Clinical utility of ultrasound versus magnetic resonance imaging for deciding to proceed with uterine artery embolization for presumed symptomatic fibroids.

AIM: To compare the diagnostic utility of pelvic ultrasound (US) and magnetic resonance imaging (MRI) on the clinical decision to proceed with uterine artery embolization (UAE). MATERIALS AND METHODS: Over 2 years, 180 consecutive women (mean age 43) sought consultation for UAE, 116 underwent pelvic US and MRI before possible UAE. US was performed prior to MRI. Imaging was analysed for leiomyoma quantity, size and location, uterine volume, and the presence of potential contraindications to UAE. Discrepancies between imaging methods and cases where discrepancies could have altered management, were recorded. RESULTS: For the 116 patients who completed imaging, the average uterine volume was 701 cm(3) using MRI versus 658 cm(3) using US (p=0.48). The average dominant leiomyoma volume was 292 cm(3) using MRI versus 253 cm(3) using US (p=0.16). In 14 (12.1%) patients US did not correctly quantify or localize leiomyomas compared with MRI (p=0.0005). Thirteen patients did not undergo UAE (patient preference n=9, pre-procedural imaging findings n=4). In the four cases where UAE was not performed due to imaging findings, relevant findings were all diagnosed by MRI compared with two by US (p=0.5). The two cases not detected by ultrasound were adenomyosis and a pedunculate subserosal leiomyoma. Of the 103 patients who underwent UAE, 14 were treated (without complication) despite the presence of a relative contraindication; all 14 relative contraindications were identified by MRI compared with 13 by US (p=1.0). CONCLUSION: MRI is more accurate than US for characterizing uterine leiomyomas. In a small but statistically insignificant number of cases, MRI identified findings that were missed by US, which changed management. For patients that are unsuitable to be assessed with MRI, ultrasound alone is sufficient for pre-UAE assessment.

Photochemical synthesis of novel dideoxynucleosides.

A series of 2',3'-dideoxynucleosides based on the apiose family was prepared from photochemical ring-expansion of a common cyclobutanone precursor. The starting ketone, (+/-) 3-[2'-(benzoyloxy)ethyl]-2,2-dimethylcyclobutanone (12) was prepared from commercially available (+/-)alpha-pinene. Since the optically pure antipodes of alpha-pinene are also commercially available, these nucleosides can be prepared optically pure using the identical procedure.

MR imaging of simple bone cysts in children: not so simple.

OBJECTIVE: The unicameral bone cyst (UBC) is a common cystic bone lesion seen in children. We review and summarize its MR findings, focusing on their appearance following contrast enhancement, and correlating them to known histologic features of UBC. SUBJECTS AND METHODS: A retrospective review of 20 cases (13 boys, 7 girls; age range, 1-17 years; mean age, 8.9) diagnosed as UBC was conducted. Clinical histories, radiographic and MR features, follow-up data, and available pathologic findings were noted. RESULTS: At initial presentation 18 (90 %) of the patients with UBC had a history of acute or remote pathologic fracture. Cysts with history of fracture displayed heterogeneous fluid signals on T1-(n = 9, 50%), and T2-weighted (n = 15, 83 %) MR images. Gadolinium-enhanced images were obtained in 15 of the 18 UBC cases with history of previous fracture. All showed enhancement with focal, thick peripheral, heterogeneous, or subcortical patterns. Focal nodules of homogeneous enhancement (diameter > 1 cm) within the UBC (n = 5) correlated with areas of ground-glass opacification on plain film. Other interesting MR features were fluid-fluid levels (n = 11), "fallen-leaf" sign (n = 1), soft-tissue changes (n = 2), and detection of septations not seen on plain film (n = 2). CONCLUSION: UBCs frequently appear complicated on MR imaging, with heterogeneous fluid signals and regions of nodular and thick peripheral enhancement related to previous pathologic fracture and early healing.