What benefit can be obtained from magnetic resonance imaging diagnosis with artificial intelligence in prostate cancer compared with clinical assessments?

The present study aimed to explore the potential of artificial intelligence(AI)methodology based on magnetic resonance(MR)images to aid in the management of prostate cancer(PCa).To this end,we reviewed and summarized the studies comparing the diagnostic and predictive performance for PCa between AI and common clinical assessment methods based on MR images and/or clinical characteristics,thereby investigating whether AI methods are generally superior to common clinical assessment methods for the diagnosis and prediction fields of PCa.First,we found that,in the included studies of the present study,AI methods were generally equal to or better than the clinical assessment methods for the risk assessment of PCa,such as risk stratification of prostate lesions and the prediction of therapeutic outcomes or PCa progression.In particular,for the diagnosis of clinically significant PCa,the AI methods achieved a higher summary receiver operator characteristic curve(SROC-AUC)than that of the clinical assessment methods(0.87 vs.0.82).For the prediction of adverse pathology,the AI methods also achieved a higher SROC-AUC than that of the clinical assessment methods(0.86 vs.0.75).Second,as revealed by the radiomics quality score(RQS),the studies included in the present study presented a relatively high total average RQS of 15.2(11.0–20.0).Further,the scores of the individual RQS elements implied that the AI models in these studies were constructed with relatively perfect and standard radiomics processes,but the exact generalizability and clinical practicality of the AI models should be further validated using higher levels of evidence,such as prospective studies and open-testing datasets.

Role of preoperative magnetic resonance imaging on the surgical outcomes of radical prostatectomy:Does preoperative tumor recognition reduce the positive surgical margin in a specific location?Experience from a Thailand prostate cancer specialized center

Objective Multiparametric magnetic resonance imaging(MRI)has become the standard of care for the diagnosis of prostate cancer patients.This study aimed to evaluate the influence of preoperative MRI on the positive surgical margin(PSM)rates.Methods We retrospectively reviewed 1070 prostate cancer patients treated with radical prostatectomy(RP)at Siriraj Hospital between January 2013 and September 2019.PSM rates were compared between those with and without preoperative MRI.PSM locations were analyzed.Results In total,322(30.1%)patients underwent MRI before RP.PSM most frequently occurred at the apex(33.2%),followed by posterior(13.5%),bladder neck(12.7%),anterior(10.7%),posterolateral(9.9%),and lateral(2.3%)positions.In preoperative MRI,PSM was significantly lowered at the posterior surface(9.0%vs.15.4%,p=0.01)and in the subgroup of urologists with less than 100 RP experiences(32%vs.51%,odds ratio=0.51,p<0.05).Blood loss was also significantly decreased when a preoperative image was obtained(200 mL vs.250 mL,p=0.02).Multivariate analysis revealed that only preoperative MRI status was associated with overall PSM and PSM at the prostatic apex.Neither the surgical approach,the neurovascular bundle sparing technique,nor the perioperative blood loss was associated with PSM.Conclusion MRI is associated with less overall PSM,PSM at apex,and blood loss during RP.Additionally,preoperative MRI has shown promise in lowering the PSM rate among urologists who are in the early stages of performing RP.

Future of prostate imaging:Artificial intelligence in assessing prostatic magnetic resonance imaging

Prostate cancer(Pca;adenocarcinoma)is one of the most common cancers in adult males and one of the leading causes of death in both men and women.The diagnosis of Pca requires substantial experience,and even then the lesions can be difficult to detect.Moreover,although the diagnostic approach for this disease has improved significantly with the advent of multiparametric magnetic resonance,that technology has certain unresolved limitations.In recent years artificial intelligence(AI)has been introduced to the field of radiology,providing new software solutions for prostate diagnostics.Precise mapping of the prostate has become possible through AI and this has greatly improved the accuracy of biopsy.AI has also allowed for certain suspicious lesions to be attributed to a given group according to the Prostate Imaging-Reporting&Data System classification.Finally,AI has facilitated the combination of data obtained from clinical,laboratory(prostate-specific antigen),imaging(magnetic resonance),and biopsy examinations,and in this way new regularities can be found which at the moment remain hidden.Further evolution of AI in this field is inevitable and it is almost certain to significantly expand the efficacy,accuracy and efficiency of diagnosis and treatment of Pca.

