Biomedical subjects

Nancy J Fischbein

Publications and source records attributed to Nancy J Fischbein.

26 records · Page 2Linked to original sources

PubMed2003

Assessment of metastatic cervical adenopathy using dynamic contrast-enhanced MR imaging.

BACKGROUND AND PURPOSE: Morphologic assessment by conventional imaging methods of lymph node metastases in patients with squamous cell carcinoma of the head and neck is, at best, insensitive. Doppler sonography has shown that lymph node metastases exhibit alterations in the number of vessels and blood flow. We assessed the ability of dynamic contrast-enhanced MR imaging to differentiate normal from diseased nodes in this patient population. METHODS: Twenty-one patients with newly diagnosed squamous cell carcinoma and no previous treatment were studied with the use of a head and neck phased array surface coil. Anatomic imaging included high resolution T1-weighted, fat-saturated fast spin-echo T2-weighted, and contrast-enhanced T1-weighted imaging (0.99-1.32 mm(3) voxels). The dynamic contrast-enhanced MR imaging was performed by using a 2D fast spoiled gradient recalled sequence with single dose bolus injection of contrast agent. Calculated values included time to peak, peak enhancement, maximum slope, and washout slope for the enhancement. All patients underwent neck dissection as part of their indicated treatment, and imaging results were correlated with pathologic findings. RESULTS: Dynamic contrast-enhanced MR imaging and pathology comparisons were obtained for 68 nodes. There was significantly longer time to peak (P <.001), lower peak enhancement (P <.05), lower maximum slope (P <.01), and slower washout slope (P <.05) in the tumor-involved nodes compared with the normal nodes. CONCLUSION: Analysis of dynamic contrast-enhanced MR imaging can differentiate normal from diseased lymph nodes in patients with squamous cell carcinoma of the head and neck.

Adult↗

PubMed2003

Central skull base osteomyelitis in patients without otitis externa: imaging findings.

BACKGROUND AND PURPOSE: Skull base osteomyelitis typically arises as a complication of ear infection in older diabetic patients, involves the temporal bone, and has Pseudomonas aeruginosa as the usual pathogen. Atypical skull base osteomyelitis arising from the sphenoid or occipital bones without associated external otitis occurs much less frequently and initially may have headache as the only symptom. The purpose of this study was to review the clinical and MR imaging features of central skull base osteomyelitis. METHODS: We retrospectively reviewed MR images obtained in six patients with central skull base osteomyelitis. No patient had predisposing external otitis or osteomyelitis of the temporal bone. RESULTS: All of our patients presented with headache, no external ear pain, and cranial nerve deficits. Five of six patients had a predisposition to infection, and the erythrocyte sedimentation rate was elevated in the five patients in whom it was checked. In each case, the diagnosis was delayed until MR imaging demonstrated central skull base abnormality, and the diagnosis was then confirmed with tissue sampling. The most consistent imaging findings were clival bone marrow T1 hypointensity and preclival soft tissue infiltration. Five of six patients were cured with no recurrence of skull base infection over a 2-4-year follow-up period. CONCLUSION: In the setting of headache, cranial neuropathy, elevated erythrocyte sedimentation rate, and abnormal clival imaging findings, central skull base osteomyelitis should be considered as the likely diagnosis. Early tissue sampling and appropriate treatment may prevent or limit further complications such as intracranial extension, empyema, or death.

Adolescent↗

PubMed2003

Congenital bifurcation of the intratemporal facial nerve.

Anomalies of the course of the facial nerve have been reported in association with middle and inner ear malformations. Bifurcation of its intratemporal portion is a rare malformation in which focal splitting of one or more facial nerve segments occurs. We describe the CT appearance of this anomaly and discuss its possible embryology. Facial nerve bifurcation is important to recognize in patients undergoing evaluation for congenital hearing loss and other congenital ear malformations.

Abnormalities, Multiple↗

PubMed2002

Three-dimensional high-resolution magnetic resonance imaging of ocular and orbital malignancies.

