Inflammation appears as high Prostate Imaging-Reporting and Data System scores on prostate magnetic resonance imaging (MRI) leading to false positive MRI fusion biopsy

Quantitative Multi-Parametric MRI of the Prostate Reveals Racial Differences

Purpose: This study investigates whether quantitative MRI and histology of the prostate reveal differences between races, specifically African Americans (AAs) and Caucasian Americans (CAs), that can affect diagnosis. Materials and Methods: Patients (98 CAs, 47 AAs) with known or suspected prostate cancer (PCa) underwent 3T MRI (T2W, DWI, and DCE-MRI) prior to biopsy or prostatectomy. Quantitative mpMRI metrics: ADC, T2, and DCE empirical mathematical model parameters were calculated. Results: AAs had a greater percentage of higher Gleason-grade lesions compared to CAs. There were no significant differences in the quantitative ADC and T2 values between AAs and CAs. The cancer signal enhancement rate (α) on DCE-MRI was significantly higher for AAs compared to CAs (AAs: 13.3 ± 9.3 vs. CAs: 6.1 ± 4.7 s-1, p < 0.001). The DCE signal washout rate (β) was significantly lower in benign tissue of AAs (AAs: 0.01 ± 0.09 s-1 vs. CAs: 0.07 ± 0.07 s-1, p < 0.001) and significantly elevated in cancer tissue in AAs (AAs: 0.12 ± 0.07 s-1 vs. CAs: 0.07 ± 0.08 s-1, p = 0.02). DCE significantly improves the differentiation of PCa from benign in AAs (α: 52%, β: 62% more effective in AAs compared to CAs). Histologic analysis showed cancers have a greater proportion (p = 0.04) of epithelium (50.9 ± 12.3 vs. 44.7 ± 12.8%) and lower lumen (10.5 ± 6.9 vs. 16.2 ± 6.8%) in CAs compared to AAs. Conclusions: This study shows that AAs have different quantitative DCE-MRI values for benign prostate and prostate cancer and different histologic makeup in PCa compared to CAs. Quantitative DCE-MRI can significantly improve the performance of MRI for PCa diagnosis in African Americans but is much less effective for Caucasian Americans.

Prostate MRI for the detection of clinically significant prostate cancer: Update and future directions

PURPOSE OF REVIEW

In recent decades, there has been an increasing role for magnetic resonance imaging (MRI) in the detection of clinically significant prostate cancer (csPC). The purpose of this review is to provide an update and outline future directions for the role of MRI in the detection of csPC.

RECENT FINDINGS

In diagnosing clinically significant prostate cancer pre-biopsy, advances include our understanding of MRI-targeted biopsy, the role of biparametric MRI (non-contrast) and changing indications, for example the role of MRI in screening for prostate cancer. Furthermore, the role of MRI in identifying csPC is maturing, with emphasis on standardization of MRI reporting in active surveillance (PRECISE), clinical staging (EPE grading, MET-RADS-P) and recurrent disease (PI-RR, PI-FAB). Future directions of prostate MRI in detecting csPC include quality improvement, artificial intelligence and radiomics, positron emission tomography (PET)/MRI and MRI-directed therapy.

SUMMARY

The utility of MRI in detecting csPC has been demonstrated in many clinical scenarios, initially from simply diagnosing csPC pre-biopsy, now to screening, active surveillance, clinical staging, and detection of recurrent disease. Continued efforts should be undertaken not only to emphasize the reporting of prostate MRI quality, but to standardize reporting according to the appropriate clinical setting.

Multiparametric MRI characteristics of prostatitis and atrophy in the peripheral zone in men without prostate cancer

PURPOSE

To analyse multiparametric magnetic resonance imaging (mpMRI) characteristics and appearance of histopathologically proven non-cancerous intraprostatic findings focussing on quantity of prostatitis and atrophy in the peripheral zone.

