Sufficient MRI graft structural integrity at 9 months after anterior cruciate ligament reconstruction with hamstring tendon autograft.

PURPOSE: To assess the MRI-measured structural integrity of hamstring autograft at 9 months after anterior cruciate ligament reconstruction (ACLR) surgery. METHODS: A prospective cohort study was conducted including 34 patients (mean age 36.8 ± 11.8 years; 73.5% males) who underwent ACLR with hamstring autograft. In addition, 36 patients (mean age 39.2 ± 10.5 years; 69.4% males) without any ACL injury were also reviewed and served as control group. The primary outcome used for examining graft maturity at 9 months after ACLR was the MRI-based signal-to-noise quotient (SNQ) of reconstructed ACL. SNQ values were stratified into 3 different categories: excellent: < 0.1; good: ≥ 0.1 and ≤ 0.19; fair: ≥ 0.2. The KT-1000 knee arthrometer was used to measure the side-to-side difference in the anterior tibial translation between the ACLR knee and the contralateral healthy knee in the ACLR group. RESULTS: Reconstructed ACLs were found with a mean SNQ of 0.078 ± 0.061, while almost all ACL-reconstructed patients (97%; 33 out of 34) were found with excellent or good SNQ values (< 0.019). The mean KT-1000 in the ACLR group was 0.071 mm ± 0.926 mm, while there were no patients in the ACLR cohort with a KT-1000 value > 3 mm. The mean 9-months MRI-based SNQ of ACLR group was significantly higher compared to the mean MRI-based SNQ of the control group (p < 0.001). Multiple regression analysis showed no correlation between SNQ and age, gender, time from injury to ACLR, graft size, or simultaneous treatment of additional intra-articular knee lesions. CONCLUSIONS: In this cohort of 34 ACL-reconstructed patients, 97% of hamstring tendon autografts demonstrated excellent/good MRI signal intensity and excellent functional results (KT-1000 < 3 mm) at 9 months after surgery. Based on this finding, it is suggested that return to sports after ACLR with hamstring autograft can be considered safe at 9 months post surgery. Furthermore, while structural integrity of the graft has been achieved at this time point, statistical differences found in SNQ values of ACL-reconstructed patients compared to ACLs of healthy individuals highlight the continuing process of graft maturation and remodelling. LEVEL OF EVIDENCE: Level III.

Graft Inclination Angles in Anterior Cruciate Ligament Reconstruction Vary Depending on Femoral Tunnel Reaming Method: Comparison Among Transtibial, Anteromedial Portal, and Outside-In Retrograde Drilling Techniques.

PURPOSE: To compare graft coronal and sagittal inclination angles in anterior cruciate ligament (ACL) reconstruction performed by different femoral tunnel drilling techniques with respect to intact native ACL. METHODS: In total, 72 patients were prospectively enrolled in the study. The inclusion criteria were complete ACL rupture and patient age between 18 and 55 years. Reconstructions were performed using 4 different femoral tunnel drilling technique: transtibial (TT), anteromedial portal with rigid (AMP-RR) or flexible (AMP-FR) reamer, and outside-in retrograde drilling (OI) techniques. Eighteen patients with intact native ACL were included as controls. Sagittal and coronal graft inclination angles were measured by magnetic resonance imaging 6 months after the procedure by 1 radiologist blinded in regards to the used technique. RESULTS: OI and AMP-FR techniques allowed for the maintenance of native-like ACL inclination in both the sagittal and coronal planes, whereas TT and AMP-RR increased the sagittal angle by a mean of 9.5° (P < .001) and 6.7° (P = .003), respectively, compared with native ACLs. AMP-RR and TT also showed increased sagittal graft inclination compared with AMP-FR (+6.1°, P = .009 and +9.0°, P < .001, respectively) and OI-drilling techniques (+5.5°, P = .024 and +8.4°, P < .001, respectively). No differences were observed among study groups in terms of coronal graft inclination. CONCLUSIONS: The study hypothesis was partially confirmed, since OI and AMP-FR techniques, but not AMP-RR, using an independent portal for femoral drilling produce a more anatomic graft inclination on the sagittal plane with respect to TT. LEVEL OF EVIDENCE: II, prospective comparative study.

