Gadopentetate Dimeglumine Enhancement Research Articles

3′-Deoxy-3′-[F-18]Fluorothymidine Positron Emission Tomography in Patients with Recurrent Glioblastoma Multiforme: Comparison with Gd-DTPA Enhanced Magnetic Resonance Imaging

The accumulation of 3'-deoxy-3'-[F-18]fluorothymidine (FLT) on positron emission tomography (PET) images in patients with glioblastoma multiforme was evaluated and correlated with gadopentetate dimeglumine (Gd-DTPA) enhancement in magnetic resonance images (MRIs). FLT studies in 10 patients with recurrent glioblastoma multiforme were retrospectively investigated. Dynamic emission data were acquired for 60 minutes immediately after injection of FLT. The standardized uptake value (SUV) for tumor and reference tissue (contralateral hemisphere and ipsilateral cerebellum) was calculated. The volumes of the metabolically active part of the tumor (V (PET)) and that of the Gd-DTPA enhancing part of the tumor (V (MR)) were calculated. FLT uptake in tumors peaked before 5 minutes and sometimes as early as 0.5 minutes, and reached a constant level at approximately 10 minutes after injection. The reference tissue time-activity curves had an early peak and reached a constant low background level. All tumors had increased FLT uptake and showed Gd-DTPA enhancement. The SUV in tumor was significantly higher than that in the reference tissue (P<0.0001). A significant correlation between V (PET) and V (MR) was found (P<0.0001) although there was a difference in the areas of Gd-DTPA enhancement and FLT uptake. These preliminary results indicate that FLT-PET may be useful for the detection of recurrent glioblastoma multiforme. Our data in a relatively small patient population do not support a clear-cut relationship between FLT accumulation and Gd-DTPA enhancement. Further pathologic correlation will determine if it can be used for detecting recurrent tumoral disease.

Correlations from gadopentetate dimeglumine-enhanced magnetic resonance imaging after methotrexate chemotherapy for hemorrhagic placenta increta

ObjectiveTo describe pre- and post-methotrexate (MTX) therapy images from pelvic magnetic resonance imaging (MRI) with gadopentetate dimeglumine contrast following chemotherapy for post-partum hemorrhage secondary to placenta increta.Material and methodA 28-year-old Caucasian female presented 4 weeks post-partum complaining of intermittent vaginal bleeding. She underwent dilatation and curettage immediately after vaginal delivery for suspected retained placental tissue but 28 d after delivery, the serum β-hCG persisted at 156 IU/mL. Office transvaginal sonogram (4 mHz B-mode) was performed, followed by pelvic MRI using a 1.5 Tesla instrument after administration of gadolinium-based contrast agent. MTX was administered intramuscularly, and MRI was repeated four weeks later.ResultsWhile transvaginal sonogram suggested retained products of conception confined to the endometrial compartment, an irregular 53 × 34 × 28 mm heterogeneous intrauterine mass was noted on MRI to extend into the anterior myometrium, consistent with placenta increta. Vaginal bleeding diminished following MTX treatment, with complete discontinuation of bleeding achieved by ~20 d post-injection. MRI using identical technique one month later showed complete resolution of the uterine lesion. Serum β-hCG was <5 IU/mL.ConclusionReduction or elimination of risks associated with surgical management of placenta increta is important to preserve uterine function and reproductive potential. For selected hemodynamically stable patients, placenta increta may be treated non-operatively with MTX as described here. A satisfactory response to MTX can be ascertained by serum hCG measurements with pre- and post-treatment pelvic MRI with gadopentetate dimeglumine enhancement, which offers advantages over standard transvaginal sonography.