METHOD

In this retrospective analysis consecutive patients with mpMRI followed by MRI/TRUS-fusion biopsy comprising targeted (TB) and systematic biopsy (SB) cores without prostate cancer (PC) at histopathology were included. Subgroup analysis was performed in younger men (≤50 years). The proportions of prostatitis and atrophy were quantified for each biopsy core based on histopathology. MRI findings in the peripheral zone (PZ) and index lesions (IL, most suspicious/representative lesion) were characterized regarding changes in T2w, ADC value, and enhancement of dynamic contrast enhancement (DCE) and correlated with quantity of prostatitis and atrophy.

RESULTS

Seventy-two patients were analysed. The median baseline characteristics were PSA 5.4 ng/ml (4.0-7.9), PI-RADS classification 3 (2-4), prostate volume 43 ml (33-57), and PSA density 0.13 ng/ml2 (0.10-0.19). Prostatitis was found in 44 % (n = 32) and atrophy in 65 % (n = 47) of cases. The quantity of atrophy demonstrated a significant correlation to T2w changes, ADC increase and DCE enhancement (p = 0.05, p = 0.05, p = 0.01), whereas quantity of prostatitis did not show any significant correlation to the MRI changes (p = 0.68, p = 0.58, p = 0.95). Quantity of prostatitis and atrophy increased with PI-RADS classification. Younger men had lower PSA (4.4 vs. 7.8 ml/ng; p < 0.001), smaller prostate volume (40 vs. 59 ml; p = 0.001), and lower PI-RADS classification (2-3 vs. 3-4; p = 0.005) and prostatitis and atrophy were less frequently observed (p ≤ 0.01, p = 0.03).

CONCLUSIONS

Quantity of atrophy and prostatitis had different influence on MRI characteristics and increased within higher PI-RADS classification. Younger men had diffuse hypointense changes at T2w images, but less quantity of prostatitis and atrophy.

Dynamic Contrast-Enhanced Study in the mpMRI of the Prostate-Unnecessary or Underutilised? A Narrative Review

The aim of this review is to summarise recent scientific literature regarding the clinical use of DCE-MRI as a component of multiparametric resonance imaging of the prostate. This review presents the principles of DCE-MRI acquisition and analysis, the current role of DCE-MRI in clinical practice with special regard to its role in presently available categorisation systems, and an overview of the advantages and disadvantages of DCE-MRI described in the current literature. DCE-MRI is an important functional sequence that requires intravenous administration of a gadolinium-based contrast agent and gives information regarding the vascularity and capillary permeability of the lesion. Although numerous studies have confirmed that DCE-MRI has great potential in the diagnosis and monitoring of prostate cancer, its role is still inadequate in the PI-RADS categorisation. Moreover, there have been numerous scientific discussions about abandoning the intravenous application of gadolinium-based contrast as a routine part of MRI examination of the prostate. In this review, we summarised the recent literature on the advantages and disadvantages of DCE-MRI, focusing on an overview of currently available data on bpMRI and mpMRI, as well as on studies providing information on the potential better usability of DCE-MRI in improving the sensitivity and specificity of mpMRI examinations of the prostate.

Patient-reported pain associated with grid-based transperineal magnetic resonance imaging (MRI)/ultrasound (US) software fusion biopsy of the prostate under local anesthesia: a multicenter experience

Background

Biopsy by transperineal (TP) approach is recommended standard for prostate cancer (PC) diagnosis. To avoid pain, patients undergoing TP biopsy may be offered sedation or general anesthesia. Our aim was to investigate the degree of patient-reported pain for magnetic resonance imaging (MRI)/ultrasound (US) fusion biopsy of the prostate being performed under local anesthesia (LA) and to study for possible factors associated with increased risk of significant pain (SP) in this setting.

Methods

In this retrospective observational study, we reviewed data of consecutive patients without a prior diagnosis of PC who underwent MRI/US software fusion biopsy of the prostate under LA with lidocaine at two centers between May 2020 and April 2022, and who reported their periprocedural pain on a Wong-Baker FACES Pain Rating Scale (0-10). We defined SP as reported pain score of 6-10. Patient and procedure characteristics together with SP were studied for interdependencies.

