Sonographic diagnosis of juvenile polyps in children

The aim of this study was to assess the diagnostic value of ultrasonography for juvenile polyps in children and their sonographic characteristics. A retrospective analysis was performed of the ultrasound findings in 27 children who were diagnosed preoperatively with juvenile polyp within the intestinal tract by ultrasonography and then confirmed by colonoscopy, laparotomy and histopathology. The ultrasonic finding common to all polyps was an isolated intraluminal nodular or massive protrusion, associated with multiple mesh-like fluid areas of different sizes. In 25 children, surrounding pedicle-like low echoes of varying lengths were seen connecting with the polyps to form "mushroom" sign. The color Doppler showed abundant blood flow signals within all polyps and pedicles in a shape of a branch or an umbrella. For seven children with an intussusception, the polyp shadow was detected in the cervical part or interior of the intussusception. Ultrasonography is, thus, considered to be a feasible method for diagnosing intestinal juvenile polyp.

Strategies for improved interpretation of computer-aided detections for CT colonography utilizing distributed human intelligence

Computer-aided detection (CAD) systems have been shown to improve the diagnostic performance of CT colonography (CTC) in the detection of premalignant colorectal polyps. Despite the improvement, the overall system is not optimal. CAD annotations on true lesions are incorrectly dismissed, and false positives are misinterpreted as true polyps. Here, we conduct an observer performance study utilizing distributed human intelligence in the form of anonymous knowledge workers (KWs) to investigate human performance in classifying polyp candidates under different presentation strategies. We evaluated 600 polyp candidates from 50 patients, each case having at least one polyp ≥6 mm, from a large database of CTC studies. Each polyp candidate was labeled independently as a true or false polyp by 20 KWs and an expert radiologist. We asked each labeler to determine whether the candidate was a true polyp after looking at a single 3D-rendered image of the candidate and after watching a video fly-around of the candidate. We found that distributed human intelligence improved significantly when presented with the additional information in the video fly-around. We noted that performance degraded with increasing interpretation time and increasing difficulty, but distributed human intelligence performed better than our CAD classifier for "easy" and "moderate" polyp candidates. Further, we observed numerous parallels between the expert radiologist and the KWs. Both showed similar improvement in classification moving from single-image to video interpretation. Additionally, difficulty estimates obtained from the KWs using an expectation maximization algorithm correlated well with the difficulty rating assigned by the expert radiologist. Our results suggest that distributed human intelligence is a powerful tool that will aid in the development of CAD for CTC.

Vanek's polyp or inflammatory fibroid polyp. Case report and review of the literature

BACKGROUND

Intussusception in an adult must make us suspect the presence of a tumor (benign or potentially dangerous) as the most frequent cause. Accurate diagnosis is of great importance in order to provide appropriate treatment and improve patient prognosis.

CLINICAL CASE

We report the case of a 42-year-old male with abdominal pain. We performed a CT and found a small bowel intussusception. Definitive diagnosis according to the surgical specimen was inflammatory fibroid polyp (Vanek's polyp).

CONCLUSIONS

Vanek's polyp is a benign lesion that occurs most frequently in the stomach and secondarily in the small bowel. Generally, it is uncommon, and its etiology is not completely known. Accurate diagnosis is done with immunohistochemistry. Because of the consequences that depend on the size and location of the lesion, it may be considered a malignant lesion. Treatment is resection.

Adult intussusception with perforation and secondary peritonitis. Case report

BACKGROUND

Intussuception is an uncommon condition in adults. It is usually secondary to an organic lesion that may be malignant. The most common clinical presentation is as a partial bowel obstruction that requires surgical management. Preoperative diagnosis remains difficult; therefore, this paper presents a case report and a brief review of adult intussusception.

CLINICAL CASE

We present the case of a 24-year-old female with a 36-h evolution of lower abdominal pain with nausea, vomiting and diarrhea and a previous episode 8 days earlier. Pneumoperitoneum was observed on chest x-ray and surgery was decided upon. Peritonitis due to ileoileal intussusception was found, caused by an inflammatory fibroid polyp with microperforations. Small bowel resection with end-to-end anastomosis was performed and the patient had an uneventful recovery.

