature of the lesion was documented by roentgenographic methods in one case. The unusual juxtaposition of the tumor cells to the endothelium seems responsible for the highly vascular appearance of the lesion on angiography, the frequency of hematogenous spread, and the grave, although delayed, prognosis.

Radio-Frequency Thrombosis of Vascular Malformations with a Transvascular Magnetic Catheter

A tiny magnetic electrode catheter introduced into the human carotid artery has been mechanically and magnetically propelled, with fluoroscopic control, to cranial arteriovenous malformations. Radio-frequency heating of the catheter tip in successive positions occludes abnormal blood vessels.

Roentgenographic appearance of lumbosacral spine and pelvis in tuberous sclerosis.

Anumber of isolated case reports have described lesions of the lumbosacral spine and pelvis in tuberous sclerosis (2–7, 9–11, 13–30). This study was undertaken to evaluate more completely the roentgenographic appearance and frequency of such lesions. Material Only cases with a well documented diagnosis of tuberous sclerosis have been included. Roentgenograms of the lumbosacral spine and pelvis were available on 58 patients ranging in age from eight to sixty-six years (Fig. 1). There were 23 males and 35 females. Findings Lesions in the lumbosacral spine and pelvis were found in 23 of our 58 patients. The age, sex, and extent of such skeletal involvement in these 23 cases are summarized in Table I. The osseous abnormalities were arbitrarily graded as minimal, moderate, or marked on the basis of the number and size of lesions. All were osteoblastic or sclerotic in appearance and ranged in diameter from a few millimeters to a few centimeters. They were usually round or ovoid, although some of the larger lesi...

Seizure Induced Disruption of Blood-Brain Barrier Demonstrated by CT

Computed tomography of the head performed soon after a generalized seizure demonstrated diffuse bilateral contrast enhancement. The patient had undergone visceral angiography for lower extremity ischemia, and a generalized seizure was observed 90 min afterward. Postictal CT, completed without additional contrast medium administration, demonstrated diffuse patchy contrast enhancement of both cerebral and cerebellar hemispheres. The mechanism of seizure induced contrast enhancement on CT is discussed.

Mechanism of Split Cranial Sutures in Metastatic Neuroblastoma

Skull metastases and split cranial sutures frequently occur in patients with neuroblastoma (4, 5, 16). This communication emphasizes the pattern of cranial and intracranial metastases found at autopsy. Radiographic and clinical findings are correlated. Material The present series consists of ten patients with neuroblastoma for whom complete autopsy evaluation was available. These were selected from more than 200 cases coded as neuroblastoma at the University of Michigan Medical Center since 1940. Cases with no autopsy, incomplete autopsy, disputed tissue diagnosis, or incidental finding of neuroblastoma after death from other causes have been excluded. Many of the patients died at home or in other hospitals. Retinoblastomas and neuroblastomas originating from olfactory epithelium (esthesioneuroblastoma, esthesio-neuroepithelioma) or other tissue inside the cranium have been eliminated. Findings A summary of the roentgenographic and necropsy findings for the 10 patients is presented in Table I. Metastases ...

Iohexol versus metrizamide for lumbar myelography: Preliminary report of double-blind trial

Lumbar myelography was performed in 38 patients; 19 received iohexol (an investigational aqueous contrast agent) and 19 received metrizamide. Iohexol is stable in solution, which is not the case with metrizamide. There was no other significant difference in diagnostic utility or quality between the two media. However, there was considerable postmyelography morbidity in the metrizamide group, but no postmyelography morbidity in the iohexol group. Preliminary clinical evidence suggests that iohexol is significantly superior to metrizamide as a contrast agent for lumbar myelography.

The Pontomesencephalic Veins: A Roentgenographic Study

The pontomesencephalic veins have in the past been beautifully demonstrated in roentgenograms of anatomical specimens (2, 3). A few authors have also identified these veins on vertebral angiography performed during life (1, 3–5, 10, 11). The present work is an attempt to investigate the pontomesencephalic venous system in greater detail, using clinical neuroradiological means. The variable roentgenographic appearances of the pontomesencephalic veins, their relationship to the anterior border of the brain stem, and their frequency of visualization on vertebral angiography will be discussed. Anatomy The blood from the major part of the pons and mesencephalon drains in an anterior direction (Fig. 1). Numerous parenchymal veins, on reaching the anterior and anterolateral surfaces of the brain stem, usually empty into larger, longitudinal venous channels which are closely associated with the anterior border of the brain stem (2–4). Occasionally, there may be only a single, midline, longitudinal vein situated b...