ObjectiveTo analyze and conclude CT and MRI imaging features of ectopic pancreas in gastrointestinal tract so as to improve the understanding of the features.MethodsThe clinical, imaging, and pathological data of 12 patients with ectopic pancreas in the gastrointestinal tract confirmed by the pathology in the Sichuan Provincial People’s Hospital from November 2016 to June 2019 were retrospectively analyzed. The characteristics of image presentation were summarized.Results① The anatomical distribution: all patients had a single lesion. Of the 12 cases, 6 cases located in the gastric body lesser curvature, 3 cases located in the gastric angle, 1 case located in the posterior wall of gastric antrum, 1 case occurred in the upper jejunum, and 1 case occurred in the terminal ileum; 8 cases located in the submucosa, 2 cases located in the submucosa and muscular layer simultaneously, 1 case located in the submucosa, muscular and serous layer simultaneously, and 1 case located in the muscular layer. ② Size of the lesions: the maxium dimensions of the lesions were all 3 cm or less, and the long axes of the lesions were parallel to the gastrointestinal tract wall in 10 cases. ③ The internal characteristics: the results of 9 of 11 cases showed the isodensity compared to main pancreas on the plain CT scan. The results of 8 patients with enhanced CT showed the moderate to obvious enhancement, with 2 cases showed the slightly enhanced flaky or tube-like foci. In the arterial phase and portal venous phase, 6 cases showed the isodensity compared to main pancreas respectively. The result of MRI in 1 patient showed the isointensity compared to main pancreas on the plain scan and obviously heterogeneous enhancement.ConclusionCT and MRI could provide some information about location, size, and internal density or intensity of ectopic pancreas, and could be helpful for diagnosis.
Objective To review the CT appearances and important differential diagnoses of various primary and secondary mesenteric neoplasms. Methods By describing the mesenteric anatiomy and major routes for the dissemination of metastatic mesenteric tumors, the article presents both the common and rare types of various primary and secondary mesenteric neoplasms, and addresses the characteristic CT appearances and important aspects of the differential diagnosis. Results CT study, especially the multislice spiral CT (MSCT), along with the clinical history and other related information, can nicely depict various mesenteric tumors and well differentiate them from infectious, inflammatory or vascular processes affecting the mesentery. Conclusion CT is the imaging method of choice for the evaluation of tumors of small bowel mesentery.
ObjectiveTo explore the application value of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) quantitative parameters and apparent diffusion coefficient (ADC) value in evaluating the differentiation degrees and T stages of rectal cancer.MethodsThe patients with rectal cancer from November 2017 to November 2019 in the Sichuan Provincial People’s Hospital were collected. The volume transfer constant (Ktrans), flux rate constant (Kep), and extravascular extracellular volume fraction (Ve), and ADC values of the tumors were measured and compared in the patients with the different differentiation degrees and T stages. The receiver operating characteristic (ROC) curve analysis was performed.ResultsAll of 53 eligible patients were included, including 13 cases of high differentiation, 30 cases of medium differentiation, and 10 cases of low differentiation; 5 cases of T1 stage, 8 cases of T2 stage, 24 cases of T3 stage, and 16 cases of T4 stage. ① There were statistical differences in the Ktrans and ADC values among the different differentiation degrees of rectal cancer (P=0.004, P<0.001), and no statistical differences in the Kep and Ve values (P>0.050) among them. The Ktrans value was increased with decreased differentiation degree (P<0.050), the ADC value was decreased with decreased differentiation degrees (P<0.050). ② There were statistical differences in the Ktrans and ADC values among the different T stages of rectal cancer (P=0.002; P=0.007), and no statistical differences in the Kep and Ve values (P>0.050) among them. The Ktrans and ADC values were statistically different between the T2 and T3 stages of rectal cancer (P=0.009, P=0.013). ③ The Ktrans and ADC values could distinguish the high and medium differentiation degrees of rectal cancer, its area under ROC curve (AUC) values were 0.677 and 0.763, respectively, and the corresponding best thresholds were 0.180/min and 1.179 mm2/s; The Ktrans and ADC values could distinguish the medium and low differentiation degrees of rectal cancer, its AUC values were 0.693 and 0.967, and the corresponding best thresholds were 0.281/min and 0.906 mm2/s; The Ktrans and ADC values could distinguish the T2 and T3 stages of rectal cancer, its AUC values were 0.862 and 0.742, and the corresponding best thresholds were 0.204/min and 1.579 mm2/s.ConclusionDCE-MRI quantitative parameters and ADC value before surgery to determine the different differentiation degrees and T stages of rectal cancer have certain reference value, the best Ktrans and ADC thresholds to distinguish different differentiation degrees and T2 to T3 stages can be obtained through statistical analysis.
