Intravenous contrast enhanced computed tomography colonoscopy in children with suspected colonic polyps

The value of colorectal filling contrast ultrasonography in diagnosing pediatric juvenile polyps

OBJECTIVES

To describe a facilitated procedure of colorectal filling contrast ultrasonography (CFCUS) and explore its value in the diagnosis of pediatric juvenile polyps.

METHODS

One hundred and eleven children with clinical signs of colorectal polyps admitted to our hospital between May 2018 and May 2021 were retrospectively reviewed. All children underwent conventional transabdominal ultrasonography (CTUS) and CFCUS prior to undergoing colonoscopy. Pathologic findings were used as the gold standard. Chi-squared tests and Mann-Whitney U tests were used for the statistical analysis.

RESULTS

Forty-five children with fifty-two colorectal polyps were confirmed via pathological examination. The sensitivity, specificity, positive predictive value, and negative predictive value of CFCUS vs. CTUS were 92.3% versus 80.7%, 100% versus 100%, 100% versus 100%, and 93.3% versus 84.8%, respectively. The missed polyps were significantly smaller than the polyps detected in diameter (7.50 ± 2.12 mm vs. 19.62 ± 7.89 mm, p < 0.0001) by CTUS. A significant difference between CTUS and CFCUS was observed in the detection rate of polyps with a diameter < 1 cm (p = 0.031) and pedicles (p < 0.001). The kappa values for the assessment of Yamada's classification between CTUS and colonoscopy and CFCUS and colonoscopy were 0.51 and 0.84, respectively. Moreover, CFCUS incidentally revealed a punctate hyperechoic area on the surface of colonic polyps in six cases, which may be suggestive of a correlation with erosion and bleeding findings.

CONCLUSION

CFCUS can increase the detection rate of polyps and pedicles, especially polyps with diameters <1 cm, and accurately evaluate Yamada's classification, providing useful preoperative information for colonoscopy.

Ultrasonography with the colonic segment-approach for colonic polyps in children

BACKGROUND

Ultrasonography (US) has been widely applied and has validated efficacy in the diagnosis of colonic polyps in children. However, little attention has been paid to improving the detection rate of polyps, optimizing the ultrasonic examination process and reducing misdiagnosis.

OBJECTIVE

To investigate the diagnostic performance of the colonic segment-approach by US in the diagnosis of colonic polyps in pediatric patients.

MATERIALS AND METHODS

One hundred fifty-nine patients who were going to have a colonoscopy from September 2014 to August 2016 were enrolled in this study. All patients received US before colonoscopy. In a preliminary study, 50 patients were chosen to determine the interobserver agreement, with half of the cases with and half of the cases without a colonic segment-approach. The other 109 patients were examined by both approaches. The sensitivity and the specificity of each approach were compared based on the outcome of colonoscopy as the gold criteria.

RESULTS

The interobserver agreement was high (0.816 for the non-segmental approach, 0.754 for the colonic segment-approach). The diagnostic sensitivity of the colonic segment-approach was higher than that of the traditional approach (82.1% vs. 57.7%, P<0.05) with 89.3% vs. 64.2% detection rate of colonic polyps in the descending colon, 81.8% vs. 60.6% in the sigmoid colon, and 81.3% vs. 43.8% in the rectum, respectively. The specificity of both methods was 100% (95% confidence interval: 86.3%-100%).

CONCLUSION

The US colonic segment-approach can improve diagnostic sensitivity for colonic polyps as a convenient method with no special requirement for equipment and examination conditions.

Staging of colorectal cancer using contrast-enhanced multidetector computed tomographic colonography

INTRODUCTION

Preoperative staging is essential for the optimal treatment and surgical planning of colorectal cancers. This study was aimed to evaluate the accuracy of colorectal cancer staging done using contrast-enhanced multidetector computed tomographic colonography (CEMDCTC).

METHODS

We recruited 25 patients with 28 proven colorectal cancers. A 16-slice multidetector computed tomography scanner was used to generate two-dimensional multiplanar reformatted sagittal, coronal and oblique coronal images, and three-dimensional virtual colonography (endoluminal) images. Axial and reformatted views were analysed, and TNM staging was done. Patients underwent surgery and conventional colonoscopy, and surgical histopathological correlation was obtained.