Results

A total of 299 patients were included. Median pain score was 2 (interquartile range: 2-4), with SP having been reported by 55 (18.4%) patients. Among patient characteristics, only age demonstrated association with SP [odds ratio (OR), per 10 years =0.53, 95% confidence interval (CI): 0.35-0.80, P=0.003] and patients aged 62 or above were significantly less likely to report SP (OR =0.33, 95% CI: 0.18-0.60, P<0.001).

Conclusions

Performing TP MRI/US fusion prostate biopsy under LA is associated with low rates of SP, with the risk being significantly lower in older men. The results of this study can serve as evidence resource for preprocedural counselling in patients especially concerned about the risk of pain.

Prostate Cancer and Its Mimics-A Pictorial Review

BACKGROUND

Multiparametric prostate MRI (mpMRI) is gaining wider recommendations for diagnosing and following up on prostate cancer. However, despite the high accuracy of mpMRI, false positive and false negative results are reported. Some of these may be related to normal anatomic structures, benign lesions that may mimic cancer, or poor-quality images that hamper interpretation. The aim of this review is to discuss common potential pitfalls in the interpretation of mpMRI.

METHODS

mpMRI of the prostates was performed on 3T MRI scanners (Philips Achieva or Siemens Magnetom Vida) according to European Society of Urogenital Radiology (ESUR) guidelines and technical requirements.

RESULTS

This pictorial review discusses normal anatomical structures such as the anterior fibromuscular stroma, periprostatic venous plexus, central zone, and benign conditions such as benign prostate hyperplasia (BPH), post-biopsy hemorrhage, prostatitis, and abscess that may imitate prostate cancer, as well as the appearance of prostate cancer occurring in these locations. Furthermore, suggestions on how to avoid these pitfalls are provided, and the impact of image quality is also discussed.

CONCLUSIONS

In an era of accelerating prostate mpMRI and high demand for high-quality interpretation of the scans, radiologists should be aware of these potential pitfalls to improve their diagnostic accuracy.

Regional Histopathology and Prostate MRI Positivity: A Secondary Analysis of the PROMIS Trial

Background The effects of regional histopathologic changes on prostate MRI scans have not been accurately quantified in men with an elevated prostate-specific antigen (PSA) level and no previous biopsy. Purpose To assess how Gleason grade, maximum cancer core length (MCCL), inflammation, prostatic intraepithelial neoplasia (PIN), or atypical small acinar proliferation within a Barzell zone affects the odds of MRI visibility. Materials and Methods In this secondary analysis of the Prostate MRI Imaging Study (PROMIS; May 2012 to November 2015), consecutive participants who underwent multiparametric MRI followed by a combined biopsy, including 5-mm transperineal mapping (TPM), were evaluated. TPM pathologic findings were reported at the whole-prostate level and for each of 20 Barzell zones per prostate. An expert panel blinded to the pathologic findings reviewed MRI scans and declared which Barzell areas spanned Likert score 3-5 lesions. The relationship of Gleason grade and MCCL to zonal MRI outcome (visible vs nonvisible) was assessed using generalized linear mixed-effects models with random intercepts for individual participants. Inflammation, PIN, and atypical small acinar proliferation were similarly assessed in men who had negative TPM results. Results Overall, 161 men (median age, 62 years [IQR, 11 years]) were evaluated and 3179 Barzell zones were assigned MRI status. Compared with benign areas, the odds of MRI visibility were higher when a zone contained cancer with a Gleason score of 3+4 (odds ratio [OR], 3.1; 95% CI: 1.9, 4.9; P < .001) or Gleason score greater than or equal to 4+3 (OR, 8.7; 95% CI: 4.5, 17.0; P < .001). MCCL also determined visibility (OR, 1.24 per millimeter increase; 95% CI: 1.15, 1.33; P < .001), but odds were lower with each prostate volume doubling (OR, 0.7; 95% CI: 0.5, 0.9). In men who were TPM-negative, the presence of PIN increased the odds of zonal visibility (OR, 3.7; 95% CI: 1.5, 9.1; P = .004). Conclusion An incremental relationship between cancer burden and prostate MRI visibility was observed. Prostatic intraepithelial neoplasia contributed to false-positive MRI findings. ClinicalTrials.gov registration no. NCT01292291 © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Harmath in this issue.

