Injection Of Gadolinium-diethylenetriamine Pentaacetic Acid Research Articles

Assessment of Middle-Ear Status During Experimental Otitis Media Using Magnetic Resonance Imaging

Magnetic resonance imaging has proved to be a useful tool for in vivo imaging of a variety of tissues. In this study, magnetic resonance imaging was applied to the middle ear of experimental animals with otitis media. Results showed that the presence and distribution of effusion within the middle-ear space could be readily determined. Moreover, following injection of gadolinium-diethylenetriaminepentaacetic acid, a contrast agent, the inflamed middle-ear mucosa could be resolved. A comparison between magnetic resonance imaging and tympanometry with respect to the diagnosis of effusion showed that negative pressure tympanograms were equivocal (50% effusion) and that flat or normal tympanograms were in error in approximately 20% of the observations. These data document a role for magnetic resonance imaging in in vivo studies of the pathogenesis of otitis media with effusion.

Intradural Spinal Metastases in Pediatric Patients with Primary Intracranial Neoplasms

Recently, the application of intravenous gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) has been shown to improve the detection of intradural extramedullary spinal disease in adults. The ability of Gd-DTPA enhanced magnetic resonance (MR) to detect intradural extramedullary spinal metastases was studied in pediatric brain tumor patients. Spinal MR images before and after intravenous injection of Gd-DTPA were analyzed retrospectively in eight pediatric patients with known intracranial neoplasms and clinically suspected subarachnoid tumor seedings. Contrast enhanced spinal MR was compared with CT myelography in four of these patients. In our pediatric population Gd-DTPA enhanced images revealed tumor seeding not appreciable on noncontrast images. Although CT myelography has been the accepted standard investigation in the evaluation of suspected spinal metastases in children, we found that contrast enhanced MR is equal or superior in sensitivity to CT myelography. Spinal MR also provided information not obtainable via CT myelography. In the future, Gd-DTPA enhanced spinal MR should be considered in the initial evaluation of suspected subarachnoid spinal metastases in pediatric patients with known primary brain tumors.

Rheumatoid arthritis: evaluation of hypervascular and fibrous pannus with dynamic MR imaging enhanced with Gd-DTPA.

The knees of 20 patients with rheumatoid arthritis and two healthy volunteers were evaluated with magnetic resonance (MR) imaging. Spin-echo sequences were performed, and the signal-intensity patterns of normal and pathologic articular soft-tissue structures were quantitatively evaluated with a dynamic FLASH (fast low-angle shot) sequence after bolus intravenous injection of gadolinium diethylenetriaminepentaacetic acid. In contrast to the spin-echo images obtained before injection of contrast material, it appears possible with this technique to distinguish joint effusion from hypervascular pannus formations and to grade the vascularity of proliferative synovitis. Flat pannus deposits on the articular surface and subchondral pannus masses were identified only by their marked enhancement of signal intensity after injection of contrast material. Dynamic MR imaging appears to yield decisive information for diagnosing rheumatoid arthritis.

Myocardial infarct size after reperfusion therapy: assessment with Gd-DTPA-enhanced MR imaging.

In 21 patients with proved acute myocardial infarction, the size of the infarct was estimated with serial magnetic resonance (MR) imaging after intravenous injection of gadolinium diethylenetriaminepentaacetic acid (DTPA) (0.2 mmol per kilogram of body weight). Early reperfusion after thrombolytic therapy or percutaneous transluminal coronary angioplasty performed during the acute phase of infarction was documented with coronary angiography in nine patients (group 1). In 12 patients (group 2), no reperfusion was achieved (n = 5) or no thrombolytic therapy was given (n = 7). All group 2 patients were considered to have no reperfusion. Infarct sizes measured with MR imaging were significantly smaller in group 1 than in group 2 at 8 days +/- 4 after infarct onset (8% +/- 5% vs 15% +/- 4%, respectively; P less than .001). Serial MR images showed individual variations in infarct size, findings that may be clinically significant. Estimation of infarct size with Gd-DTPA-enhanced MR imaging is accurate in demonstrating the effect of successful reperfusion therapy on infarct size.