Recent Research Advances in Imaging of Prostate Cancer

Imaging study plays a crucial role in the diagnosis of prostate cancer. As early screening and management of prostate cancer has evolved over the past decade, research is now focusing on how to detect clinically significant prostate cancer and avoid overdiagnosis accurately. This article provides an overview of recent advances in imaging in prostate cancer diagnosis, including new ultrasound imaging techniques, positron emission computed tomography, multiparametric magnetic resonance imaging, and emerging areas such as imaging histology, by systematically reviewing and summarizing the existing literature.

Targeted prostate biopsy： value of multiparametric magnetic resonance imaging in detection of localized cancer

Prostate cancer is the second most common cancer in men, with 1.1 million new cases worldwide reported by the World Health Organization in one recent year. Transrectal ultrasound （TRUS）-guided biopsy has been used for the diagnosis of prostate cancer for over 2 decades, but the technique is usually blind to cancer location. Moreover, the false negative rate of TRUS biopsy has been reported to be as high as 47%. Multiparametric magnetic resonance imaging （mp-MRI） includes T1- and T2-weighted imaging as well as dynamic contrast-enhanced （DCE） and diffusion-weighted imaging （DWI）. mp-MRI is a major advance in the imaging of prostate cancer, enabling targeted biopsy of suspicious lesions. Evolving targeted biopsy techniquesmincluding direct in-bore biopsy, cognitive fusion and software-based MRI-ultrasound （MRI-US） fusion--have led to a several-fold improvement in cancer detection compared to the earlier method. Importantly, the detection of clinically significant cancers has been greatly facilitated by targeting, compared to systematic biopsy alone. Targeted biopsy via MRI-US fusion may dramatically alter the way prostate cancer is diagnosed and managed.

Role of serial multiparametric magnetic resonance imaging in prostate cancer active surveillance

AIM:To examine whether addition of 3T multiparametric magnetic resonance imaging(mp MRI)to an active surveillance protocol could detect aggressive or progressive prostate cancer.METHODS:Twenty-three patients with low risk disease were enrolled on this active surveillance study,all of which had Gleason score 6 or less disease.All patients had clinical assessments,including digital rectal examination and prostate specific antigen(PSA)testing,every 6 mo with annual 3T mp MRI scans with gadolinium contrast and minimum sextant prostate biopsies.The MRI images were anonymized of patient identifiers and clinical information and each scan underwentradiological review without the other results known.Descriptive statistics for demographics and follow-up as well as the sensitivity and specificity of mp MRI to identify prostate cancer and progressive disease were calculated.RESULTS:During follow-up(median 24.8 mo)11 of 23 patients with low-risk prostate cancer had disease progression and were taken off study to receive definitive treatment.Disease progression was identified through upstaging of Gleason score on subsequent biopsies for all 11 patients with only 2 patients also having a PSA doubling time of less than 2 years.All 23 patients had biopsy confirmed prostate cancer but only 10 had a positive index of suspicion on mp MRI scans at baseline(43.5% sensitivity).Aggressive disease prediction from baseline mpM RI scans had satisfactory specificity(81.8%)but low sensitivity(58.3%).Twentytwo patients had serial mp MRI scans and evidence of disease progression was seen for 3 patients all of whom had upstaging of Gleason score on biopsy(30% specificity and 100% sensitivity).CONCLUSION:Addition of mp MRI imaging in active surveillance decision making may help in identifying aggressive disease amongst men with indolent prostate cancer earlier than traditional methods.

