Matthew J. Kuhn

MRI evaluation of “solitary” brain metastases with triple-dose gadoteridol: comparison with contrast-enhanced CT and conventional-dose gadopentetate dimeglumine MRI studies in the same patients

The purpose of this investigation was to compare the sensitivity and safety of high dose gadoteridol (Pro Hance) with routine dose gadopentetate dimeglumine (Magnevist) in the detection of intracranial metastases on magnetic resonance imaging (MRI) when a solitary intracranial lesion was detected on contrast-enhanced cranial computed tomography (CT). Four patients, each with a solitary intracranial metastasis demonstrated on contrast-enhanced CT were studied prospectively with both 0.3 mmol/kg gadoteridol and 0.1 mmol/kg gadopentetate dimeglumine. Images were acquired before and immediately following contrast administration. Both of the MR studies were performed between two and six days of each other and within 1 wk of the cranial CT. Scan parameters and injection rates were identical on both occasions. Patient monitoring for the gadoteridol study included physical examination, vital signs and laboratory tests at several pre-determined times. Eighteen total metastases were demonstrated on MRI compared to the four on CT. Seven were visualized on the unenhanced MR images, nine on the scans using gadopentetate dimeglumine, and all eighteen on the scans using gadoteridol. Additional lesions were seen on the gadoteridol images in all four patients. No adverse events attributable to contrast media occurred. No significant changes in vital signs or laboratory values occurred.

Primary B-cell lymphoma of the clivus: case report.

BACKGROUND Lymphomas usually present in extranodal sites late in the course of the disease. Moreover, it is uncommon for a primary non-Hodgkins lymphoma to present with cranial nerve palsies; reports in the literature are rare. CASE DESCRIPTION We report the case of a 60-year-old woman with complaints of headache and double vision. MRI revealed an expansive clival lesion without pituitary invasion. An endoscopic transsphenoidal procedure was performed for diagnosis and partial resection of the mass. CONCLUSION Primary diffuse large B-cell lymphoma of the clivus is rare. An endoscopic transsphenoidal approach to the skull base is described, along with characteristic clinical, radiologic, and pathologic findings of the lesions.

Unilateral cerebral cortical and basal ganglia enhancement following overdosage of nonionic contrast media

A 69-year-old woman developed seizures after cerebral angiography immediately preceded by coronary angiography. The preceding coronary angiography resulted in hyperconcentration, hyperosmolar loading, and overdosing of the nonionic contrast medium. A CT examination demonstrated gyriform enhancement throughout the left cortex and the left basal ganglia. Preloading with contrast material, as in this case, predisposes to disruption of the blood-brain barrier during selective common carotid or vertebral artery injection with nonionic contrast.

Intracranial extension of basal cell carcinoma of the scalp

A case of recurrent basal cell carcinoma of the right occipital scalp is reported. Plain film, CT, and MRI examinations of the head demonstrated direct neoplastic invasion through the occipital bone and meninges into the right cerebellar hemisphere.

Absence of the septum pellucidum and related disorders

We present an illustration of the spectrum of intracranial abnormalities associated with absence of the septum pellucidum to better define and illustrate this disorder. CT and 1.5 Tesla MRI examinations of fifteen patients with absence of the septum pellucidum were meticulously analyzed and correlated with clinical and laboratory studies. The findings were compiled and categorized based upon the presence and type of associated radiologic abnormalities. Absence of the septum pellucidum may occur as an isolated abnormality (n = 3). In most patients (n = 12), associated complex developmental abnormalities are present which include heterotopias, hypoplastic falx, ventricular clefts, encephalocele, small pituitary gland, small optic nerves and chiasm, and corpus callosal dysgenesis. Inferior pointing and a squared-off appearance of the frontal horns are frequently noted. These, or other, more severe ventricular configuration deformities are present in all patients. We have portrayed the complete range of findings associated with absence of the septum pellucidum using an illustrative approach to clarify the different patterns of radiologic abnormalities which may be seen with this complex entity.

