In order to address the issues of spatial induction bias and lack of effective representation of global contextual information in colon polyp image segmentation, which lead to the loss of edge details and mis-segmentation of lesion areas, a colon polyp segmentation method that combines Transformer and cross-level phase-awareness is proposed. The method started from the perspective of global feature transformation, and used a hierarchical Transformer encoder to extract semantic information and spatial details of lesion areas layer by layer. Secondly, a phase-aware fusion module (PAFM) was designed to capture cross-level interaction information and effectively aggregate multi-scale contextual information. Thirdly, a position oriented functional module (POF) was designed to effectively integrate global and local feature information, fill in semantic gaps, and suppress background noise. Fourthly, a residual axis reverse attention module (RA-IA) was used to improve the network's ability to recognize edge pixels. The proposed method was experimentally tested on public datasets CVC-ClinicDB, Kvasir, CVC-ColonDB, and EITS, with Dice similarity coefficients of 94.04%, 92.04%, 80.78%, and 76.80%, respectively, and mean intersection over union of 89.31%, 86.81%, 73.55%, and 69.10%, respectively. The simulation experimental results show that the proposed method can effectively segment colon polyp images, providing a new window for the diagnosis of colon polyps.
Humans ; Colonic Polyps/diagnostic imaging* ; Computer Simulation ; Electric Power Supplies ; Semantics ; Image Processing, Computer-Assisted

Colonic Neoplasms ; pathology ; Colonic Polyps ; pathology ; Fluorodeoxyglucose F18 ; Humans ; Lymphatic Metastasis ; diagnostic imaging ; Male ; Middle Aged ; Positron-Emission Tomography ; Radiography

OBJECTIVETo assess the clinical values of CT colonography (CTC) in the diagnosis of colonic polyps.

METHODSForty-two patients who were clinically suspicious of colonic polyps or underwent colonic polyps screening received both CTC and conventional colonoscopy. Sixteen or 64-slice spiral CT 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.

RESULTSNinety and 61 polyps were found by CTC and conventional colonoscopy, respectively. Sensitivity and PPV were 80.3%/55.6% by per-polyp 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. Sensitivity, PPV, specificity, NPV, and accuracy by per-patient were 97.1%, 89.5%, 42.9%, 75.0%, and 88.1%, respectively.

CONCLUSIONCTC can clearly reveal the morphology of colonic polyps and can be used as a routine monitoring method for the clinical diagnosis of polyps.

Adult ; Aged ; Aged, 80 and over ; Colonic Polyps ; diagnostic imaging ; Colonography, Computed Tomographic ; methods ; Female ; Humans ; Male ; Middle Aged ; Sensitivity and Specificity

Colorectal carcinoma is a common lethal disease with signs and symptoms that may be nonspecific. Computed tomography (CT) of the abdomen and pelvis with or without contrast is frequently performed for various general abdominal complaints, but unlike CT colonography, the large bowel may not be optimally prepared for evaluation. As such, careful and diligent assessment of the non-prepared colon in all CT images of the abdomen and pelvis is important, as it ensures that incidental colorectal malignancy is not missed, especially in older patients. This article gives an overview of multidetector CT imaging signs and subtle clues to aid in the diagnosis of colorectal carcinoma, as well as their pitfalls.
Colonic Polyps ; pathology ; Colonography, Computed Tomographic ; Colorectal Neoplasms ; diagnosis ; diagnostic imaging ; Diagnosis, Differential ; Humans ; Incidental Findings ; Pelvis ; diagnostic imaging ; Radiography, Abdominal ; Tomography, X-Ray Computed

