Imaging protocols for renal multiparametric MRI and MR urography: results of a consensus conference from the French Society of Genitourinary Imaging.

OBJECTIVES: To develop technical guidelines for magnetic resonance imaging aimed at characterising renal masses (multiparametric magnetic resonance imaging, mpMRI) and at imaging the bladder and upper urinary tract (magnetic resonance urography, MRU). METHODS: The French Society of Genitourinary Imaging organised a Delphi consensus conference with a two-round Delphi survey followed by a face-to-face meeting. Two separate questionnaires were issued for renal mpMRI and for MRU. Consensus was strictly defined using a priori criteria. RESULTS: Forty-two expert uroradiologists completed both survey rounds with no attrition between the rounds. Fifty-six of 84 (67%) statements of the mpMRI questionnaire and 44/71 (62%) statements of the MRU questionnaire reached final consensus. For mpMRI, there was consensus that no injection of furosemide was needed and that the imaging protocol should include T2-weighted imaging, dual chemical shift imaging, diffusion-weighted imaging (use of multiple b-values; maximal b-value, 1000 s/mm2) and fat-saturated single-bolus multiphase (unenhanced, corticomedullary, nephrographic) contrast-enhanced imaging; late imaging (more than 10 min after injection) was judged optional. For MRU, the patients should void their bladder before the examination. The protocol must include T2-weighted imaging, anatomical fast T1/T2-weighted imaging, diffusion-weighted imaging (use of multiple b-values; maximal b-value, 1000 s/mm2) and fat-saturated single-bolus multiphase (unenhanced, corticomedullary, nephrographic, excretory) contrast-enhanced imaging. An intravenous injection of furosemide is mandatory before the injection of contrast medium. Heavily T2-weighted cholangiopancreatography-like imaging was judged optional. CONCLUSION: This expert-based consensus conference provides recommendations to standardise magnetic resonance imaging of kidneys, ureter and bladder. KEY POINTS: • Multiparametric magnetic resonance imaging (mpMRI) aims at characterising renal masses; magnetic resonance urography (MRU) aims at imaging the urinary bladder and the collecting systems. • For mpMRI, no injection of furosemide is needed. • For MRU, an intravenous injection of furosemide is mandatory before the injection of contrast medium; heavily T2-weighted cholangiopancreatography-like imaging is optional.

Imaging protocols for CT urography: results of a consensus conference from the French Society of Genitourinary Imaging.

OBJECTIVES: To develop technical guidelines for computed tomography urography. METHODS: The French Society of Genitourinary Imaging organised a Delphi consensus conference with a two-round Delphi survey followed by a face-to-face meeting. Consensus was strictly defined using a priori criteria. RESULTS: Forty-two expert uro-radiologists completed both survey rounds with no attrition between the rounds. Ninety-six (70%) of the initial 138 statements of the questionnaire achieved final consensus. An intravenous injection of 20 mg of furosemide before iodinated contrast medium injection was judged mandatory. Improving the quality of excretory phase imaging through oral or intravenous hydration of the patient or through the use of an abdominal compression device was not deemed necessary. The patient should be imaged in the supine position and placed in the prone position only at the radiologist's request. The choice between single-bolus and split-bolus protocols depends on the context, but split-bolus protocols should be favoured whenever possible to decrease patient irradiation. Repeated single-slice test acquisitions should not be performed to decide of the timing of excretory phase imaging; instead, excretory phase imaging should be performed 7 min after the injection of the contrast medium. The optimal combination of unenhanced, corticomedullary phase and nephrographic phase imaging depends on the context; suggestions of protocols are provided for eight different clinical situations. CONCLUSION: This expert-based consensus conference provides recommendations to standardise the imaging protocol for computed tomography urography. KEY POINTS: • To improve excretory phase imaging, an intravenous injection of furosemide should be performed before the injection of iodinated contrast medium. • Systematic oral or intravenous hydration is not necessary to improve excretory phase imaging. • The choice between single-bolus and split-bolus protocols depends on the context, but split-bolus protocols should be favoured whenever possible to decrease patient irradiation.

Endovascular treatment of juxta-anastomotic venous stenoses of forearm radiocephalic fistulas: long-term results and prognostic factors.

