Computed tomography of the nose.
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Foreign Bodies↗
Biomedical subjects
A G Osborn
Publications and source records attributed to A G Osborn.
Stereotaxic frame and computer software for CT-directed neurosurgical localization.
A clinical stereotaxic head frame designed for use with computed tomography (CT) body scanners is described. Frame geometry and a CT localization system provide an accuracy and versatility that should lead to optimal clinical usefulness. Initial phantom and clinical studies are presented.
Humans↗
Angiographic spectrum of cervical and intracranial fibromuscular dysplasia.
Cephalocervical or intracranial fibromuscular dysplasia (FMD) can be identified by its characteristic angiographic appearance. Most of these lesions occur adjacent to the C1-2 interspace, characteristically sparing the origins and proximal segments of the major extracranial vessels. Approximately 65% of our patients had bilateral involvement of the cervical internal carotid arteries. Thirty percent were associated with one or more intracranial aneurysms. The vertebral arteries were involved in 10% of the cases. Twenty-four of 25 cases were associated with symptoms of either subarachnoid hemorrhage or focal cerebral ischemia.
Adult↗
Radiologic-pathologic correlation. Epidermoid tumor of the cerebellopontine angle.
This case demonstrated the classic gross pathologic, CT, and MR appearances of epidermoid tumors. The imaging features and differential diagnosis are summarized.
Adult↗
Intracranial meningioma.
This case shows many of the imaging features classically associated with meningiomas. The illustrations show common location, shape, and local effects as well as enhancement characteristics. Hyperostosis and bone destruction, a fluid "cleft" surrounding the extraaxial mass, gray-white interface displacement, and secondary intraparenchymal changes are correlated with gross pathology findings. These key features are summarized in Table 1 and the composite anatomic diagram (Fig. 6).
Aged↗
Intracranial neurenteric cysts: imaging and pathology spectrum.
BACKGROUND AND PURPOSE: Intracranial neurenteric (NE) cysts are rare congenital lesions that may be mistaken for other, more common non-neoplastic cysts as well as cystic neoplasms. We delineate the imaging spectrum, pathologic findings, and differential diagnosis of NE cysts. METHODS: History, imaging, surgical and pathologic findings were analyzed retrospectively in 18 patients with intracranial NE cysts. Fifteen were surgically proved cases; 3 exhibited classic imaging findings and are being followed clinically. RESULTS: Thirteen cysts were located in the posterior fossa; 12 of 13 were extra-axial. Size varied from 1.2 x 0.8 x 0.6 cm to 3.4 x 3 x 2.5 cm. Five were supratentorial, measuring from 7 x 5 x 3 to 9 x 6 x 7 cm. All were frontal and off the midline. Seven of 18 patients had CT scans. Cysts varied widely in attenuation. None enhanced. Eighteen of 18 had MR images. Sixteen of 18 were hyperintense, and 2 were isointense to CSF on T1-weighted imaging. Sixteen of 18 were hyperintense on T2-weighted imaging. All cysts were hyperintense to CSF on fluid-attenuated inversion recovery (FLAIR) sequences. Diffusion imaging was performed on 2 patients. One case showed mild restriction. Mild posterior rim enhancement was seen in 5 cases at the site where the cyst adhered to brain parenchyma. CONCLUSION: The imaging spectrum for NE cysts is broader than previously reported. Intracranial NE cysts should be considered in the differential diagnosis for intracranial extra axial cystic lesions both above and below the tentorium.
Adolescent↗
Is there a scientist in the house? An endangered species: the neuroradiologist as clinician-investigator.
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Humans↗
The radiologic assessment of trigeminal neuropathy.
The clinical and radiologic records of 76 patients with trigeminal neuropathy and an abnormal imaging study (CT and/or MR) were analyzed retrospectively. The trigeminal nerve (cranial nerve V) was divided into proximal (brainstem, preganglionic, gasserian ganglion, and cavernous sinus) and distal (extracranial V1, V2, and V3) segments. Lesions were organized according to segments and correlated with the type and distribution of clinical symptoms or signs. The purpose of the study was to (1) determine the efficacy of clinical localization of cranial nerve V lesions, (2) compare CT and MR for cranial nerve V imaging, (3) develop an MR protocol for effective cranial nerve V imaging, and (4) construct a differential diagnosis by anatomic segment for lesions of cranial nerve V. Clinical localization was found to be extremely inaccurate. CT was not as sensitive as MR for lesions involving the basal cisterns and skull base and will not detect the most common brainstem lesions (small infarcts and multiple sclerosis plaques). The MR protocol developed does not rely heavily on clinical localization. On the basis of lesions found in this series, a differential diagnosis by segment was developed. Patients with cranial nerve V symptoms should undergo MR imaging according to the protocol provided in this article. CT is not as effective as MR in imaging some cranial nerve V segments. Clinical localization is inaccurate.
Adolescent↗
Radiographic evaluation of brachial plexopathy.