【Abstract】ObjectiveBy using multidetectorrow spiral CT (MDCT), to investigate the CT imaging features of inflammatory diseases in retroperitoneal space with correlation of radiological anatomy.MethodsThe clinical and laboratory dada of 30 patients with proven inflammatory diseases of retroperitoneal space were collected. All patients underwent MDCT plain scanning and portal venous acquisition. CT imaging data generated at portal venous phase were processed with coronal, sagittal and oblique multiplanar reformation (MPR) technique.ResultsAcute pancreatitis and various types of renal infection were the two main sources of retroperitoneal inflammation. Depending on the specific anatomic locations, retroperitoneal inflammation of different subspaces demonstrated characteristic imaging features. Spreading of inflammatory process across subspaces was also quite common.ConclusionMDCT is the imaging method of choice to depict comprehensively and clearly the inflammatory diseases of various retroperitoneal spaces.
ObjectiveTo explore performances of functional magnetic resonance imaging (MRI) in evaluation of hepatic warm ischemia-reperfusion injury.MethodThe relative references about the principle of functional MRI and its application in the assessment of hepatic warm ischemia-reperfusion injury were reviewed and summarized.ResultsThe main functional MRI techniques for the assessment of hepatic warm ischemia-reperfusion injury included the diffusion weighted imaging (DWI), intravoxel incoherent motion (IVIM), diffusion tensor imaging (DTI), blood oxygen level dependent (BOLD), dynamic contrast enhancement MRI (DCE-MRI), and T2 mapping, etc.. These techniques mainly used in the animal model with hepatic warm ischemia-reperfusion injury currently.ConclusionsFrom current results of researches of animal models, functional MRI is a non-invasive tool to accurately and quantitatively evaluate microscopic information changes of liver tissue in vivo. It can provide a useful information on further understanding of mechanism and prognosis of hepatic warm ischemia-reperfusion injury. With development of donation after cardiac death, functional MRI will play a more important role in evaluation of hepatic warm ischemia-reperfusion injury.
【Abstract】Objective To investigate the appropriate reconstruction techniques of multidetectorrow spiral CT angiography (MDCTA) to depict the collateral vessels in cavernous transformation of the portal vein (CTPV) caused by tumor thrombosis of hepatocellular carcinoma (HCC). Methods MDCTA scanning was performed during the portal venous phase after intravenous contrast materials in 18 HCC patients with CTPV induced by tumor thrombosis. Raw data were reconstructed with thin slice thickness followed by 2D and 3D angiographic reconstruction methods, including maximum intensity projection(MIP), shade surface display （SSD） and volume rendering technique(VRT). Results MDCTA with MIP reconstruction accurately depicted both the tumor thrombus within the portal vein and the collateral vessels of CTPV including the biliary (cystic vein and pericholedochal veinous plexus) and the gastric (left and right gastric veins) branches. However, VRT and SSD methods did poorly in showing the tumor thrombus and the collateral vessels. Conclusion MDCTA with MIP reconstruction is the method of choice to evaluate the collateral vessels of CTPV.
