To Evaluate the Damage of Renal Function in CIAKI Rats at 3T: Using ASL and BOLD MRI

Purpose. To investigate noninvasive arterial spin-labeling (ASL) and blood oxygen level-dependent imaging (BOLD) sequences for measuring renal hemodynamics and oxygenation in contrast induced acute kidney injury (CIAKI) rat.Materials and Methods. Thirteen SD rats were randomly grouped into CIAKI group and control group. Both ASL and BOLD sequences were performed at 24 h preinjection and at intervals of 0.5, 12, 24, 48, 72, and 96 h postinjection to assess renal blood flow (RBF) and relative spin-spin relaxation rate(R2*), respectively.Results. For the CIAKI group, the value of RBF in the cortex (CO) and outer medulla (OM) of the kidney was significantly decreased (P<0.05) at 12–48 h and regressed to baseline level (P=NS) at 72–96 h. In OM, the value ofR2*was increased at 0.5–48 h (P<0.05) and not statistically significant (P=NS) at 72 and 96 h. Conclusions. RBF in OM and CO and oxygen level in OM were decreased postinjection of CM. ASL combining BOLD can further identify the primary cause of the decrease of renal oxygenation in CIAKI. This approach provides means for noninvasive monitoring renal function during the first 4 days of CIAKI in clinical routine work.

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Evaluation of placental oxygenation index using blood oxygen level-dependent magnetic resonance imaging (BOLD-MRI) during normal late pregnancy

The Journal of Maternal-Fetal & Neonatal Medicine ◽

10.1080/14767058.2021.1878140 ◽

2021 ◽

pp. 1-13

Author(s):

Shoichi Magawa ◽

Masafumi Nii ◽

Masaki Ishida ◽

Shinichi Takase ◽

Ryohei Nakayama ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Oxygenation Index ◽

Late Pregnancy ◽

Blood Oxygen Level Dependent ◽

Blood Oxygen ◽

Oxygen Level ◽

Resonance Imaging ◽

Blood Oxygen Level ◽

Bold Mri

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Evaluation of Renal Tissue Oxygenation Using Blood Oxygen Level-Dependent Magnetic Resonance Imaging in Chronic Kidney Disease

Kidney & Blood Pressure Research ◽

10.1159/000515709 ◽

2021 ◽

pp. 1-11

Author(s):

Fen Chen ◽

Han Yan ◽

Fan Yang ◽

Li Cheng ◽

Siwei Zhang ◽

...

Keyword(s):

Renal Function ◽

Tissue Oxygenation ◽

Blood Oxygen Level Dependent ◽

Renal Tissue ◽

Selection Method ◽

Resonance Imaging ◽

Blood Oxygen Level ◽

Bold Mri ◽

Function Group ◽

Renal Function Group

Background: Blood oxygen level-dependent magnetic resonance imaging (BOLD-MRI) has been widely used to assess renal oxygenation changes in different kidney diseases in recent years. This study was designed to evaluate and compare renal tissue oxygenation using 2 BOLD-MRI analysis methods, namely, the regional and whole-kidney region of interest (ROI) selection methods. Methods: The study ended up with 10 healthy controls and 40 chronic kidney disease (CKD) patients without dialysis. Their renal BOLD-MRI data were analyzed using whole-kidney ROI selection method and compared with regional ROI selection method. Results: We found the cortical, medullary, and whole-kidney R2* values were significantly higher in CKD patients than those in controls. Compared with the regional ROI selection method, the whole-kidney ROI selection method yielded higher cortical R2* values in both controls and CKD patients. The whole-kidney R2* values of deteriorating renal function group were significantly higher than those in stable renal function group. Conclusions: Cortical and medullary oxygenation was decreased significantly in CKD patients compared with the healthy controls, particularly in the medulla. The whole-kidney R2* values were positively correlated with kidney function and inversely correlated with the estimated glomerular filtration rate and effective renal plasma flow. Whole-Kidney R2* value might effectively predict the progression of renal function in patients with CKD.

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Measurement of renal tissue oxygenation with blood oxygen level-dependent MRI and oxygen transit modeling

AJP Renal Physiology ◽

10.1152/ajprenal.00575.2013 ◽

2014 ◽

Vol 306 (6) ◽

pp. F579-F587 ◽

Cited By ~ 29

Author(s):

Jeff L. Zhang ◽

Glen Morrell ◽

Henry Rusinek ◽

Lizette Warner ◽

Pierre-Hugues Vivier ◽

...

