Central Gland Research Articles

Accelerated 3D T2 mapping with dictionary-based matching for prostate imaging.

To develop a fast and accurate method for 3D T2 mapping of prostate cancer using undersampled acquisition and dictionary-based fitting. 3D high-resolution T2 -weighted images (0.9 × 0.9 × 3 mm3 ) were obtained with a multishot T2 -prepared balanced steady-state free precession (T2 -prep-bSSFP) acquisition sequence using a 3D variable density undersampled Cartesian trajectory. Each T2 -weighted image was reconstructed using total variation regularized sensitivity encoding. A flexible simulation framework based on extended phase graphs generated a dictionary of magnetization signals, which was customized to the proposed sequence. The dictionary was matched to the acquired T2 -weighted images to retrieve quantitative T2 values, which were then compared to gold-standard spin echo acquisition values using monoexponential fitting. The proposed approach was validated in simulations and a T1 /T2 phantom, and feasibility was tested in 8 healthy subjects. The simulation analysis showed that the proposed T2 mapping approach is robust to noise and typically observed T1 variations. T2 values obtained in the phantom with T2 prep-bSSFP and the acquisition-specific, dictionary-based matching were highly correlated with the gold-standard spin echo method (r = 0.99). Furthermore, no differences were observed with the accelerated acquisition compared to the fully sampled acquisition (r = 0.99). T2 values obtained in prostate peripheral zone, central gland, and muscle in healthy subjects (age, 26 ± 6 years) were 97 ± 14, 76 ± 7, and 36 ± 3 ms, respectively. 3D quantitative T2 mapping of the whole prostate can be achieved in 3 minutes.

Duplicated Prostate Artery Central Gland Blood Supply: A Retrospective Analysis and Classification System

Angiograms and cone-beam computed tomography scans of 36 consecutive prostate artery embolization patients (72 hemipelves) between October 2014 and February 2018 were reviewed. The hemipelves were classified according to the presence of dual central gland (CG) blood supply and the pattern of vascularization: Type 1 with a single CG blood supply (83.3%; n = 60); Type 2 with 2 independent CG arteries with overlapping territories (9.7%; n = 7); and Type 3 with 2 independent CG arteries with isolated territories (7%; n = 5). Up to 20% of pelvic sides may have more than 1 independent CG prostate artery that should be searched for during prostate artery embolization.

Prostate Artery Embolization for Lower Urinary Tract Symptoms Secondary to Benign Prostatic Hyperplasia: Results From a Prospective FDA-Approved Investigational Device Exemption Study

ObjectiveTo evaluate the safety and efficacy of prostate artery embolization (PAE) for lower urinary tract symptoms (LUTS) attributed to benign prostatic hyperplasia (BPH). MethodsA prospective, single-center, open-label FDA-approved study was conducted to evaluate the safety and efficacy of PAE for LUTS secondary to BPH. We enrolled men ≥ 45, prostate volume > 40 g, International prostate symptom score (IPSS) > 13, peak flow rate (Qmax) ≤ 12 mL/s, and voided volume ≥ 125 mL. Patients were evaluated with questionnaires (IPSS, quality-of-life [QoL], International index of erectile function, and male sexual health questionnaire for ejaculatory dysfunction) and clinical measures (postvoid residual volume and Qmax at baseline 1, 3, and 12 months) after PAE. Baseline and 6-month total prostate (TV) and central gland (CG) volumes were obtained. Results45 patients (mean volume: 99 cc, range: 30-214 g) were treated over the course of the 3-year study. At 1 month, there were improvements in IPSS (23.6 ± 6.1 to 12.0 ± 5.9, P < .0001), QoL (4.8 ± 0.9 to 2.6 ± 1.6, P < .0001), Qmax (5.8 ± 1.0 to 12.4 ± 6.8,P < .0001). At 3 months, there were improvements in IPSS (10.2 ± 6.0, P < .0001), QoL (2.4 ± 1.6, P < .0001) and Qmax (15.3 ± 12.3, P < .0001). At 6 months, there were improvements in IPSS (11.0 ± 7.6, P < .0001) and QoL (2.3 ± 1.7, P < .0001). At 1 year, there were improvements in IPSS (12.4 ± 8.4,P < .0001) and QoL (2.6 ± 1.6, P < .0001). There were reductions in postvoid volume residues: baseline 157 ± 45, 1 month 123 ± 47, P = .057, 3 months 127 ± 114, P = .34, 6 months 112±116, P = .002 and 1 year 109±116 P = .025. Median decreases in TV and CG were 18% (CI: 13-27) (P = 0.0001) and 27% (CI: 20-36)(P = 0.0001), respectively. Self-limited adverse events included dysuria (n = 13), hematuria (n = 6), hematospermia (n = 2), urinary frequency (n = 3) and retention (n = 2). No severe adverse events, nontarget embolization, or adverse effects on erectile function or sexual health. ConclusionThis prospective clinical trial demonstrates that PAE is safe and efficacious for BPH, with significant improvement in LUTS and reduction in TV and CG volumes.

