








































Key Words Competing Interests Article Information

Prostate cancer, multi-parametric MRI,  
micro-ultrasound, PI-RADS, PRI-MUS

None declared. Received on July 5, 2021 
Accepted on August 14, 2021 
This article has been peer reviewed.

Soc Int Urol J. 2022;3(1):8–13

DOI: 10.48083/DHNC9428

8 SIUJ  •  Volume 3, Number 1  •  January 2022 SIUJ.ORG

This is an open access article under the terms of a license that permits non-commercial use, provided the original work is properly cited.  
© 2022 The Authors. Société Internationale d'Urologie Journal, published by the Société Internationale d'Urologie, Canada.

ORIGINAL RESEARCH

Comparing Micro-Ultrasound With mpMRI in 
Detecting Clinically Significant Prostate Cancer
Guan Hee Tan,1,2 Brian Wodlinger,3 Christian Pavlovich,4 Laurence Klotz2

1 Sunway Medical Centre, Petaling Jaya, Malaysia 2 Department of Urology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Canada  
3 Exact Imaging, Markham, Canada 4 Department of Urology, The James Buchanan Brady Urological Institute, Johns Hopkins University School of Medicine,  
Baltimore, United States

Abstract

Objectives To compare the performance of micro-ultrasound (mUS) with multi-parametric magnetic resonance 
imaging (mpMRI) in detecting clinically significant prostate cancer.
 
Materials and Methods Retrospective data from consecutive patients with any indication for prostate biopsy in  
2 academic institutions were included. The operator, blinded to mpMRI, would first scan the prostate and annotate 
any mUS lesions. All mUS lesions were biopsied. Any mpMRI lesions that did not correspond to mUS lesion upon 
unblinding were additionally biopsied. Grade group (GG) ≥ 2 was considered clinically significant cancer. The Jeffreys 
interval method was used to compare performance of mUS with mpMRI with the non-inferiority limit set at −5%. 

Results Imaging and biopsy were performed in 82 patients with 153 lesions. mUS had similar sensitivity to mpMRI 
(per-lesion analysis: 78.4% versus 72.5%), but lower specificity, positive predictive value, negative predictive value, and 
area under the curve. Micro-ultrasound found GG ≥ 2 in 13% of cases missed by mpMRI, while mpMRI found GG ≥ 
2 in 11% of cases missed by mUS. The difference 0.020 (95% CI −0.070 to 0.110) was not statistically significant 
(P  =  0.33). 

Conclusion The sensitivity of mUS in detecting GG ≥ 2 disease was similar to that of mpMRI, but the specificity 
was lower. Further evaluation with a larger sample size and experienced operators is warranted.

Introduction

Prostate biopsies are usually guided by transrectal ultrasound (TRUS) platforms that operate at 6 to 9 MHz[1]. 
Systematic biopsies of the prostate, the mainstay of prostate cancer diagnosis for the last 30 years, have many 
limitations, including both under-diagnosis of significant cancer and the identification of many men with clinically 
insignificant cancer. Multi-parametric magnetic resonance imaging (mpMRI) detects clinically significant cancer 
on the basis of alterations in cell density and ductal anatomy[2–4]. The Prostate Imaging Reporting and Data System  
(PI-RADS 2.0) was developed to standardize interpretation and reporting of mpMRI findings[5].

Many national guidelines now recommend mpMRI before TRUS biopsy[6–7]. Multi-parametric MRI with 
targeted biopsy appears to reduce the number of men requiring a biopsy and the over-detection of clinically  
insignificant cancer without compromising significant cancer detection[2,8]. However, in many regions of the world 
access to mpMRI is limited, and performing an mpMRI in all men at risk is not feasible. Multi-parametric MRI  
before biopsy also means 2 procedures, requiring that the patient to return for fusion targeted biopsy if suspicious 
lesions are detected.