RESULTS

The diagnostic accuracies for TNM colorectal cancer staging were 92.3% for T staging, 42.3% for N staging and 96.1% for M staging using CEMDCTC. There was excellent positive correlation for T staging between CEMDCTC and both surgery (κ-value = 0.686) and histopathology (κ-value = 0.838) (p < 0.0001), and moderate positive correlation for N staging between CEMDCTC and surgery (κ-value = 0.424; p < 0.0001). The correlation between CEMDCTC and histopathology for N staging was poor (κ-value = 0.186; p < 0.05); the negative predictive value was 100% for lymph node detection. Moderate positive correlation was seen for M staging between CEMDCTC and both surgery (κ-value = 0.462) and histopathology (κ-value = 0.649). No false negatives were identified in any of the M0 cases.

CONCLUSION

CEMDCTC correlated well with pathologic T and M stages, but poorly with pathologic N stage. It is an extremely accurate tool for T staging, but cannot reliably distinguish between malignant lymph nodes and enlarged reactive lymph nodes.

Colonic polyps and polyposis syndromes in pediatric patients

PURPOSE OF REVIEW

Gastrointestinal polyps are commonly encountered during childhood and are one of the most common causes of rectal bleeding in this age group. Most polyps are benign and located in the colon, with the most frequent type being juvenile polyps. However, in older pediatric patients, if multiple polyps are present, in patients who have a positive family history, or if polyps are located outside of the colon, either adenomatous polyps or polyps associated with genetic abnormalities are more common.

RECENT FINDINGS

Imaging techniques such as ultrasound and computed tomographic colonoscopy have recently been utilized to identify simple juvenile colonic polyps in children with rectal bleeding in whom there is a high index of suspicion. Colonoscopy with polypectomy is still required for histologic evaluation and resection of the polyp. There have been significant advances in genetic testing and management of hereditary gastrointestinal cancer syndromes with onset in childhood or adolescence that may ultimately reduce long-term morbidity and mortality. In addition to enhanced gastrointestinal and extraintestinal malignancy screening for affected individuals, specific gene mutations within a given condition such as adenomatous polyposis coli may predict clinical course and timing of specific interventions such as colectomy. In other conditions such as phosphatase and tensin homolog hamartoma tumor syndrome, phenotype may not be predicted by genotype.

SUMMARY

Pediatricians, pediatric gastroenterologists, and adult gastroenterologists caring for children should understand how to differentiate benign polyps in the pediatric age group from those associated with a higher risk of complications including recurrence risk and risk of development of intestinal or extraintestinal malignancy. Recent advances in genetic testing, as well as development of consensus guidelines, are key in the identification, screening, and follow-up of children and adolescents with polyposis syndromes.

Comparison of CT colonography with conventional colonoscopy in patients with ulcerative colitis

RATIONALE AND OBJECTIVE

Patients with ulcerative colitis require recurrent conventional colonoscopy (CC) to define the extent of the disease. Computed tomography (CT) colonography (CTC) can be used as an alternative technique for studying the colon in these patients. The purpose of the study was to compare the findings of CTC to CC in patients with ulcerative colitis.

MATERIALS AND METHODS

Twenty patients proven to have ulcerative colitis on biopsy and in clinical remission state were enrolled in the study. They underwent CTC and CC within 1 week of each test. The investigators performing CTC and CC were blinded to the findings of each other. The chi-square test, kappa test, sensitivity, and specificity were used to compare the findings on CTC and CC. In addition, patient acceptance for both the procedures was compared.

RESULTS

Sensitivity and specificity on CTC for detecting granular appearance were 81.0% and 73.8%, respectively, and for pseudopolyps were 82.1% and 84.5%, respectively. Good correlation was seen between CTC and CC for detection of granular appearance and pseudopolyps. Loss of haustral folds, wall thickening, pericolonic vascularity, and pericolonic lymph nodes seen on CTC were found to correlate with intraluminal findings seen on CC. Patient acceptance for CTC was better than that for CC.

CONCLUSIONS

CTC can be used for evaluating patients with ulcerative colitis who are in remission.