Abstract 4539: Examination of zone-based radiomic features for characterization of dominant intraprostatic lesions using MR multi-modal information

Abstract Purpose: We investigated radiomic features extracted from dominant intraprostatic lesions (DILs) of the peripheral zone (PZ) and central gland (CG) from MR multi-modal images of 20 patients with prostate cancer (PCa). Remaining prostate gland (RPG) were included in the analysis. Material and Methods: 20 biopsy-proven PCa patients with no prior radiation treatment were studied. Axial T2 weighted images (T2WI) and diffusion weighted images (DWI) were acquired of the pelvis using a 3T MR scanner. ADC maps were constructed from DWIs. Region of interests delineating DILs and RPGs were contoured on each MR modality. 168 radiomic features were extracted from DIL and RPG volumes (15 pairs from PZ and 5 pairs from CG). Radiomic features were categorized into 8 different sets: Intensity Based Histogram (IBH, 9 features), Gray Level Run Length (GLRL, 7 features), Law's Textural Information (LAWS, 18 features), Discrete Orthonormal Stockwell Transform (DOST, 18 features), Local Binary Pattern (LBP, 6 features), 2D Wavelet Transform (2DWT, 48 features), 2D Gabor Filter (2DGF, 40 features), and Gray Level Co-Occurrence Matrix (GLCM, 22 features). ANOVA (with Bonferroni adjustment), overall mean percent difference (OMPD), and the Fisher combined probability were used to test the following 7 hypotheses: (1) DILs of PZ and CG from T2WI (2) DILs of PZ and CG from ADC (3) DILs and RPGs of PZ from T2WI (4) DILs and RPGs of PZ from ADC (5) DILs and RPGs of CG from T2WI (6) DILs and RPGs of CG from ADC (7) DILs of PZ for T2WI and ADC. Results: Results imply that among 168 radiomics features, only 5 (DOST, and 2DGF, OMPD=107.8%), 2 (2DWT, and 2DGF, OMPD=141.7%), 13 (IBH, 2DWT, and GLCM, OMPD=%226.6), 17 (IBH, 2DWT, and GLCM, OMPD=179.7%), 18 (IBH, 2DWT, and GLCM, OMPD=321.9%), 18 (IBH, 2DWT, and GLCM, OMPD=726.1%), and 74 (IBH, GLRL, LAWS, DOST, LBP, 2DWT, 2DGF, GLCM, OMPD=1564%) features are discriminant (pFisher &amp;lt;0.050 with Confidence Level of 95%) for hypotheses no. 1 through 7 respectively. Conclusion and Discussion: Results for the discriminant features identified from hypotheses no. 1 and 2 can be used to construct a predictive model with a higher performance that benefits from the zone-based information (PZ and CG) as a-priori knowledge. As most of the discriminant features in tests no. 1 to 7 are primarily entropy-based, this suggests that potential feature-based biomarkers of DILs in PCa patients are more associated with spatial-locality, and frequency-based characteristics of MR images. The high value of the OMPD for test no. 7, strongly supports the use of the two MR modalities for increasing the information gain in perfecting predictive models for detection of DILs in PCa studies. The results of this pilot study, albeit subject to confirmation in a larger patient population, suggest a potential role for the use of zone-based radiomics information in models developed for detection of DILs in PCa patients. Citation Format: Hassan Bagher-Ebadian, Branislava Janic, Chang Liu, Milan V. Pantelic, David Hearshen, Mohamed Elshaikh, Benjamin Movsas, Indrin J. Chetty, Ning Wen. Examination of zone-based radiomic features for characterization of dominant intraprostatic lesions using MR multi-modal information [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4539.

