Imaging diagnosis of prostatic cancer / 第二军医大学学报

Prostate cancer is one of the mostly-seen malignant tumors in men worldwide. Imaging technique has recently become increasing important in the diagnosis, staging, and post-treatment follow-up of prostate cancer. In this article, we review the values of conventional and functional imaging methods and molecular imaging approach in the diagnosis and staging of prostate cancer.

Value of magnetic resonance cholangiopancreatography for diagnosis of pancreas divisum / 第二军医大学学报

Objective: To investigate the value of magnetic resonance cholangiopancreatography(MRCP) in the diagnosis of pancreas divisum by comparing with endoscopic retrograde cholangiopancreatography (ERCP). Methods: The MRCP and ERCP images of 8 patients with pancreas divisum were retrospectively analyzed. The diagnostic accuracy and findings by MRCP were compared with those by ERCP. Results: MRCP had a diagnostic accuracy of 87.5%(7/8) based on the result of ERCP. ERCP displayed the dominant dorsal pancreatic ducts in all 8 cases and ventral pancreatic ducts in 6 cases; MRCP also displayed the dominant dorsal pancreatic ducts in all 8 cases, but the ventral pancreatic ducts only in 3 cases. Conclusion: As a non-invasive technique, MRCP has important clinical value in the diagnosis of pancreas divisum.

Diagnosis value of DWI, T2 WI and dynamic enhanced MR imaging for early liver abscess / 第二军医大学学报

Objective: The imaging diagnosis of early liver abscess is difficult. This study is to evaluate the diagnostic value of DWI, T2WI and dynamic enhanced MR imaging for early liver abscess. Methods: DWI, T2WI and dynamic enhanced imaging scans were performed in 17 patients with 17 early liver abscesses. The signal intensities and ADC values of necrotic area, non-necrotic area and normal liver were measured and compared. Results: The ADC value of the necrotic areas of liver abscesses ([0.88±0.09] mm2/s) was significantly lower than those of normal liver ([1.31±0.12] mm2/s,P<0.05) and non-necrotic area of liver abscesses ([1.43±0.18] mm2/ s,P<0.05); there was also significant difference between the ADC values of the normal liver and non-neocrotic area (P<0.05). The necrotic areas had a hyperintensity characteristic on DWI, T2WI and a hypointensity characteristic on T1 WI; no enhancement was found on dynamic enhanced imaging. The non-necrotic areas had moderate hyperintensity on DWI, T2 WI and hypointensity on T1 WI; there was obvious enhancement on dynamic enhanced imaging. Conclusion: The early liver abscess is characterized on magnetic resonance imaging. The DWI scan is helpful for diagnosis of early liver abscess.

In vivo proton magnetic resonance spectroscopy of hepatocellular carcinoma and cholangiocarcinoma / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the value of in vivo proton magnetic resonance spectroscopy (1H MRS) in the assessment of hepatocellular carcinoma (HCC) and cholangiocarcinoma.</p><p><b>METHODS</b>1H MRS was performed in normal volunteers and in patients with pathologically confirmed HCC and cholangiocarcinomas using a whole-body 1.5-T scanner. The choline-to-lipid ratios were measured by dividing the peak area of choline at 3.2 ppm and lipid at 1.3 ppm.</p><p><b>RESULTS</b>The ratio of choline-to-lipid for normal liver, cholangiocarcinomas, and HCC were 0.07 +/- 0.04, 0.11 +/- 0.06, and 0.52 +/- 0.15, respectively. The ratio of choline-to-lipid was significantly higher in HCC compared than those in cholangiocarcinomas or normal livers (P < 0.05). However, it was not significantly different between cholangiocarcinomas and normal livers (P > 0.05).</p><p><b>CONCLUSION</b>In vivo 1H MRS can reflect the pathological changes of HCC and cholangiocarcinomas at metabolic level and thus is useful in the diagnosis of these two cancers.</p>

Magnetic resonance imaging of artificial lumbar disks: safety and metal artifacts / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>This study was to investigate the safety of two types of commercially available lumbar artificial discs (CHARITE and PRODISC-L) during a magnetic resonance imaging (MRI) procedure in a 1.5-Tesla MR system, and to evaluate the size of metal artifacts on the MR image for different sequences.</p><p><b>METHODS</b>A 1.5-Tesla clinical MR imaging system was used. The degree of deflection of the endplates of two artificial discs was evaluated by an angle-measurement instrument at the portals of the MRI scanner. The heating effect of the radio frequency (RF) magnetic field was evaluated by using "worst-case" imaging sequences on a human cadaver implanted with an artificial lumbar disc at the L5/S1 intervertebral disc location. The temperatures of the tissue adjacent to the implant, and of the L4/L5 intervertebral disc (used as a control) were measured, respectively, using a digital probe thermometer before and after the MRI scan sequence. A rectangular water phantom was designed to evaluate the metal artifacts of these two artificial discs under different MR imaging sequences.</p><p><b>RESULTS</b>The maximal deflection angle of the endplate of the implants under a static MR field was 7.5 and 6.0 degrees, for the CHARITE and PRODISC-L, respectively. The difference between temperature rise of tissue adjacent to the two types of artificial discs and the temperature rise of the L4/L5 control location was 0.4 and 0.6 degrees C, respectively. The size of metal artifacts on images of TSE (T1/T2 -weighted), STIR and Turbo Dark Fluid sequences were relatively less than those of TSE fat saturation, Flash and SE (T1-weighted) sequences.</p><p><b>CONCLUSIONS</b>The CHARITE and the PRODISC-L artificial disc do not present an additional hazard or risk to a patient undergoing an MRI procedure using a scanner operating with a static magnetic field of 1.5 T or lower. Image artifacts from the implants may present problems if the anatomical region of interest is in or near the area where these implants are located (e.g., vertebral canal at affected segment).</p>

Value of magnetic resonance cholangiopancreatography for diagnosis of pancreas divisum / 第二军医大学学报

Objective:To investigate the value of magnetic resonance cholangiopancreatography(MRCP)in the diagnosis of pancreas divisum by comparing with endoscopic retrograde cholangiopancreatography(ERCP).Methods:The MRCP and ERCP images of 8 patients with pancreas divisum were retrospectively analyzed.The diagnostic accuracy and findings by MRCP were compared with those by ERCP.Results:MRCP had a diagnostic accuracy of 87.5%(7/8)based on the result of ERCP.ERCP displayed the dominant dorsal pancreatic ducts in all 8 cases and ventral pancreatic ducts in 6 cases;MRCP also displayed the dominant dorsal pancreatic ducts in all 8 cases,but the ventral pancreatic ducts only in 3 cases.Conclusion:As a non-invasive technique,MRCP has important clinical value in the diagnosis of pancreas divisum.