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Purpose: To evaluate if subgroups of patients assigned to MRI category PI-RADS 4 regarding clinical and MRI imaging aspects have distinct risks of prostate cancer (PCa) to facilitate adequate clinical management of this population, especially after negative targeted biopsy.Methods: This prospective, IRB approved single center cross-sectional study includes 931 consecutive patients after mp-MRI at 3 T for PCa detection. 193 patients with PI-RADS assessment category 4 received subsequent combined targeted MRI/US fusion-guided and systematic 12-core TRUS-guided biopsy as reference standard and were finally analyzed. The primary endpoint was PCa detection of PI-RADS 4 with MRI subgroup analyses. Secondary endpoints were analyses of clinical data, location of PCa, and detection of targeted biopsy cores.Results: PCa was detected in 119 of 193 patients (62%) including clinically significant PCa (csPCa; Gleason score ≥3 + 4 = 7) in 92 patients (48%). MRI subgroup analysis revealed 95% PCa (73% csPCa) in unambiguous PI-RADS 4 index lesions without additional, interfering signs of prostatitis in the peripheral zone or overlaying signs of severe stromal hyperplasia in the transition zone according to PI-RADS v2. Transition zone confined PI-RADS-4-lesions with overlaying signs of stromal hyperplasia showed PCa only in 11% (4% csPCa). Targeted biopsy cores missed the csPCa index lesion in 7% of the patients. PSA density (PSAD) was significantly higher in PCa patients.Conclusions: Small csPCa can reliably be detected with mp-MRI by experienced readers, but can be missed by targeted MR/US fusion biopsy alone. Targeted re-biopsy of unambiguous (peripheral) PI-RADS-4-lesions is recommended; whereas transition zone confined PI-RADS-4-lesions with overlaying signs of stromal hyperplasia might be followed-up by re-MRI primarily. [ABSTRACT FROM AUTHOR]

Purpose: This study investigates preoperative lymph node metastases (LNM) detection accuracy by MRI and CT in patients with prostate cancer (PCA).Methods: All patients with preoperative MRI, CT or both and subsequent radical prostatectomy (RPE) and lymphadenectomy (LA) were included in this retrospective cohort study. Prostate specific antigen (PSA), PI-RADS, ISUP grade group, clinical and pathological tumor (T) stage was compared between negative and positive nodal (N) stage. LNM were assessed with size and localization and weather they were preoperatively detected or not. In patients with preoperative CT and MRI, the results were compared intermodally. The reference standard was the histopathological results after RPE and LA.Results: A total of 228 patients were analysed including 24 patients with confirmed LNM (N1; 11%). PSA (median 9.7 vs. 14 ng/ml), PI-RADS (median 4 vs. 5), ISUP (median 2 vs. 4), and cT/pT-stage (median T2 vs. T3) was significantly higher in patients with LNM. No LNM were found in patients with ISUP-1-PCA. MRI was able to detect 67% of patients with LNM. Lymph node metastases presented on MRI predominantly small, round-shaped, located parailiacally with a minimum SAD of 4 mm (vs. CT SAD of 8 mm). In comparison, MRI was superior to CT in the detection of LNM (sensitivity 81% vs. 33%; specificity 99% vs. 97).Conclusion: LNM were very rare in patients with PSA < 10 ng/ml, PI-RADS ≤ 4, and ≤ cT2. MRI could detect LNM up to 4 mm with a moderate sensitivity and high specificity. Thus, MRI might optimise the preoperative diagnostic and therapy planning of patients with PCA, whereas CT was clearly limited for N-stage assessment. [ABSTRACT FROM AUTHOR]

Objectives: This study evaluates cases with clinically significant prostate cancer (csPCa) missed by targeted biopsy (TB) and analyzes the diagnostic impact of an additional systematic biopsy (SB) in a large patient collective.Methods: Consecutive patients with a 3 T multiparametric prostate MRI (mpMRI) and a subsequent MRI/US fusion-guided TB plus 12-core US-guided SB from 01/2014 to 04/2019 were included in this study. Primary study endpoint was the analysis of cases with a csPCa missed by TB and detected by SB. Secondary study objectives were the PCa detection and the correlation with clinical and MRI parameters.Results: In total 785 patients met the inclusion criteria. 342 patients had a csPCa (median PSAD 0.29 ng/mL/cm3). In 42 patients (13 %), a csPCa was detected only by SB. In 36 of these cases, the localization of the positive SB cores matched with the cancer suspicious region described on mpMRI (mCSR). Cases with a csPCA missed by TB showed either an insufficient MRI segmentation (prostate boundary correlation) (31 %) and/or insufficient lesion registration (lesion transfer, tracking, and/or matching) (48 %), a missed small lesion (14 %), or a failed center of a large lesion (10 %). Median PSAD of patients with non-significant PCa detected by SB was 0.15 ng/mL/cm3.Conclusions: Main reasons for missing a csPCa by TB were insufficient prostate segmentation or imprecise lesion registration within MRI/US fusion-guided biopsy. Consequently, verification of MRI quality, exact mCSR assessment, and advanced biopsy experience may improve accuracy. Altogether, an additional SB adds limited clinical benefit in men with PSAD ≤ 0.15 ng/mL/cm3. [ABSTRACT FROM AUTHOR]