Size matters! Aurora A controls Drosophila larval development

In metazoans, organisms arising from a fertilized egg, the embryo will develop through multiple series of cell divisions, both symmetric and asymmetric, leading to differentiation. Aurora A is a serine threonine kinase highly involved in such divisions. While intensively studied at the cell biology level, its function in the development of a whole organism has been neglected. Here we investigated the pleiotropic effect of Aurora A loss-of-function in Drosophila larval early development. We report that Aurora A is required for proper larval development timing control through direct and indirect means. In larval tissues, Aurora A is required for proper symmetric division rate and eventually development speed as we observed in central brain, wing disc and ring gland. Moreover, Aurora A inactivation induces a reduction of ecdysteroids levels and a pupariation delay as an indirect consequence of ring gland development deceleration. Finally, although central brain development is initially restricted, we confirmed that brain lobe size eventually increases due to additive phenotypes: delayed pupariation and over-proliferation of cells with an intermediate cell-identity between neuroblast and ganglion mother cell resulting from defective asymmetric neuroblast cell division.

Quantitative diffusion MRI using reduced field-of-view and multi-shot acquisition techniques: Validation in phantoms and prostate imaging

PurposeTo evaluate the reproducibility of quantitative diffusion measurements obtained with reduced Field of View (rFOV) and Multi-shot EPI (msEPI) acquisitions, using single-shot EPI (ssEPI) as a reference. MethodsDiffusion phantom experiments, and prostate diffusion-weighted imaging in healthy volunteers and patients with known or suspected prostate cancer were performed across the three different sequences. Quantitative diffusion measurements of apparent diffusion coefficient, and diffusion kurtosis parameters (healthy volunteers), were obtained and compared across diffusion sequences (rFOV, msEPI, and ssEPI). Other possible confounding factors like b-value combinations and acquisition parameters were also investigated. ResultsBoth msEPI and rFOV have shown reproducible quantitative diffusion measurements relative to ssEPI; no significant difference in ADC was observed across pulse sequences in the standard diffusion phantom (p = 0.156), healthy volunteers (p ≥ 0.12) or patients (p ≥ 0.26). The ADC values within the non-cancerous central gland and peripheral zone of patients were 1.29 ± 0.17 × 10−3 mm2/s and 1.74 ± 0.23 × 10−3 mm2/s respectively. However, differences in quantitative diffusion parameters were observed across different number of averages for rFOV, and across b-value groups and diffusion models for all the three sequences. ConclusionBoth rFOV and msEPI have the potential to provide high image quality with reproducible quantitative diffusion measurements in prostate diffusion MRI.

