The Usefulness of Virtual Cystoscopy with Spiral CT in Evaluating Bladder Tumor

PURPOSE: To compare the role and clinical usefulness of virtual and convetional cys-t o s c o py in patientswith known bladder tumors. MATERIALS AND METHODS: S eventeen patients with a known bladder tumor underwentvirtual and conventional cystoscopy. As a result of conventional cystoscopy and s u r g e r y, 32 tumors weredetected. Prior to examination, each patient lay supine on the CT table, and the urinary bladder was catheterized,drained of all urine, and inflated with air. Spiral CT of the pelvis was then performed. CT data were transferredto a separate workstation and three-dimensional and virtual cystoscopic images were reconstructed. The latter wereinterpreted by two radiologists, who recorded the number, size, morphology, and exact location of the massesobserve d. The results of virtual CT cystoscopy were correlated with conventional cystoscopic findings. RESULTS:Twenty - two (69%) of 32 bladder tumors detected during conventional cystoscopy were visualized by virtualcystoscopy. Four (36%) of 11 tumors measured 0.5 cm or less, 15 (83%) of 18 measured 0.5 -3 cm and all (100%) oftumors measured 3 cm or more. With regard to tumor morphology, six (86%) of seven sessile tumors and 16 (64%) of25 which were pedunculated were detected. The procedure was well tol-erated by all patients, and no complicationswere reported. CONCLUSION: Due to its intrinsic weakness, virtual cystoscopy cannot replace itscon-ventional counterpart, though by developing data scan and acquisition techniques and software, and on thebasis of clinical experience, the latter can be used in the future for the diagnosis and follow up ofbladder tumors.

Multishot Echoplanar MR Imaging of the Female Pelvis: Comparison with T2 weighted Fast Spin Echo Imaging

PURPOSE: To compare the usefulness of multishot echoplanar imaging (EPI) with T2-weighted fast spin-echoimaging (FSE) for the evaluation of female pelvic organs and pathologic conditions. MATERIALS AND METHODS:Twenty-nine patients with pelvic lesion underwent MR imaging (GE Medical Systems) using a pelvic array coil (GEMedical Systems). Axial EPI (TR/TE=2,000/80, 6mm slice thickness, 2.5mm gap, multishot 16) and T2-weighted FSE(TR/TE=3,400/117, 5mm slice thickness, 1.5mm gap, ETL=12) were obtained. Overall image quality, the parametrialvenous plexus, anatomy of the uterine zone and outer margin, identification of the ovaries, pelvic pathologiccondition, and frequency of artifact, as seen on EPI and FSE imaging were reviewed separately by two radiologists. RESULTS: For overall imaging quality, EPI was superior to FSE in 14% of patients(4/29), equal in 24%(7/29), andinferior in 62%(18/29). For delineation of the parametrial venous plexus, EPI was superior to FSE in 79%(23/29).For uterine zonal anatomy and the outer margin, EPI was inferior to FSE in 55%(16/29) and in 45%(13/29),respectively. On EPI, visualization of the ovary was rated superior to FSE in 0%(0/9), equal in 52%(15/29), andinferior in 48%(14/29). Conspicuity of pelvic pathologic lesions was superior in 14%(4/29), equal in 52%(15/29),and inferior in 48%(14/29). Image distortion and susceptibility artifacts were seen on EPI in six cases, while onFSE motion artifacts were seen in two cases. CONCLUSIONS: As EPI is inferior to FSE in overall image quality,delineation of the normal anatomy of pelvic organs and conspicuity of pelvic lesions, it cannot replace FSE forimaging the female pelvis. However, because EPI reduces imaging time, further technical progress in this area maystimulate the use of ultrafast imaging of the femal pelvis.