Recently, the availability of multidetector-row CT (MDCT) and continuous refinement in three-dimensional (3D) imaging process have greatly expanded the role of CT in evaluating patients with gastrointestinal diseases. MDCT is the latest advancement in CT technology and is now more readily available. This imaging modality can offer full examination of the entire intestinal tract as well as powerful information about the bowel itself and its surrounding structures, which are inherent advantages of CT over conventional barium or optical endoscopic studies. In most cases, MDCT with various 3D technologies can make an easy, rapid, and accurate diagnosis by one-stop imaging, and enables to avoid other examinations. Therefore, knowledge and awareness of valuable clinical applications and proper scan technique of MDCT imaging is essential to achieve the diagnostic goal of one-step imaging.
Barium Sulfate/diagnostic use ; Colonic Neoplasms/diagnosis/radiography ; Colonic Polyps/diagnosis/radiography ; Colonography, Computed Tomographic/instrumentation/*methods ; *Enema ; Humans ; Imaging, Three-Dimensional ; Tomography, Spiral Computed/instrumentation/*methods

BACKGROUNDColonic polyps are frequently encountered in clinics. Computed tomographic colonography (CTC), as a painless and quick detection, has high values in clinics. In this study, we evaluated the application value of computer-aided detection (CAD) in CTC detection of colonic polyps in the Chinese population.

METHODSCTC was performed with a GE 64-row multidetector computed tomography (MDCT) scanner. Data of 50 CTC patients (39 patients positive for at least one polyp of ≥ 0.5 cm in size and the other 11 patients negative by endoscopic detection) were retrospectively reviewed first without computer-aided detection (CAD) and then with CAD by four radiologists (two were experienced and another two inexperienced) blinded to colonoscopy findings. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of detected colonic polyps, as well as the areas under the ROC curves (Az value) with and without CAD were calculated.

RESULTSCAD increased the overall sensitivity, specificity, positive predictive value, negative predictive value and accuracy of the colonic polyps detected by experienced and inexperienced readers. The sensitivity in detecting small polyps (5 - 9 mm) with CAD in experienced and inexperienced readers increased from 82% and 44% to 93% and 82%, respectively (P > 0.05 and P < 0.001). With the use of CAD, the overall false positive rate and false negative rate for the detection of polyps by experienced and inexperienced readers decreased in different degrees. Among 13 sessile polyps not detected by CAD, two were ≥ 1.0 cm, eleven were 5 - 9 mm in diameter, and nine were flat-shaped lesions.

CONCLUSIONSThe application of CAD in combination with CTC can increase the ability to detect colonic polyps, particularly for inexperienced readers. However, CAD is of limited value for the detection of flat polyps.

Adult ; Aged ; Colonic Polyps ; diagnosis ; diagnostic imaging ; Colonography, Computed Tomographic ; methods ; Female ; Humans ; Male ; Middle Aged ; Retrospective Studies ; Sensitivity and Specificity ; Young Adult

In this paper, we review and summarize some progresses achieved in last few years in computer-aided diagnosis of multi-dimensional medical images for breast tumors, micro-calcification, lung nodules, colonic polyps and coronary arterial diseases.
Breast Neoplasms ; diagnosis ; Calcinosis ; diagnosis ; Colonic Polyps ; diagnosis ; Coronary Artery Disease ; diagnosis ; Diagnosis, Computer-Assisted ; methods ; Diagnostic Imaging ; trends ; Female ; Humans ; Multiple Pulmonary Nodules ; diagnosis

