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PubMed2003

Gadolinium-enhanced magnetic resonance fluoroscopy used as micturating cystourethrography: experiences in adult male patients.

RATIONALE AND OBJECTIVE: To approach the concept of magnetic resonance (MR) imaging-monitored micturating cystourethrography (MRMCU) by using gadolinium-enhanced real-time MR fluoroscopy. METHODS: MRMCU was performed in 21 male patients (27-76 years) subsequent to gadolinium excretory MR urography. Patients were examined in supine position at 1.5 T. For MR fluoroscopy of the urethra during micturition, we used a T1-weighted single-slice gradient-echo sequence with continuous radial k-space acquisition. Image reconstruction was obtained with the sliding-window technique reaching a frame rate of 25/s. The image plane was guided interactively through the urethra, the bladder and the ureters without stopping the scan. RESULTS: Two patients were unable to void in supine position. With MR fluoroscopy, the flow of gadolinium-enhanced urine through the urethra was visualized in 19 patients, in 14 of whom with complete demonstration of the urethral anatomy subdivided into 5 segments. Four urethral segments were identified in 1 patient, 3 segments in 2 patients, 2 segments in 3 patients, and 1 segment in 1 patient. MRMCU demonstrated changes in the urethral anatomy and the urine flow in 2 patients with a neobladder and in 1 patient with hypertrophy of the prostate. Subject to the limitation of antegrade gadolinium application, interactive MRMCU allowed to determine whether the ureters were enhanced by gadolinium or not. CONCLUSION: Gadolinium-enhanced MR fluoroscopy using radial k-space acquisition has achieved complete demonstration of the segmental anatomy of the urethra in 74% of the male adult patients who were able to accomplish micturition. Although MR fluoroscopy was able to visualize the gadolinium-enhanced ureters, the current data do not permit to conclude that MRMCU can demonstrate vesicoureteral reflux, especially in children.

Adult↗
PubMed2002

A new class of gadolinium complexes employed to obtain high-phasing-power heavy-atom derivatives: results from SAD experiments with hen egg-white lysozyme and urate oxidase from Aspergillus flavus.

Seven gadolinium complexes are shown to be excellent compounds for the preparation of heavy-atom derivatives for macromolecular crystallography projects. De novo phasing has been carried out using single-wavelength anomalous diffraction (SAD) on a series of gadolinium-derivative crystals of two proteins: hen egg-white lysozyme and urate oxidase from Aspergillus flavus. Lysozyme derivative crystals were obtained by co-crystallizing the protein with the corresponding gadolinium complex at a concentration of 100 mM. Diffraction data were collected to a resolution of 1.7 A using Cu K(alpha) radiation from a rotating-anode generator, making use of the high anomalous signal of gadolinium at this wavelength. Urate oxidase derivative crystals were obtained by soaking native crystals in 100 mM gadolinium complex solutions. Diffraction data were collected to a resolution close to 3 A using X-rays at the Gd L(III) absorption edge, taking advantage of the sharp white line on that edge. For all urate oxidase derivative crystals and three of the lysozyme crystals, SAD phasing led to electron-density maps of very high quality, allowing unambiguous chain tracing. From this study, the binding effectiveness of the gadolinium complexes seems to be related to the nature of the precipitant used for crystallization. These gadolinium complexes represent a new class of high-phasing-power heavy-atom derivatives that may be used for high-throughput structure-determination projects.

Animals↗
PubMed1997

Longitudinal study of soluble adhesion molecules in multiple sclerosis: correlation with gadolinium enhanced magnetic resonance imaging.

