Intermixed Normal Tissue within Prostate Cancer: Effect on MR Imaging Measurements of Apparent Diffusion Coefficient and T2—Sparse versus Dense Cancers

Langer, Deanna L.; Kwast, Theodorus H. van der; Evans, Andrew; Sun, Laibao; Yaffe, Martin J.; Trachtenberg, John; Haider, M.

doi:10.1148/radiol.2493080236

Cited by 225 publications

(155 citation statements)

References 28 publications

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“…This difference disappeared when the fit of the monoexponential decay was limited to the early echoes. The previously published prostate T2 relaxation times based on monoexponential fits range from approximately 60 ms for tumor and the central gland to more than 300 ms for the peripheral zone (13)(14)(15)(16)(17)(18)(19). There is a large scatter in the estimates, presumably due to the variation in acquisition techniques.…”

Section: Discussionmentioning

confidence: 99%

Three‐dimensional balanced steady state free precession imaging of the prostate: Flip angle dependency of the signal based on a two component T2‐decay model

Storås

Gjesdal²,

Gadmar

et al. 2010

Magnetic Resonance Imaging

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Purpose: To investigate the contrast of three-dimensional balanced steady state free precession (3D bSSFP) in the two component T2 model and to apply the results to optimize 3D bSSFP for prostate imaging at 1.5 Tesla. Materials and Methods:In each of seven healthy volunteers, six 3D bSSFP acquisitions were performed with flip angles (a) equally spaced between 10 and 110 . Predictions of signal and contrast were obtained from synthetic bSSFP images calculated from relaxation parameters obtained from a multi-spin-echo acquisition. One biexponential and two monoexponential models were applied. Measured and predicted signals were compared by simple linear regression. Results:The measured contrast to signal ratio increased continuously with a. Mean R 2 for the biexponential model was almost constant for a in the range 50-110 . The biexponential model was a better predictor of the measured signal than the monoexponential model. A monoexponential model restricted to the echoes TE ¼ 50-125 ms performed similar to the biexponential model. The predicted contrast peaked at a between 50 and 90 .Conclusion: Prostate imaging with bSSFP benefited from high flip angles. The biexponential model provided good signal prediction while predictions from the monoexponential models are dependent on the range of TE used for T2 determination. IN PROSTATE IMAGING, anatomical details are excellently depicted by MRI using T2-weighted rapid acquisition with relaxation enhancement (RARE) (also known as T2W-TSE or T2W-FSE), which has been the gold standard (1,2).Diagnostic performance has improved as new technological developments such as endorectal coil imaging and increasing field strengths has allowed for imaging at higher resolutions (2-4). The T2W-RARE applies a 2D sampling regime. Hence, imaging is constrained to relatively thick (>3 mm) slices. The diagnostic performance is expected to improve if throughplane image resolution is increased. To achieve thinner slices, a 3D sampling regimen is required. Ikonen et al (5) demonstrated thin-slice (1.5 mm) prostate imaging by applying the 3D dual-echo steady state (DESS) (6) technique. Further improvements in resolution may be gained by applying the simpler and more time-efficient balanced steady state free precession (bSSFP) sequence also known as balanced FFE, TrueFISP,. This technique is ideal for 3D scanning because it may be implemented with very short repetition time (TR) without loss of signal.The contrast of bSSFP has been thoroughly described (7-9). It is dependent on the tissue T2/T1-ratio, flip angle, and resonance offset. It has been shown that T2 decay in prostate tissue is of biexponential nature (10,11). The bSSFP signal may be predicted based on the results of the two component model. This presumably provides a more accurate tool for sequence optimization than the use of the monoexponential model.The aim of this work was to investigate the contrast of 3D bSSFP in the light of a two component T2 model and to apply the results to optimize high resolution 3D bSSFP for prostate im...

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Section: Discussionmentioning

confidence: 99%

Three‐dimensional balanced steady state free precession imaging of the prostate: Flip angle dependency of the signal based on a two component T2‐decay model

Storås

Gjesdal²,

Gadmar

et al. 2010

Magnetic Resonance Imaging

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“…Reinsberg et al [50] noted that DWI with the tumour occupying approximately 30% of the voxel, sensitivity and specificity were 67% and 60%, but when tumour occupied approximately 70% of the voxel, sensitivity and specificity increased to 93% and 57% respectively. In the recent study by Langer et al [64] it was shown that DWI is unable to differentiate between sparse PC (as defined by tumour of less than 40% within the lesion) and normal PZ tissue. Logically, higher resolution imaging would improve lesion detection, although this needs further validation.…”

