Streaming hypointensity in hemorrhagic glioblastoma multiforme. An illustrative case.

The computed tomography, the magnetic resonance and the angiographic features of a patient with the unusual findings of multicentric intraparenchymal, subependymal and intraventricular hemorrhage in association with glioblastoma multiforme are presented. The utility of MR in demonstrating an irregular, streaming pattern of hypointensity within the lesion (and thereby suggesting an underlying neoplasm) is briefly discussed.

Practical CT dosimetry.

The dose from computed tomography (CT) examinations is not negligible from a radiation safety standpoint. Occasionally, one encounters a case in which an unsuspected pregnant woman undergoes a CT pelvic scan, and the radiologist is required to estimate the dose to the fetus. This article addresses practical methods of CT dosimetry with a specific discussion on fetal dose estimate. Three methods are described: (1) the use of a dose chart, (2) the pencil ionization chamber method, and (3) the thermoluminescence dosimetry (TLD) method.

Scintigraphy in evaluation of the hypoplastic right hepatic lobe: a rare variant.

A rare variant of right hepatic lobe hypoplasia associated with high gallbladder position in the right upper abdomen is described. Pain is frequent and may be due to cholelithiasis. It is important to recognize this variant because an associated hypertrophic left hepatic lobe can clinically masquerade as an abdominal mass. Radionuclide studies and abdominal computerized tomography are useful in defining the hypertrophied left hepatic lobe and ectopic gallbladder. The duodenum and hepatic flexure are positioned high due to space left by the hypoplastic right lobe.

Discrepant sulfur colloid and radioparticle liver uptake in superior vena cava obstruction: case report.

The presence of collateral venous channels connecting the upper extremity veins and portal vein via the paraumbilical veins is considered the probable explanation for the observed scintigraphic hepatic "hot spot". This is seen in [99mTc]sulfur colloid liver imaging and perfusion lung imaging with 99mTc radiolabeled particles injected into an antecubital vein in the presence of superior vena caval (SVC) obstruction. The typical distribution is one of focal uptake centrally, anteriorly, and inferiorly. An unusual pattern is described in this report and mechanisms proposed for the "diffuse homogeneous" hepatic uptake also observed in a patient with SVC obstruction undergoing a perfusion lung scan.

Thoracic extramedullary hematopoiesis in sickle-cell disease.

The radiographic manifestations of thoracic extramedullary hematopoiesis are unilateral or bilateral, smooth, sharply delineated, often lobulated paraspinal masses without erosion of the vertebral bodies or ribs, sometimes associated with subpleural, paracostal masses. These radiographic findings were encountered in eight adult patients with homozygous sickle-cell disease. In one patient, the masses encompassed essentially the entire thoracic paravertebral area bilaterally. In the other seven patients, the masses were unilateral and limited to the region of the eighth to the 12th thoracic vertebrae. Two of the eight patients had lateral subpleural masses that were not contiguous with the paraspinal masses and that were located medial to the lateral portions of the ribs. Follow-up in seven of the cases ranged from 2 to 15 years and demonstrated, after relatively rapid growth initially, either no change in size or slow growth. Each patient was asymptomatic with regard to the thoracic masses. Histologic verification was not available in any case because of the lack of clinical indication for invasive diagnostic or therapeutic procedures. The presence of well-defined unilateral or bilateral paraspinal masses and/or paracostal masses in patients with homozygous sickle-cell disease and without related symptoms should alert one to the possibility of the presence of extramedullary hematopoiesis. These masses tend to be slow-growing and should not be subjected to aggressive diagnostic and therapeutic measures.

Computed tomography of strangulated gastric hernia complicated by perforation and pneumothorax.

A case of traumatic rupture of the diaphragm with partial gastric herniation is reported. The initial radiographic presentation was left lower lobe pneumonia. Subsequent strangulation and perforation of the stomach caused pneumothorax. Serial chest radiographs, computed tomography of the chest and abdomen with oral contrast, and a high index of suspicion were instrumental to the diagnosis. Pneumothorax, though rare, must be recognized as a morbid, obstructive phase complication of traumatic diaphragmatic hernia requiring immediate surgical intervention.

Sarcoidosis of the parotid gland.

The clinical and radiological features of parotid-gland sarcoidosis in 22 patients are presented. This occurred in association with systemic disease as painless, diffuse and nonnodular parotid swelling. Conventional sialography usually demonstrated normal proximal ducts, a few fragile distal ducts and non-specific parenchymal nodules. Computed tomography, with or without simultaneous sialography, defined and characterised such nodules and demonstrated normal periparotid anatomy. Sialography contributes little additional information to thorough clinical examination in non-nodular or multinodular glands. However, solitary nodules appear to be better investigated by sialography, CT and CT-guided aspiration, thereby allowing diagnosis and direct medical therapy and avoiding surgery. Ultrasonography and nuclear scintigraphy were of little value in this study.

Computed tomography of adult colonic intussusception: clinical and experimental studies.

The CT features of a case of adult ileocolic intussusception and of experimentally induced ileocolic, cecocolic, and colocolic intussusceptions are presented. Both the clinical and experimental cases demonstrated (1) "target" masses with enveloped, eccentrically located areas of low density and (2) interspersed low- and high-density stripes within the intussusception producing a "layered" or "stratified" pattern. This layered pattern of abdominal masses may be characteristic of intussusceptions regardless of location.

