Dose response of the intravascular contrast agent gadofosveset trisodium in MR perfusion imaging of the myocardium using semiquantitative evaluation.

PURPOSE: To evaluate appropriate injection protocols for gadofosveset at 1.5 and 3 T magnetic resonance imaging (MRI) for semiquantitative myocardial perfusion analysis. MATERIALS AND METHODS: Eighteen young healthy volunteers were subjected to first-pass perfusion cardiac scans at 1.5 and 3 T MRI using three different injection protocols for gadofosveset (0.00375, 0.0075, and 0.0150 mmol/kg bodyweight) and two perfusions. At both field strengths a T1-weighted saturation recovery turboFLASH sequence with parallel imaging was employed. Peak signal-to-noise ratio (SNR), maximum contrast enhancement ratio (CER), peak-baseline difference, and upslope values were assessed. Moreover, sectors with dark banding artifacts were evaluated. RESULTS: Significant differences of the upslope values for first compared to second perfusion could be observed for the medium- and high-dose groups at 1.5 T (P < 0.01), but not at 3 T. Sectors with dark banding artifacts during first perfusion occurred significantly more often at the highest dose of gadofosveset compared to the lowest dose at 1.5 T (P = 0.04) and 3 T (P < 0.01). CONCLUSION: The best injection protocol for semiquantitative perfusion analysis at 1.5 T is 0.00375 mmol/kg, as higher doses lead to lower upslope values during the second perfusion. At 3 T 0.0075 mmol/kg should be used to avoid dark banding artifacts.

Dose response of the intravascular contrast agent gadofosveset trisodium in MR perfusion imaging of the myocardium using a quantitative evaluation.

This study was performed to determine the best concentration of gadofosveset at 1.5 and 3 T MRI for quantitative myocardial perfusion analysis. 18 healthy volunteers have been examined at a 1.5 and a 3 T MRI system assigned to one of three dose groups: low dose (0.00375 mmol/kg), medium dose (0.0075 mmol/kg), high dose (0.0150 mmol/kg). A T1-weighted saturation recovery turboFLASH sequence with parallel imaging was used. Two perfusion scans were performed for each field strength and volunteer. Peak signal-to-noise-ratio, maximum contrast-enhancement-ratio and myocardial blood flow (MBF) were calculated. MBF values were significantly higher at 1.5 T in the medium and the high dose groups than in the low dose group (p < 0.001). Higher MBF values could be found at 3 T for the second perfusion scan in the medium and both perfusion scans in the high dose group compared to the low dose group. Optimal dose of gadofosveset for quantitative perfusion analysis at 1.5 T is 0.00375 mmol/kg as higher doses caused overestimation of the MBF. At 3 T 0.0075 mmol/kg seems to be the best dose for a single perfusion scan, while for a second perfusion scan MBF may be overestimated.

MRI for detection of anomalous pulmonary venous drainage in patients with sinus venosus atrial septal defects.

Purpose of this survey was to estimate the value of MRI for the assessment of the anatomical and functional features of sinus venosus atrial septal defect (SVD). This prospective study included 13 surgically proven cases of SVD out of 81 subjects submitted to MRI due to inconclusive transthoracic echocardiography (TTE) or suspicion of high intracardiac and/or extracardiac shunt volumes based on echocardiographic findings. MRI examination included cine SSFP sequences, contrast-enhanced 3D gradient-echo (GE) sequences for MR angiography (MRA) and phase-contrast flow-measurements. MRI revealed nine patients with a superior and four with an inferior SVD. Anomalous pulmonary venous drainage (APVD) was observed only in subjects with a superior SVD, and it was right-sided in all cases. All MRI and MRA results for the SVD patients were confirmed intraoperatively. The Correlation coefficient between MR flow measurements and cardiac catheterisation was 0.94 (P<0.0001). According to MRI the rest of the subjects (n=68) presented a secundum ASD, whereas in 18% an APVD coexisted. The latter MR outcomes concurred with the cardiac catheterisation (n=56) and operative (n=12) results. MRI provides a reliable, non-invasive method for evaluation of SVDs, APVDs and shunt quantification.

Contrast-enhanced whole-heart coronary MRA using Gadofosveset 3.0 T versus 1.5 T.