http://SIUJ.org
mailto:Laurence.Klotz%40sunnybrook.ca?subject=SIUJ


To address these limitations, a novel micro-ultra-
sound (mUS) platform that operates at 29MHz was 
developed. This system generates high-resolution (70µ) 
images of the prostate. This resolution, compared with 
200µ in conventional ultrasound, is the diameter of pros-
tatic ducts, and therefore detects alterations in ductal 
anatomy. This offers the opportunity for improved 
detection of high-grade cancers characterized by loss of 
normal acinar lumens and tighter cellular packing. As 
with PI-RADS for mpMRI, a prostate risk identification 
using mUS (PRI-MUS) protocol has been developed to 
standardize sonographic lesions[9]. In addition to supe-
rior resolution, this technology offers the convenience of 
conventional ultrasound such as real-time imaging and 
targeted biopsy during the same procedure, office-based 
set-up, relatively easy access compared with MRI, and 
considerably less expensive equipment. The mUS plat-
form is novel, and evidence regarding its accuracy in 
prostate cancer diagnosis is lacking. This study compares 
the performance of mUS in detecting clinically signifi-
cant prostate cancer with that of mpMRI.

Materials and Methods
Inclusion and Exclusion Criteria
Data for this study were retrospectively gathered from 
electronic health records. We included consecutive 
patients between April 2019 and April 2020 who had 
any indication for prostate biopsy: (1) elevated PSA, (2) 
abnormal digital rectal examination (DRE), and/or (3) 
any suspicious mpMRI lesions. All patients must have 
had an mpMRI of the prostate before biopsy within the 
last year. mpMRIs were 3T with an abdominal coil. Data 
were obtained from Sunnybrook Health Sciences Centre 
and Johns Hopkins University School of Medicine. 
These procedures were performed as a standard of care, 
and research ethics board approval was not required or 
sought for the study. 

Procedure 
A single urologist who had been trained on the device 
performed the TRUS biopsies or provided direct 

supervision of the fellow. All patients were prepared with 
prophylactic antibiotics and enema and placed in the 
left lateral position as for standard TRUS biopsy. TRUS 
was performed using the mUS platform that operated at  
29 MHz with a side-firing mUS probe. Critically, for the 
patients in this study, high-resolution ultrasound was 
performed and formally annotated with the operator 
scrupulously blinded to the patient’s prostate cancer 
history and mpMRI findings.

The prostate gland was measured and scanned for any 
visible target lesions. TRUS abnormalities were formally 
annotated and given a PRI-MUS score. The TRUS anno-
tation was “locked” before the mpMRI findings were 
reviewed. One percent lignocaine was then injected 
into the prostate-seminal vesicle angle as local anaesthe-
sia. The operator then reviewed the mpMRI. The loca-
tions of visible mpMRI lesions were identified from the 
radiologist’s report. Targeted samples of every mUS and 
mpMRI lesions were performed. In most cases, 3 cores 
were taken of each region of interest. Cognitive targeting 
was performed on mpMRI-only visible lesions. We did 
not perform systematic biopsy.

Analysis 
Clinically significant prostate cancer was defined as 
GG ≥ 2. Per target lesion and per-patient analyses were 
performed. Sensitivity, specificity, positive predictive 
value (PPV), negative predictive value (NPV), and 
area under the receiver operating characteristic (ROC) 
curve were used as performance measures for mUS and 
mpMRI. The added value of mUS was the number of 
cases with PRI-MUS ≥ 3 and GG ≥ 2 in which mpMRI 
was PI-RADS < 3, or PI-RADS ≥ 3 and GG < 2. The 
added value of mpMRI was the number of cases with 
PI-RADS ≥ 3 and GG ≥ 2 in which mUS was PRI-MUS 
< 3, or PRI-MUS ≥ 3 and GG < 2. The Jeffreys interval 
method was used to compare the performance of mUS 
with that of mpMRI, with the non-inferiority limit set at 
−5%. P ≤ 0.05 was considered significant. All statistical 
calculations were performed using IBM SPSS Statistics 
Version 26.

Results 
Between April 2019 and April 2020, imaging and biopsy 
were performed in 82 patients with 153 lesions. GG ≥ 
2 prostate cancer was diagnosed in 33 patients (40.2%) 
and 51 (33.3%) of the biopsied lesions. The median age 
was 68.3 (IQR = 63.3 to 74.8) years, and median PSA was 
8.0 (IQR = 5.7 to 11.6) ng/mL. Sixty patients (73.2%) had 
been diagnosed with prostate cancer in the past. Among 
them, 39 patients (65%) were on active surveillance, 
and 21 patients (35%) were being followed up after prior 
focal therapy. Table 1 shows the breakdown of normal, 
equivocal, and suspicious mpMRI and mUS studies.