Diffusion weighted imaging (DWI) is the most important sequence for detection and grading prostate cancer (PCa), but it is considerably prone to artifacts. New approaches like zoomed single-shot imaging (z-EPI) with advanced image processing or multi-shot readout segmentation (rs-EPI) try to improve DWI quality. This study evaluates objective and subjective image quality (IQ) of rs-EPI and z-EPI with and without advanced processing. Fifty-six consecutive patients (67 ± 8 years; median PSA 8.3 ng/ml) with mp-MRI performed at 3 Tesla between February and October 2019 and subsequently verified PCa by targeted plus systematic MRI/US-fusion biopsy were included in this retrospective single center cohort study. Rs - EPI and z-EPI were prospectively acquired in every patient. Signal intensities (SI) of PCa and benign tissue in ADC, b1000, and calculated high b-value images were analyzed. Endpoints were signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), PCa contrast intensity (CI), and subjective IQ on a 5-point scale evaluated by three blinded readers. Wilcoxon signed rank test, Friedman test and Cohen's kappa coefficient was calculated. SNR, CNR, and PCa CI of z-EPI with and without advanced processing was superior to rs-EPI (p < 0.01), whereas no significant differences were observed between z-EPI with and without advanced processing. Subjective IQ was significantly higher for z-EPI with advanced processing compared rs-EPI for ADC, b1000, and calculated high b-values (p < 0.01). Compared to z-EPI without advanced processing, z-EPI with advanced processing was superior for ADC and calculated high b-values (p < 0.01), but no significant differences were shown for b1000 images. Z -EPI with and without advanced processing was superior to rs-EPI regarding objective imaging parameters and z-EPI with advanced processing was superior to rs-EPI regarding subjective imaging parameters for the detection of PCa. [ABSTRACT FROM AUTHOR]

To determine the capability of Gadolinium-free arterial spin labelling (ASL) sequences as novel, contrast-free, non-invasive alternative perfusion imaging method to differentiate prostate cancer (PCA) from benign prostate tissue compared to conventional DCE MRI. Thirty men with histologically confirmed PCA were included in this prospectively enrolled single center cohort study. All patients received multiparametric MRI (T2, DWI, DCE) at 3 T with additional ASL of the PCA lesion. Primary endpoint was differentiability of PCA versus benign prostate tissue by signal intensities (SI) and contrast ratios (CR) in ASL in comparison to DCE. For DCE also Signal-Enhancement-Ratio (SER) of native and early contrast enhancement SI was assessed. Secondary objectives were differences regarding PCA localisation in peripheral (PZ) or transition zone (TZ) and PCA detection. In both, ASL and DCE, average SI of PCA differed significantly from SI in benign tissue in the TZ and PZ (p < 0,01, respectively). ASL had significantly higher CR discerning PCA and benign tissue in PZ and TZ (PZ = 5.19; TZ = 6.45) compared to DCE SI (PZ = 1.61; TZ = 1.43) and DCE SER (PZ = 1.59; TZ = 1.43) (p < 0.01, respectively). In subjective evaluation, PCA could be detected in ASL in 28 patients, compared to 29 in DCE. ASL had significantly higher CR differentiating PCA from benign tissue in PZ and TZ compared to DCE. Visual detection of PCA does not differ significantly between the two sequences. As perfusion gadolinium-based contrast media is seen more critical in the last few years, ASL seems to be a promising alternative to DCE in PCA detection. [ABSTRACT FROM AUTHOR]

Abstract Purpose Reproducibility of quantitative perfusion analysis of DCE requires a standardized AIF acquisition. However, there are many different approaches for AIF assessment so that the absolute values of perfusion parameters may vary depending on the used method. This study analyzes the influence of the method of AIF determination on quantitative DCE-MRI. Methods In this retrospective, single-center, cohort study three different methods of AIF determination in 50 consecutive patients with multiparametric MRI of the prostate were conducted. As a reference, AIF was selected manually by defining a region of interest in an artery manually (AIF m). The second method (AIF a), based on an automated algorithm and the third, population-derived AIF p where then compared. Primary endpoint were differences in the performance of the perfusion parameters Ktrans, ve and k ep regarding the AIF acquisition methods, secondary endpoints consisted of the evaluation of differences in the peripheral and transition zone of the prostate (PZ, TZ). Results In all three methods, Ktrans, ve , and k ep were significantly higher in PZ than in TZ with Ktrans showing least overlapping. There were no significant differences for Ktrans determined with AIF m and AIF a (0.3 ± 0.2 min−1 for PZ for both and 0.5 ± 0.3 min−1 for TZ in AIF m and 0.4 ± 0.3 min−1 in AIF a), while there were great differences between AIF a and AIF p and AIF m and AIF p (0.1 ± 0.03 min−1 for TZ and PZ in AIF p). Spearman test demonstrated good correlation of values for Ktrans and k ep in all 3 methods (ρ ≥ 0.76). AIF a showed a success rate of 98% in finding the artery. Conclusion AIF a is a recommendable user-independent automatical method to determine quantitative perfusion parameters allowing an objective measurement and saving interactive time for the radiologist. AIF p may be applied as second alternative method. [ABSTRACT FROM AUTHOR]

