We reviewed spinal MR images of 58 patients with 98 compressed vertebrae. Benign (47 vertebrae) or malignant (51 vertebrae) etiology was established by biopsy or radiologic follow-up. Compressed vertebrae were analyzed for presence and characteristics of signal abnormality, altered vertebral contour, Schmorl's nodes, pedicular involvement, and contrast uptake. Statistical analysis was performed. Diffuse and homogeneous decrease in signal intensity on T1-weighted images, convex vertebral contour, involvement of the pedicles, and a lumbar location were more frequently observed in malignant fractures (P < .01). A thoracic location, lack of signal change, or a band-like abnormality and absence of pedicular involvement or contour abnormality characterized benign fractures (P < .01). Schmorl's nodes and enhancement did not help establish a diagnosis. When a constellation of MR criteria are applied, the accuracy of the diagnosis of malignant and benign vertebral compression fractures may reach 94%.

Adult↗

PubMedDate not supplied

Dynamic imaging of intracranial lesions using fast spin-echo imaging: differentiation of brain tumors and treatment effects.

The purpose of this study was to develop a technique for differentiating between recurrent brain tumors and treatment-related changes, such as radiation necrosis, using dynamic MRI. Ninety-five patients with intracranial mass lesions were evaluated using T1-weighted fast spin-echo (FSE) MRI at 1.5 T. Pathologies included treatment-related changes (n = 32), primary tumors (n = 41), metastatic tumors (n = 5), meningiomas (n = 4), and mixed primary/treatment related changes (n = 13). Signal enhancement-time curves were analyzed by fitting to a sigmoidal-exponential function. Maximal enhancement rates were calculated as the first derivative of the fitted curve. Based on the maximal enhancement rates, treatment-related changes could be differentiated from primary tumors, metastatic tumors, and meningiomas at the P < .05 confidence level. Lesions of mixed tumor and treatment-related change had intermediate values. Dynamic MRI can be used to differentiate treatment-related changes from primary tumors in previously treated patient populations based on maximal enhancement rates. Individual case studies demonstrate the clinical significance of these findings.

Adolescent↗

PubMedDate not supplied

Primary cerebral lymphoma in acquired immunodeficiency syndrome (AIDS)--CT manifestations.

Primary lymphoma of the brain in AIDS is being observed with increased frequency; five pathologically proven cases are presented. Although the CT patterns may correlate well with patterns previously described in lymphoma, occasionally an irregular ring-like lesion may occur which is difficult to distinguish from toxoplasmosis or other inflammatory processes without appropriate pathological material.

Acquired Immunodeficiency Syndrome↗

PubMedDate not supplied

A second look at unenhanced spinal magnetic resonance imaging of malignant leptomeningeal disease.

The purpose of this study is to evaluate the use of unenhanced magnetic resonance (MR) imaging in identifying malignant leptomeningeal disease (MLD). Included in this study were fifty patients with evidence of leptomeningeal enhancement on post-gadolinium MR images and with cytological confirmation of MLD. Unenhanced, T1-weighted spin-echo (SE) MR images of the spine were analyzed for loss of cerebrospinal fluid (CSF) clarity, poor definition of the conus medullaris, thickened and clumped nerve roots, and nodules. Patterns of leptomeningeal enhancement on post-gadolinium, T1-weighted SE images were noted. Findings of MLD on unenhanced MR images were observed in 41 (85%) of 48 studies of the lumbar spine, 10 (50%) of 20 studies of the thoracic spine, and two (33%) of six studies of the cervical spine. In the lumbar spine, thickened and clumped nerve roots, poor definition of the conus medullaris, loss of CSF clarity, and nodules were observed with decreasing frequency. The signs of MLD on unenhanced images of the cervicothoracic spine included nodules and clouding of CSF. Patterns of leptomeningeal enhancement included linear, linear/nodular, nodular, enhancement of nerve roots, and stacking, with tumor filling the lumbosacral canal. Findings of MLD were present on 73% of the unenhanced MR images of the spine. Recognition of MLD on unenhanced MR images can guide the appropriate work-up and therapeutic approach.

Adult↗

PubMedDate not supplied

Kissing intrasellar carotid arteries in acromegaly: CT demonstration.

Acromegaly is a disease with protean manifestations that are well described in the literature. One finding infrequently encountered is aneurysmal dilatation of the internal carotid arteries and their branches. A case is presented, with CT documentation, in which the enlarged cavernous portions of the internal carotid arteries prolapsed into the sella turcica and enlarged it. Frontal bossing, frontal sinus enlargement, a dense cortical calvarium, prominent inion, and proptosis secondary to extraocular muscular enlargement were findings also present in this patient. The sella CT appearance has brought the term "kissing intrasellar arteries" to mind to suggest the diagnosis.