Reperfused and nonreperfused myocardial infarction: diagnostic potential of Gd-DTPA--enhanced MR imaging.

Forty-five patients with suspected acute myocardial infarction were examined with magnetic resonance (MR) imaging before and serially up to 30 minutes after intravenous injection of gadolinium diethylenetriaminepentaacetic acid (DTPA), 0.1 mmol/kg of body weight. Coronary angiography after thrombolytic therapy was performed in all patients to assess reperfusion. Intensity ratios between both reperfused and nonreperfused infarcted areas and normal myocardium increased significantly up to 15-20 minutes after administration of Gd-DTPA and were still elevated 30 minutes after injection (P less than .0001). In accordance with the findings in experimental studies, four distribution patterns of infarct enhancement were observed. The overlap in enhancement patterns and similar maximal intensity ratios after Gd-DTPA administration for both reperfused and nonreperfused infarcts preclude a reliable differentiation on the basis of these factors alone. Significant enhancement of both reperfused and nonreperfused infarcts allows adequate infarct imaging up to at least 30 minutes after administration of Gd-DTPA.

Gadolinium-DTPA enhanced dynamic MR imaging in the evaluation of cisplatinum nephrotoxicity.

Gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA) enhanced dynamic magnetic resonance (MR) imaging was used to monitor the nephrotoxic effects of cis-platinum (cis-diamminedichloroplatinum; CDDP), a chemotherapeutic agent that produces damage in the proximal convoluted tubule. Ten New Zealand white rabbits (NZWs) were divided into two groups and were evaluated at two clinically relevant doses of CDDP. Group 1 (four NZWs) received CDDP intravenously at 125 mg/m2 over 1 h. Rabbits in Group 2 (six NZWs) were infused with CDDP at 40 mg/m2 each day for 5 consecutive days. Dynamic MR images were performed in the axial plane at 1.5 T using a gradient recalled acquisition in the steady state sequence with an echo time of 11 ms, a repetition time of 20 ms, and a flip angle of 10 degrees after a bolus injection of Gd-DTPA 0.1 mmol/kg. Thirty-two sequential post Gd-DTPA images (5.12 s/image) were obtained over 2 min 45 s at a single location. All rabbits underwent baseline normal and serial post CDDP Gd-DTPA enhanced dynamic MR scans. Analysis of the alterations in the normal pattern of renal enhancement caused by CDDP was facilitated by using a stacked profile image and quantitative region of interest measurements of signal intensity. Normally, after the injection of Gd-DTPA, a dark band promptly appears in the outer cortex of the kidneys and migrates centripetally toward the papilla, reflecting the tubular concentration of Gd-DTPA. In Group 1 rabbits, nephrotoxicity due to CDDP was observed as early as 9 h after administration of the drug, with a complete disappearance of the dark band by 7 days. In Group 2 rabbits, the band disappeared gradually and reappeared 2-10 days after the completion of CDDP treatment, indicative of tubular damage and recovery with return of the concentrating ability of the kidney. These results illustrate the feasibility of using Gd-DTPA dynamic MR as a sensitive monitor of drug induced alterations of renal function.

Benefits of Gd-DTPA for MR imaging of intracranial abnormalities.

Forty patients with symptoms of intracranial disease were studied with magnetic resonance before and after intravenous injection of gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA). The T1- and T2-weighted images were obtained in all patients. Ninety brain lesions were found in 36 patients, including primary (20 patients) and metastatic (six) tumors, hemorrhage (one), progressive multifocal leukoencephalopathy (one), cysticercosis (one), infarction (four), and postoperative changes (four). Postcontrast images revealed lesions not seen on precontrast scans in eight (20%) patients. Also, the postcontrast images showed a change in appearance of the lesions in 20 (50%) that provided helpful information for assessing the abnormality in 20 cases (50%). Gadolinium-DTPA did not obscure any of the lesions seen on precontrast scans. It improved conspicuity, helped characterize and delineate the extent of lesions, and increased the sensitivity for detection of cerebral abnormalities.