CONCLUSIONS

Adult intussusception is an infrequent condition with nonspecific symptoms such as pain, nausea and vomiting. With more frequent use of tomography in patients with abdominal pain, correct diagnosis can be achieved. Treatment requires resection of the involved bowel without attempted reduction.

Intraoperative ultrasound in colorectal surgery

PURPOSE

To assess the accuracy of intraoperative ultrasound (IOUS) as a localizing technique for colorectal resections, and its impact on surgical management.

METHODS

Twenty-five patients (15 men and 10 women; mean age, 74.4 years) with early cancers (p T1), or polyps, not amenable to endoscopic removal were selected. IOUS was used as a sole method of intraoperative localization. Its performance was evaluated through review of preoperative colonoscopy reports, intraoperative findings, histopathology reports, and clinical follow-up.

RESULTS

The lesions were situated in the cecum (n = 5), ascending colon (n = 3), transverse colon (n = 4), descending colon (n = 7), and rectum (n = 6). IOUS technique allowed correct localization in 24 of 25 patients, visualization of the bowel wall, and its penetration by malignant tumors. In rectal lesions, IOUS showed clearly the tumor and its margin, which facilitated performance sphincter-sparing procedure.

CONCLUSION

In patients with small polyps and early cancers of colon and rectum, IOUS may be effectively used as a sole method of intraoperative localization and provide additional information that may alter decision making with regard to surgical technique.

Computer-aided detection of colorectal polyps: can it improve sensitivity of less-experienced readers? Preliminary findings

PURPOSE

To determine whether computer-aided detection (CAD) applied to computed tomographic (CT) colonography can help improve sensitivity of polyp detection by less-experienced radiologist readers, with colonoscopy or consensus used as the reference standard.

MATERIALS AND METHODS

The release of the CT colonographic studies was approved by the individual institutional review boards of each institution. Institutions from the United States were HIPAA compliant. Written informed consent was waived at all institutions. The CT colonographic studies in 30 patients from six institutions were collected; 24 images depicted at least one confirmed polyp 6 mm or larger (39 total polyps) and six depicted no polyps. By using an investigational software package, seven less-experienced readers from two institutions evaluated the CT colonographic images and marked or scored polyps by using a five-point scale before and after CAD. The time needed to interpret the CT colonographic findings without CAD and then to re-evaluate them with CAD was recorded. For each reader, the McNemar test, adjusted for clustered data, was used to compare sensitivities for readers without and with CAD; a Wilcoxon signed-rank test was used to analyze the number of false-positive results per patient.

RESULTS

The average sensitivity of the seven readers for polyp detection was significantly improved with CAD-from 0.810 to 0.908 (P=.0152). The number of false-positive results per patient without and with CAD increased from 0.70 to 0.96 (95% confidence interval for the increase: -0.39, 0.91). The mean total time for the readings was 17 minutes 54 seconds; for interpretation of CT colonographic findings alone, the mean time was 14 minutes 16 seconds; and for review of CAD findings, the mean time was 3 minutes 38 seconds.

CONCLUSION

Results of this feasibility study suggest that CAD for CT colonography significantly improves per-polyp detection for less-experienced readers.

Feasibility study of computed tomography colonography using limited bowel preparation at normal and low-dose levels study

The purpose was to evaluate low-dose CT colonography without cathartic cleansing in terms of image quality, polyp visualization and patient acceptance. Sixty-one patients scheduled for colonoscopy started a low-fiber diet, lactulose and amidotrizoic-acid for fecal tagging 2 days prior to the CT scan (standard dose, 5.8–8.2 mSv). The original raw data of 51 patients were modified and reconstructed at simulated 2.3 and 0.7 mSv levels. Two observers evaluated the standard dose scan regarding image quality and polyps. A third evaluated the presence of polyps at all three mSv levels in a blinded prospective way. All observers were blinded to the reference standard: colonoscopy. At three times patients were given questionnaires relating to their experiences and preference. Image quality was sufficient in all patients, but significantly lower in the cecum, sigmoid and rectum. The two observers correctly identified respectively 10/15 (67%) and 9/15 (60%) polyps ≥10 mm, with 5 and 8 false-positive lesions (standard dose scan). Dose reduction down to 0.7 mSv was not associated with significant changes in diagnostic value (polyps ≥10 mm). Eighty percent of patients preferred CT colonography and 13% preferred colonoscopy (P<0.001). CT colonography without cleansing is preferred to colonoscopy and shows sufficient image quality and moderate sensitivity, without impaired diagnostic value at dose-levels as low as 0.7 mSv.