Abbreviations 
AUC area under the curve
GG  grade group
mpMRI multi-parametric magnetic resonance imaging 
mUS  micro-ultrasound
NPV negative predictive value
PI-RADS Prostate Imaging Reporting and Data System
PPV positive predictive value
PRI-MUS prostate risk identification using micro-ultrasound
TRUS transrectal ultrasound

9SIUJ.ORG SIUJ  •  Volume 3, Number 1  •  January 2022

Comparing Micro-Ultrasound With mpMRI in Detecting Clinically Significant Prostate Cancer

http://SIUJ.org


The per-lesion analysis of mUS and mpMRI perfor-
mance in detection of GG ≥ 2 prostate cancer showed 
similar sensitivity with mUS (78.4%) and mpMRI 
(72.5%). There was concordance in 73 lesions (47.7%) 
between mUS and mpMRI, ie, visible on both imaging 
modalities. The specificity, PPV, NPV, and AUC of mUS 
were lower than mpMRI (Table 2). When the thresh-
old for biopsy was set at PRI-MUS/PI-RADS ≥ 3, mUS 
maintained similar sensitivity but lower specificity, 
PPV, NPV, and AUC than mpMRI. However, when the 
threshold for biopsy was set at PRI-MUS/PI-RADS ≥ 4, 
mpMRI showed better sensitivity, PPV, NPV, and AUC 
than mUS. The specificity of the 2 imaging modalities 
was equal in this case at 60.8% (Table 3).

In per-patient analysis, the sensitivity of mUS was 
again similar to that of mpMRI (97.0% versus 97.0%). The 
specificity, PPV, NPV, and AUC of mUS in per-patient 
analysis were lower than mpMRI (Table 4). Micro-ultra-
sound found GG ≥ 2 in 13% of cases missed by mpMRI 
while mpMRI found GG ≥ 2 in 11% of cases missed by 
mUS. The difference 0.020 (95% CI −0.070 to 0.110) was 
not statistically significant (P = 0.33).

Twenty-one lesions (13.7%) detected by mUS in this 
study were located anteriorly. Seven of these (33.3%) 

TABLE 1. 

Patient demographics 

Variables

Patients, n 82

Lesions, n 153

Age, years, median (IQR) 68.3 (63.3 to 74.8)

PSA, ng/mL, median (IQR) 8.0 (5.7 to 11.6)

Prostate volume, mL, median (IQR) 33.0 (24.3 to 44.2)

Prior biopsy with cancer, n (%) 60 (73.2)

Number of PRI-MUS 5 lesions, n (%) 11 (7.2)

Number of PRI-MUS 4 lesions, n (%) 55 (36.0)

Number of PRI-MUS 3 lesions  
(equivocal mUS), n (%)

68 (44.4)

Number of PRI-MUS <3 lesions  
(mUS invisible or clinically  
insignificant lesions), n (%)

19 (12.4)

Number of PI-RADS 5 lesions, n (%) 25 (16.3) 

Number of PI-RADS 4 lesions, n (%) 49 (32.0)

Number of PI-RADS 3 lesions  
(equivocal mpMRI), n (%)

16 (10.5)

Number of PI-RADS <3 lesions  
(mpMRI invisible or clinically 
insignificant lesions), n (%)

63 (41.2)

IQR: interquartile range; mUS: micro-ultrasound; mpMRI:  
multi-parametric magnetic resonance imaging

TABLE 2. 

Per-lesion analysis of performance metrics comparing 
mUS and mpMRI for detection of GG ≥ 2 PCa 

Modality Sensitivity Specificity PPV NPV AUC

mUS 78.4% 7.8% 29.9% 42.1% 0.52

mpMRI 72.5% 46.1% 40.2% 77.0% 0.65

mUS: micro-ultrasound; mpMRI: multi-parametric magnetic 
resonance imaging; GG: grade group

TABLE 3. 