Multicenter, double-blind, randomized, intraindividual crossover comparison of gadobenate dimeglumine and gadopentetate dimeglumine for MR angiography of peripheral arteries.

PURPOSE: To prospectively compare the image quality and diagnostic performance achieved with doses of gadobenate dimeglumine and gadopentetate dimeglumine of 0.1 mmol per kilogram of body weight in patients undergoing contrast material-enhanced magnetic resonance (MR) angiography of the pelvis, thigh, and lower-leg (excluding foot) for suspected or known peripheral arterial occlusive disease. MATERIALS AND METHODS: Institutional review board approval was granted from each center and informed written consent was obtained from all patients. Between November 2006 and January 2008, 96 patients (62 men, 34 women; mean age, 63.7 years +/- 10.4 [standard deviation]; range, 39-86 years) underwent two identical examinations at 1.5 T by using three-dimensional spoiled gradient-echo sequences and randomized 0.1-mmol/kg doses of each agent. Images were evaluated on-site for technical adequacy and quality of vessel visualization and offsite by three independent blinded readers for anatomic delineation and detection/exclusion of pathologic features. Comparative diagnostic performance was determined in 31 patients who underwent digital subtraction angiography. Data were analyzed by using the Wilcoxon signed-rank, McNemar, and Wald tests. Interreader agreement was determined by using generalized kappa statistics. Differences in quantitative contrast enhancement were assessed and a safety evaluation was performed. RESULTS: Ninety-two patients received both agents. Significantly better performance (P < .0001; all evaluations) with gadobenate dimeglumine was noted on-site for technical adequacy and vessel visualization quality and offsite for anatomic delineation and detection/exclusion of pathologic features. Contrast enhancement (P < or = .0001) and detection of clinically relevant disease (P < or = .0028) were significantly improved with gadobenate dimeglumine. Interreader agreement for stenosis detection and grading was good to excellent (kappa = 0.749 and 0.805, respectively). Mild adverse events were reported for four (six events) and five (eight events) patients after gadobenate dimeglumine and gadopentetate dimeglumine, respectively. CONCLUSION: Higher-quality vessel visualization, greater contrast enhancement, fewer technical failures, and improved diagnostic performance are obtained with gadobenate dimeglumine, relative to gadopentetate dimeglumine, when compared intraindividually at 0.1-mmol/kg doses in patients undergoing contrast-enhanced MR angiography for suspected peripheral arterial occlusive disease.

Gadobenate dimeglumine and gadofosveset trisodium for MR angiography of the renal arteries: Multicenter intraindividual crossover comparison.

OBJECTIVE: This prospective multicenter intraindividual crossover study was designed to compare gadobenate dimeglumine and gadofosveset trisodium at approved doses with respect to the image quality and diagnostic performance of contrast-enhanced MR angiography (CE-MRA) in the detection of clinically relevant renal artery stenosis. SUBJECTS AND METHODS: Thirty-nine subjects (17 men, 22 women; age range, 30-86 years; mean 62 +/- 13.3 [SD] years) with known or suspected renovascular disease underwent a first CE-MRA examination with 0.1 mmol/kg gadobenate dimeglumine and a second examination 3-12 days later with 0.03 mmol/kg gadofosveset. Identical T1-weighted spoiled gradient-refocused echo coronal first-pass images were acquired for 38 of the 39 patients. For 15 of the 38 patients, additional sagittal or axial images or both were acquired with gadofosveset during the steady-state phase. Thirty-four patients underwent digital subtraction angiography, which was the reference standard. Three independent blinded readers assessed source images and maximum-intensity-projection reconstructions to detect clinically relevant (> 50%) renal artery stenosis. Diagnostic performance (sensitivity, specificity, accuracy, positive and negative predictive values) was evaluated with the McNemar and Wald tests. Matched-pair determinations of diagnostic preference were evaluated with Wilcoxon's signed rank test. Reader agreement was determined with kappa analysis, and safety was assessed. RESULTS: Comparison of first-pass images revealed superior sensitivity (75.7-86.5% vs 68.4-76.3%), specificity (92.1-98.6% vs 90.5-93.9%), accuracy (88.9-96.2% vs 85.9-90.3%), positive predictive value (70.0-94.1% vs 65.0-76.3%), and negative predictive value (94.0-96.6% vs 91.7-93.9%) with gadobenate dimeglumine. Significant superiority was noted for specificity (p < or = 0.02), accuracy (p < or = 0.005), and positive predictive value (p < or = 0.018). Steady-state images showed no benefit of gadofosveset. Reader agreement was good to excellent (gadobenate dimeglumine, kappa = 0.855; gadofosveset, kappa = 0.776). Reader preference was for gadobenate dimeglumine in 11, 17, and 13 patients and for gadofosveset in five, four, and five patients. No safety concerns were noted. CONCLUSION: Better diagnostic performance and reader preference were found for gadobenate dimeglumine than gadofosveset in first-pass renal CE-MRA.