Efficacy of Contrast-Enhanced MR Imaging in Cardiomyopathy: An Experimental Study Using Bio 14.6 Hamsters

Rationale and Objectives Myocardial fibrosis was evaluated with magnetic resonance (MR) imaging in Bio14.6 hamsters. Materials and Methods Gated gradient-echo T1-weighted images and spin-echo images with gadopentetate dimeglumine enhancement (0.2 mmol/kg) were obtained. Results Myocardial enhancement persisted for 13 minutes after administration of gadopentetate dimeglumine, and myocardial signal intensity peaked at 13 minutes on gradient-echo T1-weighted images. The enhanced areas were greater in Bio14.6 hamsters at 25–42 weeks than at 10 weeks. Pathologic data revealed enhancement with inflammation at 10 weeks and fibrosis with vessel proliferation at 25–42 weeks. Pathologic fibrotic change was greater at 32–42 weeks than at 10 weeks. The myocardium of 42-week-old Bio14.6 hamsters showed remarkable contrast enhancement, which continued for 13 minutes. There was no correlation between gadolinium enhancement and pathologic findings in the evaluation of myocardial degeneration and fibrosis. Conclusion Gadolinium-enhanced MR imaging was useful for estimating myocardial fibrotic changes with vessel proliferation and myocardial damage.

Evaluation of early response to SU101 target-based therapy in patients with recurrent supratentorial malignant gliomas using FDG PET and Gd-DTPA MRI.

Changes in [18F]-2-fluoro-2-deoxyglucose (FDG) uptake and gadopentetate dimeglumine (Gd-DTPA) enhancement before and after the first course of treatment with a cytostatic agent SU101 (N-[(4-trifluoromethyl)-phenyl]-5-methylisoxazole-4-carboxamide, SUGEN) were assessed using positron emission tomography (PET) and magnetic resonance imaging (MRI) in a pilot study of 8 patients with recurrent supratentorial malignant gliomas. The localization and the volume of Gd-DTPA enhancement and FDG hypermetabolism were analyzed. PET and MRI studies were performed one week before and 7.6+/-3.7 weeks after administration of SU101. The ratios of mean tumor activity to mean contralateral white matter and ipsilateral cerebellar activity were calculated for tumor regions, and SUV values corrected to the subjects' body surface area and glucose level (SUVbsa*glu) were calculated for nontumor regions. Five patients had a substantial increase of tumor volume on both PET and MRI during the first course of SU101. PET and MRI showed roughly equivalent volume changes. Large tumor volume increases were associated with a short time to clinical progression. The metabolic change in the tumor following the first course of SU101 varied from patient to patient, ranging from a 31% reduction to a 43% increase in FDG uptake ratio. Changes in FDG uptake were not predictive of time to progression or survival. In 2 patients with marked clinical deterioration and rapid tumor growth, there were differences in localization of Gd-DTPA enhancement and FDG hypermetabolism suggesting that hypermetabolism beyond the area of contrast enhancement may be of value in predicting rapid progression of high-grade glioma. SU101 did not induce any appreciable changes in SUVbsa*glu for non-tumor brain in 6 of 8 patients.

Effect of the rate of gadopentetate dimeglumine administration on abdominal vascular and soft-tissue MR imaging enhancement patterns.

To delineate dynamic gadopentetate dimeglumine enhancement profiles within the abdomen as a guide to improve gadolinium-enhanced magnetic resonance (MR) angiography. Fifteen patients (eight women, seven men; aged 19-80 years) underwent fast three-dimensional spoiled gradient-recalled-echo imaging with the keyhole technique during the administration of 0.1 mmol/kg gadopentetate dimeglumine by means of bolus (10-second) injection (n = 5), 60 second injection (n = 5), or slow (120-230-second) pump injection (n = 5). Injection was initiated 10 seconds after imaging began. Regions of interest were constructed within the aorta, inferior vena cava, liver, spleen, renal cortex, muscle, and fat. Inclusion of phantoms of gadopentetate dimeglumine in tubes allowed estimation of intravascular gadolinium concentration. Maximal arterial enhancement occurred with bolus administration; maximal parenchymal organ enhancement, with 60-second injection. Slow pump injection resulted in a longer time to preferential arterial to venous enhancement (120 seconds +/- 14 [+/-standard deviation]) than did bolus (48 seconds +/- 64) or 60-second (88 seconds +/- 39) injections. The peak arterial to venous enhancement ratio was 6.3 +/- 3.3 for the bolus injection, 4.7 +/- 1.6 for the 60-second injection, and 3.3 +/- 1.3 for the slow pump injection. The dynamics and magnitude of abdominal vascular and soft-tissue enhancement are affected by the rate of gadopentetate dimeglumine administration.