Neurologic signs and symptoms of brachial plexopathy may be subtle or confusing, making clinical localization of disease along the length of the brachial plexus difficult. To determine the most direct radiographic approach to diagnosing and anatomically delineating the cause of brachial plexopathy, we reviewed the clinical and radiographic records of 43 patients presenting with signs and symptoms referable to the brachial plexus who received CT and/or myelography as part of their radiographic evaluation. The study population was divided into two groups, those with and those without trauma. Significant deficiencies were detected in the radiographic evaluation of the nontraumatic group, with 35% of these patients having an incomplete or inappropriate CT examination that failed to visualize the full extent of the brachial plexus. In four patients, this led to a significant (greater than 6 months) delay in diagnosis. It was concluded that trauma patients presenting with brachial plexus symptoms should have cervical myelography first, rather than CT. Patients without a history of trauma should be classified on the basis of clinical findings as having central (cord, epidural space, neural foramen) or peripheral (retroclavicular space, axillary apex) disease. If the abnormality is central, myelography should be the first technique used; if peripheral disease is present, CT should be the first study. If the disease extends beyond the confines of the anatomic compartment suggested clinically, the other technique should be used for further evaluation. CT scan protocols for brachial plexus evaluation should employ bolus/drip contrast enhancement to distinguish vascular structures from masses.(ABSTRACT TRUNCATED AT 250 WORDS)
Adolescent↗
CT/MR spectrum of far lateral and anterior lumbosacral disk herniations.
Forty-eight patients had 50 extraforaminal disk herniations (EFDHs) demonstrated on CT and/or MR by (1) presence of disk density or disk signal material lateral to the neural foramen, (2) displacement or obliteration of paravertebral fat, and (3) nerve root or ganglion compression or displacement. Forty-one of 50 EFDHs had a coexisting intraforaminal component; nine of 50 had an isolated far lateral herniated nucleus pulposus. EFDHs typically occurred in the absence of a coexisting intraspinal disk herniation. Migratory fragments were seen in 50% of all cases and were at or cephalad to the interspace of origin in all cases. Forty-six percent of EFDHs were at L2-L3 or L3-L4, although the most commonly affected level was L4-L5 (38%). EFDHs, which were often overlooked (15/50 scans reviewed), are an important preventable cause of failed intraspinal diskectomy. EFDHs can be readily identified on both CT and MR if appropriate scans are obtained from L2 through S1 and if the neural foramina and paravertebral spaces are carefully examined.
Adult↗
Uncovertebral and facet joint dislocations in cervical articular pillar fractures: CT evaluation.
Computed tomographic (CT) scans and plain radiographs of 21 patients with surgically treated fractures or dislocations of the cervical spine were reviewed. CT effectively demonstrated the locked or perched facets and half of the 13 articular pillar fractures. The fracture lines through the articular pillar were difficult to detect in some cases or to distinguish from a facet joint in others. However, distraction of an adjacent uncovertebral or facet joint was demonstrated by CT in each case of articular pillar fracture or locked or perched facet. Therefore, CT demonstration of a distracted facet or uncovertebral joint is an indirect sign of an unstable fracture or of a dislocation that may be more readily recognized on plain radiographs or pluridirectional tomograms.
Cervical Vertebrae↗
Simplified CT-guided stereotaxic biopsy.
A stereotaxic frame worn during computed tomographic (CT) scanning of the head produces landmarks in each section that are used to relate section coordinates to frame coordinates. A small, commercially available, programmable calculator is used to interrelate frame and CT section geometry. The system can be used with any CT scanner that can specify (x,y) coordinates of a pixel, obviating the need for extensive modifications of the CT computer software. Representative clinical cases are presented.
Biopsy↗
Ocular melanoma.
Uveal melanoma is the second most frequent ocular malignancy after metastasis and the most common primary ocular malignant neoplasm in adults. The diagnosis is usually made from clinical examination and ocular ultrasound. CT and MR may be helpful for further evaluation.
Aged↗
Spinal nerve enhancement with Gd-DTPA: MR correlation with the postoperative lumbosacral spine.
PURPOSE: To search for a probable source of the recurrent signs and symptoms associated with lumbosacral postsurgical syndrome on intravenous gadolinium-enhanced MR. METHODS: A retrospective study of 120 patients with recurrent symptomatology following lumbar disk surgery was carried out with spin-echo MR pre- and postenhancement with gadopentetate dimeglumine (0.1 mmol/kg). In addition, 10 asymptomatic subjects were evaluated at least 6 months postoperatively using the same imaging protocol. RESULTS: 21.6% of the symptomatic subjects (N = 26) had enhancement of one or more spinal nerve root. This enhancement was focal or multisegmental, and involved single or multiple nerve roots. The abnormal neural enhancement was associated with otherwise isolated epidural fibrosis in 88.5%, and with herniated nucleus pulposus in the remaining 11.5%. The overall clinical correlation of single root enhancement with a monoradiculopathy and multiroot enhancement with a polyradiculopathy was 95.7%. However, 21.7% of these same cases also showed additional nerve root enhancement that did not have an overt clinical correlation. All of these latter patients were imaged relatively early in the postoperative period (5 days to 8 months). The 10 patients in the asymptomatic group all manifested degrees of postoperative epidural scarring on MR, but no abnormal radicular enhancement or other associated pathology. CONCLUSION: In the chronic postoperative phase (more than 6 to 8 months), the presence of radicular enhancement on MR imaging in symptomatic individuals, and its absence in asymptomatic subjects, suggests that neural enhancement serves as a marker for active neural pathology that may in certain individuals be related temporally to the signs and symptoms associated with the lumbosacral postsurgical syndrome.
Adult↗