Objectives: This study prospectively evaluates objective image quality (IQ), subjective IQ, and PI-RADS scoring of prostate MRI at 3.0T (3T) and 1.5T (1.5T) within the same patients.Methods: Sixty-three consecutive patients (64±9years) were prospectively included in this non-inferiority trial, powered at 80% to demonstrate a ≤10% difference in signal-to-noise (SNR) and contrast-to-noise ratio (CNR) of T2-weighted and diffusion-weighted imaging (T2WI, DWI) at 1.5T compared to 3T. Secondary endpoints were analysis of subjective IQ and PI-RADS v2 scoring.Results: All patients received multi-parametric prostate MRI on a 3T (T2WI, DWI, DCE) and bi-parametric MRI (T2WI, DWI) on a 1.5T scanner using body coils, respectively. SNR and CNR of T2WI were similar at 1.5T and 3T (p=0.7-1), but of DWI significantly lower at 1.5T (p<0.01). Subjective IQ was significantly better at 3T for both, T2WI and DWI (p<0.01). PI-RADS scores were comparable for both field strengths (p=0.05-1). Inter-reader agreement was excellent for subjective IQ assessment and PI-RADS scoring (k=0.9-1).Conclusion: Prostate MRI at 1.5T can reveal comparable objective image quality in T2WI, but is inferior to 3T in DWI and subjective IQ. However, similar PI-RADS scoring and thus diagnostic performance seems feasible independent of the field strength even without an endorectal coil. [ABSTRACT FROM AUTHOR]

Purpose: This study analyzes the value of dynamic contrast-enhanced MRI (DCE) of the prostate on 1.5 T and 3 T examinations in patients within PI-RADS category 4.Methods: In this retrospective, bi-centric, cohort study all consecutive patients classified as PI-RADS 4 in mpMRI with 100 verified prostate cancers (PCa) in subsequent MRI/US-guided fusion biopsy were included for 1.5 T and 3 T, each. PCa detection in index lesions (IL) upgraded to PI-RADS 4 based on positive DCE findings was compared between 1.5 T and 3 T. Secondary objectives are subgroup analysis of PZ lesions and comparison of ISUP grade group distribution between 1.5 T and 3 T.Results: In total, 293 patients within PI-RADS category 4, including 152 (mean 66 ± 8y; median PSA 6.4 ng/ml;116 PZ IL) in the 1.5 T group and 141 (mean 65 ± 8y; median PSA 7.2 ng/ml;100 PZ IL) in the 3 T group were included. Overall amount of PCa (66 % vs 71 %; p = 0.346) and portion of upgraded IL (28 % vs 21 %; p = 0.126) did not differ significantly. At 1.5 T PCa detection was higher in upgraded PZ lesions compared to 3 T (23 % vs 14 %; p = 0.048). The amount of upgraded PZ lesions with ISUP grade group 2-5 PCa was significantly higher at 1.5 T versus 3 T (13.8 % vs 4.0 %; p = 0.007). 33 % (11/33; 1.5 T) and 32 % (10/31; 3 T) of the ISUP grade group 1 PCa of the PZ lesions were detected in upgraded lesions (10% of all PZ index lesions, respectively).Conclusion: DCE enabled the detection of a substantial amount of additional clinically significant PCa in prostate mpMRI at 1.5 T. The effect was smaller at 3 T and was accompanied in relation to 1.5 T by higher risk of overdiagnosis due to detection of additional low-risk PCa. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate image quality and diagnostic value of multiparametric prostate MRI (mpMRI) in patients with total hip replacement (THR) at 1.5 and 3 Tesla.Methods: In this retrospective multicenter cohort study patients with uni- or bilateral THR and 1.5 T or 3 T mpMRI were included. Seventy consecutive, standard-of-care examinations per field strength were evaluated regarding their diagnostic value. The overall diagnostic value and prostate imaging quality score (PI-QUAL) were assessed. Artifact severity in the localizer and mpMRI sequences (T2w, DWI, DCE) was scored on a 3-point scale. Correlation between diagnostic value and artifacts was analysed. Moreover, a subgroup analysis focussed on image quality at different 3 T scanner generations.Results: 140 consecutive patients (mean age 72, median PSA value 8.3 ng/ml) were included. When comparing 1.5 T to 3 T examinations, no significant differences were observed regarding the artifact severity of DWI and the localizer and the overall diagnostic value of the images. There was a strong correlation between the diagnostic value, PI-QUAL score, and artifact severity in the localizer and DWI. T2w and DCE sequences showed overall low artifacts. Significant improvement in image quality for 3 T at the latest scanner generation was observed, especially for DWI (p < 0.03).Conclusions: MpMRI of patients with THR can be conducted at both field strengths without significant differences in artifacts. The localizer might be useful as an early forecasting feature for diagnostic value and particularly for contrast medium application decision. Patients with THR could benefit from technically advanced scanner generation and rs/ptx-EPI DWI sequences. [ABSTRACT FROM AUTHOR]

