Computed high b-value diffusion-weighted imaging improves lesion contrast and conspicuity in prostate cancer.
BACKGROUND
To evaluate whether very high b-value computed diffusion-weighted imaging (cDWI) is able to provide better contrast between the foci of prostate cancer and background tissue than the standard apparent diffusion coefficient (ADC) map, and whether this improved contrast could be used to improve the tumor detection.


METHODS
Very high b-value cDWI series up to b4000 were created for 14 patients with high-grade prostate cancer. Contrast-to-noise ratios (CNRs) and CNR-to-ADC ratios were calculated. Three blinded readers also assessed the tumor conspicuity on a standard five-point scale.


RESULTS
The tumor CNR increased with increasing b-values in all the patients up to a maximum average CNR of 75.1 for a b-value of 4000 (average CNR for the ADC maps: 10.0). CNR/ADC ratios were higher than 1 (indicating higher CNR than respective ADC) for cDWI of 1500 and higher, with a maximum of 6.5 for cDWI4000. The average subjective tumor conspicuity scores for cDWI2000, 3000 and 4000 were significantly higher than that of the ADC (4.0): 4.5 (P=0.018), 4.5 (P=0.017) and 4.6 (P=0.012).


CONCLUSIONS
cDWI is able to provide better contrast between the foci of prostate cancer and background tissue compared with a standard ADC map. This resulted in improved subjective tumor conspicuity.
Department of Radiology & Medical Imaging, University of Virginia Health System, Charlottesville, VA, USA.
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Feuerlein
Department of Radiology, University of Michigan Health System, Ann Arbor, MI, USA.
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MS
Davenport
Department of Radiology & Medical Imaging, University of Virginia Health System, Charlottesville, VA, USA.
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Krishnaraj
Department of Radiology, University of Basel, Basel, Switzerland.
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EM
Merkle
Department of Radiology, Duke University Medical Center DUMC, Durham, NC, USA.
R T
RT
Gupta
D000368:Aged; D038524:Diffusion Magnetic Resonance Imaging; D006801:Humans; D008297:Male; D008875:Middle Aged; D011467:Prostate / Q000000981:diagnostic imaging* / Q000473:pathology; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D011859:Radiography; D019275:Radiopharmaceuticals / Q000627:therapeutic use
D019275:Radiopharmaceuticals