Prostatic Artery Embolization in the Treatment of Localized Prostate Cancer: A Bicentric Prospective Proof-of-Concept Study of 12 Patients

PurposeTo provide initial data on tumoricidal efficacy of embolization on prostate cancer via histopathologic examination of prostatectomy specimens after embolization. Materials and MethodsIn this bicentric prospective trial, 12 men with localized prostate cancer underwent radical prostatectomy 6 weeks after prostatic artery embolization (PAE) from October 2016 to May 2017. PAE was performed with the use of 100-μm Embozene microspheres (Boston Scientific, Natick, Massachusetts). Response of prostate cancer tissue to PAE was assessed according to tumor regression grades. The major outcome measure was complete histopathologic absence of viable cancer cells, including secondary foci, in the prostatectomy specimens. ResultsComplete necrosis of the index lesion was found in 2 patients and partial necrosis in 5. Considering secondary cancerous foci, viable cancer cells were found in all 12 patients. Pathologic specimens were characterized by demarcated zones of necrotic tissue predominantly located in the central gland. Two patients required additional surgery to remove necrotic bladder tissue caused by PAE. ConclusionsPAE with the use of 100-μm microspheres failed to achieve complete elimination of tumor cells. Extensive tumor regression was induced in some lesions, highlighting the need for further assessment of PAE as a potential treatment option for prostate cancer.

Three-dimensional proton magnetic resonance spectroscopy and diffusion-weighted imaging in the differentiation of incidental prostate carcinoma from benign prostate hyperplasia.

The present study evaluated three-dimensional proton magnetic resonance spectroscopy (MRS) and diffusion-weighted imaging (DWI) features in differentiating incidental prostate carcinoma (IPCa) and benign prostate hyperplasia (BPH) in the central gland of the prostate. The clinical and imaging data of 9 patients with IPCa, 118 patients with BPH [including those with glandular hyperplasia (GH), stromal hyperplasia (SH) and mixed hyperplasia (MH)], were retrospectively analyzed. The mean (choline + creatine)/citrate (CC/C) value of 3D MRS, the apparent diffusion coefficient (ADC) value and the minimal ADC value of DWI were compared between carcinoma and non-carcinoma tissues. The mean CC/C values were 1.04±0.28, and 1.09±0.58 in IPCa and BPH, respectively (t=-0.205, P=0.838). No significant difference in CC/C values (χ2=2.595, P=0.458) could be detected between IPCa, GH, SH and MH groups. The ADC values of the central gland only differed between IPCa (1.48±0.18) ×10-3 and GH (1.60±0.16) ×10-3 mm2/sec (P=0.037). The minimal ADC values were similar between IPCa (1.15±0.10) ×10-3 and BPH (1.14±0.11) ×10-3 mm2/sec, no significant differences could be detected between IPCa and GH (P=0.930), IPCa and SH (P=0.192), and IPCa and MH (P=0.544). Although the ADC values of the central gland of the prostate differed between IPCa and GH, the findings of the present study therefore indicate that combining 3D MRS with DWI cannot potentially improve the detection of IPCa.

Support Vector Machines (SVM) classification of prostate cancer Gleason score in central gland using multiparametric magnetic resonance images: A cross-validated study

PurposeTo assess the performance of Support Vector Machines (SVM) classification to stratify the Gleason Score (GS) of prostate cancer (PCa) in the central gland (CG) based on image features across multiparametric magnetic resonance imaging (mpMRI). Materials and methodsThis retrospective study was approved by the institutional review board, and informed consent was waived. One hundred fifty-two CG cancerous ROIs were identified through radiological-pathological correlation. Eleven parameters were derived from the mpMRI and histogram analysis, including mean, median, the 10th percentile, skewness and kurtosis, was performed for each parameter. In total, fifty-five variables were calculated and processed in the SVM classification. The classification model was developed with 10-fold cross-validation and was further validated mutually across two separated datasets. ResultsWith six variables selected by a feature-selection and variation test, the prediction model yielded an area under the receiver operating characteristics curve (AUC) of 0.99 (95% CI: 0.98, 1.00) when trained in dataset A2 and 0.91 (95% CI: 0.85, 0.95) for the validation in dataset B2. When the data sets were reversed, an AUC of 0.99 (95% CI: 0.99, 1.00) was obtained when the model was trained in dataset B2 and 0.90 (95% CI: 0.85, 0.95) for the validation in dataset A2. ConclusionThe SVM classification based on mpMRI derived image features obtains consistently accurate classification of the GS of PCa in the CG.