OBJECTIVE: To assess whether serial serum levels of soluble forms of intercellular adhesion molecule-1 (sICAM-1) and vascular cell adhesion molecule-1 (sVCAM-1) are useful as surrogate markers of disease activity in multiple sclerosis (MS). BACKGROUND: Increased levels of sICAM-1 and sVCAM-1 have been described in cross-sectional, but not longitudinal, studies of patients with MS. Although they appear to correlate with clinical and MRI markers of disease activity, their role as potential surrogate markers remains undefined. METHODS: Serial serum levels of sICAM-1 and sVCAM-1 were measured in patients with MS undergoing monthly gadolinium-enhanced MRI studies of the brain (462 gadolinium-enhanced MRI in 57 patients) and in 12 normal control subjects. Ten patients had primary progressive (PP), 22 relapsing remitting (RR), and 25 secondary progressive (SP) disease. RESULTS: Levels of sICAM-1 and sVCAM-1 were increased intermittently in patients with all subtypes of MS. Median levels of sICAM-1 were elevated in patients with MS compared with normal controls (normal controls median [interquartile range] = 176[119-209] compared with PP = 502[194-1768], RR = 419[158-481], and SP = 352[196-469] ng/mL; p = 0.04). After excluding patients with PP MS, patients with high sICAM-1 levels had a greater number of gadolinium-enhancing lesions per study (1.9[0.9-4.3]) than patients with normal levels (0.4[0-2.7], p = 0.03), and patients with MRI studies with no gadolinium-enhancing lesions had lower associated sICAM-1 levels (200 ng/mL[85-561]) than patients with only persistent (349 ng/mL[82-615]) or new enhancing lesions (497 ng/mL[108-667], p = 0.03). Patients with RR or SP disease that progressed clinically during the study had a greater number of gadolinium-enhancing lesions per MRI study (3.5[0.4-5.5]) than did patients in whom disease did not progress (1.2 [0.3-2.7], p = 0.03). The patients with progressive disease tended to have higher sICAM-1 levels (469 ng/mL [196-1019]) than patients in whom disease did not progress (353 ng/mL [171-469], p = 0.07). Although MS patients tended to have higher sVCAM-1 levels than did normal controls, this finding was not significant. No correlation could be found between levels of sVCAM-1 and gadolinium enhancement on MRI. CONCLUSIONS: Patients with MS have elevated levels of sICAM-1, which correlate with gadolinium enhancement on MRI and possibly short-term disease progression. Soluble ICAM-1, and not sVCAM-1, may therefore be suitable as a long-term surrogate marker of disease activity in MS.

Adult↗
PubMed1999

Detection of hepatocellular carcinoma arising in cirrhotic livers: comparison of gadolinium- and ferumoxides-enhanced MR imaging.

OBJECTIVE: We prospectively compared the detectability of hepatocellular carcinoma (HCC) arising in cirrhotic livers using dynamic gadolinium-enhanced fast low-angle shot (FLASH), ferumoxides-enhanced T2-weighted turbo spin-echo, and ferumoxides-enhanced T2*-weighted FLASH MR imaging. SUBJECTS AND METHODS: Fifty-three patients with HCC (32 men and 21 women) who were 33-86 years old (mean, 63 years old) were enrolled in a prospective MR study to assess hepatic lesions using both gadopentetate dimeglumine and ferumoxides. Dynamic gadolinium-enhanced imaging was obtained before and 30, 60, and 180 sec after rapid bolus injection of gadopentetate dimeglumine (0.1 mmol/kg). Ferumoxides-enhanced T2-weighted turbo spin-echo imaging and ferumoxides-enhanced T2*-weighted FLASH imaging were performed between 30 min and 2 hr after i.v. infusion of ferumoxides (10 micromol/kg). Images were analyzed qualitatively and quantitatively. A receiver operating characteristic curve study was performed to compare the diagnostic value of gadolinium-enhanced imaging with that of ferumoxides-enhanced imaging for the detection of HCC. RESULTS: Quantitative analysis revealed a significantly higher percentage of signal-intensity loss and higher liver-lesion contrast-to-noise ratio on ferumoxides-enhanced T2*-weighted FLASH imaging than on ferumoxides-enhanced T2-weighted turbo spin-echo imaging. The percentage of signal-intensity loss and liver-lesion contrast-to-noise ratio on ferumoxides-enhanced images was significantly higher in patients with mild liver cirrhosis (Child's class A) than in patients with severe liver cirrhosis (Child's class C). Qualitative analysis showed that dynamic gadolinium-enhanced images revealed significantly higher lesion conspicuity than did ferumoxides-enhanced T2-weighted turbo spin-echo images. According to receiver operating characteristic analysis, dynamic gadolinium-enhanced FLASH imaging achieved the highest sensitivity, and ferumoxides-enhanced T2*-weighted FLASH imaging was the second most sensitive. We found that ferumoxides-enhanced turbo spin-echo imaging was the least valuable technique for revealing HCC lesions. Gadolinium-enhanced imaging revealed more HCC lesions than did ferumoxides-enhanced imaging, particularly for lesions smaller than 2 cm in diameter. CONCLUSION: Ferumoxides-enhanced imaging revealed fewer findings, such as lesion conspicuity of HCCs arising in cirrhotic livers, than did gadolinium-enhanced FLASH imaging.

