A Y Oner1, H Celik, S O Oktar, T Tali. 1. Gazi University School of Medicine, Department of Radiology, Besevler-Ankara, Turkey. yusuf@tr.net <yusuf@tr.net>
Abstract
AIM: To evaluate prospectively the improvement in the signal:noise ratio (SNR), with the use of parallel technique in single breath-hold diffusion-weighted imaging (DWI) of the liver and its affect on apparent diffusion coefficient (ADC) measurements. MATERIALS AND METHODS: This study was approved by our institutional review board. Written informed consent was obtained from all participants. Fifteen patients underwent single breath-hold DWI of the liver with and without parallel imaging technique. SNR and ADC values were measured over a lesion-free right hepatic lobe by two radiologists in both series. When a focal hepatic lesion was present the contrast:noise ratio (CNR) and ADC were also measured. Paired Student's t-tests were used for statistical analysis. RESULTS: Mean SNR values of the liver were 20.82+/-7.54 and 15.83+/-5.95 for DWI with and without parallel imaging, respectively. SNR values measured in DWI using parallel imaging were found to be significantly higher (p<0.01). Mean ADC of the liver were 1.61+/-0.45 x 10(-3)mm(2)/s and 1.56+/-0.28 x 10(-3)mm(2)/s for DWI with and without parallel imaging, respectively. No significant difference was found between the two sequences for hepatic ADC measurement (p>0.05). Overall lesion CNR was found to be higher in DWI with parallel imaging. CONCLUSION: Parallel imaging is useful in improving SNR of single breath-hold DWI of the liver without compromising ADC measurements.
AIM: To evaluate prospectively the improvement in the signal:noise ratio (SNR), with the use of parallel technique in single breath-hold diffusion-weighted imaging (DWI) of the liver and its affect on apparent diffusion coefficient (ADC) measurements. MATERIALS AND METHODS: This study was approved by our institutional review board. Written informed consent was obtained from all participants. Fifteen patients underwent single breath-hold DWI of the liver with and without parallel imaging technique. SNR and ADC values were measured over a lesion-free right hepatic lobe by two radiologists in both series. When a focal hepatic lesion was present the contrast:noise ratio (CNR) and ADC were also measured. Paired Student's t-tests were used for statistical analysis. RESULTS: Mean SNR values of the liver were 20.82+/-7.54 and 15.83+/-5.95 for DWI with and without parallel imaging, respectively. SNR values measured in DWI using parallel imaging were found to be significantly higher (p<0.01). Mean ADC of the liver were 1.61+/-0.45 x 10(-3)mm(2)/s and 1.56+/-0.28 x 10(-3)mm(2)/s for DWI with and without parallel imaging, respectively. No significant difference was found between the two sequences for hepatic ADC measurement (p>0.05). Overall lesion CNR was found to be higher in DWI with parallel imaging. CONCLUSION: Parallel imaging is useful in improving SNR of single breath-hold DWI of the liver without compromising ADC measurements.