Contrast-enhanced MR imaging of brain lesions: a large-scale intraindividual crossover comparison of gadobenate dimeglumine versus gadodiamide

BACKGROUND AND PURPOSE: The higher relaxivity of gadobenate dimeglumine compared with gadodiamide is potentially advantageous for contrast-enhanced brain MR imaging. This study intraindividually compared 0.1-mmol/kg doses of these agents for qualitative and quantitative lesion enhancement.MATERIALS AND METHODS: Adult patients with suggested or known brain lesions underwent 2 identical MR imaging examinations at 1.5T, one with gadobenate dimeglumine and the other with gadodiamide. The agents were administered in randomized order separated by 3–14 days. Imaging sequences and postinjection acquisition timing were identical for the 2 examinations. Three blinded readers evaluated images qualitatively for diagnostic information (lesion extent, delineation, morphology, enhancement, and global preference) and quantitatively for contrast-to-noise ratio (CNR).RESULTS: One hundred thirteen of 138 enrolled patients successfully underwent both examinations. Final diagnoses were intra-axial tumor, metastasis, extra-axial tumor, or other (47, 27, 18, and 21 subjects, respectively). Readers 1, 2, and 3 demonstrated global preference for gadobenate dimeglumine in 63 (55.8%), 77 (68.1%), and 73 (64.6%) patients, respectively, compared with 3, 2, and 3 patients for gadodiamide (P < .0001, all readers). Highly significant (P < .0001, all readers) preference for gadobenate dimeglumine was demonstrated for all qualitative end points and for CNR (increases of 23.3%–34.7% and 42.4%–48.9% [spin-echo and gradient-refocused echo sequences, respectively] for gadobenate dimeglumine compared with gadodiamide). Inter-reader agreement was good for all evaluations (κ = 0.47–0.69). Significant preference for gadobenate dimeglumine was demonstrated for all lesion subgroup analyses.CONCLUSION: Significantly greater diagnostic information and lesion enhancement are achieved on brain MR imaging with 0.1-mmol/kg gadobenate dimeglumine compared with gadodiamide at an equivalent dose.

Effective management of patients with tumors of the central nervous system (CNS) depends on accurate detection and characterization of enhancing lesions. Enhancement of tumors on gadolinium-enhanced MR imaging is a key imaging feature used in guiding surgical resection, delineating appropriate radiosurgical target volumes, and following patients for disease recurrence.^1,2Five gadolinium-based contrast agents are currently approved by the US Food and Drug Administration for MR imaging of the CNS. Although these agents have different molecular structures and physicochemical properties, they share the ability to transiently accumulate in areas with an abnormal blood-brain barrier, leading to faster T1 relaxation times and demonstrable contrast enhancement. Of these agents, gadobenate dimeglumine (Gd-BOPTA, MultiHance; Bracco, Milan, Italy) exhibits the highest R1 and R2 relaxivity in vivo.^3,4 The increased relaxivity derives from weak and transient interactions of the Gd-BOPTA contrast-effective molecule with serum albumin^5,6 and leads to increased signal-intensity (SI) enhancement relative to that obtained with other agents at an equivalent dose. Recent comparative studies in patients with brain or spinal tumors^7–12 have shown that this increased SI enhancement translates into significantly greater diagnostic performance compared with gadopentetate dimeglumine (Gd-DTPA, Magnevist; Bayer Healthcare, Leverskusen, Germany)^7–9 and an agent approved solely in Europe (gadoterate meglumine, Gd-DOTA; Dotarem; Guerbet, Aulnay-sous-Bois, France).¹⁰On the basis of R1 relaxivity values alone,^3,4 one might expect similar diagnostic superiority for gadobenate dimeglumine over gadodiamide (Gd-DTPA-BMA, Omniscan; GE Healthcare, Waukesha, Wis) when these agents are compared at equivalent doses, particularly given the similar diagnostic performance of gadodiamide and gadopentetate dimeglumine in patients with CNS disease.^13,14 However, whereas early interindividual parallel-group studies to compare gadobenate dimeglumine and gadodiamide revealed equivalence for a double (0.2 mmol/kg of body weight [BW]) dose (or a 1.5-fold dose) of gadobenate dimeglumine compared with a triple (0.3 mmol/kg BW) dose of gadodiamide, little if any differences were noted between single (0.1 mmol/kg BW) doses of these agents.^15,16 The aim of this study (MR EvaluatioN of MultiHance And OmniscaN for Contrast Enhancement [the MR-ENHANCE study]) was, therefore, to compare more accurately these 2 agents by using a controlled multicenter double-blind randomized intraindividual crossover study design in which each patient received 0.1-mmol/kg doses of both these agents in 2 identical MR imaging examinations.     