DIFFERENTIATION BETWEEN BENIGN PROSTATIC HYPERPLASIA AND PROSTATE CANCER IN THE TRANSITIONAL ZONE EVALUATED BY ~1H MAGNETIC RESONANCE SPECTROSCOPIC IMAGING

Objective To quantitatively evaluate the metabolic changes of benign prostatic hyperplasia(BPH) and prostate cancer in the transitional zone using magnetic resonance spectroscopic imaging(MRSI),and to analyze the characteristics and differences of the spectra in this zonal area.Methods Eighteen patients with prostate cancer in the transitional zone underwent magnetic resonance imaging(MRI)/MRSI examinations.The(Choline+Creatine)/Citrate(CC/Ci) ratio and the Choline/Creatine(Cho/Cr) ratio were evaluated in each voxel with cancer or BPH confirmed by pathological results.Discriminant analysis was used to determine the power of the two ratios in differentiation between cancer and BPH.Results The CC/Ci ratio and Cho/Cr ratio for cancer voxels were significantly higher than those in the voxels with BPH in the transitional zone(CC/Ci:2.36±1.31 vs.0.85±0.29,P<0.01;Cho/Cr:4.14±1.79 vs.1.26±0.45,P<0.01).As for the discriminant function with the CC/Ci ratio and the Cho/Cr ratio,the specificity,sensitivity,and accuracy were 98.6%,85.7%,92.9% respectively for the differentiation between cancer and BPH.Conclusions The prostate cancer is characterized by higher CC/Ci ratio and Cho/Cr ratio compared to BPH in the transitional zone.Both CC/Ci ratio and Cho/Cr ratio have high specificity,sensitivity,and accuracy in their discriminative power between cancer and BPH in this zonal area.

Computed tomography and magnetic resonance imaging findings of metastatic rectal linitis plastica from prostate cancer:A case report and review of literature

Linitis plastica is a rare condition showing circumferentially infiltrating intramural anaplastic carcinoma in a hollow viscus, resulting in a tissue thickening of the involved organ as constricted, inelastic, and rigid. While most secondary rectal linitis plastica(RLP) is caused by metastasis from stomach, breast, gallbladder, or bladder cancer, we report an extremely rare and unique case of secondary RLP due to prostate cancer with computed tomography(CT) and magnetic resonance imaging(MRI) findings, including diffusion weighted imaging(DWI). A 78-year-old man presented with approximately a 2-mo history of constipation and without cancer history. On sigmoidoscopy, there was a luminal narrowing and thickening of rectum with mucosa being grossly normal in its appearance. On contrast-enhanced CT,marked contrast enhancement with wall thickening of rectum was noted. On pelvic MRI, rectal wall thickening showed a target sign on both T2-weighted imaging and DWI. A diffuse infiltrative lesion was suspected in the prostate gland based on low signal intensity on T2-weighted imaging and restricted diffusion. A transanal full-thickness excisional biopsy revealed metastasis from a prostate adenocarcinoma invading the submucosa to the muscularis propria consistent with metastatic RLP. We would like to emphasize the CT and MRI findings of metastatic RLP due to prostate cancer.

Dynamic contrast-enhanced magnetic resonance imaging of prostate cancer: A review of current methods and applications

In many areas of oncology, dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI) has proven to be a clinically useful, non-invasive functional imaging technique to quantify tumor vasculature and tumor perfusion characteristics. Tumor angiogenesis is an essential process for tumor growth, proliferation, and metastasis. Malignant lesions demonstrate rapid extravasation of contrast from the intravascular space to the capillary bed due to leaky capillaries associated with tumor neovascularity. DCE-MRI has the potential to provide information regarding blood flow, areas of hypoperfusion, and variations in endothelial permeability and microvessel density to aid treatment selection, enable frequent monitoring during treatment and assess response to targeted therapy following treatment. This review will discuss the current status of DCE-MRI in cancer imaging, with a focus on its use in imaging prostate malignancies as well as weaknesses that limit its widespread clinical use. The latest techniques for quantification of DCE-MRI parameters will be reviewed and compared.

