Correlation between maternal meal and fetal motion during fetal MRI.

BACKGROUND: Motion remains a major limitation of fetal magnetic resonance imaging (MRI). Some centers have required mothers to fast before MRI in an effort to reduce motion; however, there is no current literature that describes the effect of maternal diet on fetal activity. OBJECTIVE: The objective is to define associations between specific foods and beverages consumed before and the severity of fetal motion during fetal MRI. MATERIALS AND METHODS: Patients were asked to recall the specific foods or drinks consumed before their scan. An experienced technologist rated the level of fetal activity on a 3-point scale, from much less motion than normal (1) to much more (3). Two hundred twenty-eight patients were included. A non-inferiority test was used to establish statistical equivalence between the MR scores of those having a particular food item and those not. For items not shown to be equivalent, an additional superiority analysis evaluated for the presence of any significant difference. Additional data on time from meal to MRI and amniotic fluid index were also analyzed. RESULTS: Eleven of 15 comparisons were statistically significant for equivalence (P<0.05). In the remaining four categories, a superiority analysis revealed no significant differences. Analysis of meal-to-scan times showed no significant association with mean MR score (P=0.57). Amniotic fluid index correlated positively with scores, but the association was not statistically significant (P=0.39). CONCLUSION: Neither fasting nor a specific consumption was associated with a significant difference in fetal motion on MR. It is therefore likely unnecessary for mothers to alter their diets on the day of an MRI study.

Technical and anatomical factors affecting intra-arterial chemotherapy fluoroscopy time and radiation dose for intraocular retinoblastoma.

BACKGROUND: Intra-arterial chemotherapy has an increasingly prominent role in the management of retinoblastoma. One concern regarding this technique is procedural radiation exposure. OBJECTIVES: To examine the effects of our institution's procedural technique on fluoroscopy parameters for patients undergoing intra-arterial chemotherapy infusions for intraocular retinoblastoma. Secondary goals included describing the effect of anatomical variations of the carotid siphon and ophthalmic artery on radiation dose. METHODS: A retrospective review of pediatric patients with retinoblastoma referred to interventional neuroradiology for chemosurgery was performed. Techniques were classified as: A (1.2 Fr or 1.5 Fr microcatheter with continuous verapamil flush, advanced without guide through a 2 Fr sheath) or B (1.5 Fr or 1.7 Fr microcatheter advanced within a 4 Fr base catheter, through a 4 Fr sheath). Statistical analysis was performed to determine if there was a significant difference in fluoroscopy parameters based on technique or due to anatomical variation. RESULTS: 26 patients were treated with 94 intra-arterial chemotherapy infusions. 34 procedures were performed using technique A and 60 using technique B. Mean fluoroscopy time (4.75 min), fluoroscopy dose (23.3 mGy), and dose-area product (DAP; 85.2 µGy.m2) for technique A were significantly lower (p value <0.05) than for technique B, 14.0 min., 191 mGy, and 586 µGy.cm2, respectively. CONCLUSIONS: Microcatheter-only technique with continuous verapamil infusion resulted in decreased fluoroscopy times, DAP, and radiation doses at our institution for the treatment of intraocular retinoblastoma. Furthermore, our fluoroscopy times using this technique are the lowest reported in the current literature. Additionally, our anatomical analysis has demonstrated a positive correlation between increasing vessel tortuosity and fluoroscopy times.