Dynamic Contrast Enhanced Study in Multiparametric Examination of the Prostate—Can We Make Better Use of It?

We sought to investigate whether quantitative parameters from a dynamic contrast-enhanced study can be used to differentiate cancer from normal tissue and to determine a cut-off value of specific parameters that can predict malignancy more accurately, compared to the obturator internus muscle as a reference tissue. This retrospective study included 56 patients with biopsy proven prostate cancer (PCa) after multiparametric magnetic resonance imaging (mpMRI), with a total of 70 lesions; 39 were located in the peripheral zone, and 31 in the transition zone. The quantitative parameters for all patients were calculated in the detected lesion, morphologically normal prostate tissue and the obturator internus muscle. Increase in the K_trans value was determined in lesion-to-muscle ratio by 3.974368, which is a cut-off value to differentiate between prostate cancer and normal prostate tissue, with specificity of 72.86% and sensitivity of 91.43%. We introduced a model to detect prostate cancer that combines K_trans lesion-to-muscle ratio value and iAUC lesion-to-muscle ratio value, which is of higher accuracy compared to individual variables. Based on this model, we identified the optimal cut-off value with 100% sensitivity and 64.28% specificity. The use of quantitative DCE pharmacokinetic parameters compared to the obturator internus muscle as reference tissue leads to higher diagnostic accuracy for prostate cancer detection.

Bioptic prostatic inflammation correlates with false positive rates of multiparametric magnetic resonance imaging in detecting clinically significant prostate cancer

Introduction

The aim of this article was to determine the impact of bioptic prostatic inflammation (PI) on the false positive rate of multiparametric magnetic resonance imaging (mp-MRI) in detecting clinically significant prostate ancer (csPCa).

Material and methods

Our prostate biopsy database was queried to identify patients who underwent mp-MRI before PB at our institution. A dedicated uropathologist prospectively assessed bioptic PI using the Irani scores. We evaluated the association between mp-MRI findings, bioptic Gleason grade (GG) and aggressiveness of PI, and PCa detection.

Results

In total, 366 men were included. In patients with Prostate Imaging Reporting and Data System (PIRADS) 4-5 lesions, the csPCa (GG ≥2) rate was significantly higher in those with low-grade than in those with high-grade PI (36% vs 29.7%; p = 0.002), and in those with low-aggressive than in those with high-aggressive PI (37.7% vs 30.1%; p = 0.0003). The false positive rates of PIRADS 4–5 lesions for any PCa were 34.2% and 57.8% for low- and high-grade PI, respectively (p = 0.002); similarly, they were 29.5% and 59.4% for mildly and highly-aggressive PI (p = 0.0003). Potential study limitations include its retrospective analysis and single-center study and lack of assessment of the type of PI.

Conclusions

Bioptic PI directly correlates with false positive rates of mp-MRI in detecting csPCa. Clinicians should be aware that PI remains the most common pitfall of mp-MRI.

SUVmax/ADC Ratio as a Molecular Imaging Biomarker for Diagnosis of Biopsy-Naïve Primary Prostate Cancer

Background:

Gallium-68-prostate-specific membrane antigen (⁶⁸Ga-PSMA) positron emission tomography/computed tomography (PET/CT) has recently been shown to be very high accuracy in biopsy-naïve prostate cancer (PCa) detection and can potentially improve the low specificity noted with diffusion-weighted magnetic resonance imaging (DW-MRI), especially in instances of prostate inflammation. We aimed to compare the diagnostic accuracy of DW-MRI and PSMA PET/CT using apparent diffusion coefficient (ADC) and maximum standardized uptake (SUV_max) values in the diagnosis of PCa.

