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Biomedical subjects

C F Lanzieri

Publications and source records attributed to C F Lanzieri.

At least 19 recordsLinked to original sources

Papillary endolymphatic sac tumors: CT, MR imaging, and angiographic findings in 20 patients.

PURPOSE: To determine the computed tomographic (CT), magnetic resonance (MR) imaging, and angiographic findings of papillary endolymphatic sac tumors. MATERIALS AND METHODS: Clinical and imaging studies in 20 patients (aged 17-65 years) with histopathologically proved papillary endolymphatic sac tumors were retrospectively reviewed. Patients underwent CT (n = 18), MR imaging (n = 15), or angiography (n = 12). CT scans were evaluated for bone erosion and calcification; MR images, for signal intensity, enhancement patterns, and flow voids; and angiograms, for tumoral blood supply. RESULTS: All tumors were destructive and contained calcifications centered in the retrolabyrinthine region at CT. The MR imaging appearance varied with lesion size; 12 of 15 tumors showed increased signal intensity at T1-weighted imaging. The high-signal-intensity area was circumferential in lesions 3 cm or smaller and was scattered throughout the lesion in advanced tumors. Only tumors larger than 2 cm had flow voids. The blood supply arose predominantly from the external carotid artery. Large tumors had additional supply from the internal carotid and posterior circulation. CONCLUSION: Papillary endolymphatic sac tumors are destructive, hypervascular lesions that arise from the temporal bone retrolabyrinthine region. Increased signal intensity at unenhanced T1-weighted MR imaging is common and may help distinguish these lesions from more common, aggressive temporal bone tumors.

Adenocarcinoma

Treatment of embolic stroke as a medical emergency. Implications in a managed care environment.

Encouraging innovations should be a concern of the providers/gatekeepers of health-care if lower health-care costs are to become a reality. Controlled prices and improper incentives will dramatically slow innovation in American medicine. For the vertically integrated health-care system providing capitated coverage, the aggressive treatment of stroke is a sound financial decision.

Cerebrovascular Disorders

Correlative measurement of anterior margin of the anulus for surgical planning.

STUDY DESIGN: This study was a retrospective anatomic correlation of intervertebral disc dimensions with current surgical guidelines. OBJECTIVES: To develop safer guidelines for disc instrumentation. SUMMARY OF BACKGROUND DATA: Anterior perforation of the anulus fibrosus and injury to intra-abdominal structures is a known complication of lumbar discectomy. Coplanar magnetic resonance imaging of the lumbar intervertebral discs could decrease the rate of complication using axial 11-weighted scans. METHODS: Three measurements through the intervertebral discs of the lumbar spine were taken in 50 patients. These were correlated with current surgical guidelines for lumbar instrumentation. RESULTS: Most of the measurements exceeded the current suggested guidelines for instrumentation at 3 cm. CONCLUSIONS: Current guidelines for introduction of instruments into the lumbar disc spaces should be reevaluated. Appropriate measurements should be made on an individual basis.

Adult

The calvarium.

The calvarium is a crucial structure that can manifest a great deal of pathology. The plain film remains the main imaging modality, although CT and MRI are becoming increasingly important. We discuss its anatomy, normal variants, congenital and developmental anomalies, hematologic disease, idiopathic disorders, neoplasms, metabolic disease, trauma, and the postoperative skull. Whenever possible, we emphasize CT and MRI.

Bone Diseases

Complementary use of computed tomography and magnetic resonance imaging in assessing skull base lesions.

Twenty-six patients underwent computed tomography (CT) and magnetic resonance imaging (MRI) of skull base lesions at the Cleveland Clinic Foundation. CT provided improved bone detail, documenting invasion of the lamina papyracea, orbital floor, fovea ethmoidalis, cribriform plate, pterygoid plates, hard palate, and skull base. MRI defined invasion of the orbit, dura, brain, and cavernous sinus. Improved soft-tissue-tumor interface was evident on MRI. MRI was superior to CT in determining carotid artery involvement. MRI distinguished between tumor and retained secretions in the paranasal sinuses. Combining radiographic tumor staging reliably predicted surgical findings; however, MRI consistently yielded sufficient diagnostic information and the additional expense of performing two imaging procedures may not be justified.