Per-lesion analysis of performance metrics comparing mUS and mpMRI for detection of GG ≥ 2 PCa  
at various PRI-MUS/PI-RADS thresholds for biopsy 

Modality and PRI-MUS/PI-RADS  
threshold for biopsy

Sensitivity Specificity PPV NPV AUC

mUS, PRI-MUS ≥3 78.4% 7.8% 29.9% 42.1% 0.431 (95% CI 0.332 to 0.531)

mpMRI, PI-RADS ≥3 72.5% 48.0% 41.1% 77.8% 0.603 (95% CI 0.509 to 0.697)

mUS, PRI-MUS ≥4 51.0% 60.8% 39.4% 71.3% 0.559 (95% CI 0.462 to 0.656)

mpMRI, PI-RADS ≥4 68.6% 60.8% 46.7% 79.5% 0.647 (95% CI 0.555 to 0.739)

mUS: micro-ultrasound; mpMRI: multi-parametric magnetic resonance imaging; GG: grade group

10 SIUJ  •  Volume 3, Number 1  •  January 2022 SIUJ.ORG

 ORIGINAL RESEARCH

http://SIUJ.org


were clinically significant cancers. One (14.3%) was not 
detected by mpMRI. Twenty-five mpMRI lesions (16.3%) 
were labelled as anterior. Eleven (44.0%) were clinically 
significant cancer, and 1 (9.1%) was missed by mUS.

Discussion 
Micro-ultrasound technology that offers high-resolution 
real-time images of the prostate has the potential to 
enhance prostate cancer diagnosis. Little has been 
published on the performance of mUS compared with 
mpMRI. Preliminary studies demonstrate comparable 
sensitivity and specificity to mpMRI[10–14]. A limitation 
of many of these studies is the lack of rigorous blinding 
of the mpMRI results when interpreting the mUS. 
The results of this current study represent an early 
comparative experience with mUS blinded to mpMRI at 
2 academic institutions. 

Our awareness of the learning curve mandated an 
aggressive approach to identifying and biopsying subtle 
abnormalities to minimize the risk of missing signifi-
cant cancer. This resulted in a small number of biopsied 
locations, n = 19 (12.4%) assigned as invisible (PRI-MUS 
< 3). In contrast, 40% of biopsied lesions were assigned 
PI-RADS < 3 on mpMRI. In a series reported by a highly 
experienced mpMRI centre, the proportion of non-sus-
picious mpMRI cases was as high as 49%, and equiv-
ocal cases were only 6%[15]. We biopsied considerably 
more equivocal mUS lesions (PRI-MUS 3) n = 68 (44.4%) 
compared with only 16 (10.5%) PI-RADS 3 mpMRI 
lesions. This is likely because this is an early experi-
ence with the mUS technology, and the operators were 
anxious not to miss cancers. It is likely that the low speci-
ficity will improve with experience, as clinicians become 
more familiar with non-significant mUS patterns and 
acquire the confidence to exclude these from biopsy. 
Refraining from biopsy of smaller PRI-MUS 3 lesions 
will facilitate this.

This inclusive strategy resulted in a comparable sensi-
tivity to mpMRI in the detection of GG ≥ 2 disease 
(78.4% versus 72.5%) in the per-lesion analysis. This was 
also apparent in the per-patient analysis in which the 
sensitivity of mUS was 97.0% compared with 97.0% for 

mpMRI, using a biopsy threshold of PRI-MUS/PI-RADS 
≥ 3. This approach with mUS resulted in low specific-
ity (7.8%) with an AUC of 0.52 in per-lesion analysis. 
Per-patient analysis also showed low specificity (8.2%) 
and AUC 0.64 at a biopsy threshold of PRI-MUS ≥ 3. 
Despite the difference in specificity, the AUCs of mUS 
and mpMRI were similar. This trend of high sensi-
tivity but low specificity with mUS was also apparent 
in another contemporary study[16]. Importantly, we 
demonstrated that mUS was able to detect GG ≥ 2 in 
13% of cases not diagnosed by mpMRI. Wiemer et al. 
analyzed 159 patients and found 20 (12.6%) patients who 
were negative on targeted mpMRI-guided biopsy had 
in fact harboured clinically significant prostate cancer 
when biopsied with mUS guidance[17]. Their finding in 
this aspect was very similar to our result. 

About 44% of the mUS scans were categorized as 
PRI-MUS 3. Among the 68 PRI-MUS 3 lesions, 14 
(20.6%) were found to be significant cancers. In contrast, 
only 2 (12.5%) of the PI-RADS 3 lesions showed clini-
cally significant cancer. Much as the PI-RADS grad-
ing system has been repeatedly modified over the last 
decade, the low specificity of PRI-MUS 3 in this series 
suggests that further refinement of the PRI-MUS 3 
pattern is warranted.