Patients and Methods:

A retrospective study comparing and analyzing the diagnostic accuracy of prebiopsy DW-MRI and ⁶⁸Ga-PSMA PET/CTs done in patients with suspected PCa (raised prostate specific antigen [PSA] and/or positive digital rectal examination) from January 2019 to December 2020. The standard of reference was transrectal ultrasound-guided biopsies.

Results:

Sixty-seven patients were included in the study, mean age: 70 years (range 49–84), mean PSA: 23.2 ng/ml (range 2.97–45.6). Biopsy was positive for PCa in 56% (n = 38) and negative in 43% (n = 29). Of the benign results, benign hyperplasia was noted in 75% (n = 22) and prostatitis in 25% (n = 7). Of the PCa, 55% (n = 21) of were high International Society of Urological Pathology (ISUP) grade (4–5) and 45% (n = 17) low/intermediate ISUP grade (1–3). Overall the sensitivity/specificity/Accuracy for prediction of PCa of MRI using prostate imaging and reporting data system version 2 criteria and PSMA PET/CT using PCa molecular imaging standardized evaluation criteria was 92.1%/65.5%/80.5% and 76.3%/96.5%/85.1% respectively. Mean apparent diffusion co-efficient (mean ADC) value of benign lesions and PCa was 1.135 × 10^-3 mm²/s and 0.723 × 10^-3 mm²/s, respectively (P = 0.00001). Mean SUV_max and ADC of benign and PCa lesions was 4.01 and 16.4 (P = 0.000246). Mean SUV_max/ADC ratio of benign and malignant lesions was 3.8 × 103 versus 25.21 × 103 (P < 0.000026). Inverse correlation was noted between ADC and SUV_max values (R = −0.609), inverse correlation noted between ADC and Gleason's score (R = −0.198), and positive correlation of SUV_max and SUV_max/ADC with Gleason's score (R = 0.438 and R = 0.448). Receiver operating characteristic curve analysis revealed a SUV_max cutoff 6.03 (sensitivity/specificity - 76%/90%, area under the curve (AUC) - 0.935, Youden index (YI) - 0.66), ADC cutoff of 0.817 × 10⁻³ mm²/s (sensitivity/specificity – 79%/86%, AUC – 0.890, YI - 0.65), and SUV_max/ADC ratio cutoff of 7.43 × 103 (sensitivity/specificity – 87%/98%, AUC - 0.966, YI - 0.85) for PCa diagnosis.

Conclusion:

For diagnosis of biopsy-naïve PCas, the combination of diffusion-weighted MRI and PSMA PET/CT (i.e., SUV_max/ADC ratio) shows better diagnostic accuracy than either used alone and the combination of PET and MRI is especially useful when distinguishing cancer from prostatitis.

The Etiology and Pathophysiology Genesis of Benign Prostatic Hyperplasia and Prostate Cancer: A New Perspective

Background: The etiology of benign prostatic hyperplasia and prostate cancer are unknown, with ageing being the greatness risk factor. Methods: This new perspective evaluates the available interdisciplinary evidence regarding prostate ageing in terms of the cell biology of regulation and homeostasis, which could explain the timeline of evolutionary cancer biology as degenerative, inflammatory and neoplasm progressions in these multifactorial and heterogeneous prostatic diseases. Results: This prostate ageing degeneration hypothesis encompasses the testosterone-vascular-inflamm-ageing triad, along with the cell biology regulation of amyloidosis and autophagy within an evolutionary tumorigenesis microenvironment. Conclusions: An understanding of these biological processes of prostate ageing can provide potential strategies for early prevention and could contribute to maintaining quality of life for the ageing individual along with substantial medical cost savings.