PURPOSE: To evaluate long-term results of endovascular procedures in treatment of venous juxta-anastomotic stenoses (JASs) of native forearm radiocephalic arteriovenous fistulas (AVFs) and to identify prognostic factors influencing these results. MATERIALS AND METHODS: During a 124-month period, 147 endovascular interventions were performed in 75 forearm radiocephalic AVFs with JASs defined as stenoses located within the first 5 cm of the outflow vein. Prognostic factors included patient characteristics (age, sex, diabetes), AVF-related characteristics (location on forearm, age, maturity), stenosis-related characteristics (position relative to anastomosis, length, and degree), and degree of residual stenosis and delay of restenosis after the first endovascular procedure. RESULTS: At 1 and 3 years, access primary patency (PP) rates were 46.6% (95% confidence interval [CI], 36.3%-59.9%) and 25.5% (95% CI, 15.7%-41.6%) and assisted PP (APP) rates were 81.3% (95% CI, 72.6%-91.1%) and 63.2% (95% CI, 50.6%-79.0%), respectively. Stenosis degree of 50%-75% (P = .017), stenosis length of 10 mm or more (P = .017), and time before first restenosis of less than 6 months (P = .03) significantly increased the frequency of endovascular procedures during follow-up. However, only the degree of residual stenosis after the first endovascular treatment significantly affected long-term APP (P = .039). When residual stenosis was less than 50%, 1- and 2-year access APP rates were 84.6% (95% CI, 75.8%-94.4%) and 76.1% (95% CI, 64.6%-89.6%), respectively. When it was at least 50%, the respective APP rates were 62.3% (95% CI, 38.9%-99.9%) and 46.8% (95% CI, 22.4%-97.7%). CONCLUSIONS: Endovascular treatment of JASs in forearm radiocephalic AVFs provides good long-term results except when the residual stenosis after the first procedure is 50% or more. In that case, the optimal treatment remains to be determined.

Is it possible to model the risk of malignancy of focal abnormalities found at prostate multiparametric MRI?

OBJECTIVE: To evaluate whether focal abnormalities (FAs) depicted by prostate MRI could be characterised using simple semiological features. METHODS: 134 patients who underwent T2-weighted, diffusion-weighted and dynamic contrast-enhanced MRI at 1.5 T before prostate biopsy were prospectively included. FAs visible at MRI were characterised by their shape, the degree of signal abnormality (0 = normal to 3 = markedly abnormal) on individual MR sequences, and a subjective score (SS(1) = probably benign to SS(3) = probably malignant). FAs were then biopsied under US guidance. RESULTS: 56/233 FAs were positive at biopsy. The subjective score significantly predicted biopsy results (P < 0.01). As compared to SS(1) FAs, the odds ratios (OR) of malignancy of SS(2) and SS(3) FAs were 9.9 (1.8-55.9) and 163.8 (11.5-2331). Unlike FAs' shape, a simple combination of MR signal abnormalities (into "low-risk", "intermediate" and "high-risk" groups) significantly predicted biopsy results (P < 0.008). As compared to "low risk" FAs, the OR of malignancy of "intermediate" and "high-risk" FAs were 4.5 (1.1-18.4) and 52.7 (6.8-407) in the overall population and 5.4 (1.1-27.2) and 118.2 (6.1-2301) in PZ. CONCLUSIONS: A simple combination of signal abnormalities of individual MR sequences can significantly stratify the risk of malignancy of FAs, holding promise of a more standardised interpretation of MRI by readers with varying experience. KEY POINTS: • Using multiparameter(mp)-MRI, experienced uroradiologists can stratify the malignancy risk of prostatic lesions • The shape of prostatic focal abnormalities in the peripheral zone does not help predicting malignancy. • A simple combination of findings at mp-MRI can help less-experienced radiologists.

Prostate cancer ablation with transrectal high-intensity focused ultrasound: assessment of tissue destruction with contrast-enhanced US.

PURPOSE: To assess contrast material-enhanced ultrasonographic (US) findings seen after high-intensity focused ultrasound (HIFU) ablation of prostate cancer and correlate the US findings with post-HIFU biopsy findings. MATERIALS AND METHODS: The study was ethics committee approved. Written informed consent was obtained from all patients. Twenty-eight patients referred for HIFU prostate cancer ablation underwent contrast-enhanced prostate US before treatment, gadolinium-enhanced magnetic resonance (MR) imaging and repeat contrast-enhanced US 1-3 days after treatment, and contrast-enhanced US-guided biopsy 30-45 days after treatment. The contrast-enhanced US enhancement patterns of the biopsy sites--assigned a score of S0 for no enhancement, S1 for mild and/or patchy enhancement, or S2 for marked enhancement--were compared with corresponding biopsy findings, which were assigned a score of B0 for necrosis and/or fibrosis without viable prostate gland tissue, B1 for vascularized tissue without viable gland tissue, or B2 for viable gland tissue (benign or malignant). Then, six additional patients underwent contrast-enhanced prostate US 15-30 minutes and 1 day after HIFU ablation, and the results of these two US examinations were compared. RESULTS: Contrast-enhanced US performed on days 1-3 and days 30-45 after HIFU ablation depicted a large devascularized zone with peripheral enhancing areas that were localized anteriorly in all 28 patients, posteriorly in nine, laterally in five, and at the apex in 20 patients. MR findings were concordant. At biopsy, viable gland tissue was found at nine (6.2%) of 146 S0 sites, 10 (34%) of 29 S1 sites, and 44 (60%) of 73 S2 sites. The odds ratios for finding viable tissue (score B1 or B2) at S1 and S2 sites as opposed to S0 sites were 21 (95% confidence interval [CI]: 6, 71) and 73 (95% CI: 22, 243), respectively (P < .0001). Contrast-enhanced US performed 15-30 minutes and 1 day after treatment in the six additional patients had similar findings. CONCLUSION: Contrast-enhanced US is a promising tool for distinguishing between ablated (devascularized) and viable (enhancing) tissue immediately after HIFU treatment.

