Volume 168 Number I, Part 2

479 THE VALUE OF MAGNETIC RESONANCE IMAGING IN THE EVALUATION OF PATIENTS AT RISK FOR PLACENTA

ACCRET A. J Ludmir, GA Holland", T Bader', JA Wheeler', I Forouzan,

HY Kresselx, Dept. OB/GYN, Beth Israel Hospital, Boston, MA and Depts. OB/GYN, Radiology, Pathology, Univ. of PA, Philadelphia, PA OBJECTIVE: To detennine the value of magnetic resonance imaging (MRJ) in diagnosing uterine wall invasion by placental villi in patients at risk for placenta accreta. STUDY DESIGN: After obtaining infonned consent, five patients in the third trimester were studied with MRJ. All patients had prior histories of uterine scars and had placenta previas documented by transabdominal ultrasound. High resolution MRJ was performed at 1.5 tesla with multi coil imaging (Signa Scanner, General Electric Medical Systems, Milwaukee, WI). Scans were perfonned with 3-4 mm thick contiguous sections through the uterus with flow sensitive gradient echo and both TI and T2 weighted spin echo scans. All scans were read prospectively. The following were detennined in each case: placental localization, vascularization of the implantation site, and planes between the uterus and bladder. RESULTS: One of the five patients was diagnosed on MRI as having a placenta accreta MRI in this patient revealed an irregular placental myometrial interface with several areas of focal increased signal in a hypointense band of myometrium. These findings were not seen in the other four patients studied and were felt to be due to a placenta accreta. The study was repeated two weeks later and showed the same findings. At surgery. a placenta accreta associated with hemorrhage required cesarean hysterectomy. MRJ of the hysterectomy specimen was compared to the histologic sections and good correlation was found in the degree and location of myometrial invasion. There were no false positives and no false negatives as determined by pathology and the postpartum clinical course. CONCLUSIONS: In patients with history of uterine scars and a placenta previa. MRJ provides a promising tool in identifying the patient at risk for hemorrhage and cesarean hysterectomy from placenta accreta.

480 EVALUATION OF THE UTERINE CERVIX BY MAGNETIC RESONANCE IMAGING IN THE NON PREGNANT, PREGNANT AND POSTPARTUM STATE. J Ludmir, GA Holland", S Underberg­

Davisx, LB Holland", HY Kressel" Dept. OB/GYN, Beth Israel Hospital, Boston, MA, Depts. OB/GYN and'Radiology, Univ. of PA, Philadelphia. PA OBJECTIVE: To detennine if magnetic resonance imaging (MRJ) can detect differences in the cervical stroma in the non pregnant, pregnant, and postpartum states. STUDY DESIGN: After obtaining infonned consent, 77 patients were studied with MRJ at 1.5 tesla (Signa Scanner, General Electric Medical Systems, Milwaukee, WI). All subjects were scanned with T2 weighted images of 5-4 mm thickness in axial and sagittal planes. Subjects included the following: 20 non pregnant patients of reproductive age without uterine anomalies referred for MRJ of adnexal masses, 10 patients in the late first and early second trimester referred for MRl of pelvic masses. Ten patients in the third trimester referred for MRJ pelvimetry, and 33 patients on the fifth to tenth day postpartum referred for MRJ to rule out pelvic abscesses and thrombophlebitis (6 vaginal deliveries and 25 cesarean sections). All scans were reviewed by two radiologists, and the signal intensities on T2 weighted images of the cervices were compared to skeletal muscle. RESULTS: Differences in the signal intensities of the cervices when compared to skeletal muscle were noted in each group. In the non pregnant state, all 20 cervices had hypointense signal. In the late first and early second trimester, 9 had isointense signal and 1 had hypointense signal. In the third trimester all 10 were hyperintense. In the postpartum patient, al 33 patients had cervices that were isointense regardless of route of delivery. CONCLUSIONS: MRJ provides an objective method for assessing the cervix in the non pregnant and pregnant states. Evaluation of cervical intensity may reflect changes in cervical connective tissue biochemistry during pregnancy and labor. The value of this technique in the patient at risk for cervical incompetence and/or pretenn labor requires further study.

