Objective To evaluate the imaging features of pancreatic neuroendocrine carcinoma （PNEC）. Methods The imaging data of 7 patients with PNECs proved by surgery and pathology in West China Hospital of Sichuan University from Jul. 2007 to Dec. 2012 were retrospectively analyzed. The boundary， density， and strengthening features of tumor were observed. Results Seven tumors were found in all patients with 2 in pancreatic head， body， and tail， respectively. There was 1 tumor in pancreatic body and tail too. Five tumors were with unclear boundary. Five tumors had hypodense enhancement and 2 had isodense enhancement. Two cases had distal pancreatic duct dilation. None of them had liver metastases or lymph node involvement. Conclusion PNEC has certain characteristics on imaging. It is difficult to distinguish diagnosis from pancreatic cancer.
Abstract： Objective To assess the effects of simultaneous antegrade/retrograde cardioplegia (SARC) on myocardial perfusion and energy metabolism in ischemic myocardium using magnetic resonance imaging (MRI). Methods After the hearts were harvested from 18 domestic pigs, left anterior descending artery, aorta, anterior ascending cardiac vein and coronary sinus were cannulated to establish the perfusion routes. 6 hearts were used to assess the effects of SARC on myocardial perfusion. Energy metabolism was observed in the other 12 pig hearts. MRI was used to monitor the distribution of contrast agent (gadoliniumdiethylenetriamine penlaacetic acid, Gd-DTPA) in the myocardium after its injection through arterial and retrograde perfusion routes. The efficacies in sustaining myocardial perfusion and energy metabolism were evaluated by using phosphorus-31 magnetic resonance spectroscopy (31P MRS) during antegrade cardioplegia (AC) and SARC respectively. Results It was found that injection of Gd-DTPA into the aorta during AC did not result in signal increase in the ischemic myocardium on MRI. During SARC, however, Gd-DTPA was found in the ischemic region as well as in the other regions, no matter if it was given into the aorta or into the coronary sinus. Moreover,31P spectra showed that occlusion of LAD during AC resulted in severe decrease of the levels of phosphocreatine (PCr) and adenosine triphosphate (ATP), while the level of inorganic phosphate (Pi) increased in LAD-support myocardium. The abnormal metabolic changes were completely abolished by use of SARC. Conclusion It is concluded that SARC can deliver cardioplegic solution to the myocardium distal to a coronary occlusion and can sustain normal energy metabolism in the jeopardized myocardium.
【Abstract】ObjectiveTo evaluate the value of MR imaging with a contrast-enhanced multi-phasic isotropic volumetric interpolated breath-hold examination (VIBE) in diagnosis of primary liver carcinoma. MethodsThirty-two consecutive patients with surgical-pathologically confirmed 42 foci of primary carcinoma of liver underwent comprehensive MR examination of the upper abdomen, routine two-dimensional (2D) T1WI and T2WI images were acquired before administration of Gd-DTPA for contrast enhancement. Then, contrast-enhanced multi-phasic VIBE was acquired followed by 2D T1WI images. The lesion appearances on hepatic arterial, portal venous and equilibrium phases of VIBE sequence were carefully observed along with delineation of hepatic arterial and portal venous structures. The lesion detection rates and lesion characterization ability were compared among various MR sequences. Results33(78.6%), 30(71.4%), 38(90.5%) and 42(100%) foci were displayed respectively on T2WI, non-enhanced T1WI, enhanced T1WI and enhanced 3D-VIBE images (P＜0.05). The hepatic arterial anatomy of 30 patients （93.8%） and the portal venous structure of 31 patients （96.9%） were clearly depicted on enhanced 3D-VIBE images. Using MIP and MPR reconstruction techniques, the feeding arteries of 14 foci and draining vein of 12 foci were clearly displayed.ConclusionHigh-quality 3D-VIBE images are not only better than 2D images in lesion detection and characterization for primary liver carcinoma, but also able to provide much more information about hepatic vascular anatomy.
ObjectiveTo investigate the role of amygdala volume index(AVI) in surgcial evaluation in patients with mesial temporal lobe epilepsy (mTLE), including clinical features, etiologies and surgical outcome. MethodsThirty six patients were diagnosed as mTLE after surgical evaluation including clinical manifestations, video-electroencephalogram (VEEG) and magnetic resonance imaging (MRI) at the Second Affiliated Hospital of Zhejiang University between March 2013 and March 2016. Bilateral amygdala AVI was then calculated from amygdala volumes on MRI, which were measured with region of interest (ROI) analysis. All patients were treated surgically. Etiologies of mTLE were further confirmed by the histopathology of the resected tissue. ResultsAmong the 35 patients, there is a strong correlation between AVI on the lesion side and age of onset (R =-0.389, P = 0.019) as well as age of surgery (R =-0.357, P = 0.032). No obvious relation can be seen between AVI and gender, history of febrile convulsion, duration of epilepsy, secondary generalized seizure, side of lesion, presurgical seizure frequency and electrode implantation. There is no significant difference in AVI among the five etiologies. At follow-up, thirty patients (80.5%) reached seizure-free, AVI on the lesion side is nota predictor of surgical failure (P > 0.05). ConclusionAVI plays a role in etiology evaluation in patients with mesial temporal lobe epilepsy. Moreover, a larger AVI on the lesion side is correlated with an earlier age of onset. There is limited value of amygdala volume insurgical outcome prediction of patients with mTLE.
Objective To summary the principle of magnetic resonance spectroscopy imaging and its application progress in diagnosis and differential diagnosis of pancreatic cancer. Methods The newest related literatures of home and abroad were collected and reviewed. Results Magnetic resonance spectroscopy imaging was a technology using the magnetic resonance phenomena and chemical shift phenomena to measure molecular organization. The spectroscopy most commonly used in clinical and scientific research includes 1H， 31P， and 23Na. Conclusion Magnetic resonance spectroscopy as the only approach to noninvasive quantitative provding biochemical information in vivo， has an important significance to the diagnosis and differential diagnosis of pancreatic cancer.
