Aims and objectives
The Prostate Imaging‒Reporting and Data System version 2 (PI-RADS v2) guidelines designated diffusion-weighted imaging (DWI) as the dominant sequence in prostate magnetic resonance imaging (MRI) for guiding localization and risk assessment of focal peripheral zone (PZ) lesion [1].
The guidelines introduced and advised to use the “high b-values” (> 1400 s/mm2) images routinely,
if the signal-to-noise (SNR) adequate.
Several recent studies have reported that DWI using b= 1500‒2500 s/mm2 was optimal and superior to conventional DWI using b = 1000 s/mm2 (DWI1000) [2-9].
Although higher...
Methods and materials
Patients
The Institutional Review Board of our institution approved this retrospective study,
and waived the requirement for informed consent.
From August 2015 to July 2016,
188 patients with biopsy-proven prostate cancer underwent multiprarametric prostate MRI followed by radical prostatectomy.
The exclusion criteria were as follows: outside MRI (n = 27) or MRI without DWI1500 (n = 3),
preoperative androgen deprivation therapy (n = 1),
and prostate sarcoma (n = 2).
Finally,
154 consecutive patients (mean age,
64 years; range,
43-78 years) were included in our...
Results
The patient and cancer characteristics are summarized in Table 1.
Table 2 presents the visual assessment results on DWI1000 and DWI1500 for detecting the CSCs for the both readers (Figures 1‒3).
The sensitivity,
specificity and diagnostic accuracy for the experienced reader were the same between DWI1000 and DWI1500 (p> 0.05).
The sensitivity for the less-experienced reader was greater at DWI1500 (80%) than at DWI1000 (76.7%),
which was not significant (p > 0.05).
The specificity for the less-experienced reader was greater at DWI1000 (50%) than at...
Conclusion
DWI is the dominant sequence in multiparametric prostate MRI for evaluating the index lesion in the PZ lesion and the secondary sequence for the TZ.
The background signal suppression progressively increases with increasing b-values on DWI.
The normal PZ is not fully suppressed and continues to show mildly increased signal on DWI because of T2-shine through effects,
resulting in obscure some tumors on DWI of b values ,
higher b-value DWI may improve the contrast to noise ratio between cancerous and normal tissues via removing...
References
1.Weinreb JC,
Barentsz JO,
Choyke PL,
Cornud F,
Haider MA,
Macura KJ,
Margolis D,
Schnall MD,
Shtern F,
Tempany CM et al: PI-RADS Prostate Imaging - Reporting and Data System: 2015,
Version 2.
European urology 2016,
69(1):16-40.
2.Rosenkrantz AB,
Parikh N,
Kierans AS,
Kong MX,
Babb JS,
Taneja SS,
Ream JM: Prostate Cancer Detection Using Computed Very High b-value Diffusion-weighted Imaging: How High Should We Go? Academic radiology 2016,
23(6):704-711.
3.Rosenkrantz AB,
Hindman N,
Lim RP,
Das K,
Babb JS,
Mussi TC,
Taneja SS: Diffusion-weighted...