Updates in advanced diffusion-weighted magnetic resonance imaging techniques in the evaluation of prostate cancer

Diffusion-weighted magnetic resonance imaging(DWMRI) is considered part of the standard imaging protocol for the evaluation of patients with prostate cancer.It has been proven valuable as a functional tool for qualitative and quantitative analysis of prostate cancer beyond anatomical MRI sequences such as T2-weighted imaging. This review discusses ongoing controversies in DW-MRI acquisition, including the optimal number of b-values to be used for prostate DWI, and summarizes the current literature on the use of advanced DWMRI techniques. These include intravoxel incoherent motion imaging, which better accounts for the nonmono-exponential behavior of the apparent diffusion coefficient as a function of b-value and the influence of perfusion at low b-values. Another technique is diffusion kurtosis imaging(DKI). Metrics from DKI reflect excess kurtosis of tissues, representing its deviation from Gaussian diffusion behavior. Preliminary results suggest that DKI findings may have more value than findings from conventional DW-MRI for the assessment of prostate cancer.

Magnetic resonance imaging for prostate cancer before radical and salvage radiotherapy: What radiation oncologists need to know

External beam radiotherapy(EBRT) is one of the principal curative treatments for patients with prostate cancer(PCa). Risk group classification is based on prostate-specific antigen(PSA) level, Gleason score, and T-stage. After risk group determination, the treatment volume and dose are defined and androgen deprivation therapy is prescribed, if appropriate. Traditionally, imaging has played only a minor role in T-staging due to the low diagnostic accuracy of conventional imaging strategies such as transrectal ultrasound, computed tomography, and morphologic magnetic resonance imaging(MRI). As a result, a notable percentage of tumours are understaged, leading to inappropriate and imprecise EBRT. The development of multiparametric MRI(mp MRI), an imaging technique that combines morphologic studies with functional diffusion-weighted sequences and dynamic contrastenhanced imaging, has revolutionized the diagnosis and management of PCa. As a result, mpM RI is now used in staging PCa prior to EBRT, with possible implications for both risk group classification and treatment decisionmaking for EBRT. mpM RI is also being used in salvageradiotherapy(SRT), the treatment of choice for patients who develop biochemical recurrence after radical prostatectomy. In the clinical context of biochemical relapse, it is essential to accurately determine the site of recurrence-pelvic(local, nodal, or bone) or distant-in order to select the optimal therapeutic management approach. Studies have demonstrated the value of mpM RI in detecting local recurrences-even in patients with low PSA levels(0.3-0.5 ng/m L)-and in diagnosing bone and nodal metastasis. The main objective of this review is to update the role of mpM RI prior to radical EBRT or SRT. We also consider future directions for the use and development of MRI in the field of radiation oncology.

The current role of prostate multiparametric magnetic resonance imaging

Prostate multi-parametric magnetic resonance imaging(mpMRI)has shown excellent sensitivity for Gleason
7 cancers,especially when their volume is
0.5 mL.As a result,performing an mpMRI before prostate biopsy could improve the detection of clinically significant prostate cancer(csPCa)by adding targeted biopsies to systematic biopsies.Currently,there is a consensus that targeted biopsies improve the detection of csPCa in the repeat biopsy setting and at confirmatory biopsy in patients considering active surveillance.Several prospective multicentric controlled trials recently showed that targeted biopsy also improved csPCa detection in biopsy-naǐve patients.The role of mpMRI and targeted biopsy during the follow-up of active surveillance remains unclear.Whether systematic biopsy could be omitted in case of negative mpMRI is also a matter of controversy.mpMRI did show excellent negative predictive values(NPV)in the literature,however,since NPV depends on the prevalence of the disease,negative mpMRI findings should be interpreted in the light of a priori risk for csPCa of the patient.Nomograms combining mpMRI findings and classical risk predictors(age,prostatespecific antigen density,digital rectal examination,etc.)will probably be developed in the future to decide whether a prostate biopsy should be obtained.mpMRI has a good specificity for detecting T3 stage cancers,but its sensitivity is low.It should therefore not be used routinely for staging purposes in low-risk patients.Nomograms combining mpMRI findings and other clinical and biochemical data will also probably be used in the future to better assess the risk of T3 stage disease.