[Virtual colonoscopy--and then? Relevance of small colorectal polyps]

Colorectal carcinomas are the second most frequent malignant tumors in Germany and originate predominantly from benign polyps (adenoma-carcinoma sequence). Optical colonoscopy is still the gold standard for diagnosis and treatment colorectal polyps. However, CT colonography ("virtual colonoscopy") provides an alternative procedure with similar diagnostic performance but without the possibility of endoscopic polypectomy. Because of the high prevalence (approx. 30 %) of colon polyps in the screening population, virtual colonoscopy is useful for screening only, if a small number of the lesions must be subsequently removed endoscopically. Most of these lesions must represent such a low risk of malignant transformation in order for a control examination to be sufficient. According to a comprehensive review of the literature, the risk potential of small polyps up to a size of 5 - 6 mm can be summarized as follows: Up to 75 % of all polyps found in screening programs belong to the group of "small polyps". Only approx. 1.5-2 % of these contain advanced atypia and less than 0.05 % are carcinomas. Growth speed lies in the range of approx. 0.4 mm in 2 years, but regression can be observed as well. The very few existing growth studies cannot provide reliable information about how quickly these small lesions may turn malignant.

CONCLUSION

The risk potential of small polyps can be considered to be low. Nevertheless, because only poor data is available, a definitive statement cannot be made about the spontaneous course of these lesions. Therefore, further studies examining the natural growth behavior of small polyps are necessary, before control examinations (in intervals of two to three years) rather than immediate endoscopic polypectomy can be recommended as an adequate approach in screening programs.

[New imaging methods for bowel imaging]

Advances in ultra fast high resolution imaging using MRI and CT allow the detailed depiction of the gastrointestinal tract within a breathold. In this article we give an overview on new diagnostic avenues depicting the stomach, small bowel and colon. Additionally recently introduced techniques such as "virtual endoscopy" and "virtual pathology" are explained.

Comparison of routine and unprepped CT colonography augmented by low fiber diet and stool tagging: a pilot study

BACKGROUND

We performed a pilot study examining the feasibility of a new unprepped CT colonography (CTC) strategy: low fiber diet and tagging (unprepped) vs. low fiber diet, tagging and a magnesium citrate cleansing preparation (prepped). Prior reports of tagging were limited in that the residual stool was neither measured and stratified by size nor did prior reports subjectively evaluate the ease of interpretation by a reader experienced in interpreting CTC examinations.

METHODS

Prospective randomized to unprepped n = 14 and prepped n = 14. Colonic segments were subjectively evaluated for residual stool that would potentially interfere with interpretation. Scores were given in the following categories: percentage of residual stool that was touching or nearly touching mucosa, the largest piece of retained stool, effectiveness of tagging, height of residual fluid, degree of distention, ease of interpretation, and reading time.

RESULTS

Ease of the CT read (scale where 4 = optimal read) averaged 1.3 for the unprepped group and 2.3 for the prepped group. The mean read time averaged 17.5 min for unprepped and 17.9 min for prepped. The degree of distention (scale where 4 = well distended) averaged 3.7 for unprepped and 3.6 for prepped. Supine and prone images combined, the unprepped group had 160 segments with stool; prepped group had 58 segments. The amount of stool covering the mucosa in all segments averaged 1.6 (33%-66% coverage) in the unprepped group and 0.35 (<33% mucosal coverage) in the prepped group. The mean size of the largest piece of stool was 33.67 mm for unprepped and 4.01 mm for prepped. Percentage of tagged stool was not significantly different between the groups (range of 94-98%). The height of residual fluid averaged 8.37 mm for unprepped and 13.4 mm for prepped. Three polyps in three patients were found during optical colonoscopy (OC) in the unprepped group (5, 6, and 10 mm), none of which were prospectively detected at CTC. Three polyps in three patients were detected during OC in the prepped group (5, 10, and 15 mm), two of which were prospectively detected at CTC. Two false-positive lesions were observed at CTC in one patient in the prepped group.

