Arterial input function for quantitative dynamic contrast-enhanced MRI to diagnose prostate cancer.

PURPOSE This study aims to analyze the ability of quantitative dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) to distinguish between prostate cancer (PCa) and benign lesions in transition zone (TZ) and peripheral zone (PZ) using different methods for arterial input function (AIF) determination. Study endpoints are identification of a standard AIF method and optimal quantitative perfusion parameters for PCa detection. METHODS DCE image data of 50 consecutive patients with PCa who underwent multiparametric MRI were analyzed retrospectively with three different methods of AIF acquisition. First, a region of interest was manually defined in an artery (AIFm); second, an automated algorithm was used (AIFa); and third, a population-based AIF (AIFp) was applied. Values of quantitative parameters after Tofts (Ktrans, ve, and kep) in PCa, PZ, and TZ in the three different AIFs were analyzed. RESULTS Ktrans and kep were significantly higher in PCa than in benign tissue independent from the AIF method. Whereas in PZ, Ktrans and kep could differentiate PCa (P < .001), in TZ only kep using AIFpdemonstrated a significant difference (P = .039). The correlations of the perfusion parameters that resulted from AIFm and AIFa were higher than those that resulted from AIFp, and the absolute values of Ktrans, kep, and ve were significantly lower when using AIFp. The values of quantitative perfusion parameters for PCa were similar regardless of whether PCa was located in PZ or TZ. CONCLUSION Ktrans and kep were able to differentiate PCa from benign PZ independent of the AIF method. AIFaseems to be the most feasible method of AIF determination in clinical routine. For TZ, none of the quantitative perfusion parameters provided satisfying results.

Comparison of quantitative and semiquantitative dynamic contrast-enhanced MRI with respect to their correlation to delayed gadolinium-enhanced MRI of the cartilage in patients with early rheumatoid arthritis.

OBJECTIVE: The objective of this study was to investigate the correlation between semiquantitative and quantitative dynamic contrast-enhanced (DCE) parameters with delayed gadolinium-enhanced magnetic resonance imaging (MRI) of the cartilage (dGEMRIC). METHODS: Fifteen patients with early rheumatoid arthritis (RA) from the ArthroMark cohort were investigated at a 3-T MRI scanner. The metacarpophalangeal (MCP) joint of the index finger was examined with DCE-MRI and dGEMRIC. Semiquantitative and quantitative DCE perfusion parameters were calculated. The RA MRI score of the second MCP joint and the joint space width were measured. RESULTS: Significant correlations were noted between both semiquantitative and quantitative DCE parameters and the RA MRI score of the second MCP joint. There was a significant negative correlation between DCE parameters and dGEMRIC. No association between joint space width and DCE parameters was observed. CONCLUSIONS: Semiquantitative and quantitative analyses of perfusion are applicable to show that cartilage damage correlates with the inflammation activity despite the absence of joint space narrowing.