Section: Voxel Sizementioning

confidence: 99%

Diffusion weighted imaging in prostate cancer

2010

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Diffusion-weighted imaging has generated substantial interest in the hope that it can be developed into a robust technique to improve the accuracy of MRI for the evaluation of prostate cancer. This technique has the advantages of short acquisition times, no need for intravenous administration of contrast medium, and the ability to study diffusion of water molecules that indirectly reflects tissue cellularity. In this article, we review the existing literature on the utility of DWI in tumour detection, localisation, treatment response, limitations of the technique, how it compares with other imaging techniques, technical considerations and future directions.

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“…On the other hand, densely growing cancers do show lower quantitative T2 values. 10 A limitation of T2-weighted imaging is that focal areas of low signal intensity in the peripheral zone do not always represent cancer. Benign abnormalities such as chronic prostatitis, atrophy, scars, post irradiation or hormonal treatment effects, hyperplasia, and post biopsy hemorrhage may mimic tumor tissue.…”

Section: Discussionmentioning

confidence: 99%

Role of multiparametric MRI in detection of prostatic lesions; of evaluation contrast enhanced MRI, diffusion weighted imaging and MR spectroscopy in malignant and benign prostatic lesions

Yadav

Bhargava

2016

Int J Res Med Sci

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INTRODUCTIONProstate cancer is the most common cancer detected in men in the United States. Approximately 230,000 American men were diagnosed with prostate cancer in 2005.1 Prostate cancer is the second leading cause of cancer death for men.Despite the efficiency of clinical staging, it remains imperfect for precise local cancer staging and intra ABSTRACT Background: Prostate cancer is the most commonly diagnosed cancer in males and one of the leading causes of cancer-related death in men. Pretreatment assessment of prostate cancer is divided into detection, localization, and staging; accurate assessment is a prerequisite for optimal clinical management and therapy selection. The purpose of the study is to determine the diagnostic accuracy of multiparametric MRI for prostatic cancer detection using T2 weighted MR imaging, diffusion weighted imaging (DWI) and contrast enhanced MRI. To determine the use of MR spectroscopy in prostatic lesions. Methods: It is a prospective single institutional study done on 29 patients with prostate lesions and elevated PSA level. Axial, coronal and sagittal images were obtained using T1WI, T2WI and STIR sequences. Advanced sequences like Diffusion weighted images, Spectroscopy and post gadolinium T1WI were taken after the basic MRI images. Results: Study was done in 29 patients, age was ranging between 51years to 90 years, mean age is 70.7 years. On multiparametric MRI findings 45% were detected malignant lesions and 55% patients detected benign lesions. On biopsy correlation 42% of these cases turned out to be malignant and 58% as benign lesions. Detection of malignancy by T2WI imaging alone given sensitivity of 80.1% and specificity of 85.4%.By DWI alone sensitivity was 85.7% and specificity was 89.4%,on MRS sensitivity is 90.6% and specificity was 91.1%. Combined (MRI+DWI+MRS) gave sensitivity of 92.3% and specificity of 94.4% for detection of malignant prostatic lesion. Positive predictive value is 90% and negative predictive value was 88%. Conclusions: The best characterization of prostatic cancer in individual patients will most likely result from a multiparametric exam. Recent advances include additional functional and physiologic MR imaging techniques (diffusion weighted imaging, MR spectroscopy, and perfusion imaging), which allow extension of the obtainable information beyond anatomic assessment. Multiparametric MR imaging provides the highest accuracy in diagnosis and staging of prostate cancer.

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Intermixed Normal Tissue within Prostate Cancer: Effect on MR Imaging Measurements of Apparent Diffusion Coefficient and T2—Sparse versus Dense Cancers

Abstract: Sparse prostate tumors have similar ADC and T2 values to those of normal PZ tissue. This may limit MR imaging detection and the assessment of tumor volume of some cancers.

Cited by 225 publications

References 28 publications

Three‐dimensional balanced steady state free precession imaging of the prostate: Flip angle dependency of the signal based on a two component T2‐decay model

Three‐dimensional balanced steady state free precession imaging of the prostate: Flip angle dependency of the signal based on a two component T2‐decay model

Diffusion weighted imaging in prostate cancer

Role of multiparametric MRI in detection of prostatic lesions; of evaluation contrast enhanced MRI, diffusion weighted imaging and MR spectroscopy in malignant and benign prostatic lesions

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