聴神経腫ように対するＭＲＩ診断 Ｇｄ‐ＤＴＰＡ造影法を中心に

Magnetic resonance imaging (MRI) was performed in 21 patients with clinical and histologic diagnoses of acoustic tumor with 0.15 Tesla and 0.5 Tesla whole body image scanner (Hitachi G-10, G-50). Eleven patients were evaluated by MRI before and after an intravenous injection of 0.1mmol/kg of gadolinium-diethylene triamine pentaacetic acid (Gd-DTPA). Contrast enhancement was seen in all cases. The degree of enhancement was greater with T-1 weighed images such as saturation-recovery (500/20-30) and inversion-recovery (2000/500/20) than with T-2 weighed images such as spin-echo (2000/20-60) sequences. The differentiation of tumor parenchyma from the cystic portion is easier with Gd-DTPA enhancement. After enhancement there was a reduction of measured T-1 value in all measured cases while no significant change was seen in T-2 value. No short time side effects were encountered and no significant change was seen in blood urea, creatinine, electrolytes, liver function tests, blood coagulation or urinalysis after injection of Gd-DTPA. Although much more work will be required to evaluate this contrast agent, Gd-DTPA is a promising MRI contrast enhancer for the clinical assessment of acoustic tumor.

Aerosolized gadolinium-DTPA enhances the magnetic resonance signal of extravascular lung water.

Gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA), a contrast agent for magnetic resonance imaging, was administered by either aerosol or intravenous injection to rats. Proton relaxation times in excised lungs and kidneys were then measured. With increasing concentrations of aerosolized Gd-DTPA, the spin-lattice relaxation time (T1) of lungs decreased (enhanced) significantly (P less than .001), an effect that persisted for at least 80 minutes; there was no change in kidney T1. After intravenous injection of Gd-DTPA, lung T1 did not change, but kidney T1 decreased significantly (P less than .001), confirming previous observations of renal clearance. It is concluded that aerosolized Gd-DTPA is a more efficacious method of delivery of paramagnetic contrast agent to the lungs than intravenous injection, and that the lack of systemic effect after aerosolization indicates that enhancement was limited to the extravascular compartment.

Gadolinium-DTPA as a contrast agent in MRI: initial clinical experience in 20 patients.

Magnetic resonance imaging (MRI) was performed in 20 patients before and after intravenous administration of gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) in a dose of 0.1 mmol/kg. Twelve of the patients had clinical and histologic diagnoses of cerebral tumor, six had hepatic tumors, one had hepatic cysts, and one had transitional cell carcinoma of the bladder. Contrast enhancement was seen with all tumors, but not with the hepatic cysts. The degree of enhancement was greater than that seen with computed tomography (CT) in 13 cases, equal to it in six, and less in one. Contrast enhancement was detectable as long as 18 hr after injection of Gd-DTPA in one case of cerebral tumor. The margin between cerebral tumor and peritumoral edema could be delineated with contrast-enhanced MRI to the degree possible with contrast-enhanced CT. In the liver isointense enhancement was seen with saturation-recovery (SR), inversion-recovery (IR), and spin-echo (SE) sequences although not with all three sequences simultaneously. In general IR sequences were most sensitive for display of the contrast agent, but the enhancement often decreased the difference between abnormal and normal tissue. No short-term side effects were encountered and no significant change was seen in urea, creatinine, electrolytes, liver function tests, blood coagulation, or urine testing after injection of Gd-DTPA. Although much more work will be required to evaluate this contrast agent, these initial experiences are very promising.