Significant changes of T2 value in the peripheral zone and seminal vesicles after ejaculation.

To analyse the quantitative changes of the prostate and seminal vesicles (SV) on magnetic resonance imaging (MRI) after ejaculation. Ten healthy young males were enrolled for T2-weighted and T2 mapping MRI before and after two consecutive ejaculations. T2 values of the peripheral zone (PZ) and the central gland (CG) at the midgland of the prostate were compared before and after ejaculation, respectively. T2 values of the PZ at the apex and base were also compared before and after, respectively. Pre- and post-ejaculation SV volumes were compared. The Wilcoxon's signed rank test with Bonferroni adjustment was used for comparison. After ejaculation, T2 values of the PZ significantly decreased (mean, 119±20 vs. 105±21, p=0.002) while those of the CG did not significantly change at the midgland. At the apex, T2 values of the PZ also decreased significantly (mean, 114±9 vs. 94±7, p=0.002). On the other hand, T2 values of the PZ did not change at the base. SV volumes were significantly reduced after ejaculation (mean, 11.1±7.7mL vs. 7.2±6.7mL, p=0.002). Ejaculation decreases T2 values of the PZ at the midgland and apex, and reduces SV volumes. Abstinence periods should be considered in evaluating the prostate and SV on MRI. • T2 values decrease after ejaculation in the apical-mid peripheral zone. • Ejaculation does not affect T2 values of the central gland. • Volume of the seminal vesicles decreases after ejaculation. • An abstinence period should be considered before pelvic MRI in men.

3-T multiparametric MRI characteristics of prostate cancer patients suspicious for biochemical recurrence after primary focal cryosurgery (hemiablation).

We aimed to report on multiparametric MRI (mpMRI) characteristics of post-primary focal cryosurgery (PFC) patients suspected of biochemical recurrence (BCR) by the Phoenix criteria. We retrospectively reviewed all patients at our institution who had undergone PFC. Prostate-specific antigen nadir was determined using 2 or more post-PFC values. Suspicion of BCR was determined using the Phoenix criteria (nadir+2ng/ml). At the discretion of the physician, pre-and post-PFC 3-T mpMRIs were obtained and in a few cases biopsies were performed. Ninety (58.4%) of 154 consecutive patients who underwent PFC were included in our analysis and had a median (range) age and prostate volume of 66.5 (48-82)years and 40.5 (16-175) ml, respectively. Of those suspected of BCR (37/90, 41.1%), with a median time to BCR of 19.9 (7.0-38.5) months, 27 patients (73.0%) underwent a post-PFC mpMRI. Twenty-two (81.5%) of these mpMRIs were found with 24 suspicious lesions. A considerable number (9/24, 37.5%) of these lesions were located in the central gland of the prostate. Seven of 24 lesions exhibited adverse mpMRI characteristic; 4 (16.7%) had capsular contact, 2 (8.2%) showed frank extracapsular extension, and 1 (4.2%) showed seminal vesicle invasion. Five (45.5%) of 11 patients with positive post-PFC mpMRIs were positive on biopsy (4/5, 80% were clinically significant prostate cancer). Post-PFC mpMRI, at Phoenix suspicion of BCR, may help identify a significant number of patients failing post-PFC.