BACKGROUND/AIMS: Incidentally detected focal 18F-fluorodeoxyglucose (FDG) uptake was compared with colonoscopy. We investigated the characteristics of colon adenomas which were revealed on PET/CT. Then we identified whether additional colonoscopy was necessary in patients with lesions which were revealed on PET/CT but had no matched lesions on colonoscopy. METHODS: We retrospectively reviewed 95 patients who underwent colonoscopy within a 6 month interval after they had focal FDG uptake from January 2010 to May 2012 at National Police Hospital in Korea. Also, we analyzed 30 patients who underwent additional colonoscopy within 2 years after they had no matched lesions on primary colonoscopy. RESULTS: PET/CT depicted 54.6% (41/75) of adenomas and adenocarcinomas. The PET visibility of colon adenoma was significantly associated with degree of dysplasia (p=0.027), histologic type (p=0.040), and the size (p=0.038). The positivity rate was increased with higher degree of dysplasia (low-grade dysplasia, 47%; high-grade dysplasia, 78%; adenocarcinoma, 100%) and villous patterns of histologic type (tubular, 46.8%; tubulovillous, 87.5%; villous, 100%). Patients with adenomas larger than 10 mm (87.5%) had higher detection rate compared to those with adenomas smaller than 10 mm (49.0%). Among the 30 patients who underwent additional colonoscopy, only one patient had a 6 mm sized tubular adenoma (low-grade dysplasia). CONCLUSIONS: Incidental focal colonic uptake may indicate advanced adenoma or adenocarcinoma. Thus, it justifies performing colonoscopy for identifying the presence of colon neoplasms. However, in case of unmatched lesions between PET/CT and colonoscopy, there was little evidence that additional colonoscopy would yield benefits.
Adenocarcinoma/pathology/radiography/radionuclide imaging ; Adenoma/pathology/radiography/radionuclide imaging ; Adult ; Aged ; Colonic Neoplasms/pathology/*radiography/*radionuclide imaging ; Colonic Polyps/pathology ; Colonoscopy ; Female ; Fluorodeoxyglucose F18/diagnostic use ; Humans ; Male ; Middle Aged ; Multimodal Imaging ; Positron-Emission Tomography ; Radiopharmaceuticals/diagnostic use ; Retrospective Studies ; Tomography, X-Ray Computed

OBJECTIVETo assess the clinical values of computed tomographic colonography (CTC) in diagnosis of colonic polyps.

METHODSForty-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.

RESULTSNinety 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.

CONCLUSIONCTC can clearly reveal the morphology of colonic polyps and be used as a routine monitoring method for the clinical diagnosis of polyps.

Adult ; Aged ; Aged, 80 and over ; Colonic Polyps ; diagnosis ; diagnostic imaging ; pathology ; Colonography, Computed Tomographic ; Colonoscopy ; Female ; Humans ; Hyperplasia ; pathology ; Male ; Middle Aged ; Neoplasms ; pathology ; Predictive Value of Tests ; Sensitivity and Specificity

OBJECTIVE: To investigate the diagnostic value of CT colonography for the detection of colorectal polyps. MATERIALS AND METHODS: From December 2004 to December 2005, 399 patients underwent CT colonography and follow-up conventional colonoscopy. We excluded cases of advanced colorectal cancer. We retrospectively analyzed the CT colonography findings and follow-up conventional colonoscopy findings of 113 patients who had polyps more than 6 mm in diameter. Radiologists using 3D and 2D computer generated displays interpreted the CT colonography images. The colonoscopists were aware of the CT colonography findings before the procedure. RESULTS: CT colonography detected 132 polyps in 107 of the 113 patients and conventional colonoscopy detected 114 colorectal polyps more than 6 mm in diameter in 87 of the 113 patients. The sensitivity of CT colonography analyzed per polyp was 91% (41/45) for polyps more than 10 mm in diameter and 89% (101/114) for polyps more than 6 mm in diameter. Thirteen polyps were missed by CT colonography and were detected on follow-up conventional colonoscopy. CONCLUSION: CT colonography is a sensitive diagnostic tool for the detection of colorectal polyps and adequate bowel preparation, optimal bowel distention and clinical experience are needed to reduce the rate of missing appropriate lesions.
Adult ; Aged ; Aged, 80 and over ; Colonic Polyps/*diagnosis ; Colonography, Computed Tomographic/*methods ; Colonoscopy/methods ; Colorectal Neoplasms/*diagnosis ; Contrast Media/administration & dosage ; False Negative Reactions ; False Positive Reactions ; Follow-Up Studies ; Humans ; Image Processing, Computer-Assisted ; Imaging, Three-Dimensional ; Iohexol/analogs & derivatives/diagnostic use ; Middle Aged ; Observer Variation ; Predictive Value of Tests ; Radiographic Image Enhancement/methods ; Retrospective Studies ; Sensitivity and Specificity