Location of residual cancer after transrectal high-intensity focused ultrasound ablation for clinically localized prostate cancer.

UNLABELLED: What's known on the subject ? and What does the study add? Transrectal High-Intensity Focused Ultrasound (HIFU) ablation has been used as a minimally invasive treatment for localized prostate cancer for 15 years. Five-year disease-free survival rates of 66-78% have been reported, challenging the results of external-beam radiation therapy. Usually, a 6-mm safety margin is used in the apex to preserve the urinary sphincter and potency. The influence of this 6-mm margin on the results of the treatment has never been assessed. This retrospective study of a cohort of 99 patients who underwent systematic biopsy 3-6 months after HIFU ablation for prostate cancer (with a 6-mm safety margin in the apex) shows that post-HIFU residual cancer is found more frequently in the apex. Therefore, new strategies improving the prostate destruction at the apex while preserving the urinary continence need to be found. OBJECTIVE: • To evaluate whether the location (apex/midgland/base) of prostate cancer influences the risk of incomplete transrectal high-intensity focused ultrasonography (HIFU) ablation. PATIENTS AND METHODS: • We retrospectively studied 99 patients who underwent prostate cancer HIFU ablation (Ablatherm; EDAP, Vaulx-en-Velin, France) with a 6-mm safety margin at the apex, and had systematic biopsies 3-6 months after treatment. • Locations of positive pre- and post-HIFU sextants were compared. • The present study included two analyses. First, sextants negative before and positive after treatment were recoded as positive/positive, hypothesizing that cancer had been missed at pretreatment biopsy. Second, patients with such sextants were excluded. RESULTS: • Pre-HIFU biopsies found cancer in all patients and in 215/594 sextants (36.2%); 55 (25.6%) positive sextants were in the apex, 86 (40%) in the midgland and 74 (34.4%) in the base. • After treatment, residual cancer was found in 36 patients (36.4%) and 50 sextants (8.4%); 30 (60%) positive sextants were in the apex, 12 (24%) in the midgland and eight (16%) in the base. • Both statistical analyses found that the locations of the positive sextants before and after HIFU ablation were significantly different (P < 0.001), with a higher proportion of positive apical sextants after treatment. • At the first analysis, the mean (95% confidence interval) probability for a sextant to remain positive after HIFU ablation was 8.8% (3.5-20.3%) in the base, 12.7% (5.8-25.9%) in the midgland and 41.7% (27.2-57.89%) in the apex. • At the second analysis, these same probabilities were 5.9% (1.9-17%), 9.9% (3.9-23.2%) and 27.3% (13.7-47%), respectively. CONCLUSION: • When a 6-mm apical safety margin is used, residual cancer after HIFU ablation is found significantly more frequently in the apex.

Teleradiology as a relevant indicator of the impact of COVID-19 pandemic management on emergency room activities: a nationwide worrisome survey.

OBJECTIVES: To evaluate the impact of COVID-19's lockdown on radiological examinations in emergency services. METHODS: Retrospective, multicentre analysis of radiological examinations requested, via our teleradiology network, from 2017 to 2020 during two timeframes (calendar weeks 5-8 and then 12-15). We included CT scans or MRIs performed for strokes, multiple traumas (Body-CT), cranial traumas (CTr) and acute non-traumatic abdominal pain (ANTAP). We evaluated the number and percentages of examinations performed, of those with a pathological conclusion, and of examinations involving the chest. RESULTS: Our study included 25 centres in 2017, 29 in 2018, 43 in 2019 and 59 in 2020. From 2017 to 2019, the percentages of examinations were constant, which was also true for chest CTs. Each centre's number of examinations, gender distribution and patient ages were unchanged. In 2020, examinations significantly decreased: suspected strokes decreased by 36% (1052 vs 675, p < 0.001), Body-CT by 62% (349 vs 134, p < 0.001), CTr by 52% (1853 vs 895, p < 0.001) and for ANTAP, appendicitis decreased by 38% (45 vs 90, not statistically significant (NS)) sigmoiditis by 44% (98 vs 55, NS), and renal colic by 23% (376 vs 288, NS). The number of examinations per centre decreased by 13% (185.5 vs 162.5, p < 0.001), whereas the number of examinations of the "chest" region increased by 170% (1205 vs 3766, p < 0.001). CONCLUSION: Teleradiology enabled us to monitor the impact of the COVID-19 pandemic management on emergency activities, showing a global decrease in the population's use of care.