Angiography, Digital Subtraction

Use of gadolinium-enhanced MR imaging for differentiating mucoceles from neoplasms in the paranasal sinuses.

The purpose of this study was to determine whether additional clinically useful information could be obtained from gadolinium-enhanced magnetic resonance (MR) imaging compared with the information obtained from nonenhanced MR imaging and computed tomography (CT). Therefore, the authors selected 41 patients, whose results at CT examinations demonstrated a variety of pathologic conditions of the paranasal sinuses, to undergo MR imaging both with and without the use of gadopentetate dimeglumine for contrast enhancement. In 22 of 35 cases of neoplasms and mucoceles occurring separately, the lesions were correctly differentiated by established MR signal criteria alone. However, 32 of these 35 cases were accurately differentiated when gadolinium-enhanced MR images were obtained. Six cases demonstrated co-existing neoplasm and mucocele: Gadolinium-enhanced MR enabled correct differentiation of five of these lesions, while unenhanced MR enabled correct differentiation of three. On the basis of these results, the authors conclude that the use of gadopentetate dimeglumine for contrast enhancement at MR imaging is useful for differentiating mucoceles from neoplasms in the sinonasal tract.

Contrast Media

Magnetic resonance imaging of the nasopharynx.

Imaging of the upper aerodigestive tract, mainly the nasopharynx and oropharynx, has always challenged the radiologist. It is clear that MRI has a leading role in the diagnosis and treatment planning of patients with diseases of the head and neck. This is especially true in the nasopharynx. Although improvements have been made in x-ray diagnosis through the years, subtle diagnoses have been difficult to make because of the variations in airway contour and the superimposition of areas of interest. CT allowed the deep soft tissue planes to be evaluated and provides a complement to the physical examination of the nasopharynx, oral pharynx, and skull base. MRI possesses many advantages over other imaging modalities. The ability to differentiate between inflammatory and neoplastic diseases is extremely important for tumor staging and patient management. At the present time it is not possible to predict the histology of a nasopharyngeal tumor, but the ability to differentiate between various histologic types would be of obvious importance. More experience is needed before this bridge can be crossed.

Carcinoma, Squamous Cell

Three-dimensional surface rendering of nasal anatomy from computed tomographic data.

This article investigates the potential of using three-dimensional surface-rendered computed tomographic reconstructions for demonstrating normal and pathologic intranasal anatomy. Three-dimensional surface renderings of the intranasal structures were generated in 38 patients from coronal high-resolution computed tomographic images. Because of the complex anatomy, three-dimensional images were believed to be useful for surgical planning. There may be a correlation between the appearance of the uncinate process and severity of inflammatory sinus disease.

Humans

MR imaging characteristics of tuberculous spondylitis vs vertebral osteomyelitis.

Retrospective evaluation was made of four patients with tuberculous spondylitis who had been studied by MR with T1- and T2-weighted images in the sagittal plane and spin-density-weighted images in the axial plane. Evaluation was made of the distribution of abnormal signals within the body and posterior elements of the vertebrae, the intervertebral disk, and the associated paraspinal and epidural areas. In two of the cases, three-level involvement was seen with noninvolvement of intervening disks; metastases were misdiagnosed. One patient had anterior/inferior erosion of the vertebral body without visualization of the disk. The last patient had the more typical MR characteristics of intervertebral disk infection. Plain film examination showed only degenerative changes in three of the four cases. MR revealed more extensive involvement than the plain films did. Involvement of the posterior element and posterior vertebral body was prominent in three of the four cases. This is a significant finding since these patients are more likely to have neurologic symptoms and require laminectomy. Follow-up examinations in two cases showed increased signal on T1-weighted images, suggesting infiltration of hemopoietic marrow with fat, as has been described for degenerative osteoarthritis. The anatomy of the microcirculation of the vertebral body is related to the patterns of vertebral osteomyelitis, and discrepancies can be seen between the findings in our cases and the MR criteria previously noted for pyogenic vertebral osteomyelitis. The MR findings in our patients generally were more typical of neoplasm than of infection. These findings may reflect the characteristics of the tuberculous organism relative to the age-dependent pattern of vertebral microcirculation. Correct diagnosis of tuberculous spondylitis in young to middle-aged adults requires correlation of MR and clinical findings.

