Postoperative Imaging of Endometriosis.

Endometriosis is a highly prevalent disease that affects 10%-15% of women of reproductive age worldwide and is mainly associated with chronic pelvic pain and infertility. With the widespread use of imaging for the diagnosis and monitoring of endometriosis, combined with the ability of surgery to eradicate the disease and address infertility, there has been a significant increase in recent years in imaging examinations for postoperative evaluation of endometriosis. US and MRI are used not only to help diagnose and map endometriosis but also to evaluate refractory symptoms, residual lesions, and complications at posttreatment assessment. Knowledge of surgical techniques and recognition of expected postoperative imaging findings are crucial to differentiate postoperative changes from residual disease and/or recurrence. The authors discuss imaging aspects of postoperative endometriosis, with an emphasis on the imaging approach, comprehension of surgical techniques, recognition of the expected findings, possible complications, and analysis of residual disease or recurrence. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material. See the invited commentary by VanBuren in this issue. The slide presentation from the RSNA Annual Meeting is available for this article.

Interobserver agreement of PI-RADS v. 2 lexicon among radiologists with different levels of experience.

BACKGROUND: Evaluation of interobserver agreement of the PI-RADS v2 lexicon is important to validate the uniformity of this widely used classification. PURPOSE: To determine the interobserver agreement of PI-RADS v2 lexicon among eight radiologists with varying levels of experience. STUDY TYPE: Retrospective. POPULATION: In all, 160 consecutively imaged men with confirmatory targeted biopsy. FIELD STRENGTH/SEQUENCE: 3T scanner without an endorectal coil. T2 -weighted imaging (T2 w), diffusion-weighted imaging (DWI), apparent diffusion coefficient (ADC) map and dynamic contrast-enhanced sequence were performed. ASSESSMENT: Eight radiologists (two highly experienced, two moderately experienced, and four less experienced) independently read 130 lesions in the peripheral zone (PZ) and 30 lesions in the transition zone (TZ), blinded to clinical MRI indication and biopsy results. The features described in PI-RADS v2 for TZ and PZ lesions were evaluated. STATISTICAL TESTS: Conger's kappa, percentage of concordance, and first-order agreement coefficient (AC1) were used to evaluate interobserver agreement. RESULTS: From the features evaluated on PZ lesions, definite extraprostatic extension (EPE) / invasive behavior on T2 w had good agreement (AC1 = 0.80), and the others had fair agreement (AC1 = 0.32-0.40). From the features evaluated on TZ lesions, two had good agreement: definite EPE/invasive behavior (AC1 = 0.77) and moderate/marked hypointensity (AC1 = 0.67) on T2 w. Encapsulation and lenticular shape on T2 w, focal (not indistinct) on DWI and ADC map, and marked hypointensity on ADC map (AC1 = 0.45 to 0.60) had moderate agreement, whereas heterogeneous and circumscribed (not obscured margins) on T2 w, marked hyperintensity on high-b-value DWI, and the presence or not of early enhancement in the lesion/region of the lesion (AC1 = 0.30 to 0.38) had fair agreement. DATA CONCLUSION: Interobserver agreement in PI-RADS v2 lexicon ranges from fair to good among radiologists and improves with increasing experience. LEVEL OF EVIDENCE: 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2020;51:593-602.

Renal Stone Features Are More Important Than Renal Anatomy to Predict Shock Wave Lithotripsy Outcomes: Results from a Prospective Study with CT Follow-Up.

Introduction: Lower pole kidney stones have been associated with poor shock wave lithotripsy (SWL) outcomes because of its location. However, the real impact of collecting system anatomy on stone clearance after SWL is uncertain. There is a lack of prospective well-controlled studies to determine whether lower pole kidney stones have inferior outcomes than nonlower pole kidney stones when treated with SWL. Methods: We prospectively evaluated patients with a single kidney stone of 5-15 mm undergoing SWL from June 12 through January 19. All patients were subjected to computed tomography before and 3 months after the procedure. Demographic data (age, gender, and body mass index), stone features (stone size, stone area, stone density, and stone-skin distance-SSD), and collecting system anatomy (infundibular length and width, and infundibulopelvic angle) were recorded. Outcomes (fragmentation and stone clearance rates) were compared between lower pole and nonlower pole cases. Then, a multivariate analysis including all variables was performed to determinate which parameters significantly impact on SWL outcomes. Results: One hundred and twenty patients were included in the study. Mean stone size was 8.3 mm and mean stone density was 805 Hounsfield units. Overall stone fragmentation, success, and stone-free rates were 84.1%, 64.1%, and 34.1%, respectively. There were no significant differences in stone fragmentation (76.0% vs 71.4%; p = 0.624), success rate (57.6% vs 53.3%; p = 0.435), and stone-free rate (40.2% vs 35.7%; p = 0.422) in the lower vs nonlower pole groups, respectively. On multivariate analysis, only stone density (p < 0.001) and SSD (p = 0.006) significantly influenced fragmentation. Stone size (p = 0.029), stone density (p = 0.002), and SSD (p = 0.049) significantly influenced kidney stone clearance. Conclusions: Stone size, stone density, and SSD impact on SWL outcomes. Lower pole kidney stones have similar fragmentation and stone clearance compared with nonlower pole kidney stones.

