Liver magnetic resonance imaging: how we do it.

Magnetic resonance imaging is used for evaluating focal liver lesions, hepatic vascular diseases, biliary diseases and diffuse liver diseases in children. MRI examinations take a long time, often requiring sedation or anesthesia in smaller children. This makes it essential to understand the concepts and technique necessary to obtain an optimal examination for answering the clinical question while minimizing the need for sedation/anesthesia. We discuss key concepts including appropriate sequence selection, choice of contrast media, dynamic imaging, phases of contrast enhancement and protocol organization.

Diagnostic Performance of a Sonographic Volume and Solid Vascular Tissue Score (VSVTS) for Preoperative Risk Assessment of Pediatric and Adolescent Adnexal Masses.

STUDY OBJECTIVE: To evaluate the diagnostic performance of a Volume and Solid Vascular Tissue Score (VSVTS) for preoperative risk assessment of pediatric and adolescent adnexal masses. DESIGN: A retrospective cohort study comprised of all female individuals who presented with an adnexal mass that was managed surgically between April 2011 and March 2016. SETTING: The Hospital for Sick Children (Toronto, Ontario, Canada). PARTICIPANTS: Female individuals 1-18 years of age who presented to a large tertiary pediatric hospital with an adnexal mass that was managed surgically. MAIN OUTCOME MEASURES: Main outcome measures included diagnostic performance of the VSVTS for malignancy via sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (LR+), negative likelihood ratio (LR-), and receiver operating characteristic area-under-the-curve (AUC) analysis. RESULTS: A total of 179 masses in 169 subjects were included. The malignancy rate was 10.6%. The AUC for the VSTVS was 0.919. A VSTVS cut-off value of 4 achieved a sensitivity of 79% (95% CI 0.54-0.93), specificity of 88% (95% CI 0.82-0.93), PPV of 0.44 (95% CI 0.33-0.56), NPV of 0.97 (95% CI 0.94-0.99), LR+ of 6.77 (95% CI 4.18-10.97), and LR- of 0.24 (95% CI 0.10-0.57). CONCLUSIONS: A sonographic scoring system based on the volume and presence of solid vascular tissue improves PPV for preoperative risk stratification of adnexal masses in the pediatric and adolescent population compared to existing ultrasound-only approaches. Further prospective research is needed to determine how best to incorporate components of such scoring systems into clinical management algorithms.