Application of computed tomographic colonography in diagnosis of colonic polyps / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To assess the clinical values of computed tomographic colonography (CTC) in diagnosis of colonic polyps.</p><p><b>METHODS</b>Forty-two patients who were clinically suspicious of colonic polyps or underwent colonic polyps screening received examinations with both CTC and conventional colonoscopy. Sixteen- or 64-slice spiral computed tomography and professional imaging processing techniques were used for evaluation. Per-polyp and per-patient results were analyzed. Those by per-polyp were subsequently divided into > or = 10 mm group, 5-10 mm group, and < or =5 mm group. Sensitivity, positive predictive value (PPV), specificity, negative predictive value (NPV), and accuracy were calculated using statistical method for diagnostic studies, with conventional colonoscopy as a gold standard.</p><p><b>RESULTS</b>Ninety and 61 polyps were found by CTC and conventional colonoscopy, respectively. The per-polyp sensitivity/PPV were 80.3%/55.6% in total, and 100%/92.9%, 93.8%/65.2%, and 68.8%/ 41.5% in the > or = 10 mm group, 5-10 mm group, and < or =5 mm group, respectively. The per-patient sensitivity, PPV, specificity, NPV, and accuracy were 97.1%, 89.5%, 42.9%, 75.0%, and 88.1%, respectively.</p><p><b>CONCLUSION</b>CTC can clearly reveal the morphology of colonic polyps and be used as a routine monitoring method for the clinical diagnosis of polyps.</p>

Diffusion weighted imaging combined with magnetic resonance conventional sequences for the diagnosis of rectal cancer / 中国医学科学院学报

<p><b>OBJECTIVE</b>To evaluate the clinical value of diffusion weighted imaging (DWI) combined with conventional sequences of magnetic resonance imaging (T1 and T2-weighted imaging) for the diagnosis of rectal cancer.</p><p><b>METHODS</b>DWI and conventional sequences were performed in 29 patients with endoscopically diagnosed rectal cancer and 15 patients without rectal cancer. Two doctors who were blind to the history of the patients interpreted the imaging findings. The sensitivity and specificity of conventional sequences with and without DWI were analyzed using receiver operating characteristic curve (ROC).</p><p><b>RESULTS</b>The areas under ROC were 0.915 and 0.930 for conventional sequences alone, and 0.990 and 0.994 for conventional sequences with DWI, respectively, indicating that although both of them were optimal methods for the diagnosis of rectal cancer, the accuracy of conventional sequences with DWI was significantly superior to that of conventional sequence alone (P < 0.05). The Kappa value was 0.850 for conventional sequences alone and 0.858 for DWI with conventional sequences.</p><p><b>CONCLUSION</b>DWI was necessary for the diagnosis of rectal cancer when performing conventional sequences.</p>

Imaging features of autoimmune pancreatitis / 中国医学科学院学报

<p><b>OBJECTIVE</b>To explore the clinical, pathological, and imaging features of autoimmune pancreatitis (AlP).</p><p><b>METHODS</b>The clinical data of 10 patients (all men; aged 47-80 years, mean 61.3 years) with AlP in our hospital between March 2000 and August 2007 were retrospectively analyzed. gamma-globulin, immunoglobulin C (IgG), rheumatoid factors, and autoantibodies were examined for all cases. The imaging findings were reviewed, which included helical computed tomography (CT), endoscopic ultrasonography (EUS), and B-mode ultrasound in all patients, magnetic resonance cholangiopancreatography (MRCP) in 9 patients, and endoscopic retrograde cholangiopancreatography (ERCP) in 7 patients. Follow-up imaging results were available in 5 patients.</p><p><b>RESULTS</b>Clinically, the most common early symptoms included obstructive jaundice (9/10) and non-specific abdominal pain (1/10), accompanied by the elevated levels of serum gamma-globulin, IgG or the presence of autoantibodies. Diabetes mellitus was detected at presentation in 2 patients. imaging findings included: CT showed diffuse (n=9) and focal (n=1) enlargement of pancreas. Minimal peripancreatic stranding was found in 7 patients, with no pancreatic pseudocyst and calcification. Six patients had enlarged peripancreatic lymph nodes. After contrast injection for 4 patients, delayed enhancement of the pancreatic parenchyma was observed, along with low-density capsule-like rim surrounding the pancreas. Magnetic resonance imaging showed diffuse enlargement of pancreas in 9 patients. MRCP showed diffuse (n=6) and segmental (n=3) irregular narrowing of the main pancreatic duct. B-mode ultrasound showed diffuse (n=9) and focal (n=1) enlargement of the pancreas. EUS showed diffuse (n=9) and focal (n=1) enlargement with hypoecho. ERCP showed stricture of distal common bile duct and irregular dilation of proximal bile ducts in 7 patients, diffuse stricture in main pancreatic duct in 4 patients, and segmental stricture in 3 patients. During the follow-up, abnormalities of imaging and serum markers were resolved after steroid therapy in 5 patients.</p><p><b>CONCLUSION</b>AIP is a distinctive type of chronic pancreatitis that shows specific imaging features.</p>

Using of multislice helical CT colonography in patients with malignant lesions of colon / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To investigate the techniques and clinical applications of multislice helical computed tomography (CT) colonography in colonic lesions.</p><p><b>METHODS</b>Fifty-nine patients with malignant lesions of colon underwent volume scanning using multislice helical CT. Four types of reconstruction including CT virtual colonoscopy (CTVC), shaded surface display (SSD), Raysum, and multiple planar reconstruction (MPR) were used for image post-processing. The results were compared with those of colonoscopy and pathology.</p><p><b>RESULTS</b>Multislice helical CT colonography detected 54 colorectal carcinomas, 4 adenomas with focal carcinoma, 1 non-Hodgkin's lymphoma (NHL). The lesions' number, size, location, morphology, stricture of intestinal cavity, infiltration, and metastasis were shown satisfactorily by multislice helical CT colonography. Whole colon could be shown in all patients. CT colonography displayed 4 synchronous colonic tumors, 1 ascending colon carcinoma combined with left renal carcinoma among 54 patients with colonic carcinomas. The accuracy of location of CT colonography was 100%. There were 9 cases that CT showed the tumor location was different from the finding of conventional colonoscopy, while all of the CT location were proven exact by operation. CT colonography also displayed the infiltration of serous layer and fatty tissue in 45 cases; 21 cases matched the pathological results in all the 24 cases of suspicious lymph node metastasis, the sensitivity was 87.5%, the specificity was 90.6%; 9 cases hepatic metastasis, 2 ovarian metastasis, and 1 double adrenal gland metastasis.</p><p><b>CONCLUSIONS</b>Multislice helical CT colonography is effective in preoperative diagnosis, location, stage, and making treatment plan of colorectal carcinoma. It can display the portion not seen during colonoscopy and may have an adjunctive role.</p>