Malignancy Rate, Histologic Grade, and Progression of Bosniak Category III and IV Complex Renal Cystic Lesions.

OBJECTIVE: The primary purpose of this study is to determine the malignancy rate, histologic grade, and initial stage of surgically treated complex renal cysts classified as Bosniak category III or IV. For nonsurgical lesions, a secondary objective was to evaluate lesion progression on follow-up examinations. MATERIALS AND METHODS: We searched our database for cystic lesions classified as Bosniak III or IV category on CT or MRI from January 2008 to April 2016. Surgically resected lesions, per category, were correlated with information on pathologic reports to obtain malignancy rates. For malignant lesions, histologic grade and initial stage were evaluated. Imaging follow-up of at least 2 years was used to evaluate progression of clinically followed lesions. RESULTS: We included 86 lesions in 85 patients in the final analysis. Of the 60 surgically resected lesions (70%), 46 (77%) were malignant and 14 (23%) were benign. Malignancy rates were 72% for Bosniak category III lesions and 86% for Bosniak category IV lesions. Most malignant cysts were early-stage (pT1) cysts with low histologic grades (89% of Bosniak III lesions and 91% of Bosniak IV lesions). Follow-up studies of the surgically resected lesions did not show local recurrence, metastasis, or lymph node enlargement. Among patients with lesions managed by watchful waiting (n = 26), all lesions remained unchanged in terms of size and complexity after at least 2-years of follow-up. CONCLUSION: Although high malignancy rates were observed for both Bosniak category III and IV lesions, our results suggest that such malignant cysts are usually early-stage tumors with a low histologic grade. Lesions that underwent follow-up remained unchanged on control examinations. These findings may indicate low aggressiveness of these lesions, supporting the idea that more conservative approaches may be used.

Complete Calcified Ureteral Stent: A Combined 1-Session Approach.

OBJECTIVE: To demonstrate a successful 1-session approach to a complete calcified ureteral stent, preserving the affected kidney without complications. PATIENT AND METHODS: A 33-year-old man presented at our service with an increased urinary frequency, afebrile urinary tract infection, and left lumbar pain. He underwent a ureterolithotripsy with ureteral stenting 3 years ago. After that intervention, he was lost to follow-up. A noncontrast computed tomography scan revealed a complete calcified ureteral stent (FECal V). After careful preoperative planning, the patient was submitted to a combined 1-step approach including left semirigid ureteroscopy, left percutaneous nephrolithotomy, and an open cystolithotomy in supine decubitus. This video demonstrates the surgical steps of the procedure for a FECal V (completely calcified) stent removal. RESULTS: Operative time was 240 minutes. The calcified stent was completely removed. A 6 Fr ureteral catheter and a 16 Fr nephrostomy tube were left at the end of the procedure. No double-J stent was used to avoid the same kind of complication. The patient had no peri- or postoperative complications. A computed tomography scan was performed in the first postoperative day (POD) and revealed 2 small residual fragments (7 mm and 6 mm). The ureteral catheter was removed on the first POD, and the nephrostomy tube on the second POD. The patient was discharged from hospital on the third POD. The patient is now scheduled to a flexible ureteroscopy to treat the small residual fragments. CONCLUSION: Forgotten ureteral stent is a surgical challenge, requiring multiple approaches and advanced urologic techniques. Our video illustrates that a less invasive and combined 1-step procedure to preserve the kidney is both safe and feasible, when performed by an experienced surgeon.

Prostate cancer discrimination in the peripheral zone with a reduced field-of-view T(2)-mapping MRI sequence.