Impact of Chronic Prostatitis on the PI-RADS Score 3: Proposal for the Addition of a Novel Binary Suffix

We examined the impact of chronic prostatitis on the diagnostic performance of multiparametric magnetic resonance imaging (mpMRI). In this retrospective study, 63 men underwent 3T mpMRI followed by MRI/ultrasound fusion biopsy to exclude/confirm clinically significant prostate cancer (csPCa). A total of 93 lesions were included for evaluation. Images were assessed by two radiologists. Prostatitis was graded visually on T2-weighted and contrast-enhanced sequences. The correlation of prostatitis features with the assigned Prostate Imaging Reporting and Data System (PI-RADS) and the presence of csPCa were assessed, and the clinical and functional imaging parameters for differentiating between prostatitis and significant tumors were examined. Histopathological analysis was used as the reference standard. The rate of PI-RADS 3 scores tended to be higher in the presence of radiologically severe prostatitis compared with no/discrete prostatitis (n = 52 vs. n = 9; p = 0.225). In severe prostatitis, csPCa was determined in only 7.7% (4/52) of PI-RADS 3 lesions. In severe chronic prostatitis, a binary prostatitis suffix (e.g., PI-RADS 3 i+ versus i−) within the radiological report may help assess the limitations of mpMRI interpretability because of severe prostatitis and avoid unnecessary biopsies. Mean apparent diffusion coefficient (ADC_mean) was the best marker (cutoff 0.93 × 10⁻³ mm²/s) to differentiate between csPCa/non csPCa in severe prostatitis.

Single-cell Spatial Proteomic Revelations on the Multiparametric MRI Heterogeneity of Clinically Significant Prostate Cancer

PURPOSE

Multiparametric MRI (mpMRI) has become an indispensable radiographic tool in diagnosing prostate cancer. However, mpMRI fails to visualize approximately 15% of clinically significant prostate cancer (csPCa). The molecular, cellular, and spatial underpinnings of such radiographic heterogeneity in csPCa are unclear.

EXPERIMENTAL DESIGN

We examined tumor tissues from clinically matched patients with mpMRI-invisible and mpMRI-visible csPCa who underwent radical prostatectomy. Multiplex immunofluorescence single-cell spatial imaging and gene expression profiling were performed. Artificial intelligence-based analytic algorithms were developed to examine the tumor ecosystem and integrate with corresponding transcriptomics.

RESULTS

More complex and compact epithelial tumor architectures were found in mpMRI-visible than in mpMRI-invisible prostate cancer tumors. In contrast, similar stromal patterns were detected between mpMRI-invisible prostate cancer and normal prostate tissues. Furthermore, quantification of immune cell composition and tumor-immune interactions demonstrated a lack of immune cell infiltration in the malignant but not in the adjacent nonmalignant tissue compartments, irrespective of mpMRI visibility. No significant difference in immune profiles was detected between mpMRI-visible and mpMRI-invisible prostate cancer within our patient cohort, whereas expression profiling identified a 24-gene stromal signature enriched in mpMRI-invisible prostate cancer. Prostate cancer with strong stromal signature exhibited a favorable survival outcome within The Cancer Genome Atlas prostate cancer cohort. Notably, five recurrences in the 8 mpMRI-visible patients with csPCa and no recurrence in the 8 clinically matched patients with mpMRI-invisible csPCa occurred during the 5-year follow-up post-prostatectomy.

CONCLUSIONS

Our study identified distinct molecular, cellular, and structural characteristics associated with mpMRI-visible csPCa, whereas mpMRI-invisible tumors were similar to normal prostate tissue, likely contributing to mpMRI invisibility.

Expected impact of MRI-related interreader variability on ProScreen prostate cancer screening trial: a pre-trial validation study

BACKGROUND

The aim of this study is to investigate the potential impact of prostate magnetic resonance imaging (MRI) -related interreader variability on a population-based randomized prostate cancer screening trial (ProScreen).