【Abstract】ObjectiveTo evaluate the role of MRA, IPVG and DUS in the hemodynamics studies of portal hypertension. MethodsThirtyeight patients with portal hypertension were examined with Philips Gyroscan 1.0 Tesla MR imaging system. 3DDCE MRA and 2DPC MR were used for study of portal venous anatomy and its hemodynamics. The results were compared with those obtained from IPVG and DUS. Results3DDCE MRA could clearly display the anatomical imaging of portal venous system and its imaging quality was better than that of IPVG. The data of hemodynamics from 2DPC MR including diameter, blood velocity and blood flow were closely correlated to those from DUS. ConclusionAs a noninvasive technique, MRA can display the anatomy of portal venous system and measure its hemodynamics exactly. It should be applied as the first choice in hemodynamics evaluation for portal hypertension.
ObjectiveTo analyze the MR findings of primary gallbladder carcinoma so as to improve the diagnostic accuracy. MethodsA retrospective study was developed involving 15 primary gallbladder carcinoma patients identified by postoperative pathology between January 2010 and March 2013. Imaging findings were analyzed including lesions location, enhancement characteristics, the dilatation of bile ducts and gallstones. ResultsAmong the 15 gallbladder carcinoma patients, 5 were misdiagnosed as neoplasms in the porta hepatis combined with dilation of intrahepatic bile ducts. Intra- and extrahepatic bile ducts dilated in 7 patients, which were misdiagnosed as tumors or inflammation. Two cases of gallbladder carcinoma with right lobe mass were misdiagnosed as gallbladder polyps. One patient was misdiagnosed as cholecystitis. The retrospective analysis revealed that the gallbladder wall thickened in 12 cases, with focal thickening in 9 and diffuse thickening in 3 cases. Enhanced scanning demonstrated that gallbladder wall enhanced in varying degrees, and 11 cases had delayed enhancement features. There were 8 patients with gallstones and 2 with gallbladder wall nodules. ConclusionPrimary gallbladder carcinoma can easily cause bile duct dilatation, and manifests as focal or diffuse mural thickening, often accompanied by gallstones.
This study aims to explore the potential of polyaspartic acid grafted dopamine copolymer (PAsp-g-DA) chelated Fe3+ for magnetic resonance imaging (MRI) visual photothermal therapy. Polyaspartic acid grafted copolymer of covalently grafted dopamine and polyethylene glycol (PAsp-g-DA/PEG) was obtained by the ammonolysis reaction of poly succinimide (PSI), and then chelated with Fe3+ in aqueous solution. The relaxivity in vitro, magnetic resonance imaging enhancement in vivo and photothermal conversion effect at 808 nm were investigated. The results showed that polymeric iron coordination had good near-infrared absorption and photothermal conversion properties, good magnetic resonance enhancement effect, and good longitudinal relaxation efficiency under different magnetic field intensities. In summary, this study provides a new magnetic resonance visual photothermal therapeutic agent and a new research idea for the research in related fields.
Magnetic resonance (MR) imaging is an important tool for prostate cancer diagnosis, and accurate segmentation of MR prostate regions by computer-aided diagnostic techniques is important for the diagnosis of prostate cancer. In this paper, we propose an improved end-to-end three-dimensional image segmentation network using a deep learning approach to the traditional V-Net network (V-Net) network in order to provide more accurate image segmentation results. Firstly, we fused the soft attention mechanism into the traditional V-Net's jump connection, and combined short jump connection and small convolutional kernel to further improve the network segmentation accuracy. Then the prostate region was segmented using the Prostate MR Image Segmentation 2012 (PROMISE 12) challenge dataset, and the model was evaluated using the dice similarity coefficient (DSC) and Hausdorff distance (HD). The DSC and HD values of the segmented model could reach 0.903 and 3.912 mm, respectively. The experimental results show that the algorithm in this paper can provide more accurate three-dimensional segmentation results, which can accurately and efficiently segment prostate MR images and provide a reliable basis for clinical diagnosis and treatment.
Objective To investigate the effects on myocardial perfusion of simultaneous antegrade/retrograde cardiopiegia （SARC） through a single coronary artery and coronary sinus （CS）. Methods SARC was conducted in isolated pig hearts through CS in conjunction with the left anterior descending （LAD）, the left circumflex （LCX）, or the right coronary artery （RCA） respectively. After injecting magnetic resonance （MR） contrast agent （gadolinium diethyienetriamine pentaacetic acid, Gd-DTPA） into arterial or venous route, the distribution of Gd-DTPA with magnetic resonance imaging（MRI） was monitored and the effluent from the venting coronary arteries to assess the efficacy of SARC for myocardial perfusion was measured. Results Injection of Gd-DTPA into a perfusing artery during SARC resulted in increased signal intensity not only in the territory of the perfusing artery but also in the areas normally served by the other two venting coronary arteries （including the right ventrieuiar free wall）. With Gd DTPA given into the CS during SARC, the myocardium in the territories of the two venting coronary arteries was lightened. Signal intensity of the myocardium in the perfusing artery territory and right ventricuiar free wall remained unchanged. Moreover, a significant amount of effluent was collected from the venting coronary arteries during SARC： the LAD 10.5-17.7 ml/min; LCX 9.7-15.2 ml/min, and RCA 4.7-7.8 ml/min. Conclusion SARC through a single coronary artery and CS can provide homogeneous perfusion to the entire heart and is sufficient to prevent ischemic injury in the myocardium normally supported by the venting coronary arteries.