Adult↗
PubMed1996

Systemic gadolinium toxicity in patients with renal insufficiency and renal failure: retrospective analysis of an initial experience.

OBJECTIVE: To study the possible deleterious systemic effects of gadolinium in patients with impaired renal function. DESIGN: We retrospectively analyzed the routine laboratory data and clinical course of patients who had undergone a gadolinium-enhanced magnetic resonance imaging (MRI) examination of the brain and spine and had evidence of impaired glomerular filtration. MATERIAL AND METHODS: Between October 1988 and October 1992, 15,830 patients underwent gadolinium-enhanced MRI at our institution, 151 of whom had a serum creatinine value of more than 2 mg/dL. The clinical records of these 151 patients were thoroughly examined for the period from 3 days before to 30 days after the gadolinium-enhanced MRI examination. All data were analyzed in an attempt to detect any adverse events that could be related to free gadolinium as a result of dissociation from the chelating agent due to prolonged elimination times (that is, increased serum creatinine concentrations). In addition, we calculated the 90-day mortality rate for both the study group and a matched control population of 80 patients who had undergone MRI of the brain and spine before gadolinium was available. RESULTS: The overall incidence of adverse events in the study group was 3.6%. No event was severe or life threatening--nausea and rash occurred in two patients each, and seizure and headache occurred in one patient each. These findings were not significantly different from those in previous studies performed in populations with normal elimination times. Moreover, no significant difference was noted in the 90-day mortality rate (14.6% of the study group) in comparison with that in the control group (13.8%). CONCLUSION: On the basis of this initial retrospective analysis, we were unable to detect any clinical deleterious effects of administration of gadolinium for MRI examination in patients with impaired renal function. Further investigation with prospective studies is needed to confirm these initial retrospective findings.

Adult↗
PubMed2005

Calcium binding by gadolinium-based MR contrast agents.

PURPOSE: This study was conducted to characterize the alterations in ionic sodium, potassium, and calcium by gadolinium-based MR contrast agents. MATERIALS AND METHODS: An electrolyte solution (ES) containing 1.2 mM/L calcium ions,120 mM/L sodium, and 4.0 mM/L potassium were diluted with various gadolinium compounds and alterations in ionized electrolytes were measured using an ion-specific electrometer. Gadolinium compounds including Gd-DTPA, Gd-DOTA, gadoteridol, gadodiamide, meglumine/sodium diatrizoate (76% Urografin), and isotonic saline as a control were investigated. The dilution ranged from 5% (ES/test solution = 100/5) to 100%. Alterations of ionic electrolytes were measured. Calcium-binding capacities caused by each gadolinium compound also were measured. RESULTS: The alterations of ionic sodium and potassium by gadolinium compound were similar to those of isotonic saline. A significant reduction in ionized calcium was observed with Gd-DTPA and Gd-DOTA in comparison with gadoteridol and gadodiamide. CONCLUSION: Ionic gadolinium compounds induced significant reductions of calcium ions in vitro compared with non-ionic gadolinium compounds.

Calcium↗
PubMed1995

Elimination of gadolinium-DTPA by peritoneal dialysis.

Magnetic resonance urography (MRU) after i.v. injection of gadolinium-DTPA (0.1 mmol/kg bodyweight) was performed in a patient with transplant dysfunction after renal allograft transplantation. Renal replacement therapy was accomplished by means of peritoneal dialysis. Gadolinium-DTPA concentrations in urine and dialysate were measured repeatedly during a 48-h period with inductively coupled plasma atomic emission spectrometry. The total 24-h creatinine clearance was 10.8 ml/min on day 1 and 13.7 ml/min on day 2. The corresponding total gadolinium clearance was 12.8 ml/min and 15.8 ml/min respectively. Gadolinium-DTPA was removed from the body through peritoneal dialysis at a mean clearance rate of 5.13 ml/min. Plasma half-life of gadolinium-DTPA was prolonged to 9 h. No side-effects due to gadolinium-DTPA were noted. MRU provided a better visualization of the morphology of the urinary tract than scintigraphic studies. By measuring the changes of signal intensity, the gadolinium excretion could be calculated.

Adult↗
PubMed1998

Gadolinium chloride suppresses hepatic oval cell proliferation in rats with biliary obstruction.

