scholarly journals Imaging effective oxygen diffusivity in the human brain with multiparametric magnetic resonance imaging

2021 ◽  
pp. 0271678X2110484
Author(s):  
Jan Kufer ◽  
Christine Preibisch ◽  
Samira Epp ◽  
Jens Göttler ◽  
Lena Schmitzer ◽  
...  

Cerebrovascular diseases can impair blood circulation and oxygen extraction from the blood. The effective oxygen diffusivity (EOD) of the capillary bed is a potential biomarker of microvascular function that has gained increasing interest, both for clinical diagnosis and for elucidating oxygen transport mechanisms. Models of capillary oxygen transport link EOD to measurable oxygen extraction fraction (OEF) and cerebral blood flow (CBF). In this work, we confirm that two well established mathematical models of oxygen transport yield nearly equivalent EOD maps. Furthermore, we propose an easy-to-implement and clinically applicable multiparametric magnetic resonance imaging (MRI) protocol for quantitative EOD mapping. Our approach is based on imaging OEF and CBF with multiparametric quantitative blood oxygenation level dependent (mq-BOLD) MRI and pseudo-continuous arterial spin labeling (pCASL), respectively. We evaluated the imaging protocol by comparing MRI-EOD maps of 12 young healthy volunteers to PET data from a published study in different individuals. Our results show comparably good correlation between MRI- and PET-derived cortical EOD, OEF and CBF. Importantly, absolute values of MRI and PET showed high accordance for all three parameters. In conclusion, our data indicates feasibility of the proposed MRI protocol for EOD mapping, rendering the method promising for future clinical evaluation of patients with cerebrovascular diseases.

2021 ◽  
pp. 205141582110237
Author(s):  
Enrico Checcucci ◽  
Sabrina De Cillis ◽  
Daniele Amparore ◽  
Diletta Garrou ◽  
Roberta Aimar ◽  
...  

Objectives: To determine if standard biopsy still has a role in the detection of prostate cancer or clinically significant prostate cancer in biopsy-naive patients with positive multiparametric magnetic resonance imaging. Materials and methods: We extracted, from our prospective maintained fusion biopsy database, patients from March 2014 to December 2018. The detection rate of prostate cancer and clinically significant prostate cancer and complication rate were analysed in a cohort of patients who underwent fusion biopsy alone (group A) or fusion biopsy plus standard biopsy (group B). The International Society of Urological Pathology grade group determined on prostate biopsy with the grade group determined on final pathology among patients who underwent radical prostatectomy were compared. Results: Prostate cancer was found in 249/389 (64.01%) and 215/337 (63.8%) patients in groups A and B, respectively ( P=0.98), while the clinically significant prostate cancer detection rate was 57.8% and 55.1% ( P=0.52). No significant differences in complications were found. No differences in the upgrading rate between biopsy and final pathology finding after radical prostatectomy were recorded. Conclusions: In biopsy-naive patients, with suspected prostate cancer and positive multiparametric magnetic resonance imaging the addition of standard biopsy to fusion biopsy did not increase significantly the detection rate of prostate cancer or clinically significant prostate cancer. Moreover, the rate of upgrading of the cancer grade group between biopsy and final pathology was not affected by the addition of standard biopsy. Level of evidence: Not applicable for this multicentre audit.


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