Oviducal glands throughout the gonad development stages: a case study of Octopus mimus (Cephalopoda)

ABSTRACTThe oviducal glands (ODG) play a crucial role in octopus reproduction. Herein, structural changes of each section of the ODG of Octopus mimus are described histologically throughout the gonad development stages (GDS). To do this, the epithelial height, stereociliated or non-stereociliated epithelium, nucleus type (pycnotic or non-pycnotic), epithelial secretions and the value range of the macroscopic maturity index (MaMI), which directly involves ODG status, were measured. The ODG are internally constituted of two glandular units (central and peripheral glands) and one set of receptacles (the spermathecae). High epithelia (40 to 80 μm) were observed in both gland units during periods with low MaMI values (< 0.1) corresponding to III-mature and IV-pre-spawning. The stereociliated epithelium was only apparent in II-maturing and III-mature in both gland units. The nuclei were noticeably pycnotic in the central gland during III-mature, IV-pre-spawning and V-spawning, but pycnotic in the peripheral gland only during VI-depletion. The epithelium was disorganised during VI-depletion, while sulphated acid mucin was only present during III-mature in the central gland. The epithelium transformations during the GDS are related to the functions of the gland units and to their multiple secretions. The ODG histology complements the GDS and provides better reproductive status assessment.

Tomoelastography of the prostate using multifrequency MR elastography and externally placed pressurized-air drivers.

To demonstrate the feasibility of in vivo multifrequency magnetic resonance elastography (MRE) of the prostate using externally placed drivers. Three pressurized-air drivers were used to excite shear waves within the prostate at vibration frequencies of 60, 70, and 80 Hz. Full 3D wave fields were acquired by multislice spin-echo echo-planar imaging in conjunction with tomoelastography wave speed recovery for generating full field-of-view stiffness maps. Twelve healthy volunteers were repeatedly scanned to analyze test-retest reproducibility. Five patients with suspected prostate cancer were investigated to demonstrate the clinical feasibility of the method. In healthy volunteers, the shear wave speed of the entire prostate was 2.24 ± 0.20 m/s with a repeatability coefficient of 0.14 m/s and 88% intraclass correlation coefficient. No significant difference between the peripheral zone (2.27 ± 0.20 m/s) and the central gland (2.22 ± 0.23 m/s) was observed. In patients, wave-speed maps displayed stiff regions consistent with the localization of suspicious masses detected by other imaging markers. The proposed method provides reproducible quantitative maps of tissue stiffness throughout the pelvic region and can easily be integrated into clinical imaging protocols. Clinical stiffness maps display many details of potential interest for cancer diagnosis. Magn Reson Med 79:1325-1333, 2018. © 2017 International Society for Magnetic Resonance in Medicine.

Ultrahigh b-values MRI in normal human prostate: Initial research on reproducibility and age-related differences.

To investigate the reproducibility of diffusion-weighted imaging (DWI) with ultrahigh b-values, and analyze the age-related differences in normal prostates. In all, 67 healthy participants were divided into three age groups (group A, 15-30 years; group B, 31-50 years; group C, ≥51 years), and underwent DWI scanning twice with 15 b-factors from 0 to 3000 at 3.0T. Triexponential fits were applied to calculate the molecular diffusion coefficient (D), the pseudo-diffusion coefficient (D*), the ultrahigh apparent diffusion coefficient (ADCuh ), and perfusion fraction (f). The interobserver and short-term interscan reproducibility were evaluated, and the change in these parameters with age were assessed. The D, ADCuh , and f values presented good to excellent reproducibility. With increasing age, a trend of increasing D values was observed, with significant difference in both peripheral zone (PZ, P = 0.01) and central gland (CG, P = 0.01) of normal prostate tissue. The f value increased in the CG beginning at 50 years of age while the ADCuh value decreased in the PZ after 50 years of age; all of them showed significant differences between groups A and C and groups B and C (P = 0.01/0.01). The D, ADCuh , and f values have good to excellent reproducibility in the normal prostate, and these values change with age. The ultrahigh b-values magnetic resonance imaging (MRI) can provide additional information (ADCuh ), which is different from the IVIM (intravoxel incoherent motion)-derived parameters. 1 Technical Efficacy: Stage 2 J. MAGN. RESON. IMAGING 2017;46:801-812.