Liver injury due to bile duct ligation (BDL) is histologically characterized by cholestasis, bile ductular proliferation, hepatocellular damage, portal fibrosis, and ultimately biliary cirrhosis. Stem cells within the liver may act as progenitor cells for small epithelial cells termed oval cells that can differentiate into bile duct cells or hepatocytes, whereas myofibroblasts are the principal source of collagen production in fibrosis. The aims of this study were to determine 1) whether BDL induces oval cell proliferation and 2) whether blockade of Kupffer cells affects oval cell proliferation, bile duct proliferation, and myofibroblast transformation in experimental biliary obstruction. Male Sprague-Dawley rats were divided into two groups to receive either a single dose of gadolinium chloride (a selective Kupffer cell blocking agent) or vehicle. One day later, the gadolinium- and vehicle-treated groups were further subdivided to receive either BDL or sham operation. The rats were sacrificed on day 7 postoperatively. Serum was collected for measurement of aspartate aminotransferase, gamma-glutamyl transpeptidase, and bilirubin levels. Liver tissue was taken for evaluation of fibrosis, bile ductular cells, oval cells, and myofibroblasts. BDL resulted in elevated aspartate aminotransferase, gamma-glutamyl transpeptidase, and bilirubin in serum, and gadolinium pretreatment did not modify these effects. BDL induced marked oval cell proliferation, which was completely prevented by gadolinium pretreatment. Gadolinium did not affect the induction of bile duct expansion or myofibroblasts after BDL. We conclude that experimental biliary obstruction induces oval cell proliferation, which can be prevented by gadolinium pretreatment. This suggests that bile ductular proliferation and myofibroblast transformation are not mediated by Kupffer cells and that ductular proliferation can proceed in the absence of oval cells. Alternatively, gadolinium may directly affect oval cell proliferation after BDL.

Animals↗
PubMed2001

Multicenter phase Ib/II trial of the radiation enhancer motexafin gadolinium in patients with brain metastases.

PURPOSE: Motexafin gadolinium is a magnetic resonance imaging (MRI)--detectable redox active drug that localizes selectively in tumor cells and enhances the effect of radiation therapy. This phase Ib/II trial of motexafin gadolinium, administered concurrently with 30 Gy in 10 fractions whole-brain radiation therapy (WBRT), was conducted to determine maximum-tolerated dose (MTD), dose-limiting toxicity, pharmacokinetics, and biolocalization in patients with brain metastases. Additional endpoints were radiologic response rate and survival. PATIENTS AND METHODS: Motexafin gadolinium was administered before each radiation treatment in this open-label, multicenter, international trial. In phase Ib, drug dose was escalated until the MTD was exceeded. In phase II, drug was evaluated in a narrow dose range. RESULTS: In phase Ib, the motexafin gadolinium dose was escalated in 39 patients (0.3 mg/kg to 8.4 mg/kg). In phase II, 22 patients received 5 mg/kg to 6.3 mg/kg motexafin gadolinium. Ten once-daily treatments were well tolerated. The MTD was 6.3 mg/kg, with dose-limiting reversible liver toxicity. Motexafin gadolinium's tumor selectivity was established using MRI. The radiologic response rate was 72% in phase II. Median survival was 4.7 months for all patients, 5.4 months for recursive partitioning analysis (RPA) class 2 patients, and 3.8 months for RPA class 3 patients. One-year actuarial survival for all patients was 25%. CONCLUSION: Motexafin gadolinium was well tolerated at doses up to 6.3 mg/kg, was selectively accumulated in tumors, and, when combined with WBRT of 30 Gy in 10 fractions, was associated with a high radiologic response rate.

Adult↗
PubMedDate not supplied

Analysis of magnetization transfer effects on T1-weighted spin-echo scans using a simple tissue phantom simulating gadolinium-enhanced brain lesions.