Acromegaly↗

PubMedDate not supplied

Aortic arch digital arteriography: an alternative technique to digital venous angiography and routine arteriography in the evaluation of cerebrovascular insufficiency.

Digital arch arteriography is a technique in which the cervicocerebral vasculature is studied by injecting small amounts of contrast material (20 ml or less of diatrizoate meglumine 60%) into the aortic arch. It was used as the initial phase of arteriography in 100 patients with cerebrovascular disease. Five to ten series were obtained in various projections to evaluate the cerebrovascular system. Because suboptimal studies may be repeated, only 3% of carotid bifurcations were suboptimally visualized by digital arch arteriography as compared with 17% by film arch angiography. Intracranial vascular pathology was identified less reliably than with selective angiography. Digital arch arteriography yielded excellent studies in cases when digital venous angiography was suboptimal (20%). Digital arch arteriography may be preferable to digital venous angiography as a screening test in patients with significant cardiac or renal dysfunction because of the lower contrast load.

Aorta, Thoracic↗

PubMedDate not supplied

Axial CT recognition of anteroposterior displacement of fourth ventricle.

The recognition of anterior or posterior displacement of the fourth ventricle on axial computed tomography (CT) has proven to be difficult because the apparent position of this structure is variable and dependent on scanning angle. In most cases direct visualization of a lesion and its relationship to normal anatomic structures allows for the correct assessment. However, in some instances it would be advantageous for lesion localization to be able to identify relatively subtle displacements of the fourth ventricle. This is possible on CT by determining the position of this structure relative to Twining's line (the line between the tuberculum sellae and torcula). The position of the fourth ventricle, tuberculum sellae, and torcula relative to an arbitrary fixed point can be established in virtually all cases, and thus the position of the fourth ventricle relative to Twining's line can be determined. In a control group of 100 patients with normal CT examinations, the ratio of the distance from the tuberculum sellae to the center of the fourth ventricle and the distance from the tuberculum sellae to torcula (Twining's line) was between 0.47 and 0.53. In 66% of the cases the ratio was 0.49-0.51. THere were 54 posterior fossa masses evaluated by this technique. Determination of fourth ventricular position by this method proved to be of particular value in recognizing brainstem glioma, and in determining the site of origin of laterally placed posterior fossa masses.

Adult↗

PubMedDate not supplied

Spinal subarachnoid hematoma.

Explore the source record for details and available documents.

Adult↗

PubMedDate not supplied

Falx and interhemispheric fissure on axial CT: II. Recognition and differentiation of interhemispheric subarachnoid and subdural hemorrhage.

Interhemispheric hyperdensity or unenhanced computed tomography was originally considered a sign of subarachnoid hemorrhage, the "falx sign." It has since been identified as a normal feature and has also been seen with interhemispheric subdural hemorrhage. To determine the differential features of interhemispheric hemorrhage, 50 patients with subarachnoid hemorrhage and 32 patients with interhemispheric subdural hematomas were reviewed. Subarachnoid hemorrhage produced anterior interhemispheric hyperdensity only, with a zigzag contour and extension from the calvarium to the rostrum of the corpus callosum. Interhemispheric subdural hematomas produce unilateral crescentic hyperdensities that are largest in the posterior superior part of the fissure, behind and above the splenium of the corpus callosum. Interhemispheric hyperdensity in children is more complex. Because the anterior part of the fissure is narrow in younger patients, subarachnoid hemorrhage may go undetected. Likewise, interhemispheric subdural hematomas in children are smaller and more difficult to recognize. They produce asymmetric thickening of the falx shadow with extension over the tentorium. They are, however, of great significance since they are generally seen in abused patients and carry a poor prognosis.

Adolescent↗

PubMedDate not supplied

The value of unenhanced scans in differentiating lesions producing ring enhancement.

Ring enhancement with contrast material is a nonspecific computed tomographic finding seen in a variety of lesions, including benign and malignant neoplasms, inflammation, infarction, and hematoma. This lack of specificity is especially troublesome in the differentiation of self-limiting disorders (infarction and hematoma) from progressive processes (tumor or abscess) potentially requiring surgical treatment. To determine whether more specific diagnoses were possible, 115 cases with ring lesions were retrospectively evaluated for the usefulness of precontrast scan features. The presence or absence of a complete ring proved useful. A complete ring on unenhanced scans effectively excluded self-limiting processes; it was seen in none of 18 infarcts or 11 hematomas. A complete ring on unenhanced scans occurred in 37 of 65 neoplasms, and was more common in metastatic disease (2:1) than in gliomas. A complete ring on unenhanced computed tomography was also seen in four of 15 pyogenic abscesses.

Brain Abscess↗