A comparative study of magnetic resonance imaging and computed tomography in the evaluation of migraine

Seventy-four patients with classic migraine were examined by magnetic resonance imaging (MRI) and contrast enhanced head CT scanning. Patients chosen for the study ranged in age from 9 to 39 years with a mean age of 28 years. All had documented symptoms of classic migraine for over two years. Nineteen of the seventy-four patients (26%) had multiple foci of bright signal in the brain on T2 weighted MRI. None of these parenchymal abnormalities were detected on CT scans. Twenty-six patients (35%) had both MRI and CT demonstration of focal or generalized ventricular enlargement or sulcal prominence. These atrophic findings were shown equally well by both modalities. Ten patients (14%) with atrophic changes showed concomitant small bright foci of T2 signal abnormality. An additional migraine patient with homonymous hemianopsia had a large occipital lobe infarct which was seen as a region of bright T2 signal abnormality on MRI. Typical CT characteristics of an acute infarct were demonstrated.

Prenatal recognition of central nervous system complications of alloimmune thrombocytopenia

The radiological findings associated with alloimmune thrombocytopenia have not been well described. We present two such cases diagnosed in utero by ultrasound and discuss the radiographic findings of intracranial hemorrhage and hydrocephalus secondary to alloimmune thrombocytopenia. An awareness of this entity and its early diagnosis and intervention may greatly reduce the morbidity and mortality associated with alloimmune thrombocytopenia.

Electrocortical mapping, MRI, and neuropsychological measures: Evidence of Alzheimer's disease in the presence of vascular lesions

We report here a case study of a 76-year-old woman with a high school education, whose presenting psychiatric symptomatology indicated dementia of unknown etiology. Neuropsychological test results were consistent with AD, but diagnosis was complicated by an MRI showing a large right hemisphere cortical infarct and scattered subcortical changes leading to a diagnosis of possible AD. Electrocortical mapping showed the right hemisphere infarct, and gave independent evidence suggestive of AD in the relatively intact left hemisphere. This case demonstrates the utility of multidimensional assessment as an aid to differential diagnosis.

Quantitative contrast media dose evaluation for cranial computed tomography

The goal of this study was to quantitatively evaluate the CT enhancement characteristics of selected intracranial blood vessels using four different volumes of a contrast medium under otherwise identical conditions in order to help determine a cost-effective dose. In a double blind, prospective manner, 100 patients referred for contrast-enhanced cranial CT were randomly assigned to receive one of four different volumes (50, 75, 100 or 120 ml) of ioversol 320 mg I/ml which was subsequently administered intravenously at a rate of 1 ml/s via a power injector. Unenhanced images were also obtained. Scanning times, slice thickness and other parameters were identical in all patients. Scanning was initiated immediately following delivery of the full volume of contrast. Region of interest Hounsfield unit measurements were acquired in a standardized manner using a 1 mm diameter circle on the pre- and post-contrast scans of the supraclinoid left internal carotid artery (LICA), supraclinoid right internal carotid artery (RICA), basilar artery (BA), and torcular region (TR). The mean enhancement value (in Hounsfield units) for the 50 ml, 75 ml, 100 ml and 120 ml dose groups respectively were as follows for each vessel: LICA 29.9, 41.5, 63.9, 64.6; RICA 30.1, 39.4, 62.6, 65.1; BA 30.0, 41.7, 66.0, 71.9; TR 31.7, 46.8, 68.9, 74.3. There was no statistically significant (p > 0.05) difference in enhancement in any of the four vessels when the 120 ml volume was delivered compared to the 100 ml volume. However, there was a statistically significant (p < 0.05) improvement in enhancement in all four vessels when 100 ml of contrast was administered compared to 75 ml.(ABSTRACT TRUNCATED AT 250 WORDS)

Primitive neuroectodermal tumor : CT, MRI, and angiographic findings

Primitive neuroectodermal tumors (PNETs) are uncommon CNS neoplasms found usually in the first decade of life. This article presents a proven case of this lesion in a 14-month-old boy located deep in the left frontal lobe. This lesion was studied by CT, MRI, and cerebral angiography. The radiologic findings of this tumor were assessed and compared with those cases reported in the medical literature.