Paediatric Crohn's disease: a radiological review

Resistance index in mural arteries of thickened bowel wall: predictive value for Crohn disease activity assessment in pediatric patients

OBJECTIVE

To define reliable Doppler parameters in mural arteries of affected bowel loops for quantitative assessment of Crohn disease (CD) activity in pediatric population and compare Doppler parameters with Pediatric Crohn Disease Activity Index (PCDAI).

PATIENTS AND METHODS

Thirty-four pediatric patients (7 with inactive, 27 with active disease of different severity; 13 male and 21 female; mean age 13; range 7-18) with CD were prospectively evaluated by Doppler ultrasound (DUS) of affected bowel segments. Using semiquantitative color and power Doppler assessment of vascularization of thickened bowel wall and mesentery, patients were divided in four grades. Spectral measurements (peak systolic velocity (PSV), end diastolic velocity (EDV), resistance index (RI)) of mural arteries were compared with PCDAI.

RESULTS

There was a significant difference in distribution of semiquantitative color values between inactive and active group. PSV and EDV values showed no significant difference between inactive and active group, while mean RI was significantly higher in the inactive group. RI was also significantly negatively correlated with PCDAI.

CONCLUSION

Intensity of color and power Doppler signals and RI measurement of mural arteries in thickened bowel wall is linked to CD activity and therefore might be of use in pediatric patients.

Comparison of MR enterography and histopathology in the evaluation of pediatric Crohn disease

BACKGROUND

While MR enterography (MRE) is commonly used to identify segments of bowel affected by Crohn disease in children, there is little data to support this practice.

OBJECTIVE

To assess the ability of MRE to identify segments of small bowel and colon affected by pediatric Crohn disease using histopathology as the reference standard.

MATERIALS AND METHODS

Pediatric MRE examinations performed between April 2009 and December 2010 were identified. Subjects were excluded if they did not have Crohn disease, if they had Crohn disease but no correlative histopathology within 2 months of imaging, or if they had undergone prior bowel resection. Pertinent MRE and histopathology reports were reviewed, and normal and abnormal bowel segments were documented.

RESULTS

Thirty-two pediatric MRE examinations were identified with correlative histopathology. MRE had an overall sensitivity of 94% for detecting the presence of Crohn disease, in general. At the bowel segmental level, MRE had a sensitivity of 66%, specificity of 90%, positive predictive value of 85% and negative predictive value of 76%. The terminal ileum was abnormal by MRE in 11 of 15 (73%) subjects lacking a diagnostic biopsy of this bowel segment.

CONCLUSION

MRE successfully identifies small bowel and colon segments affected by pediatric Crohn disease.

Enteroclysis in older children and teenagers

BACKGROUND

Enteroclysis (EC) has been widely and successfully used for evaluation of the small bowel in adults for about 30 years. However, despite recently improved intubation and examination techniques, in many paediatric radiology centres it is still not the preferred conventional barium study for the evaluation of small bowel pathology in children.

OBJECTIVE

To share our 10 years of experience and review the feasibility of EC in 83 older children and teenagers, in terms of both technique and pathological findings.

MATERIALS AND METHODS

Between 1996 and 2006, EC was performed by the standard technique described by Herlinger to 83 children between 7 and 18 years of age. The indication for the study was jointly decided by the paediatric radiologist and the clinician. None of the examinations was converted to follow-through studies because of patient refusal or technical failure. Morphological changes, mucosal abnormalities, luminal abnormalities, perienteric structures, the location of the disease, indirect findings regarding the bowel wall and functional information were evaluated.

RESULTS

All the children tolerated the procedure without difficulty. Out of 83 patients, 63 had abnormal findings. The spectrum of diagnoses were Crohn disease (n = 23), nonspecific enteritis (n = 10), malabsorption (n = 8), intestinal tuberculosis (n = 6), intestinal lymphoma (n = 5), Peutz-Jegher syndrome (n = 3), adhesions (n = 2), Behçet disease (n = 2), back-wash ileitis due to ulcerative colitis (n = 2), common-variable immune deficiency (n = 1) and lymphangiectasis (n = 1).

CONCLUSION

EC can easily be performed in children over 7 years of age and when performed using a correct technique it shows high diagnostic performance without any complications in the evaluation of small bowel diseases in older children and teenagers.

Sonographic evaluation of inflammatory bowel disease: a prospective, blinded, comparative study

BACKGROUND

Children with inflammatory bowel disease (IBD) undergo invasive and repeated investigations, including contrast radiology and endoscopy.

OBJECTIVE

To assess transabdominal sonography of the colon and distal ileum compared to colonoscopy and barium radiology in known or suspected IBD.

MATERIALS AND METHODS

A prospectively recruited cohort of 44 children (median age 12 years, range 3.5-16.5 years; 24 males) underwent transabdominal sonography prior to colonoscopy (n=33) or barium follow-through (n=25). Diagnoses were: Crohn disease (n=25), ulcerative colitis (n=12), indeterminate colitis (n=1), normal (n=6).

RESULTS

Bowel wall thickness (BWT) and endoscopic severity were compared in 153 colonic segments. No difference was found between normal and mildly affected segments. BWT was less in normal bowel than moderate (P<0.001) or severe (P<0.001) lesions. Where BWT was >2.9 mm, sensitivity for moderate/severe disease was 48%, specificity 93%, positive predictive value 83% (likelihood ratio 7). Barium radiology showed terminal ileum abnormality in ten patients (40%). Where ileal BWT was >2.5 mm, comparative sensitivity was 75%, specificity 92%, positive predictive value 88% (likelihood ratio 9). Superior mesenteric artery Doppler did not correlate with disease severity.

CONCLUSION

Increased BWT has good positive predictive value for moderate/severe disease in the colon proximal to the rectum (>3 mm), and terminal ileum (>2.5 mm). BWT below this cannot exclude moderate/severe mucosal lesions.

Ultrasound scanning may reduce the need for barium radiology in the assessment of small-bowel Crohn's disease

AIM

Bowel wall thickening on transabdominal ultrasound scanning (USS) correlates well with Crohn's disease (CD) activity. However, the role of USS in the assessment of CD has not been fully defined. This study compared USS and barium follow-through (BaFT) in the assessment of CD.

METHODS

A retrospective case series was undertaken of 24 children with CD who underwent USS and BaFT during the same period of clinical disease activity.

RESULTS

For terminal ileum abnormality, all 13 cases with abnormal USS had abnormality on BaFT. USS did not detect five cases with affected terminal ileum and two cases with isolated proximal small-bowel CD.

CONCLUSION

BaFT is a more sensitive indicator of small-bowel CD than USS. USS has good positive predictive value of distal small-bowel CD, but BaFT should be performed in the presence of a normal USS where there is strong clinical evidence of CD.