A pattern-based approach to bowel obstruction in the newborn.

Intestinal obstruction is common in newborns, and the radiologist plays a critical role in the care of these children. Diagnosing and managing the potentially obstructed newborn can be challenging, especially given the myriad underlying pathologies that range from benign to acutely life-threatening. A familiarity with the most common diagnoses is essential, but equally important to the radiologist is a systematic approach to management of the child in this setting. We propose an approach based on the recognition of eight radiographic patterns, five upper gastrointestinal examination (UGI) patterns and four contrast enema patterns. Recognition of these patterns directs further imaging when necessary and allows triage of children who can be managed medically, those requiring elective or urgent surgery and those requiring emergent surgery.

Delayed MDCT imaging results in increased enhancement in patients with head and neck neoplasms.

OBJECTIVE: Using multidetector computed tomography, we compared the utility of a spilt bolus technique and the impact of performing delayed imaging compared with immediate imaging on tumor enhancement. METHODS: Thirty-seven patients with masses of the extracranial head and neck were imaged. An initial contrast bolus (50 cm) was administered over 30 seconds (1.67 cm/s) and an initial (immediate) imaging acquisition followed. Ninety seconds after completion of the initial bolus, a second bolus of 75 cm (2.5 cm/s) was administered and a second (delayed) acquisition obtained concurrently. Mean tumor enhancement in immediate and delayed imaging was calculated and analyzed using the paired t test. RESULTS: Mean enhancement was 68.3 +/- 21.0 Hounsfield units (HU) and 91.4 +/- 27.4 HU (n = 37) for immediate and delayed imaging groups, respectively. The mean difference between the initial and delayed enhancement was 23.1 HU (P < 0.01). CONCLUSIONS: The delayed imaging technique used resulted in a statistically significant increase in enhancement relative to immediate imaging.

Sonographic evaluation of early-stage breast cancers that undergo neoadjuvant chemotherapy.

OBJECTIVE: We prospectively evaluated low-stage breast cancers treated with neoadjuvant chemotherapy using whole-volume sonography and color Doppler imaging. METHODS: Thirty-four women with breast cancer (mean maximum size, 2.4 cm) received neoadjuvant chemotherapy with doxorubicin and docetaxel. Targeted whole-volume sonography of tumor sites was performed before and after chemotherapy to assess mass size, color pixel speed-weighted density, and American College of Radiology Breast Imaging Reporting and Data System sonographic characteristics. After chemotherapy, tumor sites were excised by lumpectomy or mastectomy. RESULTS: Three (11.3%) of 34 patients had a complete histologic response. After chemotherapy, correlation was r = 0.716 between final histologic and sonographic sizes. Compared with histologic residual tumors, sonography had 4 false-negative results, 3 false-positive results, and 27 true-positive results (sensitivity, 87%), with no false-negative results among a subgroup of tumors of 7 mm and larger (sensitivity, 100%). The 3 cases with false-positive results were histologic fibrosis or biopsy changes. Mean speed-weighted density was 0.015 before and 0.0082 after chemotherapy (P = .03). After chemotherapy, vascularity was less common within (P = .06) or adjacent to (P = .009) masses or in tumor sites (P = .05). Prechemotherapy variables of gray scale characteristics and vascularity were compared with final histologic size, and all had P > .20. CONCLUSIONS: Postchemotherapy sensitivity of sonography was high for residual tumors of 7 mm or larger. Correlation was moderate between histologic and sonographic final tumor sizes. False-positive results were caused by fibrosis or biopsy-related changes. False-negative results occurred with residual tumor size of 6 mm or smaller. After chemotherapy, vascularity usually decreased, and this was not specific for complete response. Before chemotherapy, no vascular or gray scale feature at initial imaging predicted complete responders.