Renal artery stenosis evaluation: diagnostic performance of gadobenate dimeglumine-enhanced MR angiography--comparison with DSA.

PURPOSE: To prospectively determine diagnostic performance and safety of contrast material-enhanced (CE) magnetic resonance (MR) angiography with 0.1 mmol per kilogram of body weight gadobenate dimeglumine for depiction of significant steno-occlusive disease (> or =51% stenosis) of renal arteries, with digital subtraction angiography (DSA) as reference standard. MATERIALS AND METHODS: This multicenter study was approved by local institutional review boards; all patients provided written informed consent. Patient enrollment and examination at centers in the United States complied with HIPAA. Two hundred ninety-three patients (154 men, 139 women; mean age, 61.0 years) with severe hypertension (82.2%), progressive renal failure (11.3%), and suspected renal artery stenosis (6.5%) underwent CE MR angiography with three-dimensional spoiled gradient-echo sequences after administration of 0.1 mmol/kg gadobenate dimeglumine at 2 mL/sec. Anteroposterior and oblique DSA was performed in 268 (91.5%) patients. Three independent blinded reviewers evaluated CE MR angiographic images. Sensitivity, specificity, and accuracy of CE MR angiography for detection of significant steno-occlusive disease (> or =51% vessel lumen narrowing) were determined at segment (main renal artery) and patient levels. Positive and negative predictive values and positive and negative likelihood ratios were determined. Interobserver agreement was analyzed with generalized kappa statistics. A safety evaluation (clinical examination, electrocardiogram, blood and urine analysis, monitoring for adverse events) was performed. RESULTS: Of 268 patients, 178 who were evaluated with MR angiography and DSA had significant steno-occlusive disease of renal arteries at DSA. Sensitivity, specificity, and accuracy of CE MR angiography for detection of 51% or greater stenosis or occlusion were 60.1%-84.1%, 89.4%-94.7%, and 80.4%-86.9%, respectively, at segment level. Similar values were obtained for predictive values and for patient-level analyses. Few CE MR angiographic examinations (1.9%-2.8%) were technically inadequate. Interobserver agreement for detection of significant steno-occlusive disease was good (79.9% agreement; kappa = 0.69). No safety concerns were noted. CONCLUSION: CE MR angiography performed with 0.1 mmol/kg gadobenate dimeglumine, compared with DSA, is safe and provides good sensitivity, specificity, and accuracy for detection of significant renal artery steno-occlusive disease.

Diagnostic performance of gadobenate dimeglumine enhanced MR angiography of the iliofemoral and calf arteries: a large-scale multicenter trial.