Adenomatous-Dominant Benign Prostatic Hyperplasia (AdBPH) as a Predictor for Clinical Success Following Prostate Artery Embolization: An Age-Matched Case–Control Study

To investigate the clinical impact of performing prostate artery embolization (PAE) on patients with adenomatous-dominant benign prostatic hyperplasia (AdBPH). Twelve patients from the ongoing proSTatic aRtery EmbolizAtion for the treatMent of benign prostatic hyperplasia (STREAM) trial were identified as having AdBPH; defined as two or more adenomas within the central gland of ≥1cm diameter on multi-parametric MRI (MP-MRI). These patients were age-matched with patients from the STREAM cohort, without AdBPH. Patients were followed up with repeat MP-MRI at 3months and 1year. International prostate symptom score (IPSS), international index for erectile function (IIEF), and quality of life assessment from the IPSS and EQ-5D-5S questionnaires were recorded pre-PAE and at 6weeks, 3months, and 1year. The mean age of patients was 68 (61-76). All patients had PAE as a day-case procedure. The technical success in the cohort was 23/24 (96%). There was a significant reduction in prostate volume following embolization with a median reduction of 34% (30-55) in the AdBPH group, compared to a mean volume reduction of 22% (9-44) in the non-AdBPH group (p=0.04). There was a significant reduction in IPSS in the AdBPH group following PAE when compared with the control group [AdBPH median IPSS 8 (3-15) vs. non-AdBPH median IPSS 13 (8-18), p=0.01]. IPSS QOL scores significantly improved in the AdBPH group (p=0.007). There was no deterioration in sexual function in either group post-PAE. This is the first time that AdBPH has been identified as being a predictor of clinical success following PAE.

Computational imaging reveals shape differences between normal and malignant prostates on MRI

We seek to characterize differences in the shape of the prostate and the central gland (combined central and transitional zones) between men with biopsy confirmed prostate cancer and men who were identified as not having prostate cancer either on account of a negative biopsy or had pelvic imaging done for a non-prostate malignancy. T2w MRI from 70 men were acquired at three institutions. The cancer positive group (PCa+) comprised 35 biopsy positive (Bx+) subjects from three institutions (Gleason scores: 6–9, Stage: T1–T3). The negative group (PCa−) combined 24 biopsy negative (Bx−) from two institutions and 11 subjects diagnosed with rectal cancer but with no clinical or MRI indications of prostate cancer (Cl−). The boundaries of the prostate and central gland were delineated on T2w MRI by two expert raters and were used to construct statistical shape atlases for the PCa+, Bx− and Cl− prostates. An atlas comparison was performed via per-voxel statistical tests to localize shape differences (significance assessed at p < 0.05). The atlas comparison revealed central gland hypertrophy in the Bx− subpopulation, resulting in significant volume and posterior side shape differences relative to PCa+ group. Significant differences in the corresponding prostate shapes were noted at the apex when comparing the Cl− and PCa+ prostates.

3:00 PMAbstract No. 342 - Duplicated prostate artery central gland blood supply: anatomic subtypes and relevance for prostate artery embolization

3:00 PMAbstract No. 342 - Duplicated prostate artery central gland blood supply: anatomic subtypes and relevance for prostate artery embolization

MR elastography to measure the effects of cancer and pathology fixation on prostate biomechanics, and comparison with T1, T2 and ADC