Objective To explore the differential diagnosis significance of 3.0T MRI united-sequences examination in the diagnosis of benign and malignant breast lesions. Methods A total of 67 breast lesions of 59 patients were collected prospectively, which be treated at the Sichuan Provincial People’s Hospital during July 2015 to January 2017. All patients were underwent bilateral breast 3.0T magnetic resonance plain scan, diffusion weighted imaging, and dynamic enhanced scan successively before surgical operation. Analysis of morphological features of the benign and malignant breast lesions, the time-signal intensity curve (TIC), the apparent diffusion coefficient (ADC), and the combination diagnosis of them were performed. Results Of all 59 patients, 67 lesions were confirmed by histopathology, including 18 benign lesions and 49 malignant lesions. The morphological features (including margin, shape, border, and evenness), the types of TIC of dynamic enhancement, and ADC value between the benign lesions and malignant lesions were statistically significant (P<0.05). The sensitivity and specificity of Fischer scoring system was 89.8% (44/49) and 61.1% (11/18) respectively. The sensitivity and specificity of TIC types was 83.7% (41/49) and 77.8% (14/18) respectively. The diagnostic threshold of ADC value was 1.012×10–3 mm2/s, with the sensitivity and specificity for the diagnosis was 91.8% (45/49) and 83.3% (15/18) respectively. The sensitivity and specificity of the combination of Fischer scoring system and TIC type for diagnosis between benign and malignant breast lesions was 95.9% (47/49) and 72.2% (13/18) respectively. The sensitivity and specificity of the combination of Fischer scoring system, TIC type, and ADC value for benign and malignant breast lesions was 98.0% (48/49) and 83.3% (15/18) respectively. Conclusion The combination of Fischer scoring system, TIC type, and diffusion-weighted imaging for the differential diagnosis between benign lesions and malignant lesions was more effective than single imaging method.
ObjectiveTo explore the value of magnetic resonance diffusion weighted imaging (DWI) in preoperative Bismuth-Corlette classification of hilar cholangiocarcinoma (HCCA). MethodsA total of 53 HCCA patients confirmed by postoperative pathology were retrospectively included. The accuracy of two sequence combinations, namely dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) + magnetic resonance cholangiopancreatography (MRCP) and DCE-MRI + MRCP + DWI, in evaluating the longitudinally involved bile duct segments and Bismuth-Corlette classification of HCCA was compared. Additionally, the correlation between apparent diffusion coefficient (ADC) values and tumor Bismuth-Corlette classification as well as degree of differentiation was analyzed. ResultsThere were 318 bile duct segments in 53 HCCA patients. The accuracy rate of DCE-MRI + MRCP was 93.7% (298/318), the sensitivity was 91.5% (161/176), and the specificity was 96.5% (137/142). The accuracy rate of DCE-MRI + MRCP + DWI was 96.5% (307/318), the sensitivity was 96.0% (169/176), and the specificity was 97.2% (138/142). Receiver operating characteristic (ROC) curve analysis showed that the area under the ROC curve (AUC) of DCE-MRI + MRCP + DWI was 0.966 [95%CI (0.940, 0.983), P＜0.001], and its diagnostic efficacy was superior to that of DCE-MRI + MRCP [AUC=0.940, 95%CI (0.908, 0.963), P＜0.001]. The DeLong test indicated a statistically significant difference in AUC between the two sequences (Z=2.633, P＜0.01). The accuracy rates of preoperative Bismuth-Corlette classification of HCCA evaluated by DCE-MRI + MRCP and DCE-MRI + MRCP + DWI were 86.8% (46/53) and 94.3% (50/53), respectively. After adding the DWI sequence, the consistency between Bismuth-Corlette classification results and surgical pathological classification results (Kappa=0.922, P<0.001) was higher than that of DCE-MRI + MRCP sequence (Kappa=0.820, P<0.001), with a statistically significant difference (χ2=160.370, P<0.001). In addition, the ADC value of HCCA was negatively correlated with tumordegree of differentiation (rs=–0.524, P<0.001), but had no significant correlation with its Bismuth-Corlette classification (rs=–0.058, P=0.682). ConclusionsDCE-MRI + MRCP + DWI sequence can effectively improve the accuracy in preoperative evaluation of the involvement of bile duct segments and Bismuth-Corlette classification of HCCA, which provides guidance for precise preoperative surgical planning in clinical practice. In addition, the ADC value can provide additional information required for non-invasive preoperative prediction of the prognosis of HCCA patients.