Contrast-enhanced MR angiography of the run-off vasculature: intraindividual comparison of gadobenate dimeglumine with gadopentetate dimeglumine

PURPOSE: To compare intraindividually gadobenate dimeglumine (Gd-BOPTA) with gadopentetate dimeglumine (Gd-DTPA) for multi-station MR Angiography of the run-off vessels. MATERIALS AND METHODS: Twenty-one randomized healthy volunteers received either Gd-BOPTA or Gd-DTPA as a first injection and then the other agent as a second injection after a minimum interval of 6 days. Each agent was administered at a dose of 0.1 mmol/kg bodyweight followed by a 25-mL saline flush at a single constant flow rate of 0.8 mL/second. Images were acquired sequentially at the level of the pelvis, thigh, and calf using a fast three-dimensional (3D) gradient echo sequence. Source, subtracted source, maximum intensity projection (MIP), and subtracted MIP image sets from each examination were evaluated quantitatively and qualitatively on a segmental basis involving nine vascular segments. RESULTS: Significantly (P < 0.05) higher signal-to-noise and contrast-to-noise ratios were noted for Gd-BOPTA compared to Gd-DTPA, with the more pronounced differences evident in the more distal vessels. Qualitative assessmentrevealed no differences in the abdominal vasculature, a preference for Gd-BOPTA in the pelvic vasculature, and markedly better performance for Gd-BOPTA in the femoral and tibial vasculature. Summation of individual diagnostic quality scores for each segment revealed a significantly (P = 0.0001) better performance for Gd-BOPTA compared to Gd-DTPA. CONCLUSION: Greater vascular enhancement of the run-off vasculature is obtained after Gd-BOPTA, particularly in the smaller more distal vessels. Enhancement differences are not merely dose dependent, but may be due to different vascular enhancement characteristics of the agents.     

钆贝酸二葡甲胺与钆喷酸葡胺乳腺MRI的多中心、双盲、随机、个体间交叉对照研究(检出实验)

目的利用前瞻性、多中心双盲随机数据对0.1mmol/kg剂量的钆贝酸二葡甲胺与钆喷酸葡胺对比剂增强乳腺MRI行个体间对照研究。材料与方法研究经学院评     

Contrast-enhanced MR Angiography of the renal arteries: blinded multicenter crossover comparison of gadobenate dimeglumine and gadopentetate dimeglumine