Prostate cancer transrectal HIFU ablation: detection of local recurrences using T2-weighted and dynamic contrast-enhanced MRI.

The objective was to evaluate T2-weighted (T2w) and dynamic contrast-enhanced (DCE) MRI in detecting local cancer recurrences after prostate high-intensity focused ultrasound (HIFU) ablation. Fifty-nine patients with biochemical recurrence after prostate HIFU ablation underwent T2-weighted and DCE MRI before transrectal biopsy. For each patient, biopsies were performed by two operators: operator 1 (blinded to MR results) performed random and colour Doppler-guided biopsies ("routine biopsies"); operator 2 obtained up to three cores per suspicious lesion on MRI ("targeted biopsies"). Seventy-seven suspicious lesions were detected on DCE images (n = 52), T2w images (n = 2) or both (n = 23). Forty patients and 41 MR lesions were positive at biopsy. Of the 36 remaining MR lesions, 20 contained viable benign glands. Targeted biopsy detected more cancers than routine biopsy (36 versus 27 patients, p = 0.0523). The mean percentages of positive cores per patient and of tumour invasion of the cores were significantly higher for targeted biopsies (p < 0.0001). The odds ratios of the probability of finding viable cancer and viable prostate tissue (benign or malignant) at targeted versus routine biopsy were respectively 3.35 (95% CI 3.05-3.64) and 1.38 (95% CI 1.13-1.63). MRI combining T2-weighted and DCE images is a promising method for guiding post-HIFU biopsy towards areas containing recurrent cancer and viable prostate tissue.

Evaluation of T2-weighted and dynamic contrast-enhanced MRI in localizing prostate cancer before repeat biopsy.

We assessed the accuracy of T2-weighted (T2w) and dynamic contrast-enhanced (DCE) 1.5-T magnetic resonance imaging (MRI) in localizing prostate cancer before transrectal ultrasound-guided repeat biopsy. Ninety-three patients with abnormal PSA level and negative prostate biopsy underwent T2w and DCE prostate MRI using pelvic coil before repeat biopsy. T2w and DCE images were interpreted using visual criteria only. MR results were correlated with repeat biopsy findings in ten prostate sectors. Repeat biopsy found prostate cancer in 23 patients (24.7%) and 44 sectors (6.6%). At per patient analysis, the sensitivity, specificity, positive and negative predictive values were 47.8%, 44.3%, 20.4% and 79.5% for T2w imaging and 82.6%, 20%, 24.4% and 93.3% for DCE imaging. When all suspicious areas (on T2w or DCE imaging) were taken into account, a sensitivity of 82.6% and a negative predictive value of 100% could be achieved. At per sector analysis, DCE imaging was significantly less specific (83.5% vs. 89.7%, p < 0.002) than T2w imaging; it was more sensitive (52.4% vs. 32.1%), but the difference was hardly significant (p = 0.09). T2w and DCE MRI using pelvic coil and visual diagnostic criteria can guide prostate repeat biopsy, with a good sensitivity and NPV.

Prostate dynamic contrast-enhanced MRI with simple visual diagnostic criteria: is it reasonable?

UNLABELLED: The purpose of this study was to evaluate the accuracy of prostate cancer localization with simple visual diagnostic criteria using dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI). A total of 46 consecutive patients with biopsy-proven prostate cancer underwent prostate 1.5 T MRI with pelvic phased-array coils before prostatectomy. Besides the usual T2-weighted sequences, a 30-s DCE sequence was acquired three times after gadoterate injection. On DCE images, all early enhancing lesions of the peripheral zone were considered malignant. In the central gland, only early enhancing lesions appearing homogeneous or invading the peripheral zone were considered malignant. Three readers specified the presence of cancer in 20 prostate sectors and the location of distinct tumors. Results were compared with histology; p < 0.05 was considered significant. For localization of cancer in the sectors, DCE imaging had a significantly higher sensitivity [logistic regression, odds ratio (OR): 3.9, p < 0.0001] and a slightly but significantly lower specificity (OR: 0.57, p < 0.0001). Of the tumors >0.3 cc, 50-60% and 78-81% were correctly depicted with T2-weighted and DCE imaging, respectively. For both techniques, the depiction rate of tumors >0.3 cc was significantly influenced by the Gleason score (most Gleason