Cognitive magnetic resonance imaging-ultrasound fusion transperineal targeted biopsy combined with randomized biopsy in detection of prostate cancer

BACKGROUND Prostate cancer(PCa)is one of the most common cancers among men.Various strategies for targeted biopsy based on multiparametric magnetic resonance imaging(mp-MRI)have emerged,which may improve the accuracy of detecting clinically significant PCa in recent years.AIM To investigate the diagnostic efficiency of a template for cognitive MRIultrasound fusion transperineal targeted plus randomized biopsy in detecting PCa.METHODS Data from patients with an increasing prostate-specific antigen(PSA)level but less than 20 ng/mL and at least one lesion suspicious for PCa on MRI from December 2015 to June 2018 were retrospectively analyzed.All patients underwent cognitive fusion transperineal template-guided targeted biopsy followed by randomized biopsy outside the targeted area.A total of 127 patients with complete data were included in the final analysis.A multivariable logistic regression analysis was conducted,and a two-sided P<0.05 was considered statistically significant.RESULTS PCa was detected in 66 of 127 patients,and 56 cases presented clinically significant PCa.Cognitive fusion targeted biopsy alone detected 59/127 cases of PCa,specifically 52/59 cases with clinically significant PCa and 7/59 cases with clinically insignificant PCa.A randomized biopsy detected seven cases of PCa negative on targeted biopsy,and four cases had clinically significant PCa.PSA density(OR:1.008,95%CI:1.003-1.012,P=0.001;OR:1.006,95%CI:1.002-1.010,P=0.004)and Prostate Imaging-Reporting and Data System(PI-RADS)scores(both P<0.001)were independently associated with the results of cognitive fusion targeted biopsy combined with randomized biopsy and targeted biopsy alone.CONCLUSION This single-centered study proposed a feasible template for cognitive MRIultrasound fusion transperineal targeted plus randomized biopsy.Patients with higher PSAD and PI-RADS scores were more likely to be diagnosed with PCa.

Magnetic resonance imaging for prostate cancer clinical application

As prostate cancer is a biologically heterogeneous disease for which a variety of treatment options are available, the major objective of prostate cancer imaging is to achieve more precise disease characterization. In clinical practice, magnetic resonance imaging （MRI） is one of the imaging tools for the evaluation of prostate cancer, the fusion of MRI or dynamic contrast-enhanced MRI （DCE-MRI） with magnetic resonance spectroscopic imaging （MRSI） is improving the evaluation of cancer locafon, size, and extent, while providing an indication of tumor aggressiveness. This review summarizes the role of MRI in the application of prostate cancer and describes molecular MRI techniques （including MRSI and DCE-MRI） for aiding prostate cancer management.

Application of dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI)combined with magnetic resonance spectroscopy(MRS)in prostate cancer diagnosis

Objective The aim of the study was to investigate the application of dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI)combined with magnetic resonance spectroscopy(MRS)in prostate cancer diagnosis.Methods In the outpatient department of our hospital(Sichuan Cancer Hospital,Chengdu,China),60 patients diagnosed with prostate disease were selected randomly and included in a prostate cancer group,60 patients with benign prostatic hyperplasia were included in a proliferation group,and 60 healthy subjects were included in a control group,from January 2013 to January 2017.Using Siemens Avanto 1.5 T high-field superconducting MRI for DCE-MRI and MRS scans,after the MRS scan was completed,we used the workstation spectroscopy tab spectral analysis,and eventually obtained the crest lines of the prostate metabolites choline(Cho),creatine(Cr),citrate(Cit),and the values of Cho/Cit,and(Cho+Cr)/Cit.Results Participants who had undergone 21-s,1-min,and 2-min dynamic contrast-enhanced MR revealed significant variations among the three groups.The spectral analysis of the three groups revealed a significant variation as well.DCE-MRI and MRS combined had a sensitivity of 89.67%,specificity of 95.78%,and accuracy of 94.34%.Conclusion DCE-MRI combined with MRS is of great value in the diagnosis of prostate cancer.