PURPOSE: To prospectively and intraindividually compare 0.1 mmol/kg gadobenate dimeglumine with 0.2 mmol/kg gadopentetate dimeglumine for contrast material-enhanced magnetic resonance (MR) angiography of the renal arteries. MATERIALS AND METHODS: Institutional review board approval was granted by each of three participating centers. The study accorded with international standards for good clinical practice and Declaration of Helsinki and subsequent amendments. Patients gave written informed consent before enrollment. Patients (n = 34) underwent two MR angiographic examinations more than 48 hours but less than 12 days apart. Gadobenate dimeglumine followed by gadopentetate dimeglumine was administered in 18 patients; the order of administration was reversed in 16 patients. A 1.5-T MR imager was used with a phase-encoded three-dimensional spoiled breath-hold pulse sequence. Two blinded independent readers qualitatively assessed randomized subtracted maximum intensity projection images. A three-point scale for diagnostic quality (0, poor; 1a or 1p, moderate; and 2a or 2p, adequate [a and p refer, respectively, to absence and presence of vascular lesions]) was used to score each of nine segments of the abdominal aorta and both renal arteries (possible overall score, 18). Quantitative assessment (vessel signal-to-noise ratio [SNR], vessel-muscle contrast-to-noise ratio [CNR]) of source images was performed for regions of interest in supra-, juxta-, and infrarenal aorta segments and psoas muscle. Data were tested with analysis of variance for two-period crossover design. Interreader agreement was evaluated with Cohen kappa statistics. RESULTS: No difference in mean image quality between the two contrast agents was observed; scores for gadobenate dimeglumine and gadopentetate dimeglumine were 15.15 and 15.23 for reader 1 and 16.77 and 17.01 for reader 2. The order of contrast material administration likewise produced no quality differences: readers 1 and 2 reported scores of 14.4 +/- 4.2 (standard deviation) and 16.7 +/- 2.3, respectively, when gadobenate dimeglumine was given first, and 15.2 +/- 1.8 and 16.6 +/- 1.6, respectively, when gadopentetate dimeglumine was given first. Results of quantitative evaluation showed increasing SNR and CNR with gadobenate dimeglumine in segments at progressively lower levels of the aorta, but increases in SNR and CNR at the infrarenal aorta (48.3 vs 40.6 and 44.2 vs 36.4, respectively) were not significant (P = .05 for both). CONCLUSION: Gadobenate dimeglumine at a dose of 0.1 mmol/kg is comparable to gadopentetate dimeglumine at 0.2 mmol/kg for contrast-enhanced renal MR angiography.     

Comparison of gadobenate dimeglumine and gadopentetate dimeglumine: a study of MR imaging and inductively coupled plasma atomic emission spectroscopy in rat brain tumors

BACKGROUND AND PURPOSE: After the advent of extracellular contrast media, hepatobiliary-specific gadolinium chelates were developed to improve the diagnostic value of MR imaging of the liver. Gadobenate dimeglumine (Gd-BOPTA) is a new paramagnetic contrast agent with partial biliary excretion that produces prolonged enhancement of liver parenchyma on T1-weighted images. However, whether Gd-BOPTA is useful as a contrast agent in central nervous system disease, particularly in brain tumors, is unclear. METHODS: The behavior of Gd-BOPTA as a brain tumor-selective contrast agent was compared with that of gadopentetate dimeglumine (Gd-DTPA), an MR contrast agent used in central nervous system disease, in a common dose of 0.1 mmol/kg. An MR imaging study of these two contrast agents was performed, and tissue concentrations were measured with inductively coupled plasma atomic emission spectroscopy (ICP-AES). RESULTS: Gd-BOPTA showed better MR imaging enhancement in brain tumors than did Gd-DTPA at every time course until 2 hours after administration and no enhancement in peritumoral tissue and normal brain. Corresponding results with ICP-AES showed significantly greater uptake of Gd-BOPTA in tumor samples than that in peritumoral tissue and normal brain 5 minutes after administration. Gadolinium was retained for a longer time in brain tumors when Gd-BOPTA rather than Gd-DTPA was administered. CONCLUSION: Gd-BOPTA is a useful contrast agent for MR imaging in brain tumors and possibly an effective absorption agent for neutron capture therapy.     

Renal time-resolved MR angiography: quantitative comparison of gadobenate dimeglumine and gadopentetate dimeglumine with different doses

PURPOSE: Results with different doses of gadobenate dimeglumine and gadopentetate dimeglumine were compared at magnetic resonance (MR) angiography of the renal arteries. The signal-to-noise ratio (SNR) was evaluated as a quantitative measure of image quality. MATERIALS AND METHODS: Sixty consecutive patients (age range, 24-81 years; mean age, 65 years) underwent intraarterial digital subtraction angiography (DSA) and contrast material-enhanced time-resolved MR angiography. DSA was the standard of reference. Fifteen patients received gadopentetate dimeglumine at doses of 0.2 or 0.1 mmol per kilogram of body weight. Fifteen patients received gadobenate dimeglumine at doses of 0.05 or 0.1 mmol/kg. The SNR was calculated in the aorta and both main renal arteries. The number and degree of stenoses of the renal arteries and accessory vessels were evaluated by four observers. RESULTS: SNRs with gadobenate dimeglumine at a dose of 0.1 mmol/kg were significantly superior to those with gadopentetate dimeglumine at a dose of 0.1 mmol/kg. Differences were not statistically significant between the SNRs in the other groups. Eleven (85%) of 13 hemodynamically significant renal artery stenoses were detected correctly with MR angiography as were 22 (85%) of 26 accessory renal arteries. CONCLUSION: SNRs with gadobenate dimeglumine were higher than those with gadopentetate dimeglumine, but in most cases the differences in SNRs were not statistically significant.     