CONCLUSION

There was more stool in the unprepped group and while this factor did not slow down the reading time, it made the examination subjectively harder to interpret and likely caused the three polyps in this group to be missed. We conclude that a truly unprepped strategy that leaves significant residual stool, even if well tagged, is not desirable.

Occult colorectal polyps on CT colonography: implications for surveillance

OBJECTIVE

Our purpose was to determine the prevalence of polyps that are invisible on CT colonography (CTC) in a population previously screened for colorectal neoplasms. Differences in the prevalence of occult polyps in various populations might help explain the discordant reported sensitivities for polyp detection in published reports of CTC.

SUBJECTS AND METHODS

Seventy-five consecutive patients who had been previously screened for polyps underwent same-day colonoscopy and CTC. Many of the patients had personal histories of previous polypectomies and were undergoing surveillance colonoscopy. The scans were interpreted prospectively by an experienced radiologist. Polyps missed prospectively on CTC were analyzed retrospectively by three experienced radiologists and categorized as perception errors (visible in retrospect), technical errors (e.g., obscured by feces or fluid), or occult (invisible).

RESULTS

Thirty polyps 5 mm or larger were found at colonoscopy, 18 of which were missed prospectively on CTC. Of the 18 missed polyps, 12 could not be identified in retrospect, even though they were located in clean, dry, well-distended colonic segments. These were classified as occult. Ten of the 12 occult polyps showed flat morphology on review of colonoscopy video recordings. Of the remaining six missed polyps, two were classified as perception errors, two as technical errors, and two as a combination of technical and perception error.

CONCLUSION

In this population, colonographically occult polyps were common and accounted for more detection failures than perception errors and technical errors combined. The high prevalence of occult polyps may be explained by the fact that previous screening may have led to removal of easy-to-see polyps, creating a study population with a higher percentage of hard-to-see polyps.

Factors influencing the detection of abnormalities in barium enemas performed by junior radiologists

AIM

To study the effects of patient variability, technical examination and radiologist-related factors on the radiological diagnosis of barium enema studies.

MATERIALS AND METHODS

Twenty-one residents (12 women and nine men, age 26-39 years) performed 523 double contrast barium enemas in a university hospital. Diagnoses were classified as normal (n = 203), diverticulosis (n = 224), polyps (n = 25), tumours (n = 20) and other (n = 46); five were missing diagnoses. Binary and multinomial logistic regressions were used to study the relations between the independent variables and the radiological diagnoses.

RESULTS

Patients' advanced age (p < 0.001) and obesity (p = 0.041) were significant positive predictors for the detection of any abnormalities, as was good or moderate study quality (p = 0.023). However, patients' obesity was negatively associated with the detection of polyps (p = 0.037). Pathological findings were associated with higher dose-area products (p = 0.047) than normal cases. Residents' advanced age (p = 0.029) and experience (a high number of previously performed barium enemas; p = 0.009) were negative predictors for the detection of pathological findings.

CONCLUSION

Patients' obesity hampers polyp detection, possibly due to decreased image quality or coexisting diverticula. The most experienced and oldest residents missed positive findings, possibly due to insufficient consultation of supervising radiologists, emphasizing the need for their optimal cooperation.

[Potential use of current X-ray contrast studies in the detection of small intestinal polyps in the Peutz-Jeghers syndrome]

The paper presents the results of studies of the small bowel in 9 patients with the Peutz-Jeghers syndrome. The indications for the study were the clinical picture of gastrointestinal bleeding and the symptoms of ileus. The author's intubation enterographic procedure using the better composition of barium suspension and an infusion system for administering contract substances into the small bowel, an improved fractional contrasting procedure, and a procedure employing the agent Entero-view was applied for contrasting the small bowel. All the procedures revealed an obvious picture of polyposis of the small bowel. The minimum size of detected tumors was 0.3-0.4 cm in diameter. Emphasis is laid on the quantitative image of neoplasms with Entero-view and the therapeutic effect of intubation enterography in evolving small-small intestinal intussusception.