BACKGROUND: Ultrathin-section 3-dimensional fast spin-echo (3-D FSE) T2-weighted imaging is a new magnetic resonance imaging (MRI) technique that we used in the evaluation of ocular and orbital malignancies. We evaluated the usefulness of this new technique compared with conventional MRI. METHODS: Imaging data from 26 consecutive patients seen in the Ocular Oncology Unit at the University of California-San Francisco were retrospectively reviewed by physicians from the ocular oncology and neuroradiology units. For all patients, 3-D FSE T2-weighted images (27 scans) were compared with results of conventional MRI and correlated with results of computed tomography (CT), A- and B-scan ultrasonography, ultrasound biomicroscopy, clinical examinations, and histopathology, when available. RESULTS: The 3-D FSE T2-weighted imaging sequence resulted in an overall improvement in accuracy of imaging findings in 17 (63%) of our 27 cases compared with the standard MRI protocol. The increased resolution led to the radiographic detection of additional lesions in 11 (41%) of 27 cases and to an increase in confidence in radiographic diagnosis in 6 (22%) of the remaining cases. The improved resolution of the 3-D FSE T2-weighted sequence resulted in a change of disease management in 3 (60%) of the 5 patients with nonretinoblastoma lesions. One hundred percent of active retinoblastoma lesions could be detected by means of 3-D FSE and conventional imaging; however, inactive lesions were not always detected using conventional imaging. CONCLUSIONS: The 3-D FSE T2-weighted sequence offers superior resolution of intraocular and orbital structures compared with conventional MRI. It is particularly useful in the evaluation of intraocular tumors and the nerve-sheath complex. This new technique contributes significantly to improved diagnosis and management in patients with ocular and orbital malignancies.

Eye Neoplasms↗

PubMed2002

Computed tomographic findings in patients undergoing intra-arterial thrombolysis for acute ischemic stroke due to middle cerebral artery occlusion: results from the PROACT II trial.

BACKGROUND AND PURPOSE: The purpose of this study was to evaluate the role of noncontrast CT in the selection of patients to receive thrombolytic therapy for acute ischemic stroke and to predict radiological and clinical outcomes. METHODS: One hundred eighty patients with stroke due to middle cerebral artery (MCA) occlusion were randomized 2:1 within 6 hours of onset to receive intra-arterial recombinant prourokinase plus intravenous heparin or intravenous heparin only. Four hundred fifty-four CT examinations were digitized to calculate early infarct changes, infarct volumes, and hemorrhagic changes among the 162 patients treated as randomized (108 recombinant prourokinase-treated patients and 54 control patients). CT changes were correlated with baseline stroke severity, angiographic clot location, collateral vessels, and outcome at 90 days. RESULTS: Baseline CT scans, 120 (75%) of 159, showed early infarct-related abnormalities. The baseline CT abnormality volume was not correlated with the baseline National Institutes of Health Stroke Scale (NIHSS) score (r=-0.11) but was correlated weakly with the outcome (r=0.17, P<0.05). Compared with patients with M2 occlusions, patients with M1 MCA occlusions had significantly higher baseline NIHSS scores (P<0.05), more basal ganglia involvement on CT, and larger hypodensity volumes on follow-up CTs. Compared with patients with partial or no collateral supply, patients with full collateral supply had lower baseline NIHSS scores, significantly smaller baseline CT infarct volumes, and less cortical involvement (P<0.05). CONCLUSIONS: Noncontrast CT is not correlated with baseline stroke severity and does not predict outcome in patients with stroke due to MCA occlusion. However, baseline CT changes, clinical presentation, and the evolution of CT changes are influenced by clot location and the presence of a collateral supply.

Acute Disease↗

PubMed2002

CT and MR imaging characteristics of intravestibular lipoma.