For example, MRI studies published in the years 1985 
to 1993 showed the AUC for seminal vesicle invasion 
(SVI) was 0.57 ± 0.25. Subsequent articles published 
between 1993 and 2001 described an AUC for SVI of 
0.64 ± 0.21[18]. In a later study, the AUC for tumour 
localization ranged from 0.72 to 0.83 with mpMRI[19]. 
The AUC for GG ≥ 2 prostate cancer in the present study 
was 0.647 (95% CI 0.555 to 0.739) if PI-RADS ≥ 4 lesions 
were biopsied. Improved accuracy of mpMRI can be 
attributed to better technology and image quality, as  
well as greater individual and collective experience in 
image interpretation and refinement of the criteria for 
each score.

There are concerns that mUS may not detect ante-
rior tumours effectively because of the reduced depth 
of tissue visualization at higher ultrasound frequencies. 
This is a major limiting factor only in men with marked 
prostatomegaly. We did not encounter this problem in 
the present study. Among the 7 anterior mUS lesions 
with GG ≥ 2 prostate cancer, 1 was missed by mpMRI. 
Micro-ultrasound did not detect 1 of 11 GG ≥ 2 pros-
tate cancer that were anteriorly located on the basis of 
mpMRI findings. Therefore, it appears that mUS and 
mpMRI were similar in their ability to diagnose ante-
rior tumours. A recent publication demonstrated that 
mUS was also compatible with the transperineal biopsy 
approach[20]. This method could be considered if there 
are anterior lesions that are harder to reach via the tran-
srectal route. 

11SIUJ.ORG SIUJ  •  Volume 3, Number 1  •  January 2022

Comparing Micro-Ultrasound With mpMRI in Detecting Clinically Significant Prostate Cancer

TABLE 4. 

Per-patient analysis of performance metrics comparing 
mUS and mpMRI for detection of GG ≥ 2 PCa 

Modality Sensitivity Specificity PPV NPV AUC

mUS 97.0% 8.2% 41.5% 80.0% 0.64

mpMRI 97.0% 18.4% 43.8% 90.0% 0.69

mUS: micro-ultrasound; mpMRI: multi-parametric magnetic resonance 
imaging; GG: grade group

http://SIUJ.org


The key strength of this study, compared with most 
other studies, was that the operators were blinded to 
mpMRI findings prior to mUS. This approach gave us an 
unbiased reflection of the mUS performance.

The study had limitations. All patients had at least 1 
target lesion seen on mUS and/or mpMRI. Patients with 
both negative mpMRI and mUS were excluded from the 
analysis, since in most cases they did not have a biopsy. 
Therefore, the true NPV for significant cancer cannot be 
accurately estimated. 

Sixty patients (73.2%) had prior diagnosis of pros-
tate cancer. Therefore, the results of this study might 
not reflect the performance of mUS in men who have 
only clinical suspicion of cancer. Although we included 
22 patients who did not have prior prostate cancer, this 
number was too small to yield a reliable conclusion from 
this sub-group.

Patients in this cohort had targeted biopsies only, 
without systematic biopsies. The role of systematic biop-
sies in men having targeted biopsies is evolving, and 
recent data emphasize the importance of systematic 
biopsies in higher risk patients. Had systematic biopsies 
been performed, prostate cancer would undoubtedly 

have been found in some of the patients in this trial who 
had negative targeted biopsies.

Blinding to the mpMRI results before annotating the 
ultrasound findings was self-imposed by the clinicians 
performing the biopsy. Having one clinician document 
the mUS findings and a second clinician performing the 
biopsy after reviewing the mpMRI findings would have 
enhanced this process, but it was not feasible. In addi-
tion, the mpMRI lesions were not targeted with image 
fusion technology. It should be taken into consideration 
when interpretating the results of this study.

Conclusion
Micro-ultrasound is an appealing alternative to 

mpMRI by virtue of reduced cost, complexity, and 
absence of contrast requirement. In this study, the sensi-
tivity of mUS in detecting clinically significant pros-
tate cancer was found to be similar to that of mpMRI. 
The specificity of mUS was found to be lower than 
MRI. Further evaluation with a larger sample size and 
operators who have surmounted the learning curve is 
warranted.