Hilar cholangiocarcinomas: T2-weighted spin-echo and gadolinium-enhanced FLASH MR imaging.

To investigate the use of magnetic resonance (MR) imaging with dynamic gadopentetate dimeglumine enhancement in hilar cholangiocarcinoma. Twenty-four patients (14 men, 10 women; aged 27-78 years; mean age, 51 years) with hilar cholangiocarcinoma underwent T2-weighted spin-echo MR imaging in the axial plane and multisection, breath-hold, fast low-angle shot (FLASH) MR imaging in the coronal oblique plane before and at 30, 60, 90, and 120 seconds after bolus injection of gadopentetate dimeglumine. Morphologic features were recorded, and contrast medium enhancement characteristics and contrast-to-noise ratios were calculated for each sequence. All the lesions were hyperintense on T2-weighted spin-echo images and hypointense on FLASH images. On dynamic gadolinium-enhanced images, progressive heterogeneous enhancement was seen in all patients. Intrahepatic ductal dilatation was present in every patient. Intraluminal components were seen in 11 patients, lobar atrophy in 12, and segmental portal venous occlusion or stenosis in 13. Satellite lesions were present in four patients, and hilar lymph nodal enlargement in 11. Contrast-to-noise ratios were statistically significantly higher on T2-weighted spin-echo images than on all other images. Hilar cholangiocarcinomas have consistent enhancement and morphologic features that can be demonstrated with dynamic contrast-enhanced MR imaging.

Tumor angiography using high-resolution, three-dimensional magnetic resonance imaging: Comparison of gadopentetate dimeglumine and a macromolecular blood-pool contrast agent

We compared the peritumoral vascular definition in rats using either a paramagnetic extracellular or a macromolecular contrast medium in combination with high-resolution magnetic resonance (MR) imaging. High-resolution, three-dimensional spoiled gradient-refocused acquisition in a steady state (SPGR) images were acquired from tumor-bearing Fischer-344 rats before, immediately after, and again 40 min after administration of gadopentetate dimeglumine (0.1 mmol Gd/kg; n = 10) and albumin-(Gd-DTPA)30 (0.05 mmol Gd/kg; n = 5). Small peritumoral vessels were analyzed semiquantitatively on maximum intensity projection angiograms using a 4-point scoring system; quantitative analyses included signal-to-background ratios (SBRs) and signal-to-noise ratios. Gadopentetate dimeglumine caused a transient and low-scoring (0.2 +/- 0.1, SBR = 1.9 +/- 0.2) vessel definition but strong rim enhancement (score = 1.4 +/- 0.2). Albumin-(Gd-DTPA)30 produced persistent, high-quality angiograms (score = 2.6 +/- 0.2, SBR = 7.4 +/- 0.2) but minimal rim enhancement (score = 0.3 +/- 0.2). Albumin-(Gd-DTPA)30 combined with high-resolution MR imaging produces time-persistent, detailed angiographic definition of peritumoral vessels. Vascular maps obtained with gadopentetate dimeglumine enhancement are not time persistent or of equal quality.

Enhancement and Demyefination of the Intraorbital Optic Nerve: Fat Suppression Magnetic Resonance Imaging