Breast lesion detection and characterization at contrast-enhanced MR mammography: gadobenate dimeglumine versus gadopentetate dimeglumine

PURPOSE: To prospectively and intraindividually compare equivalent (0.1 mmol per kilogram of body weight) doses of gadobenate dimeglumine and gadopentetate dimeglumine for accuracy of detection and characterization of breast lesions at contrast material-enhanced magnetic resonance (MR) mammography. MATERIALS AND METHODS: Ethics committee approval and informed consent were obtained. Twenty-six consecutive women (mean age, 47.8 years) suspected of having a breast tumor at mammography and sonography underwent two identical MR examinations at 1.5 T; examinations were separated by more than 48 hours but less than 72 hours. A T1-weighted three-dimensional gradient-echo sequence was used, and images were acquired before and at 0, 2, 4, 6, and 8 minutes after randomized injection of gadopentetate dimeglumine or gadobenate dimeglumine at an identical flow rate of 2 mL/sec. Separate and combined assessment of unenhanced, contrast-enhanced, and subtracted images was performed blindly by two readers in consensus. Accuracy for lesion detection was determined against a final diagnosis based on findings at conventional mammography, sonography, and surgery. Sensitivity, specificity, positive and negative predictive values, and overall accuracy for malignant lesion identification were determined against histologic results. Data were analyzed with the McNemar test, proportional odds models, and analysis of variance. RESULTS: MR mammography with gadobenate dimeglumine depicted significantly (P = .003) more lesions (45 of 46) than did that with gadopentetate dimeglumine (36 of 46), and detected lesions were significantly (P < .001) more conspicuous with gadobenate dimeglumine. Confidence for characterization was significantly (P = .031) greater with gadobenate dimeglumine. Comparison of the contrast agents for their ability to help identify malignant lesions revealed significant (P = .02) superiority for gadobenate dimeglumine: Sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy for malignant lesion identification were, respectively, 94.7%, 100%, 100%, 80.0%, and 95.6% with gadobenate dimeglumine and 76.3%, 100%, 100%, 47.1%, and 80.4% with gadopentetate dimeglumine. Quantitative evaluation of signal intensity-time curves revealed significantly (P < .001) greater lesion enhancement with gadobenate dimeglumine. CONCLUSION: Detection of breast lesions and accurate identification of malignant lesions at MR imaging are significantly superior with gadobenate dimeglumine in comparison with gadopentetate dimeglumine.     

Comparison of gadobenate dimeglumine with gadopentetate dimeglumine for magnetic resonance imaging of liver tumors

RATIONALE AND OBJECTIVES: To compare gadobenate dimeglumine (Gd-BOPTA) with gadopentetate dimeglumine (Gd-DTPA) for magnetic resonance imaging of the liver. METHODS: The contrast agent Gd-BOPTA or Gd-DTPA was administered at a dose of 0.1 mmol/kg to 257 patients suspected of having malignant liver tumors. Dynamic phase images, spin-echo images obtained within 10 minutes of injection, and delayed images obtained 40 to 120 minutes after injection were acquired. All postcontrast images were compared with unenhanced T1-weighted and T2-weighted images obtained immediately before injection. A full safety assessment was performed. RESULTS: The contrast efficacy for dynamic phase imaging was moderately or markedly improved in 90.9% (110/121) and 87.9% (109/124) of patients for Gd-BOPTA and Gd-DTPA, respectively. At 40 to 120 minutes after injection, the cor- responding improvements were 21.7% (26/120) and 11.6% (14/121) for spin-echo sequences and 44.5% (53/119) and 19.0% (23/121) for breath-hold gradient-echo sequences, respectively. The differences at 40 to 120 minutes after injection were statistically significant (P < 0.02). Increased information at 40 to 120 minutes after injection compared with information acquired within 10 minutes of injection was available for 24.0% (29/121) of patients with Gd-BOPTA and for 14.5% (18/124) of patients with Gd-DTPA (P < 0.03). Adverse events were seen in 4.7% (6/128) and 1.6% (2/127) of patients receiving Gd-BOPTA and Gd-DTPA, respectively. The difference was not statistically significant. CONCLUSIONS: The efficacy of Gd-BOPTA is equivalent to that of Gd-DTPA for liver imaging during the dynamic phase and superior during the delayed (40-120 minutes) phase of contrast enhancement. Both agents are safe for use in magnetic resonance imaging of the liver.     

