Renal Safety of Intravenous Gadolinium-enhanced MRI in Patients Following Liver Transplantation

Gadolinium Enhances Dual-energy Computed Tomography Scan of Pulmonary Artery

OBJECTIVE

To evaluate the feasibility of using gadopentetate dimeglumine (Gd-DTPA) for dual-energy computed tomography pulmonary angiography (CTPA).

METHODS

Sixty-six patients were randomly divided into three groups and underwent CTPA. Group A had a turbo flash scan using an iohexol injection, Group B had a turbo flash scan using Gd-DTPA, and Group C had a dual-energy scan using Gd-DTPA. The original images of Group C were linearly blended with a blending factor of 0.5 or reconstructed at 40, 50, 60, 70, 80, 90, 100, and 110 keV, respectively. The groups were compared in terms of pulmonary artery CT value, image quality, and radiation dose.

RESULTS

The pulmonary artery CT values were significantly higher in Group C_40keV than in Groups B and C, but lower than in Group A. There was no significant difference in the image noise of Groups C_40keV, B, and C. Moreover, Group A had the largest beam hardening artifacts of the superior vena cava (SVC), followed by Groups B and C. Group C_40keV showed better vascular branching than the other three groups, among which Group B was superior to Group A. The subjective score of the image quality of Groups A, B, and C showed no significant difference, but the score was significantly higher in Group C_40keV than in Groups A and B. The radiation dose was significantly lower in Group B than in Groups A and C.

CONCLUSION

Gd-CTPA is recommended to patients who are unsuitable for receiving an iodine-based CTPA. Furthermore, a turbo flash scan could surpass a dual-energy scan without consideration for virtual monoenergetic imaging.

Risk for Nephrogenic Systemic Fibrosis After Exposure to Newer Gadolinium Agents: A Systematic Review

BACKGROUND

The risk for nephrogenic systemic fibrosis (NSF) after exposure to newer versus older gadolinium-based contrast agents (GBCAs) remains unclear.

PURPOSE

To synthesize evidence about NSF risk with newer versus older GBCAs across the spectrum of kidney function.

DATA SOURCES

MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and Web of Science for English-language references from inception to 5 March 2020.

STUDY SELECTION

Randomized controlled trials, cohort studies, and case-control studies that assessed NSF occurrence after GBCA exposure.

DATA EXTRACTION

Data were abstracted by 1 investigator and verified by a second. Investigator pairs assessed risk of bias by using validated tools.

DATA SYNTHESIS

Of 32 included studies, 20 allowed for assessment of NSF risk after exposure to newer GBCAs and 12 (11 cohort studies and 1 case-control study) allowed for comparison of NSF risk between newer and older GBCAs. Among 83 291 patients exposed to newer GBCAs, no NSF cases developed (exact 95% CI, 0.0001 to 0.0258 case). Among the 12 studies (n = 118 844) that allowed risk comparison between newer and older GBCAs, 37 NSF cases developed after exposure to older GBCAs (exact CI, 0.0001 to 0.0523 case) and 4 occurred (3 confounded) after exposure to newer GBCAs (exact CI, 0.0018 to 0.0204 case). Data were scant for patients with acute kidney injury or those at risk for chronic kidney disease.

LIMITATIONS

Study heterogeneity prevented meta-analysis. Risk of bias was high in most studies because of inadequate exposure and outcome ascertainment.

CONCLUSION

Although NSF occurrence after exposure to newer GBCAs is very rare, the relatively scarce data among patients with acute kidney injury and those with risk factors for chronic kidney disease limit conclusions about safety in these populations.

PRIMARY FUNDING SOURCE

U.S. Department of Veterans Affairs. (PROSPERO: CRD42019135783).