Only 3 by routine MRI (Fig. 3, 4). Compared to CT, SWI showed 100 in the diagnostic sensitivity, specificity, accuracy, positive predictive value and negative predictive value in detecting calcifications in prostate but conventional MRI demonstrated 13.6 in diagnostic sensitivity, 100 in specificity, 75 in accuracy, 100 in positive predictive value and 74 in negative predictive value.DiscussionSWI is a new MRI technique which is more sensitive than CT, conventional MR and T2*WI GRE sequences in detecting paramagnetic blood products such as deoxyhemoglobin, methemoglobin and haemosiderin in central nervous system [5]. It has been widely used in detecting microbleeds in a variety of brain diseases such as brain trauma, stroke and vascular malformation [8?1]. In addition, SWI in spinal cord AZP-531 web trauma has also been investigated by our team and was proved valuable in detecting spinal cord hemorrhage [14]. Some recent studies in glioma haveFigure 1. A 64-year-old man with prostate cancer in peripheral zone of the prostate. Heterogeneous signal on conventional T1WI (A) and T2WI (B) (arrows) indicates tumor hemorrhage. No hemorrhage is demonstrated on CT (C). The tumor hemorrhage was also seen with SWI (D) and filtered phase image (E) (arrows). Histopathologic examination confirmed the diagnosis of prostate cancer (F). doi:10.1371/journal.pone.0053237.gSusceptibility Weighted Imaging in Prostate CancerFigure 2. A 55-year-old man with prostate cancer in central zone of the prostate. No tumor hemorrhage is demonstrated on conventional T1WI (A), T2WI (B) and CT (C), but low signal within tumor on SWI (D) and filtered phase image (E) (arrows) indicates tumor hemorrhage. Histopathologic examination confirmed the diagnosis of prostate cancer (F). doi:10.1371/journal.pone.0053237.gFigure 3. A 66-year-old man with prostate cancer in peripheral zone of the prostate. Low signal on conventional T1WI (A) and T2WI (B) (arrows) indicates tumor hemorrhage. No hemorrhage is demonstrated on CT (C). The tumor hemorrhage was also seen with SWI (D) and filtered phase image (E) (arrows). The images in second row come from another slice of the same patient. No prostatic calcification is demonstrated on conventional T1WI (F) and T2WI (G), but dot-like high density on CT (H), low signal on SWI (I) and high signal on filtered phase image (J) (arrows) indicates calcificaiton. doi:10.1371/journal.pone.0053237.gSusceptibility Weighted Imaging in Prostate CancerFigure 4. A 62-year-old man with benign prostatic hyperplasia. No prostatic calcification is demonstrated on conventional T1WI (A) and T2WI (B), but dot-like high density on CT (C), low signal on SWI (D) and high signal on filtered phase image (E) (arrows) indicates calcificaiton. doi:10.1371/journal.pone.0053237.gexplored SWI’s value and found that it’s helpful in tumor grading and patient management strategies [15,16]. But so far no studies have been done on the value of SWI in prostate cancer and other prostate diseases. As an advanced imaging technique, MRI has been gaining acceptance as an important tool in the evaluation of prostate diseases. T2WI is an important traditional sequence for the diagnosis of prostate cancer in the prostate peripheral zone but not specific. It is easy to distinguish the cancerous area which presents hypointense on T2WI from the uniform hyperintense background in the prostate peripheral zone. However, other changes such as prostatitis and fibrosis also can appear hypointense on T.Only 3 by routine MRI (Fig. 3, 4). Compared to CT, SWI showed 100 in the diagnostic sensitivity, specificity, accuracy, positive predictive value and negative predictive value in detecting calcifications in prostate but conventional MRI demonstrated 13.6 in diagnostic sensitivity, 100 in specificity, 75 in accuracy, 100 in positive predictive value and 74 in negative predictive value.DiscussionSWI is a new MRI technique which is more sensitive than CT, conventional MR and T2*WI GRE sequences in detecting paramagnetic blood products such as deoxyhemoglobin, methemoglobin and haemosiderin in central nervous system [5]. It has been widely used in detecting microbleeds in a variety of brain diseases such as brain trauma, stroke and vascular malformation [8?1]. In addition, SWI in spinal cord trauma has also been investigated by our team and was proved valuable in detecting spinal cord hemorrhage [14]. Some recent studies in glioma haveFigure 1. A 64-year-old man with prostate cancer in peripheral zone of the prostate. Heterogeneous signal on conventional T1WI (A) and T2WI (B) (arrows) indicates tumor hemorrhage. No hemorrhage is demonstrated on CT (C). The tumor hemorrhage was also seen with SWI (D) and filtered phase image (E) (arrows). Histopathologic examination confirmed the diagnosis of prostate cancer (F). doi:10.1371/journal.pone.0053237.gSusceptibility Weighted Imaging in Prostate CancerFigure 2. A 55-year-old man with prostate cancer in central zone of the prostate. No tumor hemorrhage is demonstrated on conventional T1WI (A), T2WI (B) and CT (C), but low signal within tumor on SWI (D) and filtered phase image (E) (arrows) indicates tumor hemorrhage. Histopathologic examination confirmed the diagnosis of prostate cancer (F). doi:10.1371/journal.pone.0053237.gFigure 3. A 66-year-old man with prostate cancer in peripheral zone of the prostate. Low signal on conventional T1WI (A) and T2WI (B) (arrows) indicates tumor hemorrhage. No hemorrhage is demonstrated on CT (C). The tumor hemorrhage was also seen with SWI (D) and filtered phase image (E) (arrows). The images in second row come from another slice of the same patient. No prostatic calcification is demonstrated on conventional T1WI (F) and T2WI (G), but dot-like high density on CT (H), low signal on SWI (I) and high signal on filtered phase image (J) (arrows) indicates calcificaiton. doi:10.1371/journal.pone.0053237.gSusceptibility Weighted Imaging in Prostate CancerFigure 4. A 62-year-old man with benign prostatic hyperplasia. No prostatic calcification is demonstrated on conventional T1WI (A) and T2WI (B), but dot-like high density on CT (C), low signal on SWI (D) and high signal on filtered phase image (E) (arrows) indicates calcificaiton. doi:10.1371/journal.pone.0053237.gexplored SWI’s value and found that it’s helpful in tumor grading and patient management strategies [15,16]. But so far no studies have been done on the value of SWI in prostate cancer and other prostate diseases. As an advanced imaging technique, MRI has been gaining acceptance as an important tool in the evaluation of prostate diseases. T2WI is an important traditional sequence for the diagnosis of prostate cancer in the prostate peripheral zone but not specific. It is easy to distinguish the cancerous area which presents hypointense on T2WI from the uniform hyperintense background in the prostate peripheral zone. However, other changes such as prostatitis and fibrosis also can appear hypointense on T.