OBJECTIVE: The purpose of this study was to compare gadobenate dimeglumine-enhanced MR angiography and unenhanced time-of-flight MR angiography for the detection of significant peripheral arterial occlusive disease using digital subtraction angiography as our reference standard. SUBJECTS AND METHODS: Two hundred seventy-two patients underwent MR angiography and digital subtraction angiography of the iliofemoral arteries. MR angiography was performed before (2D time-of-flight acquisitions) and after (spoiled gradient-echo acquisitions) the administration of 0.1 mmol/kg of gadobenate dimeglumine at 1-2 mL/s. Contrast-enhanced MR angiography and digital subtraction angiography of the calf arteries were performed in 241 of 272 participants. Images were evaluated on-site and by four blinded reviewers (three for MR angiography, one for digital subtraction angiography). Comparative diagnostic performance for the detection of significant (> or = 51% vessel lumen narrowing) disease was evaluated using the McNemar test and generalized estimating equations. Interobserver agreement was assessed with generalized kappa statistics. The chi-square test was used to compare technical failure rates. RESULTS: Digital subtraction angiography confirmed significant disease (597 stenoses, 386 occlusions) in 983 iliofemoral segments. The sensitivity (54-80.9%), specificity (89.7-95.3%), and accuracy (85-87.5%) of contrast-enhanced MR angiography for the detection of significant iliofemoral disease were significantly (p < 0.001, all reviewers) better than those of time-of-flight MR angiography (33.2-62.8%, 74.3-88.9%, and 68-77.3%, respectively). Similar diagnostic performance was obtained for the calf arteries. The technical failure rate with contrast-enhanced MR angiography (2.5-3.4%) was similar to that of digital subtraction angiography (1.4%) and significantly (p < 0.001) lower than that of time-of-flight MR angiography (6.2-18.0%). Significantly better reproducibility (p < 0.001) was obtained with contrast-enhanced MR angiography (82% vs 65.2% agreement; kappa = 0.66 vs 0.45). CONCLUSION: Improved diagnostic performance and reproducibility are achievable with gadobenate dimeglumine-enhanced MR angiography in patients with peripheral arterial occlusive disease.

Gadobenate dimeglumine-enhanced MR angiography: Diagnostic performance of four doses for detection and grading of carotid, renal, and aorto-iliac stenoses compared to digital subtraction angiography.

PURPOSE: To determine the diagnostic performance of contrast-enhanced MR angiography (CE-MRA) with four doses of gadobenate dimeglumine for detection of significant steno-occlusive disease of the carotid, renal, and pelvic vasculature. MATERIALS AND METHODS: Eighty-four patients with suspected disease of the renal (n = 16), pelvic (n = 41), or carotid (n = 27) arteries underwent CE-MRA (3D-spoiled gradient-echo sequences) at 1.5T. CE-MRA was performed with gadobenate dimeglumine at 0.025, 0.05, 0.1, or 0.2 mmol/kg (23, 24, 19, and 18 patients, respectively) administered at 2 mL/sec. Accuracy, sensitivity, specificity, and positive and negative predictive values (PPV and NPV, respectively) for detection of significant disease (>50% stenosis or occlusion for renal/pelvic arteries; >70% stenosis or occlusion for carotid arteries) was determined by three fully blinded, independent radiologists using conventional digital subtraction angiography (DSA) as reference standard. All comparisons were tested statistically (ANOVA, chi-square, and Mantel-Haenszel tests as appropriate) and reader agreement (kappa) was assessed. RESULTS: Values for accuracy, sensitivity, specificity, PPV, and NPV on CE-MRA were consistently higher for 0.1 mmol/kg gadobenate dimeglumine (accuracy = 95.2-97.3%, sensitivity = 84.2% (all readers), specificity = 96.9-99.2%, PPV = 80.0-94.1%, NPV = 97.6-97.7%). The greater accuracy of the 0.1 mmol/kg dose was significant (P < 0.01, all readers) compared to all other dose groups. Agreement between the three readers was good for all dose groups (kappa >/=0.58), with the highest percent agreement (85.7%) noted for the 0.1 mmol/kg dose. CONCLUSION: Significantly better diagnostic performance on CE-MRA of the renal, pelvic, and carotid arteries is achieved with a gadobenate dimeglumine dose of 0.1 mmol/kg bodyweight.