The purpose of this study was to analyze the effect of several magnetization transfer (MT) pulse and T1-weighted spin-echo (SE) sequence parameters on lesion-to-background contrast, using a simple tissue phantom emulating the T1 relaxation and MT properties of gadolinium-enhanced brain lesions. Eggbeaters (Nabisco Inc., East Hanover, NJ) liquid egg product was doped with gadolinium in six concentrations from .0 to 1.0 mmol and cooked. The gadolinium-doped egg phantom and normal volunteer brains were studied using an SE sequence with TE = 20 msec and high power, pulsed, off-resonance MT saturation. The effects of MT pulse frequency offset (1,000-6,000 Hz), sequence repetition time (TR = 500-1,000 msec, with MT power held constant), and slice-select flip angle (60-120 degrees) on the magnetization transfer ratio (MTR) and the simulated lesion-to-background contrast were determined at the different "intralesion" gadolinium concentrations. The MTR and lesion-to-background contrast of all materials were greatest at narrow MT pulse frequency offsets. There was in inverse relationship between gadolinium concentration and MTR and a positive correlation between the gadolinium concentration and lesion-to-background (L/B) contrast, a weak negative correlation between slice-select flip angle and L/B, and a negative correlation between TR and L/B. The relaxation properties and MT behavior of the egg phantom are close to that expected for enhancing brain lesions, allowing a rigorous analysis of several variables affecting lesion-to-background contrast for high MT power, T1-weighted SE sequences.

Adult↗
PubMed2002

Gadolinium-containing contrast media for radiographic examinations: a position paper.

Recently, it has been suggested that gadolinium-based contrast media could be used for radiological examinations in patients with significant renal impairment, previous severe generalized reaction to iodinated contrast media or thyroid disease about to undergo radioactive iodine treatment; however, the indications for and risks of using gadolinium agents in this way are not well known; hence, the Contrast Media Safety Committee of The European Society of Urogenital Radiology reviewed the literature to issue a position paper on this subject. A comprehensive literature review was performed and the resulting report was discussed at the Ninth European Symposium on Urogenital Radiology in Genoa, Italy, June 2002. Review of the literature indicates that according to experimental data on animals gadolinium-based contrast media have more nephrotoxic potential than iodinated contrast media in equivalent X-ray attenuating doses; therefore, gadolinium-based contrast media should not replace iodinated contrast media in patients with renal insufficiency for radiographic examinations. For patients with previous severe generalized reactions to iodinated contrast media, and in patients about to undergo thyroid treatment with radioactive iodine gadolinium-based contrast media in approved intravenous doses, up to 0.3 mmol/kg body weight will not give diagnostic radiographic information in most cases. Gadolinium-based contrast media are not approved for radiographic examinations.

Animals↗
PubMed2004

Actual clinical use of gadolinium-chelates for non-MRI applications.

For many years, alternatives to iodinated X-ray contrast media have been sought. Of the contrast media investigated to date, only CO(2) and the gadolinium-chelates have been shown to be viable alternatives for selected X-ray examinations. Therefore, we have reviewed the general literature and that specific for gadopentetate (Magnevist) in particular, since this agent has been studied the most. This review indicates that diagnostic CT examinations can be achieved following the intravenous administration of gadolinium-containing contrast media (CM) for evaluation of aortic abnormalities. Gadolinium-containing CM at the dose approved for MR imaging are not useful for CT evaluation of the abdominal parenchymal organs. Intravenous/intraarterial injections have also been used in a variety of angiographic and interventional procedures. Image quality, however, is generally inferior to iodinated contrast media. Gadolinium-containing CM require no special handling and can be administered by hand injection or via conventional angiographic automated injectors with the same flow rates and pressures as are used with iodinated contrast media. For CT, a peripheral bolus injection of a diluted gadolinium agent (1:1 with saline) of 60-90 ml at 3-5 ml/s is usually performed. Similar to all other gadolinium-chelates, the non-MRI use of gadopentetate (Magnevist) is not approved by regulatory agencies. However, the literature suggests that a dose of 0.3-0.4 mmol/kg b.w. has been safely administered for CT as well as for angiography and interventional procedures intravenously and intraarterially. Even at this dose, though, this results in a relatively small overall volume to be injected, which limits utility somewhat.

Angiography↗
PubMed1996

3D gadolinium-enhanced MR angiography of the carotid arteries.