Objective To conclude the CT manifestations and pathological features of low-grade appendiceal mucinous neoplasms. Methods We reviewed the clinical and CT findings of 24 patients with low-grade appendiceal mucinous neoplasms, who were confirmed by pathology within 1 month after CT examination in SichuanProvincial People’s Hospital from January 2018 to December 2020. The distribution, morphological characteristics, cyst wall and internal characteristics, CT value and enhancement characteristics of tumors were be detected in detail. Results ① Distribution: of the 24 patients, 22 patients located in the appendix area of the right lower quadrant, 2 patients located in the right middle abdomen, and 2 patients located in the pelvic cavity. ② Morphological characteristics: of the 24 patients, 15 patients manifested as tubular, 3 patients manifested as ellipsoidal, 5 patients manifested as saccular, and 1 patient manifested as irregular shape. The average length of tumors was about 6.4 cm (4.2–12.0 cm), and the average short diameter of tumors was about 2.2 cm (0.8–5.0 cm). The short diameter of 17 patients were more than 1.5 cm. ③ The cyst wall and internal characteristics: all the 24 patients demonstrated as cystic mass, 6 patients had evenly thin and smooth cyst wall, and other 18 patients had uneven cyst wall. Of all the patients,8 patients had arc-shaped, punctate or eggshell-like calcification. ④ The CT value and enhancement characteristics: 24 patients examined by plain CT scan, 22 patients showed uniform low density (the CT value were 7–25 HU), 2 patients contained some slightly high density, 16 patients examined by enhanced CT, the cyst wall, separation, or mural nodules of 8 patients were slightly or moderately enhanced. ⑤ Pathological results: of all the gross specimens, 15 patients showed tubular dilation, 9 patients showed partial or complete dilation as cystic mass. All the 24 patients had gelatinous or mucinous contents. Microscopically, all the patients showed low-grade mucinous epithelial hyperplasia, submucosa, and mucosal muscle atrophy, accompanied by fibrosis or calcification. Conclusion Low-grade appendiceal mucinous neoplasms show some specific CT manifestations, recognize these features can improve the accuracy of preoperative CT.
ObjectiveTo study the value of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in predicting and evaluating the efficacy of neoadjuvant chemoradiotherapy (NCRT) in the middle-low locally advanced rectal cancer (LARC).MethodsThe patients were included prospectively who were clinically diagnosed as the LARC and were scheduled to undergo the NCRT and total mesorectal excision (TME) in the Sichuan Provincial People’s Hospital from February 2018 to November 2019. The routine MRI and DCE-MRI were performed before and after the NCRT, then the TME was performed. According to the score of tumor regression grade (TRG), the patients with TGR score of 0, 1 or 2 were classified as the response to NCRT group, and those with TRG score of 3 were classified as the non-response to NCRT group; in addition, the patients with TGR score of 0 or 1 were classified as the good-response group, with TRG score of 2 or 3 were classified as the poor-response group. The differences of quantitative perfusion parameters of DCE-MRI between two groups were compared, including the volume transfer constant (Ktrans), flux rate constant (Kep), and extravascular extracellular volume fraction (Ve) and the change rates of these parameters (ΔKtrans, ΔKep, and ΔVe).ResultsForty-one patients who met the inclusion criteria were included in this study, including 27 cases in the response to NCRT group and 14 cases in the non-response to NCRT group; 11 cases in the the good-response group and 30 cases in the poor-response group. ① The values of Ktrans before the NCRT and the ΔKtrans in the response to NCRT group were higher than those in the non-response to NCRT (P<0.05), while the other indexes had no significant differences between these two groups (P>0.05). The area under the receiver operating characteristic curve (AUCs) of Ktrans and ΔKtrans in predicting the efficacy of NCRT were 0.954 and 0.709, respectively. When the optimal thresholds of Ktrans and ΔKtrans were 0.122/min and –24.2%, the specificity and sensitivity were 85.7%, 96.3% and 100%, 51.7%, respectively. ② The Ktrans value in the good-response group was higher before NCRT and which was lower after NCRT as compared with the poor-response group (P<0.05). The absolute value of the the ΔKtrans and ΔKep in the good-response group were higher than those in the poor-response group (P<0.05). The other indexes had no significant differences between these two groups (P>0.05). The AUC of Ktrans before NCRT in predicting the efficacy of NCRT was 0.953. When the optimal thresholds of Ktrans before NCRT was 0.158 /min, the specificity and sensitivity were 88.7% and 90.9%, respectively. The AUC of ΔKtrans in predicting the efficacy of NCRT was higher than that of the ΔKep (0.952 versus 0.764, Z=2.063, P=0.039). When the optimal threshold of ΔKtrans was –38.8%, the specificity and sensitivity were 76.7% and 100%, respectively.ConclusionsDCE-MRI can predict and evaluate the effect of NCRT in patients with middle-low LARC, especially Ktrans and ΔKtrans (change rate before and after NCRT) have a high diagnostic efficiency.