Evaluation of whole-body MRI with diffusion-weighted sequences in the staging of pediatric cancer patients.

BACKGROUND: The purpose of this study was to determine whether whole-body MRI (WBMRI) with diffusion-weighted sequences, which is free of ionizing radiation, can perform as well as traditional methods when used alone for staging or follow-up of pediatric cancer patients. METHODS: After obtaining approval from our institutional research ethics committee and appropriate informed consent, we performed 34 examinations in 32 pediatric patients. The examinations were anonymized and analyzed by two radiologists with at least 10 years' experience. RESULTS: The sensitivity and specificity findings, respectively, were as follows: 100% and 100% for primary tumor; 100% and 86% for bone metastasis; 33% and 100% for lung metastasis; 85% and 100% for lymph node metastasis; and 100% and 62% for global investigation of primary or secondary neoplasias. We observed excellent interobserver agreement for WBMRI and excellent agreement with standard staging examination results. CONCLUSIONS: Our results suggest that pediatric patients can be safely imaged with WBMRI, although not as the only tool but in association with low-dose chest CT (for subcentimeter pulmonary nodules). However, additional exams with ionizing radiation may be necessary for patients who tested positive to correctly quantify and locate the lesions.

Value of ultrasound in the imaging-guided transthoracic biopsy of lung lesions.

Transthoracic needle biopsy with fluoroscopic or computed tomographic guidance is a well-established and safe method for diagnosing malignant and benign thoracic lesions. Nonetheless, ultrasound is as effective as computed tomography for the guidance of transthoracic biopsies of peripheral pulmonary lesions and mediastinal tumors, and it offers some advantages. In this case report, we exemplify the proper use of ultrasound for the percutaneous biopsy of a lung lesion, aiming to show that it can be a safe, inexpensive, rapid, and effective alternative to computed tomography in appropriate cases.