References

1. Rohrbach D, Wodlinger B, Wen J, Mamou J, Feleppa E. High-frequency 
quantitative ultrasound for imaging prostate cancer using a novel 
micro-ultrasound scanner. Ultrasound Med Biol.2018 Jul;44(7):1341–
1354. doi:10.1016/j.ultrasmedbio.2018.02.014.

2. Ahmed HU, El-Shater Bosaily A, Brown LC, Gabe R, Kaplan R, Parmar 
MK, et al. Diagnostic accuracy of multiparametric MRI and TRUS 
biopsy in prostate cancer (PROMIS): a paired validating confirmatory 
study. Lancet.2017 Feb 25;389(10071):815 – 822. doi: 10.1016/
S0140-6736(16)32401-1.

3. Turkbey B, Brown AM, Sankineni S, Wood BJ, Pinto PA, Choyke 
PL. Multiparametric prostate magnetic resonance imaging in the 
evaluation of prostate cancer. C A Cancer J Clin.2016; 66: 326–336. 
doi: 10.3322/caac.21333

4. Mowatt G, Scotland G, Boachie C, Cruickshank M, Ford JA, Fraser 
C, et al. The diagnostic accuracy and cost-effectiveness of magnetic 
resonance spectroscopy and enhanced magnetic resonance imaging 
techniques in aiding the localisation of prostate abnormalities for 
biopsy: a systematic review and economic evaluation. Health Technol 
Assess.2013; 17: vii–xix, 1–281. doi: 10.3310/hta17200

5. Turkbey B, Choyke PL. Pirads 2.0: What is new? Diagnostic Interv 
Radiol.2015;21(5):382–384. doi:10.5152/dir.2015.15099

6. Mottet N, van den Bergh RCN, Briers E, De Santis M, Gillessen S, 
Grummet J, et al. EAU – EANM – ESTRO – ESUR – SIOG Guidelines 
on Prostate Cancer. Available at: https://uroweb.org/wp-content/
uploads/EAU-EANM-ESUR-ESTRO-SIOG-Guidelines-on-Prostate-
Cancer-2019.pdf. Accessed June 11, 2020.

7. Schaeffer E, Srinivas S, Antonarakis ES, Armstrong AJ, Bekelman JE, 
Cheng H, et al. NCCN clinical practice guidelines in oncology. prostate 
cancer V2.2020. Available at: https://www.nccn.org/professionals/
physician_gls/pdf/prostate_detection.pdf. Accessed June 11, 2020. 
doi: 10.6004/jnccn.2021.0008

8. Kasivisvanathan V, Rannikko AS, Borghi M, Panebianco V, Mynderse 
LA, Vaarala MH, et al. for the PRECISION Study Group Collaborators. 
MRI-targeted or standard biopsy for prostate-cancer diagnosis. 
N Engl J Med.2018 May 10;378(19):1767–1777. doi: 10.1056/
NEJM oa1801993.

9. Ghai S, Eure G, Fradet V, Hyndman ME, McGrath T, Wodlinger B, et al. 
Assessing cancer risk on novel 29 MHz micro-ultrasound images of 
the prostate: creation of the micro-ultrasound protocol for prostate 
risk identification. J Urol.2016;196(2):562– 569. doi:10.1016/j.
juro.2015.12.09

12 SIUJ  •  Volume 3, Number 1  •  January 2022 SIUJ.ORG

 ORIGINAL RESEARCH

http://SIUJ.org


10. Eure G, Fanney D, Lin J, Wodlinger B, Ghai S. Comparison of 
conventional transrectal ultrasound, magnetic resonance imaging, 
and micro-ultrasound for visualizing prostate cancer in an active 
surveillance population: a feasibility study. Can Urol Assoc J.2019 
Mar;13(3):E70–E77. doi: 10.5489/cuaj.5361. Epub 2018 Aug 30.

11. Lughezzani G, Saita A, Lazzeri M, Paciotti M, Maffei D, Lista G, et 
al. Comparison of the diagnostic accuracy of micro-ultrasound and 
magnetic resonance imaging/ultrasound fusion targeted biopsies 
for the diagnosis of clinically significant prostate cancer. Eur Urol 
Oncol.2019 May;2(3):329–332. doi: 10.1016/j.euo.2018.10.001.