New frontiers in focal therapy for prostate cancer:Prostate-specific membrane antigen positron emission tomography/magnetic resonance imaging

Imaging has a central role in the context of focal therapy(FT)for prostate cancer(PCa).Prostate-specific membrane antigen(PSMA)positron emission tomography/magnetic resonance imaging(PET/MRI)is a novel imaging modality that combines the morpho-functional information of MRI with the molecular characterization of PET.Some papers reported the potential advantages of PSMA PET/MRI in different clinical scenarios.Limited evidence on PSMA PET/MRI is available in the setting of FT.PSMA PET/MRI can be an effective imaging modality for detecting primary PCa and seems to provide accurate local staging of primary PCa.PSMA PET/MRI also shows high performance for restaging and detecting tumor recurrence.The higher soft-tissue contrast and the reduction of ionizing radiation are the main advantages reported in the literature compared to PET/computed tomography.PSMA PET/MRI could represent a turning point in the management of patients with PCa in the context of FT.Further studies are needed to confirm its applications in this specific clinical setting.

Role of magnetic resonance imaging in the diagnostic work up of clinical localized prostate cancer: A review

Imaging plays an increasingly important role in the work up of prostate cancer(PCa) and magnetic resonance imaging(MRI) is generally accepted as the most accurate and promising imaging modality in the local staging of PCa due to its high spatial resolution and excellent soft tissue contrast. The quality and performance of MRI of the prostate has improved dramatically during the last decade. Mainly, the combination of morphological information and functional information on cell density, tissue perfusion or metabolism as provided in multi-parametric prostate MRI(mp MRI) has led to a substantial increase in lesion detection and characterization. The correlation between functional parameters as provided by MRI and the aggressiveness of PCa as determined by the Gleason Score may help in differentiating clinically signifi cant from indolent PCa non-invasively. Besides these pros, radiologists are confronted with an immense amount of information and standardized acquisition, interpretation and reporting of mp MRI is not yet a reality. Furthermore, prostate MRI availability is still limited to high volume centers in many countries; hence, it is not yet a routine tool in common daily practice. Hence, development of guidelines for standardized acquisition, interpretation andreporting of prostate MRI exams is urgently needed in order to provide useful information for treating clinicians. Preferably, multi-centric clinical studies comparing MRI fi ndings to step-section histological specimens are mandatory during the coming years. Furthermore, simplification of the acquisition must be achieved in order to make this imaging modality applicable for daily use in common uro-radiological practice.

Multimodality imaging using proton magnetic resonance spectroscopic imaging and ^(18)F-fluorodeoxyglucose-positron emission tomography in local prostate cancer

AIM To assess the relationship using multimodality imaging between intermediary citrate/choline metabolism as seen on proton magnetic resonance spectroscopic imaging(1H-MRSI) and glycolysis as observed on ^(18)F-fluorodeoxyglucose positron emission tomography/computed tomography(^(18)F-FDG-PET/CT) in prostate cancer(PCa) patients. METHODS The study included 22 patients with local PCa who were referred for endorectal magnetic resonance imaging/1HMRSI(April 2002 to July 2007) and ^(18)F-FDG-PET/CT and then underwent prostatectomy as primary or salvage treatment. Whole-mount step-section pathology was used as the standard of reference. We assessed the relationships between PET parameters [standardized uptake value(SUVmax and SUVmean)] and MRSI parameters [choline + creatine/citrate(CC/Cmax and CC/Cmean) and total number of suspicious voxels] using spearman's rank correlation, and the relationships of PET and 1H-MRSI index lesion parameters to surgical Gleason score.RESULTS Abnormal intermediary metabolism on 1H-MRSI was present in 21/22 patients, while abnormal glycolysis on ^(18)F-FDG-PET/CT was detected in only 3/22 patients. Specifically, index tumor localization rates were 0.95(95%CI: 0.77-1.00) for 1H-MRSI and 0.14(95%CI: 0.03-0.35) for ^(18)F-FDG-PET/CT. Spearman rank correlations indicated little relationship(ρ =-0.36-0.28) between 1H-MRSI parameters and ^(18)F-FDG-PET/CT parameters. Both the total number of suspicious voxels(ρ = 0.55, P = 0.0099) and the SUVmax(ρ = 0.46, P = 0.0366) correlated weakly with the Gleason score. No significant relationship was found between the CC/Cmax, CC/Cmean or SUVmean and the Gleason score(P = 0.15-0.79). CONCLUSION The concentration of intermediary metabolites detected by 1H MRSI and glycolytic flux measured ^(18)F-FDG PET show little correlation. Furthermore, only few tumors were FDG avid on PET, possibly because increased glycolysis represents a late and rather ominous event in the progression of PCa.