Low-dose gadobenate dimeglumine versus standard dose gadopentetate dimeglumine for contrast-enhanced magnetic resonance imaging of the liver: an intra-individual crossover comparison

RATIONALE AND OBJECTIVES: Gadobenate dimeglumine (Gd-BOPTA) has a two-fold higher T1 relaxivity compared with gadopentetate dimeglumine (Gd-DTPA) and can be used for both dynamic and delayed liver MRI. This intraindividual, crossover study was conducted to compare 0.05 mmol/kg Gd-BOPTA with 0.1 mmol/kg Gd-DTPA for liver MRI. MATERIALS AND METHODS: Forty-one patients underwent two identical MR examinations separated by >or= 72 hours. Precontrast T1-FLASH-2D and T2-TSE sequences and postcontrast T1-FLASH-2D sequences were acquired during the dynamic and delayed (1-2 hours) phases after each contrast injection. Images were evaluated on-site by two independent, blinded off-site readers in terms of confidence for lesion detection, lesion number, character and diagnosis, enhancement pattern, lesion-to-liver contrast, and benefit of dynamic and delayed scans. Additional on-site evaluation was performed of the overall diagnostic value of each agent. RESULTS: Superior diagnostic confidence was noted by on-site investigators and off-site assessors 1 and 2 for 6, 4 and 2 patients with Gd-BOPTA, and for 3, 1 and 2 patients with Gd-DTPA, respectively. No consistent differences were noted for other parameters on dynamic phase images whereas greater lesion-to-liver contrast was noted for more patients on delayed images after Gd-BOPTA. More correct diagnoses of histologically confirmed lesions (n = 26) were made with the complete Gd-BOPTA image set than with the complete Gd-DTPA set (reader 1: 68% vs. 59%; reader 2: 78% vs. 68%). The overall diagnostic value was considered superior after Gd-BOPTA in seven patients and after Gd-DTPA in one patient. CONCLUSION: The additional diagnostic information on delayed imaging, combined with the possibility to use a lower overall dose to obtain similar diagnostic information on dynamic imaging, offers a distinct clinical advantage for Gd-BOPTA for liver MRI.     

Multicenter,double‐blind,randomized, intra‐individual crossover comparison of gadobenate dimeglumine and gadopentetate dimeglumine in MRI of brain tumors at 3 tesla

Purpose

To prospectively compare 0.1 mmol/kg doses of gadobenate dimeglumine and gadopentetate dimeglumine for contrast‐enhanced MRI of brain lesions at 3 Tesla (T).

Materials and Methods

Forty‐six randomized patients underwent a first examination with gadobenate dimeglumine (n = 23) or gadopentetate dimeglumine (n = 23) and then, after 2–7 days, a second examination with the other agent. Contrast administration (volume, rate), sequence parameters (T1wSE; T1wGRE), and interval between injection and image acquisition were identical for examinations in each patient. Three blinded neuroradiologists evaluated images qualitatively (lesion delineation, lesion enhancement, global preference) and quantitatively (lesion‐to‐brain ratio [LBR], contrast‐to‐noise ratio [CNR], % lesion enhancement). Differences were assessed using Wilcoxon's signed‐rank test. Reader agreement was determined using kappa (κ) statistics.

Results

There were no demographic differences between groups. The three readers preferred gadobenate dimeglumine globally in 22 (53.7%), 21 (51.2%), and 27 (65.9%) patients, respectively, compared with 0, 1, and 0 patients for gadopentetate dimeglumine. Similar significant (P < 0.001) preference was expressed for lesion border delineation and enhancement. Reader agreement was consistently good (κ = 0.48–0.64). Significantly (P < 0.05) higher LBR (+43.5– 61.2%), CNR (+51.3–147.6%), and % lesion enhancement (+45.9–49.5%) was noted with gadobenate dimeglumine.