Adolescent

The preoperative venogram in planning extended craniectomies.

A technique of extended craniectomy sometimes allows removal of large central or transtentorial mass lesions at a single operative sitting because it affords better exposure and control of normal structures. While seeking to avoid multiple craniotomies, this method requires permanent ligation of the transverse venous sinus. Unless there is adequate collateral venous drainage from the ipsilateral hemisphere, the patient is at risk for venous infarction in the post-craniectomy period. The purpose of this study is to propose a method of establishing the presence of collateral venous drainage preoperatively. Each carotid artery is injected with the head in a neutral position and with the head turned to the side ipsilateral to the carotid artery injection in an attempt to divert the venous flow. Fifty patients were examined using this method; seven were being evaluated for possible craniectomies. The technique identified nine patients with potential venous collaterals (20%). They would otherwise have been considered nonoperable: two of the six patients eventually operated upon (33%) fell into this category. In general, the operative procedure may be safe more often on the left than the right (45%) vs (20%). Particular attention must be given to the pattern of venous drainage from the posterior temporal lobe to avoid isolation of the venous drainage from this area.

Adult

Differentiation of large suprasellar masses by evaluation of the superior margin.

Differentiation of suprasellar masses by computed tomography criteria depends on intrasellar extension, patterns of calcification and enhancement, associated bony reaction, and cystic changes. In the case of a homogeneously enhancing suprasellar mass that does not exhibit any of these differentiating findings, separating a suprasellar meningioma from a large suprasellar pituitary adenoma has been quite difficult. We reviewed the computed tomography findings of 42 such tumors. There were 19 meningiomas and 23 pituitary adenomas chosen that had few or none of the commonly applied findings used in differentiation. Evaluation of the superior contour of these masses seems a reliable sign to use in this situation. A single upward convex curve correlated with a meningioma in 15 of 19 cases (78%), whereas a multiple upward convex curve correlated with a pituitary adenoma in 19 of 23 cases (82%). Although some pitfalls were encountered when employing this sign--such as pseudolobulations caused by the adjoining cavernous sinus, dural, or vascular structures--it nonetheless led to the correct diagnosis in approximately 80% of cases.

Adenoma

Cystic adult medulloblastomas.

The computed tomography scans of four patients who had a medulloblastoma are reviewed. In all the cases, atypical findings were present--specifically, cystic or lucent areas within the tumor. The importance of this uncommon finding associated with adult medulloblastoma is discussed.

Adolescent

The postcraniectomy site: CT appearance.

The hospital records and computed tomographic (CT) scans of 124 postcraniectomy patients were reviewed. The normal CT appearance of the operative site was defined and referred to as the "meningogaleal complex" (MGC). The CT characteristics of postoperative infections, intraaxial tumor recurrences, extraaxial tumor recurrences, and the various forms of postoperative cerebrospinal fluid collections were identified and differentiated by comparison with the normal scans. Specifically, when compared with the "postoperative baseline" anatomy, smooth thickening of the MGC often indicated postoperative infection (six cases), while nodular thickening heralded recurrent extraaxial tumor (eight cases). Recurrent intraaxial tumor adjacent to the craniectomy site caused no change in the MGC itself. A knowledge of the normal postoperative appearance of the MGC as well as good communication with the neurosurgeon can allow earlier detection of postoperative complications.

Adult