PURPOSE: To compare gadolinium-enhanced magnetic resonance angiography (MRA) of the carotid bifurcation with 2D time-of-flight (TOF) MR angiography with regard to image quality and duration of examination. MATERIALS AND METHODS: Gadolinium contrast was administered intravenously during 3D MR imaging at 1.5 Tesla in 46 patients presenting with suspected carotid occlusive disease. 2D time-of-flight MR angiography of the carotid bifurcation had been performed in each patient prior to gadolinium-enhanced MR angiography. RESULTS: Gadolinium MRA eliminated slice misregistration and in-plane saturation artifacts that occasionally degrades 2D TOF MR angiography. Gadolinium MRA required less than 4 min to image from the aortic arch to the skull base compared to 11 min for 2D TOF with comparable signal-to-noise ratio (SNR). Postprocessing was required to eliminate overlapping venous enhancement. Both techniques had susceptibility related artifactual loss of signal at the skull base and both demonstrated a linear artifact paralleling the long axis of arteries. CONCLUSION: Gadolinium-enhanced MR angiography is a promising technique for the evaluation of patients with carotid occlusive disease because it rapidly images the carotid arteries from the aortic arch to the skull base and eliminates some of the artifacts that degrade 2D TOF MR angiography.

Adult↗
PubMed1991

Combined gadolinium-enhanced and fat-saturation MR imaging of renal masses.

Combined gadopentetate dimeglumine enhancement and fat-saturation (FS) spin-echo (SE) magnetic resonance (MR) imaging for the detection and characterization of renal masses was evaluated in 43 patients with a total of 71 lesions (28 solid masses and 43 cysts). SE MR sequences compared were the following: short repetition time (TR)/echo time (TE), conventional SE, short TR/TE FS SE, long TR/TE conventional SE, gadolinium-enhanced short TR/TE conventional SE, and gadolinium-enhanced short TR/TE FS SE techniques. MR findings were compared with findings of contrast-enhanced computed tomography (CT) and with pathologic findings in all patients. The sensitivities for detection of renal masses with gadolinium-enhanced FS (71 of 71 lesions) and with gadolinium-enhanced short TR/TE conventional (65 of 71 lesions) SE sequences were significantly (P less than .01) greater than with any unenhanced (short TR/TE conventional [40 of 71 lesions], or long TR/TE [39 of 71 lesions]) SE sequence. Lesion characterization was also best with the gadolinium-enhanced FS SE sequence (65 of 71 lesions correctly classified). When combined pre- and postcontrast short TR/TE FS SE images were analyzed with both qualitative (visual) and quantitative (region-of-interest measurements) assessment, lesion characterization improved even further (70 of 71 lesions were correctly characterized). All lesions detected with CT were visualized with the gadolinium-enhanced FS SE MR sequence, which in addition depicted seven cysts and two small renal cell carcinomas. In summary, the use of gadopentetate dimeglumine, especially when combined with the FS technique, was superior to unenhanced MR imaging for detection and characterization of renal lesions.

Carcinoma, Renal Cell↗
PubMed1999

Biliary hamartomas: solitary and multiple lesions shown on current MR techniques including gadolinium enhancement.

The purpose of this study was to describe the magnetic resonance (MR) imaging features of biliary hamartomas on T1- and T2-weighted and gadolinium-enhanced sequences, and to correlate these findings with histopathology. MR imaging findings in four patients with pathologically proved biliary hamartomas are described. In all patients, MR imaging sequences, including T1- and T2-weighted and early and late gadolinium-enhanced images, were retrospectively evaluated for the size, morphology, signal intensity, and enhancement pattern of the lesions. Correlation was made between the MR imaging findings and histopathology. Biliary hamartomas ranged in diameter from 0.5 to 1.5 cm. Lesions were solitary in one patient and numerous in three patients. In all patients, the lesions were low signal on T1-weighted images and high signal and well-defined on T2-weighted images and demonstrated thin rim enhancement on early post-gadolinium images that persisted on late post-gadolinium images. No appreciable central enhancement of the lesions was observed. At histopathology, the lesions were composed of cystic spaces and fibrous stroma. Lesions showed compressed liver parenchyma surrounding the lesions (three cases) and inflammatory cell infiltrate (one case), which correlated with the rim enhancement on the gadolinium-enhanced MR images. Most of the biliary hamartomas in our small series were less than 1 cm in diameter and of high signal intensity on T2-weighted images, and had a thin rim of enhancement on early and late post-gadolinium images. The imaging features were explainable by the underlying histopathology. In patients with known malignancy, caution should be exercised not to misinterpret these lesions as metastases due to the presence of thin rim enhancement. J. Magn. Reson Imaging 1999;10:196-201, 1999.

Adult↗
PubMed1992

Neutron-capture therapy of murine ascites tumor with gadolinium-containing microcapsules.

