ABSTRACT
Objective To investigate the accuracy of high-resolution magnetic resonance imaging (MRI) in diagnosis of the lymph nodes metastases (LNMs) and stage of rectal cancer (RC).Methods The retrospective cross-sectional study was conducted.The clinicopathological data of 65 patients with RC who were admitted to the Peking University People's Hospital between April 2014 and April 2016 were collected.The results of postoperative pathological examination:of 65 patients with RC,24 had positive LNMs and 41 had negative LNMs;N0,N1 and N2 were respectively detected in 41,14 and 10 patients.Imaging data were captured using 3.0-Tesla MRI and body phased-array coil.Diagnostic criteria for LNMs of RC:criterion 1:irregular lymph node boundaries and signal characteristics were not considered;criterion 2:heterogeneous signal of lymph nodes and boundary characteristics were not considered;criterion 3:irregular lymph node boundaries and / or heterogeneous signal of lymph nodes.The American Joint Committee on Cancer (AJCC) cancer staging manual (7th edition) have established the N staging scheme for RC.Lymph nodes distribution according to the rectal lymphatic drainage:D1was located in fascia of the mesorectum;D1a above the level of tumor;D1b at the level of tumor;D1c under the level of tumor;D2 around the superior rectal artery and root of inferior mesenteric artery;D3 on the side of pelvic cavity.Observation indicators:(1) Efficiency and comparison of LNMs of RC diagnosed by high-resolution MRI according to the 3 criteria (postoperative pathological result as a gold standard).(2) Efficiency and comparison of N stage of RC diagnosed by high-resolution MRIaccording to the 3 criteria (postoperative pathological result as a gold standard).(3) Efficiency of LNMs of RC diagnosed by high-resolution MRI according to the maximum short diameter of lymph nodes:① maximum short diameter distribution of positive and negative LNMs of RC;②sensitivity,specificity,accuracy and consistency of LNMs diagnosed using different maximum short diameter of lymph nodes as a threshold (postoperative pathological result as a gold standard);③ comparison of accuracy of LNMs diagnosed using maximum short diameter of lymph nodes with highest diagnostic accuracy as a threshold and using the 3 criteria;④ sensitivity,specificity,accuracy and consistency (postoperative pathological result as a gold standard) of LNMs diagnosed using maximum short diameter of lymph nodes with highest diagnostic accuracy as a threshold combined with the highest efficiency in the (1),and its comparison in accuracy of LNMs with highest diagnostic accuracy as a threshold.(4) Distribution of LNMs of RC diagnosed by high-resolution MRI according to the 3 criteria.(5) Follow-up situations.Follow-up using outpatient examination and telephone interview was performed to detect patients' postoperative survival up to October 2016.The sensitivity,specificity,accuracy and comparison of ratio were respectively done by the chi-square test.Kappa test was used for consistency,tκ ≤ 0.40was used as low consistency,0.40＜κ≤0.60 as moderate consistency,0.60＜κ≤0.80 as higher consistency,and κ＞ 0.80 very high consistency.Results (1) Efficiency and comparison of LNMs of RC diagnosed by highresolution MRIaccording to the 3 criteria:accuracies of LNMs of RC diagnosed by high-resolution MRI according to the criterion 1,2 and 3 were respectively 93.8％,87.7％ and 90.8％,showing very.high,higher and very high consistencies compared with postoperative pathological results (κ =0.87,0.74,0.81,P＜0.05),and with no statistically significant difference in diagnostic accuracy among them (x2=1.495,P＞0.05).(2) Efficiency and comparison of N stage of RC diagnosed by high-resolution MRI according to the 3 criteria:accuracies of N stage of RC diagnosed by high-resolution MRI according to the criterion 1,2 and 3 were respectively 87.7％,83.1％ and 84.6％,showing the same higher consistencies compared with postoperative pathological result (κ =0.77,0.68,0.72,P＜0.05),and with no statistically significant difference in N stage among them (x2=0.567,P＞0.05).(3) Efficiency of LNMs of RC diagnosed by high-resolution MRI according to the maximum short diameter of lymph nodes:① maximum short diameter distribution of positive and negative LNMs of RC:maximum short diameter ranges were respectively 3-18 mm in positive LNMs and 1-9 mm in negative LNMs,and maximum short diameter ＜3 mm and ≥ 10 mm were respectively negative and positive LNMs.② Efficiency of LNMs of RC diagnosed using different maximum short diameter of lymph nodes as a threshold:diagnostic accuracy of 70.8％was the highest when maximum short diameter ＞7 mm was used as a standard of positive LNMs,showing a low consistency compared with postoperative pathological result (κ =0.29,P＜0.05).③ Comparison of accuracy of LNMs diagnosed using maximum short diameter of lymph nodes ＞7 mm as a threshold and using the 3 criteria:there was a statistically significant difference among them (x2 =15.637,P＜0.05);accuracies of LNMs of RC diagnosed by high-resolution MRI according to the criterion 1,2 and 3 were higher than that diagnosed using maximum short diameter of lymph nodes ＞7 mm as a threshold (x2 =10.354,5.656,6.923,P＜0.05).④Comparison of accuracy of LNMs diagnosed using maximum short diameter of lymph nodes ＞7 mm combined with the criterion 3 as a threshold and using maximum short diameter ＞7 mm as a threshold:the criterion 3 was used as a threshold because there was no statistically significant difference in diagnostic accuracy among the 3 criteria (P＞ 0.05).Diagnostic accuracy was 78.5％ when maximum short diameter ＞7 mm combined with the criterion 3 as a threshold,showing a low consistency compared with postoperative pathological result (κ =0.36,P＜0.05),with no statistically significant difference in diagnostic accuracy compared with maximum short diameter ＞ 7 mm as a threshold (x2=0.154,P＞0.05).(4) Distribution of LNMs of RC diagnosed by high-resolution MRI according to the 3 criteria:positive LNMs of RC diagnosed by high-resolution MRI located mostly in D1 (76.1％-83.1％)and D1b(77.8％-81.4％).(5) Follow-up situations:of 65 patients,54 were followed up for 6-25 months,with a median time of 14 months.During the follow-up,7 patients had distant metastases and 47 had tumor-free survival.Conclusions There are higher accuracies of LNMs and N stage of RC diagnosed using preoperative highresolution MRI.Diagnostic accuracy of LNMs of RC cannot be improved when characteristics of lymph node morphology and size are used as a diagnostic standard.The positive LNMs of RC locate mostly in D1 and Dib.