Objectives: To compare prostate specific membrane antigen (PSMA) Positron Emission Tomography/Computed Tomography (PET/CT) and computed tomography (CT) alone for the detection of biochemical recurrence of prostate cancer (PCa) and effect on treatment.Methods: This retrospective study included 59 patients with recently recorded biochemical recurrence of PCa (mean PSA 1.96 ± 1.64 ng/mL) after radical prostatectomy. Patients received PET/CT with either 68Ga-PSMA-11 (n = 36) or 18F-PSMA-1007 (n = 23). PET/CT and CT images were evaluated separately in regard to PCa lesion count, type, and localisation by two physicians. Histopathology, follow-up imaging and PSA levels after salvage irradiation served as reference standard. A McNemar test was used to compare detection rates. Changes in therapeutic approaches based on staging differences between CT alone and PET/CT were assessed in a virtual multidisciplinary tumour board.Results: There were 142 lesions in 50 of 59 patients. PSMA PET/CT detected 141 lesions (99.3 %) in 50 patients (84.7 %), while CT detected 72 lesions (50.7 %) in 29 patients (49.2 %). A significantly higher detection rate of PSMA PET/CT was observed on a lesion-based analysis (p < 0.0001) and on a patient based analysis (p < 0.0001). Herein, both 68Ga- and 18F-PSMA PET/CT performed significantly better than CT alone (p < 0.0001, respectively). In 9 patients (15.3 %) no relapse was detectable by either modality. All lesions detected by CT were also detected by PSMA PET/CT. In 38 patients PSMA PET/CT detected more lesions than CT alone, altering the treatment approach in 22 of these patients.Conclusion: PSMA PET/CT is superior to CT alone in detecting biochemical recurrence in PCa patients after radical prostatectomy and offered additional therapeutic options in a substantial number of patients. [ABSTRACT FROM AUTHOR]

Purpose: This study evaluates objective and subjective image quality (IQ) of three different diffusion weighted imaging (DWI) sequences in prostate MRI at 3.0 Tesla within the same patients.Method: Thirty-six consecutive patients (70 ± 8 years) with multi-parametric prostate MRI (mp-MRI; 3 T) and subsequently verified prostate cancer (PCa) by targeted plus systematic MR/US-fusion biopsy from 03/2016 to 12/2017 were included. Readout-segmented (rs) multi shot echo-planar imaging (EPI), parallel transmit (ptx) EPI, and single-shot (ss) EPI with b-values of 0, (500,) 1,000 s/mm² and calculated b1,500 were prospectively acquired of every patient. Signal intensities (SI) of PCa and benign tissue (peripheral and transition zone; PZ and TZ) in ADC, b1,000, and calculated b1,500 images were analyzed. Endpoints were signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and subjective IQ on a 5-point scale by two blinded readers.Results: For ss-EPI ADC, b-values of 1,000, and calculated 1,500 s/mm² images showed a higher SNR compared to rs-EPI and ptx-EPI (p < 0.01). CNR of PCa and benign tissue was significantly higher for rs-EPI in high b value images compared to ptx-EPI and ss-EPI (p < 0.01). Subjective IQ was significantly higher for rs-EPI (p < 0.01). Significantly higher ADC reduction combined with signal increase on high b value images for PCa compared to the surrounding healthy tissue in PZ and TZ (PCa contrast intensity) was detected for rs-EPI (p < 0.01). Single PCa lesions could only be recognized and correlated on rs-EPI.Conclusions: Rs-EPI and ptx-EPI were superior to ss-EPI regarding contrast intensity of PCA, but inferior regarding SNR. Subjective imaging parameters were superior for rs-EPI. Especially rs-EPI, but also ptx-EPI might improve and faciliate prostate cancer detection, rs-EPI at the expense of a longer acquisition time. [ABSTRACT FROM AUTHOR]