Short echo time in vivo prostate 1H-MRSI

Visualization of short echo time (TE) metabolites in prostate magnetic resonance spectroscopic imaging is difficult due to lipid contamination and pulse timing constraints. In this work, we present a modified pulse sequence to permit short echo time (TE=40ms) acquisitions with reduced lipid contamination for the detection of short TE metabolites. The modified pulse sequence employs the conformal voxel MRS (CV-MRS) technique, which automatically optimizes the placement of spatial saturation planes to adapt the excitation volume to the shape of the prostate, thus reducing lipid contamination in prostate magnetic resonance spectroscopic imaging (MRSI). Metabolites were measured and assessed using a modified version of LCModel for analysis of in vivo prostate spectra. We demonstrate the feasibility of acquiring high quality spectra at short TEs, and show the measurement of short TE metabolites, myo-inositol, scyllo-inositol, taurine and glutamine/glutamate for both single and multi-voxel acquisitions. In single voxels experiments, the reduction in TE resulted in 57% improvement in the signal-to-noise ratio (SNR). Additional 3D MRSI experiments comparing short (TE=40 ms), and long (TE=130 ms) TE acquisitions revealed a 35% improvement in the number of adequately fitted metabolite peaks (775 voxels over all subjects). This resulted in a 42\ub124% relative improvement in the number of voxels with detectable citrate that were well-fitted using LCmodel. In this study, we demonstrate that high quality prostate spectra can be obtained by reducing the TE to 40 ms to detect short T2 metabolites, while maintaining positive signal intensity of the spin-coupled citrate multiplet and managing lipid suppression.Peer reviewed: YesNRC publication: Ye

Description of a multicenter safety checklist for intraoperative hemorrhage control while clamped during robotic partial nephrectomy

Abstract Background The adoption of robotic assistance has contributed to the increased utilization of partial nephrectomy for the management of renal tumors. However, partial nephrectomy can be technically challenging because of intraoperative hemorrhage, which limits the ability to identify the tumor margin and may necessitate the conversion to open surgery or radical nephrectomy. To our knowledge, a comprehensive safety checklist does not exist to guide surgeons on the management of hemorrhage during robotic partial nephrectomy. We developed such an safety checklist based on the cumulative experiences of high volume robotic surgeons. Methods A treatment safety checklist for the management of hemorrhage during robotic partial nephrectomy was collaboratively developed based on prior experiences with intraoperative hemorrhage during robotic partial nephrectomy. Results Reducing the risk of hemorrhage during robotic partial nephrectomy begins with reviewing the preoperative imaging for renal vasculature and tumor anatomy, with a focus on accessory vessels and renal tumor proximity to the renal hilum. During hilar exposure, an attempt is made to identify additional accessory renal arteries. The decision is then made on whether to clamp the hilum (artery +/- vein). If bleeding is encountered during resection, management is based on whether the bleeding is suspected to be arterial or from venous backbleeding. Operative maneuvers that may increase the chance of success are highlighted in safety checklists for arterial and venous bleeding. Conclusions Safely performing robotic partial nephrectomy is dependent on attention to prevention of hemorrhage and rapid response to the challenge of intraoperative bleeding. Preparation is essential for maximizing the chance of success during robotic partial nephrectomy.</p