Conventional spin-echo magnetic resonance imaging (MRI) of intraorbital optic neuritis is hampered by the adjacent high signal and chemical shift artifact of orbital fat. Frequency-selective saturation pulse MRI reduces these problems and was used to determine its utility in evaluation of intraorbital optic neuritis. Eight consecutive patients with optic neuritis underwent MRI within 1 week of the onset of visual loss. Conventional MRI with T1, proton density, and T2 weighting and frequency-selective saturation pulse MRI with T1, proton density, and T2 weighting were performed. After administration of intravenous gadopentetate dimeglumine, T1-weighted conventional and frequency-selective saturation pulse MRI were performed. Frequency-selective saturation pulse MRI showed gadopentetate dimeglumine enhancement in the intraorbital optic nerve in 7 patients and the intracranial optic nerve in 3 patients. Conventional MRI failed to show optic nerve gadopentetate dimeglumine enhancement in patients with intraorbital lesions, but did show intracranial lesions. Frequency-selective saturation pulse MRI showed bilateral optic nerve enhancement in 3 patients with unilateral visual signs and symptoms. Proton density and T2-weighted conventional MRI of the brain showed no convincing signal aberrations in the optic nerves. In the MRI evaluation of intraorbital optic neuritis: (1) frequency-selective saturation pulse fat suppression MRI is superior to T1-weighted conventional MRI in the detection of gadopentetate dimeglumine enhancement; (2) frequency-selective saturation pulse proton density and T2-weighted MRI is superior to proton density and T2-weighted conventional MRI; (3) frequency-selective saturation pulse MRI showed gadopentetate dimeglumine enhancement as well as proton density/T2-weighted signal aberration in exactly the same portion of the intraorbital optic nerve.

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.

Normal venous anatomy of the brain: demonstration with gadopentetate dimeglumine in enhanced 3-D MR angiography.

This investigation evaluates whether gadopentetate dimeglumine enhancement of three-dimensional (3-D) acquisition MR angiography can generate clinically useful images of the normal venous anatomy of the brain. 3-D MR angiography of normal cerebral arterial anatomy has made rapid progress, although demonstration of detailed venous anatomy with similar techniques has been much less revealing. To overcome the limitation of slow venous flow, IV gadopentetate dimeglumine contrast enhancement was used to alter the relaxation times of blood, thus augmenting the venous signal. Several groups of patients were evaluated: we studied eight patients both with and without contrast enhancement, 20 patients and volunteers with multiple techniques to determine optimal technical parameters, and seven patients in whom enhanced MR studies were compared with standard selective biplane cut-film arterial angiograms. Only the large dural sinuses (such as the transverse sinus) could be seen on unenhanced studies owing to the saturation of slowly flowing venous spins. With contrast enhancement, many of the important small and large cerebral venous structures were routinely seen with reasonable scanning times (7 min). The venous anatomy was well seen for approximately one-half hour after injection and correlated well with angiograms. There are several important limitations to this technique, including a limited field of view, variable visibility of specific veins owing to technical and physiologic factors, confusion of enhancing non-flow-related structures, and lack of detailed physiologic information. Single excitation 3-D MR angiograms are insensitive in the evaluation of cerebral venous structures. Enhancement with gadopentetate dimeglumine affords rapid scanning and excellent visualization of the pertinent venous anatomy. The best image quality was obtained with a sequence of 50/7/30 degrees (TR/TE/flip angle).

Early cerebral infarction: gadopentetate dimeglumine enhancement.

Gadopentetate dimeglumine was administered prospectively to 50 patients who presented for magnetic resonance (MR) imaging within 2 weeks after a cortical cerebral infarction. Twenty-two patients (44%) were imaged within 3 days after clinical ictus. Abnormalities detected with gadopentetate dimeglumine enhancement were observed in 46 (92%) of 50 patients. Classic parenchymal enhancement was a late finding, observed in all patients (17 of 17) imaged at 7-14 days after infarction. Before this time, three additional phases of contrast material-related abnormalities were observed. Enhancement of vessels supplying the infarct ("intravascular enhancement sign") was the earliest finding, seen in 17 (77%) of 22 infarcts aged 1-3 days. From day 2 to day 6, abnormal enhancement of meninges adjacent to the infarct was frequently noted ("meningeal enhancement sign"). Finally, a transition phase that combined intravascular or meningeal enhancement with early parenchymal enhancement was seen from day 3 to day 6. Gadopentetate dimeglumine-enhanced MR imaging in early stroke reveals evidence of vascular engorgement and sluggish flow, which precede the development of classic parenchymal enhancement.