METHODS

From January 2014 to January 2018, 100 men aged 50-63 years with clinical suspicion of prostate cancer (PCa) in Helsinki University Hospital underwent MRI. Nine radiologists individually reviewed the pseudonymized MRI scans of all 100 men in two ProScreen trial centers. All 100 men were biopsied according to a histological composite variable comprising radical prostatectomy histology (N = 38) or biopsy result within 1 year from the imaging (N = 62). Fleiss' kappa (κ) was used to estimate the combined agreement between all individual radiologists. Sample data were subsequently extrapolated to 1000-men subgroups of the ProScreen cohort.

RESULTS

Altogether 89% men of the 100-men sample were diagnosed with PCa within a median of 2.4 years of follow-up. Clinically significant PCa (csPCa) was identified in 76% men. For all PCa, mean sensitivity was 79% (SD ±10%, range 62-96%), and mean specificity 60% (SD ±22%, range 27-82%). For csPCa (Gleason Grade 2-5) MRI was equally sensitive (mean 82%, SD ±9%, range 67-97%) but less specific (mean 47%, SD ±20%, range 21-75%). Interreader agreement for any lesion was fair (κ 0.40) and for PI-RADS 4-5 lesions it was moderate (κ 0.60). Upon extrapolating these data, the average sensitivity and specificity to a screening positive subgroup of 1000 men from ProScreen with a 30% prevalence of csPCa, 639 would be biopsied. Of these, 244 men would be true positive, and 395 false positive. Moreover, 361 men would not be referred to biopsy and among these, 56 csPCas would be missed. The variation among the radiologists was broad as the least sensitive radiologist would have twice as many men biopsied and almost three times more men would undergo unnecessary biopsies. Although the most sensitive radiologist would miss only 2.6% of csPCa (false negatives), the least sensitive radiologist would miss every third.

CONCLUSIONS

Interreader agreement was fair to moderate. The role of MRI in the ongoing ProScreen trial is crucial and has a substantial impact on the screening process.

68Ga-PSMA-11 PET/CT combining ADC value of MRI in the diagnosis of naive prostate cancer: Perspective of radiologist

Ga-PSMA-11 positron emission computed tomography /computed tomography (PET/CT) is more sensitive than magnetic resonance imaging (MRI) in detecting prostate cancer (PCa). We evaluated the value of Ga-PSMA-11 PET/CT with MRI in treatment-naive PCa.This retrospective study was approved by the hospital ethics committee. The MRI and Ga-PSMA-11 PET/CT imaging data of 63 cases of highly suspected PCa were enrolled in this study. The SUVmax and apparent diffusion coefficient (ADC), and their ratio, were assessed as diagnostic markers to distinguish PCa from benign disease.There were 107 prostate lesions detected in 63 cases. Forty cases with 64 malignant primary lesions were confirmed PCa, whereas 23 cases had 43 benign lesions. PSMA-avid lesions correlated with hypointense signal on ADC maps and hyperintense signal on diffusion-weighted imaging. The ADC of PCa was lower than that of benign lesions, and SUVmax and SUVmax/ADC of PCa was higher than that of benign lesions (P < .01). ADC had significant negative correlation with Gleason score (GS) and SUVmax, SUVmax, and SUVmax/ADC positively correlated with GS. From ROC analysis, we established cutoff values of ADC, SUVmax, and SUVmax/ADC at 1.02 × 10mm/s, 11.72, and 12.35, respectively, to differentiate PCa from benign lesions. The sensitivity, specificity, and AUC were 90.6%, 58.1%, and 0.816 for ADC, 67.2%, 97.7%, and 0.905 for SUVmax, and 81.2%, 88.4%, and 0.929 for SUVmax/ADC, respectively.Ga-PSMA-11 PET/CT combined with MRI offers higher diagnostic efficacy in the detection of PCa than either modality alone.