MRI is under evaluation for image-guided intervention for prostate cancer. The sensitivity and specificity of MRI parameters is determined via correlation with the gold-standard of histopathology. Whole-mount histopathology of prostatectomy specimens can be digitally registered to in vivo imaging for correlation. When biomechanical-based deformable registration is employed to account for deformation during histopathology processing, the ex vivo biomechanical properties are required. However, these properties are altered by pathology fixation, and vary with disease. Hence, this study employs magnetic resonance elastography (MRE) to measure ex vivo prostate biomechanical properties before and after fixation.A quasi-static MRE method was employed to measure high resolution maps of Young’s modulus (E) before and after fixation of canine prostate and prostatectomy specimens (n = 4) from prostate cancer patients who had previously received radiation therapy. For comparison, T1, T2 and apparent diffusion coefficient (ADC) were measured in parallel.E (kPa) varied across clinical anatomy and for histopathology-identified tumor: peripheral zone: 99(±22), central gland: 48(±37), tumor: 85(±53), and increased consistently with fixation (factor of 11 ± 5; p < 0.02). T2 decreased consistently with fixation, while changes in T1 and ADC were more complex and inconsistent.The biomechanics of the clinical prostate specimens varied greatly with fixation, and to a lesser extent with disease and anatomy. The data obtained will improve the precision of prostate pathology correlation, leading to more accurate disease detection and targeting.

Adenoid cystic carcinoma of the mandible: A rare clinical entity

Adenoid cystic carcinoma (ACC) is an uncommon salivary gland malignancy that presents insidiously and is generally in the advanced stage when diagnosed. Besides the oral cavity, other locations may be affected, for example, nasal cavity, paranasal sinus, pharynx, esophagus, larynx, tracheobronchial tree, eye, and external auditory canal. The primary central salivary gland neoplasms of the mandible are infrequent. Their clinical and radiographic features may be similar to odontogenic tumors, which are otherwise common. Their accurate diagnosis becomes troublesome. Hence, diagnosis should depend on stringent diagnostic criteria. This article documents the clinical, radiographic, and histological features of a case of ACC of posterior mandible.

Differential diagnosis of prostate cancer and noncancerous tissue in the peripheral zone and central gland using the quantitative parameters of DCE-MRI: A meta-analysis.

Background:The objective of this meta-analysis was to evaluate the clinical usefulness of Ktrans, Kep, and Ve values in the differential diagnosis of prostate cancer (PCa) and noncancerous tissue in the peripheral zone (PZ) and central gland (CG).Methods:A search was conducted of the PubMed, MEDLINE, EMBASE, Cochrane Library, China National Knowledge Infrastructure, and Wanfang databases from January 2000 to October 2015 using the search terms “prostate cancer,” “ dynamic contrast-enhanced (DCE),” “magnetic resonance imaging,” “Ktrans,” “Kep,” and “Ve.” Studies were selected and included according to strict eligibility criteria. Standardized mean differences (SMDs) and 95% confidence intervals (CIs) were used to compare Ktrans, Kep, and Ve values between PCa and noncancerous tissue.Results:Fourteen studies representing 484 patients highly suspicious for prostate adenocarcinoma were selected for the meta-analysis. We found that Ktrans values measured by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) were significantly higher in PCa tissue than in noncancerous tissue in the PZ (SMD 1.57, 95% CI 0.98–2.16; z = 5.21, P <0.00001) and CG (SMD 1.19, 95% CI 0.46–1.91; z = 3.21, P = 0.001). Kep values measured by DCE-MRI were significantly higher in PCa than in noncancerous tissue in the PZ (SMD 1.41, 95% CI 0.92–1.91; z = 5.59, P < 0.00001) and CG (SMD 1.57, 95% CI 0.69–2.46; z = 3.49, P = 0.0005). Ve values generated by DCE-MRI were slightly higher in PCa than in noncancerous tissue in the PZ (SMD 0.72, 95% CI 0.17–1.27; z = 2.58, P = 0.010), but sensitivity analysis found that the Ve value was unstable for differentiation between PCa and noncancerous PZ tissue. However, there was no significant difference in the Ve value between PCa and noncancerous CG tissue (SMD −0.29, 95% CI −1.18, 0.59; z = 0.65, P = 0.51).Conclusion:Our meta-analysis shows that Ktrans and Kep were the most reliable parameters for differentiating PCa from noncancerous tissue and were critical for evaluation of the internal structure of cancer. The Ve value was not helpful for distinguishing PCa from noncancerous CG tissue; its ability to distinguish between PCa and noncancerous PZ tissue remains uncertain.