Development and validation of automated 2D-3D bronchial airway matching to track changes in regional bronchial morphology using serial low-dose chest CT scans in children with chronic lung disease.

To address potential concern for cumulative radiation exposure with serial spiral chest computed tomography (CT) scans in children with chronic lung disease, we developed an approach to match bronchial airways on low-dose spiral and low-dose high-resolution CT (HRCT) chest images to allow serial comparisons. An automated algorithm matches the position and orientation of bronchial airways obtained from HRCT slices with those in the spiral CT scan. To validate this algorithm, we compared manual matching vs automatic matching of bronchial airways in three pediatric patients. The mean absolute percentage difference between the manually matched spiral CT airway and the index HRCT airways were 9.4 ± 8.5% for the internal diameter measurements, 6.0 ± 4.1% for the outer diameter measurements, and 10.1 ± 9.3% for the wall thickness measurements. The mean absolute percentage difference between the automatically matched spiral CT airway measurements and index HRCT airway measurements were 9.2 ± 8.6% for the inner diameter, 5.8 ± 4.5% for the outer diameter, and 9.9 ± 9.5% for the wall thickness. The overall difference between manual and automated methods was 2.1 ± 1.2%, which was significantly less than the interuser variability of 5.1 ± 4.6% (p<0.05). Tests of equivalence had p<0.05, demonstrating no significant difference between the two methods. The time required for matching was significantly reduced in the automated method (p<0.01) and was as accurate as manual matching, allowing efficient comparison of airways obtained on low-dose spiral CT imaging with low-dose HRCT scans.

Abnormal findings on routine upper GI series following laparoscopic Roux-en-Y gastric bypass.

BACKGROUND: The use of postoperative upper GI series (UGIS) after laparoscopic Roux-en-Y gastric bypass (LRYGBP) varies among bariatric surgeons. The authors describe the findings and impact of UGIS after LRYGBP. METHODS: From July 2003 to January 2006, 487 patients undergoing primary LRYGBP at a single academic institution had a single-contrast Gastrografin UGIS performed on the first postoperative day, without complication. Patient and operative demographics were: mean age 43 years, mean BMI 47 kg/m2, female 84%, and laparoscopic 100%. RESULTS: Of the 487 patients, the UGIS revealed 14 (2.9%) major and 88 (15.2%) minor abnormalities. Among the major UGIS abnormalities, 6 (1.2%) demonstrated a gastrojejunal anastomotic (GJA) leak, 8 (1.4%) confirmed complete obstruction at the GJA, and 1 (0.2%) disclosed a communication with the bypassed stomach. For the minor UGIS abnormalities, 45 (9.2%) displayed significant delay in contrast passage through the GJA, 23 (5.0%) had evidence of dilated loops of small and/or large bowel, and 6 (1.2%) verified miscellaneous abnormal findings (malrotation, lower esophageal dysmotility, jejunal clots). Patients with UGIS abnormalities necessitated additional procedures, delayed oral intake and/or longer length of stay (LOS). CONCLUSIONS: UGIS on postoperative day 1 is a useful means of evaluating postoperative LRYGBP anatomy and influenced postoperative care.