[Jejunal intussusception of an inflammatory fibrinoid polyp]

Intussusception of parts of the intestine in adulthood is a rare cause of ileus. In more than 90 % of all cases there is a malignant or benign tumour situated in the parts of the intestine affected. We describe a 55-year-old patient who was admitted to hospital as an emergency because of signs of a proximal intestinal obstruction. Abdominal sonography suggested the diagnosis of a typical jejunal intussusception, whereas gastroscopy yielded no pathological findings. Laparotomy was performed immediately and confirmed the diagnosis. After intraoperative de-invagination 9 cm of jejunum and an inflammatory fibrinoid polyp of 3 cm were resected.

Detection of colorectal polyps by multislice CT colonography with ultra-low-dose technique: comparison with high-resolution videocolonoscopy

BACKGROUND

This prospective study compared multislice CT colonography with ultra-low-dose technique to high-resolution videocolonoscopy as the standard for detection of colorectal cancer and polyps.

METHODS

After standard bowel preparation, 115 patients underwent multislice CT colonography with an ultra-low-dose multislice CT colonography protocol immediately before videocolonoscopy. After noise reduction by using a mathematical algorithm, ultra-low-dose multislice CT colonographic images were analyzed in blinded fashion, and the results were compared with the results of high-resolution videocolonoscopy.

RESULTS

A total of 150 lesions were detected by high-resolution videocolonoscopy in 115 patients. For ultra-low-dose multislice CT colonography, sensitivities for detection of polyps less than 5 mm in size, 5 to 10 mm, and greater than 10 mm in diameter were 76%, 91%, and 100%, respectively. Although the sensitivity for detection of flat lesions was only 50%, the sensitivity and the specificity for detection of polyps 5 mm or greater in size were 94% and 84%, respectively. For adenomatous lesions greater than 5 mm in size, sensitivity was 94% and specificity was 92%. The overall specificity was 79%. The calculated effective radiation dose ranged between 0.75 and 1.25 mSv.

CONCLUSIONS

Compared with high-resolution videocolonoscopy, ultra-low-dose multislice CT colonography has excellent sensitivity and specificity for detection of colorectal lesions 5 mm or greater in size, and the radiation exposure is relatively low. However, before this technique can be generally recommended for colorectal screening, further improvement in the detection of flat and extremely small lesions must be achieved.

Use of multidetector-row CT colonography for detection of colorectal neoplasia in patients referred via the Department of Health "2-Week-wait" initiative

AIM

Patients referred under the Department of Health 2-week wait initiative with symptoms of colorectal cancer frequently undergo whole-colon examination. We investigated the use of computed tomography (CT) colonography as an alternative to colonoscopy in this scenario.

MATERIALS AND METHODS

Fifty-four consecutive patients, referred via the 2-week wait initiative and scheduled for colonoscopy, consented to undergo multidetector CT colonography immediately before endoscopy. The site and morphology of any polyp or cancer detected by CT was noted and comparison made with subsequent colonoscopy.

RESULTS

Colonoscopy detected polyps or cancer in 29 patients (53.7%). CT colonography prospectively detected 18 of 41 (44%) polyps of 1-5 mm, three of four (75%) polyps of 6-9 mm, four of four (100%) polyps 10 mm or larger, and five of six (83%) cancers. The missed cancer occurred early in the series and was a perceptive error. The overall sensitivity, specificity, positive predictive value and negative predictive value of CT colonography for cancer and polyps 10 mm or greater on a per patient basis were 90, 100, 100 and 98%, respectively. CT detected one renal cancer and one colonic cancer, initially missed due to incomplete colonoscopy.

CONCLUSION

CT colonography is a robust technique for investigation of symptomatic patients. The learning curve must be overcome for optimal performance.