Conclusion

Brain lesion depiction at 3T is significantly improved with 0.1 mmol/kg gadobenate dimeglumine. J. Magn. Reson. Imaging 2009;29:760–767. © 2009 Wiley‐Liss, Inc.     

Enhancing lesions of the brain: intraindividual crossover comparison of contrast enhancement after gadobenate dimeglumine versus established gadolinium comparators

RATIONALE AND OBJECTIVES: Gadobenate dimeglumine (Gd-BOPTA) possesses a two-fold higher T1 relaxivity compared to other available gadolinium contrast agents. The study was conducted to evaluate the benefits of this increased relaxivity for MR imaging of intracranial enhancing brain lesions. MATERIALS AND METHODS: Forty-five patients (31 males, 14 females) with suspected glioma or cerebral metastases were evaluated. Patients received Gd-BOPTA and either Gd-DTPA (n = 23) or Gd-DOTA (n = 22) in fully randomized order at 0.1 mmol/kg body weight and at a flow rate of 2 ml/s. The second agent was administered 1-14 days after the first agent. Images were acquired precontrast (T1wSE, T2wFSE sequences) and at sequential postcontrast time-points (T1wSE sequences at 0, 2, 4, 6, and 8 and 15 min and a T1wSE-MT sequence at 12 min) at 1.0 or 1.5 T using a head coil. Determination of contrast enhancement was performed quantitatively (lesion-to-brain ratio, contrast-to-noise ratio, and percent enhancement) and qualitatively (border delineation, internal morphology, contrast enhancement, and diagnostic preference) by two independent, fully blinded readers. RESULTS: Images from 43/45 patients were available for quantitative assessment. After correction for precontrast values, significantly greater lesion-to-brain ratio (P < .003), contrast-to-noise ratio (P < .03), and percent enhancement (P < .0001) was noted by both readers for Gd-BOPTA-enhanced images at all time-points from 2 min postcontrast. Qualitative assessment of all patients similarly revealed significant preference for Gd-BOPTA for lesion border delineation (P < .004), lesion internal morphology (P < .008), contrast enhancement (P < .0001), and diagnostic preference (P < .0005). CONCLUSIONS: The greater T1 relaxivity of Gd-BOPTA permits improved visualization of intracranial enhancing lesions compared to conventional gadolinium agents.     

MR evaluation of CNS tumors: dose comparison study with gadopentetate dimeglumine and gadoteridol

In phase II and III trials of gadoteridol (Gd-HP-D03A), a new nonionic, low-osmolar contrast agent, 40 patients with intracranial neoplasms underwent magnetic resonance (MR) imaging with experimental doses of 0.05-0.3 mmol/kg. Fifteen patients also underwent contrast studies with the standard dose (0.1 mmol/kg) of gadopentetate dimeglumine. Both gadopentetate dimeglumine and gadoteridol appear to have a similar effect when given in equal doses (0.1 mmol/kg, n = 5). Lesion enhancement and delineation were better at higher experimental doses (0.2 or 0.3 mmol/kg, n = 7) and worse at a lower experimental dose (0.05 mmol/kg, n = 3). Quantitative analysis of 10 lesions examined with identical imaging protocols revealed a directly proportional relationship (r = .975) between lesion contrast ratio and dose over a range of 0.05-0.3 mmol/kg. Phantom experiments support the clinical results. Improved enhancement, detection, and delineation of central nervous system (CNS) neoplasms resulting from increased injected doses of gadoteridol have the potential to be clinically significant and may justify the possibly higher cost of increased contrast material dosage. Lower doses may not be adequate for the evaluation of most CNS tumors.     

