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Biomedical subjects

G M Hammer

Publications and source records attributed to G M Hammer.

2 recordsLinked to original sources

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.

Adenocarcinoma↗

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)

Adult↗