RATIONALE AND OBJECTIVES: To compare contrast-enhanced coronary magnetic resonance angiography (MRA) at 3.0 T with the same technique performed at 1.5 T using the contrast agent gadofosveset. MATERIALS AND METHODS: In this prospective randomized study, 19 healthy male volunteers (mean age 28 years, mean weight 79.8 kg), after signing informed consents, underwent contrast-enhanced inversion recovery three-dimensional fast low angle shot (FLASH) MRA at 1.5 and at 3.0 T. Prospective electrocardiogram-triggering was combined with adaptive respiratory gating. For contrast-enhanced images, the intravascular contrast agent gadofosveset was used. Acquisition time, signal-to-noise ratio (SNR) of coronary blood, contrast-to-noise ratio (CNR) between coronaries and adjacent myocardium or epicardial fat and image quality were analyzed for statistical differences by using a two-tailed paired-sample t-test. The ratio calculations were based on measurements performed on the raw data and the image quality was blinded and independently evaluated by two experienced radiologists using a five-point scale. RESULTS: The mean values for the acquisition time were 14.58 +/- 0.1 minutes at 1.5 T and 16.40 +/- 0.2 minutes at 3.0 T. Overall SNR of all evaluated coronary segments proved higher at 3.0 T compared to 1.5 T (74.0 +/- 42.1 at 3.0 T vs. 50.2 +/- 20.2 at 1.5 T, P = .04). Overall CNR between coronaries and myocardium was significantly increased at 3.0 T in comparison to 1.5 T (40.1 +/- 21.9 at 3.0 T vs. 24.4 +/- 17.2 at 1.5 T, P = .01). Between the two methods, no significant difference in overall CNR between coronaries and epicardial fat was observed (P = .08, NS). The 3.0 T MRA demonstrated superior overall image quality with respect to 1.5 T (2.28 +/- 0.71 at 3.0 T vs. 1.92 +/- 0.38 at 1.5T, P = .004). CONCLUSION: The use of higher field strength, 3.0 T instead of 1.5 T, resulted in similar CNR between coronaries and epicardial fat, higher SNR values and CNR between blood and myocardium, as well as an improved overall image quality, when gadofosveset in combination with electrocardiogram and respiratory triggering for coronary MRA was used.

Contrast-enhanced whole-heart MR coronary angiography at 3.0 T using the intravascular contrast agent gadofosveset.

OBJECTIVES: The purpose of this study was to compare contrast-enhanced (CE) whole-heart coronary magnetic resonance angiography (MRA) at 3.0 T using gadofosveset to noncontrast-enhanced steady-state free precession (SSFP) coronary MRA at 1.5 T. MATERIALS AND METHODS: A prospective randomized study was conducted among 20 healthy male volunteers. The same group of subjects underwent CE whole heart MRA at 3.0 T employing a 3D FLASH sequence with IR prepulse after gadofosveset injection as well as noncontrast-enhanced coronary MRA at 1.5 T using a 3D SSFP sequence with T2-preparation. Both techniques were performed using prospective ECG-triggering and adaptive respiratory gating. Acquisition time, signal-to-noise ratio of coronary blood, contrast-to-noise ratio (CNR) between coronaries and adjacent myocardium or epicardial fat, and image quality were evaluated in each case. RESULTS: A significant increase of the overall CNR between coronary blood and adjacent myocardium was measured on images acquired at 3 T in comparison to 1.5 T. The mean values were 38.9 +/- 19.6 and 26.3 +/- 15.4, respectively (P[r] < 0.005). There was no significant difference in CNR between coronary blood and epicardial fat. The mean image quality for the proximal and mid coronary segments was not statistically different between 1.5 T and 3.0 T (P > 0.05), however, the distal coronary segments were rated significantly higher for the CE MRA at 3.0 T (P = 0.02). The average acquisition time (15.29 +/- 5.73 minutes at 1.5 T vs. 17.29 +/- 5.18 minutes at 3 T) and overall image quality (2.15 +/- 0.49 at 1.5 T vs. 2.35 +/- 0.39 at 3 T) were similar for both methods. CONCLUSIONS: CE whole-heart coronary MRA at 3.0 T demonstrated higher overall CNR between coronary blood and myocardium and an improved image quality of the distal coronary segments compared with noncontrast-enhanced SSFP coronary MRA at 1.5 T.

Pulmonary vein metastasis of a sacral chordoma extending into the left atrial cavity.

Chordomas are rare malignant tumors that rise from notochordal remnants of the developing spine. Distant metastases are rare and mostly occur in patients with local recurrence. In the case reported, 14 years after radical resection of a sacral chordoma, a distant metastasis to the left pulmonary vein with large intracardiac mass, location never described before, was diagnosed. No evidence of local recurrence was observed. Although the intracardiac tumor part was successfully resected, the patient died of heart failure.