Safety characteristics of gadobenate dimeglumine: clinical experience from intra- and interindividual comparison studies with gadopentetate dimeglumine

PURPOSE: To evaluate the safety and tolerability of gadobenate dimeglumine (Gd-BOPTA) relative to that of gadopentetate dimeglumine (Gd-DTPA) in patients and volunteers undergoing MRI for various clinical conditions. MATERIALS AND METHODS: A total of 924 subjects were enrolled in 10 clinical trials in which Gd-BOPTA was compared with Gd-DTPA. Of these subjects, 893 were patients with known or suspected disease and 31 were healthy adult volunteers. Of the 893 patients, 174 were pediatric subjects (aged two days to 17 years) referred for MRI of the brain or spine. Safety evaluations included monitoring vital signs, laboratory values, and adverse events (AE). RESULTS: The rate of AE in adults was similar between the two agents (Gd-BOPTA: 51/561, 9.1%; Gd-DTPA: 33/472, 7.0%; P = 0.22). In parallel-group studies in which subjects were randomized to either agent, the rate of AE was 10.9% for Gd-BOPTA and 7.9% for Gd-DTPA (P = 0.21). In the subset of subjects receiving both agents in intraindividual crossover trials, the rate of AE was 8.0% for Gd-BOPTA and 8.5% for Gd-DTPA (P = 0.84). Results of other safety assessments (laboratory tests, vital signs) were similar for the two agents. CONCLUSION: The safety profile of Gd-BOPTA is similar to Gd-DTPA in patients and volunteers. Both compounds are equally well-tolerated in patients with various disease states undergoing MRI.     

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.     

Rectal carcinoma: Prospective comparison of conventional and gadopentetate dimeglumine enhanced fat-suppressed MR imaging

The purpose of this study is to compare the usefulness of conventional MR imaging and gadopentetate dimeglumine enhanced fat-suppressed MR imaging for the depiction and staging of rectal carcinoma. Thirty-two patients were prospectively evaluated by MR imaging using a 1.5-T unit. Based on the results of a barium study and/or digital examination, a balloon catheter was inserted to the level of the lesion before examination. Both conventional T1- and T2-weighted images and gadopentetate dimeglumine enhanced fat-suppressed T1-weighted images were obtained for all patients. The kappa statistics were performed for the evaluation of interobserver agreement and the McNemar test was performed for the analysis of staging accuracy. When only T1- and T2-weighted images were used, 5 of 32 tumors were not detected and the extent of 18 of 32 tumors were unclear. However, when gadopentetate dimeglumine enhanced fat-suppressed imaging was added, 24 of 32 tumors were well defined and only one tumor was not detected. In determining the depth of invasion, the staging accuracy was 72% for conventional imaging and 68% for all images combined. There was no significant difference between with gadopentetate dimeglumine fat-suppressed imaging and conventional imaging (P > .05). Use of gadopentetate dimeglumine (fat-suppressed imaging) resulted in overestimation of muscular invasion, peri-rectal fat invasion, and adjacent organ invasion in 12 patients, whereas nine patients were overestimated without the use of gadopentetate dimeglumine. In the detection of metastatic lymph nodes, gadopentetate dimeglumine enhanced fat-suppressed imaging also was not useful. Tumor detection was excellent using gadopentetate dimeglumine enhanced fat-suppressed images. However, the accuracy of staging was not improved by obtaining such images.     

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.     

MR imaging of soft-tissue masses: Role of gadopentetate dimeglumine

To assess the effectiveness of gadopentetate dimeglumine in the magnetic resonance (MR) imaging evaluation of soft-tissue masses without osseous involvement, 30 patients underwent MR imaging before and after administration of contrast material (0.1 mmol/ kg) of the 30 lesions, 22 were benign and eight were malignant; histologic confirmation was available in all lesions except one benign lesion. Overall, enhancement was detected in 26 (87%) of 30 lesions: 18 (82%) of the 22 benign lesions and eight (100%) of eight malignant lesions. Enhancement was characterized as homogeneous (two [11%] benign lesions, two [25%] malignant lesions), inhomogeneous (11 [61%] benign lesions, six [75%] malignant lesions), or peripheral (five [28%] benign lesions, no malignant lesions) of the 19 lesions assessed for a change in enhancement over time, seven (37%) showed an increase and two (11%) showed a decrease in signal intensity. The authors conclude that benign and malignant soft-tissue lesions could not be differentiated solely on the basis of enhancement (pattern, degree, or time course).