Gadolinium-containing microcapsules were evaluated as an agent for gadolinium neutron-capture therapy. Mice were inoculated intraperitoneally with 10(7) Ehrlich ascites tumor cells and gadolinium microcapsules and exposed to thermal neutrons for 12 min (approximately 1.86 x 10(12) neutrons cm-2). Significantly more mice given gadolinium microcapsules than those given placebo microcapsules or control survived for 60 days and considerably longer (P < 0.0001), indicating that gadolinium neutron-capture reactions effectively suppressed the growth of ascites tumor cells in mice. The results suggest that these microcapsules are an effective gadolinium carrier for neutron-capture therapy.

Animals↗
PubMed2005

Predictive value of gadolinium enhancement in differentiating ALT/WD liposarcomas from benign fatty tumors.

OBJECTIVE: To determine the predictive value of gadolinium enhancement on MRI in differentiating atypical lipomatous tumor (ALT)/well-differentiated (WD) liposarcoma from benign fatty tumors. DESIGN: All histologically proven fatty tumors with preoperative gadolinium-enhanced MRI were reviewed. Only those tumors with predominantly fatty signal were included. Sensitivity, specificity, and positive and negative predictive values for both gadolinium enhancement and biopsy as predictors for the final diagnosis of ALT/WD liposarcoma were calculated. PATIENTS: From 129 patients evaluated for fatty tumors between 1994 and 2002, the patient population was narrowed to 32 excised fatty tumors with preoperative gadolinium-enhanced MRI. RESULTS: As a predictor of ALT/WD liposarcoma, the presence of gadolinium enhancement showed 100% sensitivity, 71% specificity, 53% positive predictive value and 100% negative predictive value. Needle or incisional biopsy yielded 57% sensitivity, 100% specificity, 100% positive predictive value and 63% negative predictive value for a diagnosis of ALT/WD liposarcoma. CONCLUSIONS: Gadolinium enhancement of a homogeneous fatty soft tissue tumor is a sensitive screening tool to determine possible diagnosis of ALT/WD liposarcoma. Biopsy, on the other hand, is specific but insensitive.

Adult↗
PubMed2002

Cerebrospinal fluid changes after intravenous injection of gadolinium chelate: assessment by FLAIR MR imaging.

Fluid-attenuated inversion recovery (FLAIR) sequence is currently used in clinical practice. Some reports emphasize the possibility that, in pathologic conditions, intravenous injection of gadolinium chelates may lead to an increased signal inside the cerebrospinal fluid (CSF). The aim of this study was to evaluate the presence of CSF signal changes in pathologic conditions causing blood-brain barrier disruption or neovascularization when imaging is performed after intravenous injection of gadolinium. We obtained FLAIR sequences after gadolinium injection from 33 patients affected by different intracranial pathologies and 10 control subjects. Patients were affected by ischemic stroke in the subacute phase, from 2 to 7 days from onset of symptoms (12 patients), meningiomas (8 patients), high-grade gliomas (5 patients), previous surgical procedures for intra-axial neoplasms (5 patients), and multiple sclerosis with active plaques (3 patients). Magnetic resonance imaging was performed in patients and controls using a 1.5-T magnet, using T2- and T1-weighted FLAIR sequences. The FLAIR sequence was acquired before and 1-3 h after injection of a standard dose of gadolinium. In those patients affected by ischemic lesions, FLAIR sequences were repeated the next days and 3-4 days later. The CSF signal was visually evaluated by two readers and scored from 0 to 3 depending by the degree of enhancement. The location of CSF signal changes (close to the lesion, hemispheric, or diffuse) was also considered. The CSF signal was markedly increased after 3 h from intravenous injection of gadolinium in all the patients with stroke, in those with previous surgery, and in those with high-grade gliomas whose neoplasm's surface was in contact with the subarachnoid spaces (SAS) or ventricles; a strong enhancement was also evident inside the necrotic component of the tumor. The CSF changes were more evident close to the pathology and/or in the hemisphere involved by the pathology. Moderate CSF enhancement was observed in the SAS close to meningiomas. No signal changes were evident in all the others. In those patients with stroke imaged in the following days, CSF signal showed to be diffuse to both hemispheres the next day and returned to normal values within 2 days. In patients affected by pathologies with blood-brain barrier breakdown or neovascularization close the SAS or the ventricles, CSF changes, related to gadolinium leakage, are likely when FLAIR sequences are acquired 2-24 h after i.v. injection of the contrast. This pattern should be known in order to differentiate it from that of subarachnoid hemorrhage.

Aged↗