Combined quantitative dynamic contrast‐enhanced MR imaging and ¹H MR spectroscopic imaging of human prostate cancer

Abstract

Purpose:To differentiate prostate carcinoma from healthy peripheral zone and central gland using quantitative dynamic contrast-enhanced (DCE) magnetic resonance (MR) imaging and two-dimensional 1 H MR spectroscopic imaging (MRSI) combined into one clinical protocol. Materials and Methods:Twenty-three prostate cancer patients were studied with a combined DCE-MRI and MRSI protocol. Cancer regions were localized by histopathology of whole mount sections after radical prostatectomy. Pharmacokinetic modeling parameters, K trans and k ep , as well as the relative levels of the prostate metabolites citrate, choline, and creatine, were determined in cancer, healthy peripheral zone (PZ), and in central gland (CG).Results: K trans and k ep were higher (P Ͻ 0.05) in cancer and in CG than in normal PZ. The (choline ϩ creatine)/citrate ratio was elevated in cancer compared to the PZ and CG (P Ͻ 0.05). While a (choline ϩ creatine)/citrate ratio above 0.68 was found to be a reliable indicator of cancer, elevated K trans was only a reliable cancer indicator in the diagnosis of individual patients. K trans and (choline ϩ creatine)/citrate ratios in cancer were poorly correlated (Pearson r 2 ϭ 0.07), and thus microvascular and metabolic abnormalities may have complementary value in cancer diagnosis. Conclusion:The combination of high-resolution spatiovascular information from dynamic MRI and metabolic information from MRSI has excellent potential for improved localization and characterization of prostate cancer in a clinical setting.

Dynamic Contrast-enhanced CT for Prostate Cancer: Relationship between Image Noise, Voxel Size, and Repeatability

“…In conclusion, there is a high voxelwise repeatability of the DCE CT imaging technique for prostate cancer for kernel sizes as small as 0.1 cm 3 . With the relation between kernel size, image noise, and repeatability, it is possible to estimate at what kernel size a suffi cient repeatability can be obtained for alternative DCE CT protocols (eg, those with a reduced radiation dose).…”

“…In this way, we calculated for each patient the wSD for all parameters and for all kernels. The wSD of a particular parameter (eg, K trans or v p ), as defi ned by Bland and Altman ( 22 ), simplifi es to the following formula (Eq [3]) in the case of two measurements:…”

Multiparametric Magnetic Resonance Imaging of Prostate Cancer: Association of Quantitative Magnetic Resonance Parameters with Histopathologic Findings

“…These models are based on determining the rate of contrast exchange between plasma and extracellular space using transfer rate constants, such as K trans and k ep . These constants are elevated in many cancers (21,22). Commercial software packages were used to input DCE-MRI data and produce parametric maps, such as K trans and k ep maps that can be used for diagnostic purposes.…”

Functional magnetic resonance imaging for defining the biological target volume

“…The loss of citrate or an increase in the choline/citrate ratio is an important indicator for prostate cancer (Fig. 1) [7] . Since citrate is also present in benign hyperplastic nodules these two entities can be separated.…”