Prostate magnetic resonance imaging at 3 Tesla:Is administration of hyoscine-N-butyl-bromide mandatory?

AIM: To evaluate the value of administration of hyoscine-N-butyl-bromide (HBB) for image quality magnetic resonance imaging (MRI) of the prostate. METHODS: Seventy patients were retrospectively included in the study. Thirty-five patients were examined with administration of 40 milligrams of HBB (Buscopan ; Boehringer, Ingelheim, Germany); 35 patients were examined without HBB. A multiparametric MRI protocol was performed on a 3.0 Tesla scanner without using an endorectal coil. The following criteria were evaluated independently by two experienced radiologists on a five-point Likert scale: anatomical details (delineation between peripheral and transitional zone of the prostate, visualisation of the capsule, depiction of the neurovascular bundles); visualisation of lymph nodes; motion related artefacts; and overall image quality.RESULTS: Comparison of anatomical details between the two cohorts showed no statistically significant difference (3.9 ± 0.7 vs 4.0 ± 0.9, P = 0.54, and 3.8 ± 0.7 vs 4.2 ± 0.6, P = 0.07) for both readers. There was no significant advantage regarding depiction of local and iliac lymph nodes (3.9 ± 0.6 vs 4.2 ± 0.6, P = 0.07, and 3.8 ± 0.9 vs 4.1 ± 0.8, P = 0.19). Motion arte- facts were rated as 'none' to 'few' in both groups and showed no statistical difference (2.3 ± 1.0 vs 1.9 ± 0.9, P = 0.19, and 2.3 ± 1.1 vs 1.9 ± 0.7, P = 0.22). Overall image quality was rated 'good' in average for both cohorts without significant difference (4.0 ± 0.6 vs 4.0 ± 0.9, P = 0.78, and 3.8 ± 0.8 vs 4.2 ± 0.6, P = 0.09). CONCLUSION: The results demonstrated no significant effect of HBB administration on image quality. The study suggests that use of HBB is not mandatory for MRI of the prostate at 3.0 Tesla.

Evaluation of the tumor angiogenesis in benign prostate hyperplasia and prostatic cancer with MR perfusion-weighted imaging

Objective： To explore the application of MR perfusion-weighted imaging （PWI） in the benign and malignant prostate diseases, and evaluate the correlations of PWl features with vascular endothelial growth factor （VEGF） and microvessel density （MVD）. Methods： Seventy-four consecutive patients who were diagnosed clinically for the prostate diseases, including forty-four cases with benign prostate hyperplasia and thirty cases with prostatic cancer proved pathologically, were examined by PWI. MVD and VEGF were stained with immunohistochemical methods. Some parameters of PWl, including the steepest slope of signal intensity-time curve （SSmax） and the change in relaxation rate （ΔR2^＊ peak） at lesions, were analyzed. Correlation analysis was used to determine the relationship between the results of PWl and immunohistochemistry. Results： （1） In the benign prostate hyperplasia （BPH）, SSmax and ΔR2^＊ peak of perfusion curve were 34.2 ± 2.9 and 1.49 ± 0.11, respectively; however, in the prostatic cancer （Pca）, they were 58.6± 4.8 and 3.18 ±0.49 respectively; there were statistical differences （t = 2.16 and 2.31, P 〈 0.05）. （2） The VEGF and MVD expressions of thirty Pca patients were significantly higher than those of forty-four BPH patients （x2 = 28.64, P 〈 0.01; t = 21.2, P 〈 0.01）. MVD expressions of Pca and BPH groups showed positive associations with VEGF expressions （P 〈 0.01）. On MR perfusion-weighted imaging, SSmax and ΔR2^＊ peak showed associations with MVD and VEGF expressions （P 〈 0.01）. Conclusion： On MR perfusion-weighted imaging, SSmax and ΔR2^＊ peak can reflect MVD and VEGF expression levels in the benign and malignant prostate diseases and might be implied the tumor angiogenesis so as to distinguish benign from malignant and provide the important information for the surgeon to diagnose and treat the prostatic diseases.