BACKGROUND AND PURPOSE: Intracranial lipomas are uncommon congenital malformations that most often are asymptomatic. A rare subset of intracranial lipomas arises within the vestibule of the inner ear, which can cause sensorineural hearing loss. We present the CT and MR imaging characteristics of lipomas within the vestibule of the inner ear and propose a pathogenetic mechanism for this malformation. METHODS: We retrospectively reviewed five cases of vestibular lipoma. T1-weighted axial conventional spin-echo and T2-weighted axial fast spin-echo sequences were performed in all five cases. Four patients underwent T1-weighted fat-saturated imaging, and one underwent CT scanning with Hounsfield units measured. RESULTS: Four female patients ranging in age from 10 to 40 years and one 26-year-old male patient had sensorineural hearing loss. Two patients had progressive high-frequency loss; one, sudden-onset high-frequency loss; and two, congenital high-frequency loss. All had lesions within the vestibule that displayed hyperintensity on T1-weighted images, isointensity to slight hypointensity on T2-weighted fast spin-echo images, hypointensity with fat saturation, and fat attenuation on CT scans. Three of the cases were associated with lipoma of the cerebellopontine angle. In none of these cases were the cerebellopontine angle and labyrinthine lipomas contiguous. CONCLUSION: Intravestibular lipoma is considered when a focal hyperintense lesion is identified within the vestibule of the inner ear on T1-weighted MR images. Lesion hypointensity on fat-saturated T1-weighted MR images verifies its lipomatous nature and separates it from intralabyrinthine hemorrhage or highly proteinaceous fluid.

Adolescent↗

PubMedDate not supplied

Unilateral putaminal CT, MR, and diffusion abnormalities secondary to nonketotic hyperglycemia in the setting of acute neurologic symptoms mimicking stroke.

A 75-year-old Asian man presented with two episodes of chorea associated with nonketotic hyperglycemia. His chorea rapidly resolved after restitution of a normal serum glucose level, although an MR image obtained at the time of acute symptoms demonstrated high signal intensity on T1-weighted images, low signal intensity on T2-weighted images, and restricted diffusion, all involving the left putamen. A CT scan obtained 1 month later demonstrated faint hyperattenuation of the involved putamen. The reported pathophysiologic considerations for these imaging features are reviewed, and an original explanation is proposed.

Aged↗

PubMedDate not supplied

Diffusion-weighted and fluid-attenuated inversion recovery imaging in Creutzfeldt-Jakob disease: high sensitivity and specificity for diagnosis.

BACKGROUND AND PURPOSE: Abnormalities on diffusion-weighted images (DWIs) and fluid-attenuated inversion recovery (FLAIR) images are reported in Creutzfeldt-Jakob disease (CJD). To our knowledge, no large study has been conducted to determine the sensitivity and specificity of DWI and FLAIR imaging for diagnosing CJD. METHODS: Two neuroradiologists, blinded to diagnosis, retrospectively evaluated DWI and FLAIR images from 40 patients with probable or definite CJD and 53 control subjects with other forms of dementia and rated the likelihood of CJD on the basis of the imaging findings. RESULTS: DWI and FLAIR imaging was 91% sensitive, 95% specific, and 94% accurate for CJD. Interrater reliability was high (kappa = 0.93). Sensitivity was higher for DWI than FLAIR imaging. Abnormalities involved cortex and deep gray matter (striatum and/or thalamus) in 68% of patients with CJD, cortex alone in 24%, and deep gray matter alone in 5%. The most typical and specific patterns were corresponding hyperintensity on both FLAIR images and DWIs confined to the gray matter in the cortex, striatum, medial and/or posterior thalamus, or a combination of these areas. Narrow-window soft-copy review of artifact-free DWIs and FLAIR images and recognition of the normal variation in cortical signal intensity proved critical for successful differentiation of CJD from other dementias. CONCLUSION: Because specific patterns of abnormality on DWI and FLAIR images are highly sensitive and specific for CJD, these sequences should be performed whenever CJD is suspected.

Adult↗