OBJECTIVES: To evaluate the performance of T2 mapping in discriminating prostate cancer from normal prostate tissue in the peripheral zone using a practical reduced field-of-view MRI sequence requiring less than 3 minutes of scan time. MATERIALS AND METHODS: Thirty-six patients with biopsy-proven peripheral zone prostate cancer without prior treatment underwent routine multiparametric MRI at 3.0T with an endorectal coil. An Inner-Volume Carr-Purcell-Meiboom-Gill imaging sequence that required 2.8 minutes to obtain data for quantitative T2 mapping covering the entire prostate gland was added to the routine multiparametric protocol. Suspected cancer (SC) and suspected healthy (SH) tissue in the peripheral zone were identified in consensus by three radiologists and were correlated with available biopsy results. Differences in mean T2 values in SC and SH regions-of-interest (ROIs) were tested for significance using unpaired Student's two-tailed t-test. The area under the receiver operating characteristic curve was used to assess the optimal threshold T2 value for cancer discrimination. RESULTS: ROI analyses revealed significantly (p<0.0001) shorter T2 values in SC (85.4±12.3ms) compared to SH (169.6±38.7ms). An estimated T2 threshold of 99ms yielded a sensitivity of 92% and a specificity of 97% for prostate cancer discrimination. CONCLUSIONS: Quantitative values derived from this clinically practical T2-mapping sequence allow high precision discrimination between healthy and cancerous peripheral zone in the prostate.

Impact of renal anatomy on shock wave lithotripsy outcomes for lower pole kidney stones: results of a prospective multifactorial analysis controlled by computerized tomography.

PURPOSE: We evaluated which variables impact fragmentation and clearance of lower pole calculi after shock wave lithotripsy. MATERIALS AND METHODS: We prospectively evaluated patients undergoing shock wave lithotripsy for a solitary 5 to 20 mm lower pole kidney stone between June 2012 and August 2014. Patient body mass index and abdominal waist circumference were recorded. One radiologist blinded to shock wave lithotripsy outcomes measured stone size, area and density, stone-to-skin distance, infundibular length, width and height, and infundibulopelvic angle based on baseline noncontrast computerized tomography. Fragmentation, success (defined as residual fragments less than 4 mm in asymptomatic patients) and the stone-free rate were evaluated by noncontrast computerized tomography 12 weeks postoperatively. Univariate and multivariate analysis was performed. RESULTS: A total of 100 patients were enrolled in the study. Mean stone size was 9.1 mm. Overall fragmentation, success and stone-free rates were 76%, 54% and 37%, respectively. On logistic regression body mass index (OR 1.27, 95% CI 1.11-1.49, p = 0.004) and stone density (OR 1.0026, 95% CI 1.0008-1.0046, p = 0.005) significantly impacted fragmentation. Stone size (OR 1.24, 95% CI 1.07-1.48, p = 0.039) and stone density (OR 1.0021, 95% CI 1.0007-1.0037, p = 0.012) impacted the success rate while stone size (OR 1.24, 95% CI 1.04-1.50, p = 0.029), stone density (OR 1.0015, 95% CI 1.0001-1.0032, p = 0.046) and infundibular length (OR 1.1035, 95% CI 1.015-1.217, p = 0.015) impacted the stone-free rate. The best outcomes were found in patients with a body mass index of 30 kg/m(2) or less, stones 10 mm or less and 900 HU or less, and an infundibular length of 25 mm or less. The coexistence of significant unfavorable variables led to a stone-free rate of less than 20%. CONCLUSIONS: Obese patients with higher than 10 mm density stones (greater than 900 HU) in the lower pole of the kidney with an infundibular length of greater than 25 mm should be discouraged from undergoing shock wave lithotripsy.

Multidetector CT evaluation of the postoperative pancreas.

Several pancreatic diseases may require surgical treatment, with most of these procedures classified as resection or drainage. Resection procedures, which are usually performed to remove pancreatic tumors, include pancreatoduodenectomy, central pancreatectomy, distal pancreatectomy, and total pancreatectomy. Drainage procedures are usually performed to treat chronic pancreatitis after the failure of medical therapy and include the Puestow and Frey procedures. The type of surgery depends not only on the patient's symptoms and the location of the disease, but also on the expertise of the surgeon. Radiologists should become familiar with these surgical procedures to better understand postoperative changes in anatomic findings. Multidetector computed tomography is the modality of choice for identifying normal findings after surgery, postoperative complications, and tumor recurrence in patients who have undergone pancreatic surgery.