Computed tomography of the calvarium: a prospective study.

Retrospective analysis of high-resolution raw scanning data was prospectively applied in the evaluation of lesions of the scalp and the calvarium over a 12-month period. The spectrum of abnormalities identified and the impact of CT on both diagnosis and management of 25 patients are presented. Metastases and traumatic lesions were excluded. CT was useful in both diagnosis and subsequent patient management.

Computed tomography of carotid-cavernous fistula.

Fourteen patients with angiographically-proven carotid-cavernous fistulas were evaluated by computed tomography (CT). Unilateral or bilateral exophthalmos was noted in 12 patients. Slight blurring of the margin of the globe was present in two, presumably due to pulsations of the globe or conjunctival edema. Superior ophthalmic veins were prominent in 12 patients and were often larger on the side of the fistula. Irregularity or absence of contrast enhancement of the superior ophthalmic vein may indicate partial or complete thrombosis. Focal bulging or diffuse distention of the cavernous sinus was noted in nine patients. Enlargement of the extraocular muscles was observed in seven with swelling of the eyelids and edema of the conjunctiva in eight patients. The pattern of venous drainage, type of fistula, and time intervals between trauma, commencement of fistula, and CT scan may affect the CT manifestations of carotid-cavernous fistulas.

Inconsistent venous opacification: a pitfall of epidural venography.

The lumbar epidural venograms of 45 consecutive patients with prior normal or equivocal myelographic examinations were reviewed. Each venographic injection was performed using transfemoral double-catheter technique, abdominal compression, Valsalva maneuver, and serial filming for 12 sec. There was a 30% incidence of false "occlusions" of epidural veins suggestive of compression by a herniated intervertebral disk. These false venous occlusions were demonstrated to be such by both subsequent opacification of previously nonopacified veins and lack of opacification of previously opacified veins during repeat venography. In view of the significant incidence of spurious venous occlusions in this series, It is recommended that epidural venography with single injection should be interpreted with caution except for normal studies.

Computed tomography in acute posterior fossa infarcts.

Thirty-one cases of acute posterior fossa infarcts are reported. CT evidence of obliterated posterior fossa cisterns and hydrocephalus indicates a grave prognosis due to brainstem compression. Progressive obliteration of posterior fossa cisterns may be used as an indicator for surgical decompression. Patients with intact posterior fossa cisterns had good recoveries without surgical treatment. CT can be used to diagnose the very early phase of an acute posterior fossa infarct and has prognostic value in predicting the outcome.

Unusual neuroradiological features of intracranial cysticercosis.

The authors describe various new neuroradiological findings in cysticercosis cerebri. Features discussed include: (a) contrast enhancement in cysticercosis, including enhancement of an intraventricular cyst, basal meningeal enhancement, and enhancement in association with granulomatous reaction to cysticercosis; (b) positional cyst alterations, including cyst mobility and positional changes in cyst configuration; (c) neuroradiological features of foramen of Monro obstruction, which may be unilateral or bilateral, and may be due to cysts or adhesions; and (d) unusual angiographic features, including two cases of ring stains which corresponded to ring enhancement on CT, and a mycotic aneurysm associated with cysticercosis. For this study, the authors evaluated 102 cases of cysticercosis; 12 case reports are presented herein.

Computed tomography of posterior fossa trauma.

A group of 1,700 cases of head trauma were reviewed to determine the incidence of posterior fossa injuries and to assess the value of computed tomography (CT) in their diagnosis and management. In 57 cases (3.3%), the most significant and primary injuries were within the posterior fossa. These included epidural hematoma (EDH), acute and chronic subdural hematoma (SDH), and parenchymal hemorrhage and contusion of the cerebellum and brainstem. The prognosis varies with the location and severity of the injury. Brainstem injuries are associated with a high mortality rate. Computed tomography proves particularly useful in the early recognition of brainstem injury. The demonstration by CT of obliteration of the cisterns surrounding the brainstem is a reliable sign of a grave prognosis in brainstem injury. Contrast enhancement is useful in demonstrating whether the dural sinuses are displaced, thus differentiating EDH from SDH. Except in the rare case of vascular injury unassociated with EDH, CT correlated with the neurological examination is an accurate method of determining the nature, location, and extent of significant posterior fossa injury. Scans of high quality are mandatory, and frequent supplementary contrast studies are recommended.

CT of brainstem injury.

Cranial computed tomography (CT) scans of 1,600 head trauma patients, 67 of which demonstrated evidence of brainstem injury, were reviewed. CT diagnosis of brainstem injury was based on direct and indirect evidence. Direct signs, which include focal hemorrhage, significant intraparenchymal contrast enhancement, hemorrhagic contusion, and edema of the brainstem, appear as areas of high density, mixed density, and low density on the CT scan. Indirect signs are obliteration of the pontine, cerebellopontine angle, and perimesencephalic cisterns. Mortality and morbidity rates after brainstem injury are 2-3 times greater than for head trauma with descending transtentorial herniation, but without brainstem injury.