SPO Abstracts 429

481 FXrRAAMNIOTIC SAUNE INFUSION wrrn: FOLEY CATIJETER. IS BETTER. TIiAN 2.9 MG PROSTAGLANDIN E2 GEL IN RIPENING TIiE CERVIX BlIT DOES NOT RESULT IN VAGINAL DElJVER.Y. Fernando Arias. Divya Rouben. St. John's Mercy Medical Center. St. Louis, MO. OBJECl1VE: To compare the efficacy of extraamniotic saline infusion with a Foley catheter and 2.9 mg prostaglandin (pG) E2 vaginal gel in promoting cervical ripening, inducing labor, and facilitating vaginal delivery in patients at tenn with a noninducible cervix. STIIDY DESIGN: Prospective randomized study of 112 patients with Bishop score less than 5. RESlH.TS: Extraamniotic saline infusion with a Foley catheter was significantly better than PG E2 vaginal gel in causing cervical ripening as indicated by changes in the Bishop score (two-tailed p <0.0001, 95% confidence limits (CI) 0.86 and 2.49) and inducing labor (p <0.0001, CI 0.53 and 0.73). However, the final delivery outcome resulted in a similar proportion of cesarean deliveries (48.5%) irrespective of the method used to ripen the cervix and induce labor. Neonatal birthweight was similar between patients undergoing cesarean and patients delivering vaginally. CONUUSIONS: Extraamniotic saline infusion with a Foley catheter was more efficacious than 2.9 PG E2 gel in ripening the cervix and inducing labor. These advantages, however, did not translate into vaginal delivery indicating that factors other than cervical ripening are responsible for the high incidence of cesarean section in patients with a noninducible cervix.

482 RIPENING AND DILATION OF THE UNFAVORABLE CERVIX FOR INDUCTION OF LABOR BY A DOUBLE BALLOON DEVICE (oBD): A NON·PHARMACEUTICAL METHOD. L Atad x Y. Ben·David,x M. Hallak, R. Auslender,x J. Bornstein,x R. Diukman,x H. Abramovici.x Dept. of Ob/Gyn, Carmel Medical Center, Haifa, Israel. OBJECTIVE: To determine the efficacy of the DBD in ripening and dilation of the unfavorable cervix for induction of labor. STUDY DESIGN: 250 women with unfavorable cervixes (Bishop score <4) underwent induction of labor with the DBD. Indications were: pregnancy ind uced hypertenSion (PIH) 118 pts, post dates 69 pts, elective inductions 23 pts, others (non reassuring NST, IUGR, previous CS, diabetes) 40 pts. The DBD was inserted into the cervix, the uterine balloon inflated in the internal os, and the cervico-vaginal balloon in the external os of the cervix (100 ml NS to each balloon). Pressure produced by the inflated balloons caused gradual dilatation and effacement of the cervix. DBD was removed 12 hrs after insertion, cervix assessed for 2nd Bishop score, &: labor managed according to obstetrical criteria. ("2nd> 1st, p<0.05). RESULTS: 1st 2nd 101' Mode of Delivery

Bishop Bishop (Hrs) Vaginal (%) CS (%) PIH (n=118) 1.8 6.3' 19.4 104 (87) 14 (13) Postdates (n=69) 2.2 6.8' 20.2 54 (78) 15 (22) Elective (n=23) 2.3 7.1' 16.3 20 (86) 3 (14) Others (n=40) 2.4 6.9' 17.2 33 (83) 7 (17) Total (n=250) 2.0 6.6' 18.9 211 (84) 39 (16) IDI=lnsertion delivery interval CONCLUSIONS: 1) The DBD induces significant ripening and dilatation of the unfavorable cervix. 2) Delivery was achieved within a mean of 18.9 hrs follOWing insertion in 246 pts (98%). 3) The DBD did not cause side effects seen in pharmaceutical methods of labor induction. 4) Our CS rate was low compared to rates reported in literature for pts ind uced with an unfavorable cervix.