ABSTRACT
Objective To investigate the imaging features and differential diagnosis of obstructive jaundice caused from non-neoplastic diseases.Methods The retrospective descriptive study was conducted.The clinical data of 62 patients with obstructive jaundice caused from non-neoplastic diseases who were admitted to the Peking University People's Hospital between August 2014 and August 2016 were collected,including 13 with immunoglobulin G4 associated cholangitis (IAC),2 with primary sclerosing cholangitis (PSC),21 with recurrent purulent cholangitis (RPC),2 with Mirizzi syndrome,4 with groove pancreatitis (GP) and 20 with Lemmel syndrome.All the patients underwent plain and enhanced scans of computed tomnography (CT) and magnetic resonance imaging (MRI) and magnetic resonanced cholangio-pancreatography (MRCP).Film reading were respectively done by 2 imaging doctors,and then was analyzed again by senior doctors when there is disagreement.Observation indicators:(1) situations of imaging exanination and imaging features;(2) treatment and follow-up.Patients received laboratory and related examinations and then underwent corresponding treatment after diagnosis.Follow-up using outpatient examination and telephone interview was performed once every 6 months to detect patients' prognosis up to November 2016.Results (1) Situations of imaging examination and imaging features:of 62 patients,21 underwent plain and enhanced CT scans,7 underwent plain and enhanced MRI scans,4 underwent MRCP,15 underwent plain and enhanced CT scans and MRCP,1 underwent plain and enhanced CT scans and plain and enhanced MRI scans,3 underwent plain and enhanced MRI scans and MRCP and 11 underwent plain and enhanced CT scans,plain and enhanced MRI scans and MRCP.Imaging features of 13 patients with IAC:MRI scans showed that diffuse and symmetrical bile duct walls were thickened,with delayed enhancement.The narrowed lumen of bile duct was mainly occurred in common bile duct,without occlusion.Of 13 patients with IAC,9 were combined with IgG4 associated pancreatitis and 7 with bilateral nephropathy.Imaging features of 2 patients with PSC:MRI scans showed that bile duct wall was multiple localized thickening and persistent enhancement,that was imaging feature of liver cirrhosis.MRCP examination showed that intra-and extra-hepatic bile ducts had multifocality stricture and beading-like and/or dry twig-like dilatation,and branches of intrahepatic peripheral bile duct were reduced.Imaging features of 21 patients with RPC:MRI and CT scans and MRCP examination showed that there was thickening bile duct wall and delayed enhancement.The first and second level of intrahepatic bile duct were segmental dilatation,distal bile duct dramatically narrowed and branches of intrahepatic bile duct were reduced.Most of extrahepatic bile duct was dilatation and a few were narrow-like changes.There were stones of intrahepatic bile duct and pneumobilia.Liver parenchymal atrophy with cholangiectasis occurred most frequently in left lobe or right posterior lobe of liver.There were secondary liver abscess and cholangiocarcinoma.Imaging features of 2 patients with Mirizzi syndrome:MRI scans showed that there was common hepatic duct stricture caused by stones in the junction between neck of gallbladder and common hepatic duct,and intra-and extra-hepatic bile ducts dilatation in proximal end of stones and normal bile duct in distal end of stones.There were gallbladder and biliary fistulas,irregular gallbladder wall thickening and inflammation around the gallbladder.Imaging features of 4 patients with GP:MRI scans showed that no clear mass was detected in duodenal loop and head of pancreas,with heterogeneous and slightly irregular enhancement.Cyst formation occurred in intramural wall of duodenum and head of pancreas.Enhanced MRI scans showed that common bile duct wall was thickened and slightly irregular stricture,pancreatic duct was normal or mild expansion,and thickened duodenal wall had varying degrees of stenosis of lumen.Imaging features of 20 patients with Lemmel syndrome:MRI scans showed that pouch-like structure was detected inside of the descending duodenum,with thin cyst wall and liquid in cyst wall.MRCP examination showed dilatations of common bile duct and intra-and extra-hepatic bile ducts.(2) Treatment and follow-up:of all the 62 patients,30 underwent corresponding surgeries,including 2 with IAC,1 with PSC,7 with RPC,2 with Mirizzi syndrome,3 with GP and 15 with Lemmel syndrome,and the other 32 without surgery received corresponding medical treatment.Sixty of 62 patients were followed up for 3-17 months.During follow-up,28 patients undergoing surgery received definitive diagnosis and good recovery,2 were lost after definitive diagnosis and 32 undergoing medical treatment were in stable condition.Conclusion Non-neoplastic diseases can cause obstructive jaundice,with a higher misdiagnosis rate,imaging findings of which can be conducive to diagnose diseases and provide clinical treatment.