An unusual case of intrarenal coiled and ruptured guidewire

Objective. To the best of our knowledge there are only 3 reports of fractured guidewires inside the pelvicalyceal system, successfully removed with endourology techniques, and this is the first one presenting a tightly coiled intraparenchymal section. Material and methods: A 59-year-old woman was hospitalized for surgical treatment of a right kidney of reduced size. Past history revealed pyelolithotomy for a staghorn stone 14 months earlier at another Institution with subsequent ureteral obstruction, one failed attempt at ureteral double-J catheter insertion and one failed attempt at percutaneous nephrostomy placement 5 months postoperatively. Another nephrostomy was placed, but left indwelling briefly. CT scan demonstrated a small-size kidney with residual stone fragments and presence of a “device” in the lower pole. The tapered distal extremity of an hydrophilic guidewire, with a tightly coiled central section wedged in the renal tissue was found inside the nephrectomy specimen. Results: While the Radiologist who read the CT scan hypothesized that the “device” was a fragment of double-J ureteral stent or nephrostomy catheter, it consisted of the hydrophilic extremity of a guidewire, broken during a previous attempt at nephostomy placement. Perirenal fibrosis and inappropriate angle between the needle and the lower calyx are the likely causes of guidewire coiling during its advancement and subsequent rupture during withdrawal. Conclusions. Urologists must be aware that, although percutaneous nephrostomy has a very high technical success rate, unusual complications like guidewire fracture may occur, and that modern imaging techniques can provide an accurate picture of this condition

Staging of pelvic lymph nodes in patients with prostate cancer: Usefulness of multiple b value SE-EPI diffusion-weighted imaging on a 3.0T MR system

AbstractPurposeTo evaluate the usefulness of diffusion-weighted imaging (DWI) with a multiple b value SE-EPI sequence on a 3.0T MR scanner for staging of pelvic lymph nodes in patients with prostate cancer candidate to radical prostatectomy and extended pelvic lymph node dissection (PLND).Materials and methodsInstitutional review board approval was obtained and written informed consent was taken from all enrolled subjects. A series of 26 patients with pathologically proven prostate cancer (high or intermediate risk according to D’Amico risk groups) scheduled for radical prostatectomy and PLND underwent 3T MRI before surgery. DWI was performed using an axial respiratory-triggered spin-echo echo-planar sequence with multiple b values (500, 800, 1000, 1500s/mm2) in all diffusion directions. ADC values were calculated by means of dedicated software fitting the curve obtained from the corresponding ADC for each b value. Fitted ADC measurements were performed at the level of proximal and distal external iliac, internal iliac, and obturator nodal stations bilaterally. Lymph node appearance was also assessed in terms of short axis, long-to-short axis ratio, node contour and intranodal heterogeneity of signal intensity.ResultsA total of 173 lymph nodes and 104 nodal stations were evaluated on DWI and pathologically analysed. Mean fitted ADC values were 0.79±0.14×10−3mm2/s for metastatic lymph nodes and 1.13±0.29×10−3mm2/s in non-metastatic ones (P<0.0001). The cut-off for fitted ADC obtained by ROC curve analysis was 0.91×10–3mm2/s. A two-point-level score was assigned for each qualitative parameter, and the mean grading score was 6.09±0.61 for metastastic lymph nodes and 5.42±0.79 for non-metastatic ones, respectively (P=0.001). Using a score threshold of 4 for morphological, structural, and dimensional MRI analysis and a cut-­off value of 0.91 × 10–3 mm2/s for fitted ADC measurements of pelvic lymph nodes, per-­station sensitivity, specificity, PPV, NPV and diagnostic accuracy were 100%, 7.9%, 15.6%, 100% and 21.3%, and 84.6%, 89.5%, 57.9%, 97.1% and 88.8%, respectively.Conclusions3.0T DWI with a multiple b value SE-EPI sequence may help distinguish benign from malignant pelvic lymph nodes in patients with prostate cancer