Magnetic Resonance Imaging of Radiation Optic Neuropathy

Three patients with delayed radiation optic neuropathy after radiation therapy for parasellar neoplasms underwent magnetic resonance imaging. The affected optic nerves and chiasms showed enlargement and focal gadopentetate dimeglumine enhancement. The magnetic resonance imaging technique effectively detected and defined anterior visual pathway changes of radionecrosis and excluded the clinical possibility of visual loss because of tumor recurrence.

MR imaging of optic nerve lesions: value of gadopentetate dimeglumine and fat-suppression technique.

Eleven patients with known or suspected optic nerve lesions and eight normal subjects were examined with spin-echo technique at 1.5 T with unenhanced T1-weighted imaging, IV gadopentetate-dimeglumine-enhanced T1-weighted imaging, and enhanced T1-weighted imaging with fat suppression. Two pathologically proved and four presumed optic nerve meningiomas demonstrated significant enhancement and were best seen with the fat-suppression technique. None of the three presumed optic nerve gliomas nor the optic nerves of normal subjects demonstrated qualitative enhancement. We conclude that the use of a fat-suppression technique with gadopentetate dimeglumine enhancement improves delineation of enhancing optic nerve lesions. This technique should be useful for evaluating other anatomic regions where enhancing tissue marginates fat.

Benign lumbar arachnoiditis: MR imaging with gadopentetate dimeglumine.

MR imaging was performed in 13 patients with benign lumbar arachnoiditis both before and after IV injection of gadopentetate dimeglumine. The arachnoiditis was proved by previous myelography in 12 patients and by noncontrast MR imaging in one patient. The disease was presumably the result of previous myelography and/or surgery. It was characterized as mild in two patients, moderate in two patients, and severe in nine patients. Imaging was performed on a 1.5-T unit, and both short and long TR images were obtained before and after contrast administration. Noncontrast MR images demonstrated changes consistent with arachnoiditis in all patients. After contrast, three patients had no enhancement, three patients had minimal enhancement, three patients had mild enhancement, and four patients had moderate enhancement. In no case did contrast enhancement alter the diagnosis or reveal additional findings that could not be seen on the noncontrast images. Gadopentetate dimeglumine enhancement plays little role in the diagnosis of lumbar arachnoiditis. If used for another reason, however, short TR scans may show enhancement of adherent roots in some cases. In addition, administration of gadopentetate dimeglumine will not cause sufficient enhancement to hinder the detection of arachnoiditis on long TR images and may aid in recognition of adherent roots on short TR images.

Case report: Gadolinium-enhanced MR imaging in the management of a midline cerebral dysgerminoma

Magnetic Resonance (MR) imaging has proved to be an excellent modality for the evaluation of CNS tumors and detection of metastatic seeding through CNS pathways. We present a case of cerebral dysgerminoma in which the use of gadopentetate dimeglumine (Gd-DTPA) enhancement added important information in lesion detection and delineation for treatment planning. Our results, and a review of recent literature, suggest that Gd-DTPA-enhanced MR imaging may be useful for initial and follow-up evaluation of CNS dysgerminomas.

Spinal lesions: quantitative and qualitative temporal evolution of gadopentetate dimeglumine enhancement in MR imaging.

Seventy gadolinium-enhanced magnetic resonance imaging studies were reviewed, and 36 were selected for quantitative and qualitative analysis of the temporal evolution of contrast medium enhancement of spinal lesions. In the extradural space, lesions often showed mild increase of enhancement on delayed images, but enhancement was always visible on immediate postcontrast images. In the intradural extramedullary space, tumor nodules demonstrated most prominent enhancement on early images, although subtle, strandlike enhancement of the nerve roots showed some delayed uptake of contrast medium on later images. In the intramedullary space, enhancement often increased on delayed images, although this increase was usually mild. For clinical purposes, immediate postcontrast imaging should be sufficient to depict the majority of spinal lesions, regardless of location. However, selected cases, such as necrotic spinal cord tumors, will require delayed imaging.