12. Claros OR, Tourinho-Barbosa RR, Fregeville A, Gallardo AC, Muttin 
F, Carneiro A, et al. comparison of initial experience with transrectal 
magnetic resonance imaging cognitive guided micro-ultrasound 
biopsies versus established transperineal robotic ultrasound magnetic 
resonance imaging fusion biopsies for prostate cancer. J Urol.2020 
May;203(5):918–925. doi: 10.1097/JU.0000000000000692. Epub 
2019 Dec 10.

13. Socarrás MER , Rivas JG, Rivera VC, Elbers JR, González LL, Mercado 
IM, et al. Prostate mapping for cancer diagnosis: the Madrid protocol. 
Transperineal prostate biopsies using mpMRI fusion and micro-
ultrasound guided biopsies. J Urol.2020 Oct;204(4):726–733. doi: 
10.1097/JU.0000000000001083. Epub 2020 Apr 21.

14. Cornud F, Lefevre A, Flam T, Dumonceau O, Galiano M, Soyer P, et al. 
MRI-directed high-frequency (29MhZ) TRUS-guided biopsies: initial 
results of a single-center study. Eur Radiol.2020 Sep;30(9):4838–4846. 
doi: 10.1007/s00330-020-06882-x. Epub 2020 Apr 29.

15. van der Leest M, Erik Cornel E, Bas Israël B, Hendriks R, Padhani 
AR, Hoogenboom M, et al. Head-to-head comparison of transrectal 
ultrasound-guided prostate biopsy versus multiparametric prostate 
resonance imaging with subsequent magnetic resonance-guided 
biopsy in biopsy-naïve men with elevated prostate-specific 
antigen: a large prospective multicenter clinical study. Eur Urol.2019 
Apr;75(4):570–578. doi: 10.1016/j.eururo.2018.11.023.

16. Cornud F, Lefevre A, Flam T, Dumonceau O, Galiano M, Soyer P, et al. 
MRI-directed high-frequency (29MhZ) TRUS-guided biopsies: initial 
results of a single-center study. Eur Radiol.2020 Sep;30(9):4838–
4846. doi: 10.1007/s00330-020-06882-x. Epub 2020 Apr 29. PMID: 
32350662.

17. Wiemer L, Hollenbach M, Heckmann R, Kittner B, Plage H, Reimann 
M, et al. Evolution of Targeted Prostate Biopsy by Adding Micro-
Ultrasound to the Magnetic Resonance Imaging Pathway. Eur 
Urol Focus.2020 Jul 9:S2405 – 4569(20)30188-7. doi: 10.1016/j.
euf.2020.06.022. Epub ahead of print. PMID: 32654967.

18. Engelbrecht MR, Jager GJ, Laheij RJ, Verbeek ALM, van Lier HJ, 
Barentsz JO, et al. Local staging of prostate cancer using magnetic 
resonance imaging: a meta-analysis. Eur Radiol.2002 Sep;12(9):2294–
302. doi: 10.1007/s00330-002-1389-z.

19. Mullerad M, Hricak H, Kuroiwa K, Pucar D, Chen H-N, Kattan MW, 
et al. Comparison of endorectal magnetic resonance imaging, 
guided prostate biopsy and digital rectal examination in the 
preoperative anatomical localization of prostate cancer. J Urol.2005 
Dec;174(6):2158–2163. doi: 10.1097/01.ju.0000181224.95276.82.

20. Rodríguez Socarrás ME, Gomez Rivas J, Cuadros Rivera V, Reinoso 
Elbers J, Llanes González L, Michel Mercado I, et al. Prostate mapping 
for cancer diagnosis: the Madrid protocol. transperineal prostate 
biopsies using multiparametric magnetic resonance imaging fusion 
and micro-ultrasound guided biopsies. J Urol.2020 Oct;204(4):726–
733. doi: 10.1097/JU.0000000000001083. Epub 2020 Apr 21. PMID: 
32314932.

13SIUJ.ORG SIUJ  •  Volume 3, Number 1  •  January 2022

Comparing Micro-Ultrasound With mpMRI in Detecting Clinically Significant Prostate Cancer

http://SIUJ.org