Keyword(s):

Tissue Oxygenation ◽

Human Subjects ◽

Blood Oxygen Level Dependent ◽

Renal Tissue ◽

Blood Oxygen ◽

Oxygen Level ◽

Blood Oxygen Level ◽

Healthy Human ◽

Bold Mri ◽

Before And After

Blood oxygen level-dependent (BOLD) MRI data of kidney, while indicative of tissue oxygenation level (Po2), is in fact influenced by multiple confounding factors, such as R2, perfusion, oxygen permeability, and hematocrit. We aim to explore the feasibility of extracting tissue Po2 from renal BOLD data. A method of two steps was proposed: first, a Monte Carlo simulation to estimate blood oxygen saturation (SHb) from BOLD signals, and second, an oxygen transit model to convert SHb to tissue Po2. The proposed method was calibrated and validated with 20 pigs (12 before and after furosemide injection) in which BOLD-derived tissue Po2 was compared with microprobe-measured values. The method was then applied to nine healthy human subjects (age: 25.7 ± 3.0 yr) in whom BOLD was performed before and after furosemide. For the 12 pigs before furosemide injection, the proposed model estimated renal tissue Po2 with errors of 2.3 ± 5.2 mmHg (5.8 ± 13.4%) in cortex and −0.1 ± 4.5 mmHg (1.7 ± 18.1%) in medulla, compared with microprobe measurements. After injection of furosemide, the estimation errors were 6.9 ± 3.9 mmHg (14.2 ± 8.4%) for cortex and 2.6 ± 4.0 mmHg (7.7 ± 11.5%) for medulla. In the human subjects, BOLD-derived medullary Po2 increased from 16.0 ± 4.9 mmHg (SHb: 31 ± 11%) at baseline to 26.2 ± 3.1 mmHg (SHb: 53 ± 6%) at 5 min after furosemide injection, while cortical Po2 did not change significantly at ∼58 mmHg (SHb: 92 ± 1%). Our proposed method, validated with a porcine model, appears promising for estimating tissue Po2 from renal BOLD MRI data in human subjects.

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Comparison of blood oxygen level-dependent imaging and diffusion-weighted imaging in early diagnosis of acute kidney injury in animal models

Journal of Magnetic Resonance Imaging ◽

10.1002/jmri.26617 ◽

2019 ◽

Vol 50 (3) ◽

pp. 719-724 ◽

Cited By ~ 2

Author(s):

Bihui Zhang ◽

Yao Wang ◽

Chengyan Wang ◽

Haochen Wang ◽

Hanjing Kong ◽

...

Keyword(s):

Acute Kidney Injury ◽

Animal Models ◽

Early Diagnosis ◽

Diffusion Weighted Imaging ◽

Kidney Injury ◽

Blood Oxygen Level Dependent ◽

Blood Oxygen ◽

Oxygen Level ◽

Blood Oxygen Level ◽

And Diffusion

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Utility of blood oxygen level dependent magnetic resonance imaging in the evaluation of tissue oxygenation patterns of prostate cancer.

Journal of Clinical Oncology ◽

10.1200/jco.2013.31.6_suppl.198 ◽

2013 ◽

Vol 31 (6_suppl) ◽

pp. 198-198

Author(s):

Bishoy A. Gayed ◽

Rami Hallac ◽

Ramy F. Youssef ◽

Franto Francis ◽

Qing Yuan ◽

...

Keyword(s):

Prostate Cancer ◽

Signal Intensity ◽

Tissue Oxygenation ◽

Blood Oxygen Level Dependent ◽

Preoperative Imaging ◽

Blood Oxygen ◽

Oxygen Level ◽

Blood Oxygen Level ◽

Bold Mri ◽

Pathologic Features

198 Background: Tumor hypoxia is associated with worse pathologic features and oncological outcomes. Blood Oxygen Level Dependent (BOLD) MRI evaluates changes in endogenous contrast generated by paramagnetic deoxy-hemoglobin to non-invasively evaluate tissue oxygenation. Prior attempts using carbogen-based (95%O2 + 5%CO2) imaging were limited by patient tolerance. We present the first-in-man evaluation of a novel oxygen breathing challenge technique to monitor tissue oxygenation with BOLD MRI in patients with prostate cancer. Methods: Following IRB approval, 10 patients with clinically localized prostate cancer scheduled for radical prostatectomy underwent preoperative imaging with a 3-Tesla MRI scanner. Images were acquired using a 6-element SENSE body transmit coil and endorectal receive coil. T2* signal intensity is dependent on the concentration of deoxy-hemoglobin. Signal intensity measurements were obtained at different time points. Shorter T2* times imply the presence of hypoxia. Dynamic T2* maps were acquired while subjects breathed air for 2 mins followed by oxygen (15 l/min). Results: 10 patients (median age: 59 years (range 48-73), median PSA 6.9 ng/ml (range 2.5-25), with prostate cancer (Gleason sum 6- 7, 8-9 in 7 and 3 patients respectively) underwent BOLD MRI within 3 weeks of definitive management with a robotic assisted laparoscopic prostatectomy. All patients tolerated BOLD MRI with oxygen challenge without difficulty. Evaluation of BOLD MRI revealed wide variation in T2* values within the prostates from a median of 14.7 ± .71 ms to 44.5 ± 3.3ms. Surrounding muscle T2* values were similar for all patients, indicating that heterogeneous values were specific to each patient’s prostate. Shorter T2* values were seen in Gleason 6-7 than Gleason 8- 9 cancers, indicating more hypoxic areas in these tumors. HIF-1α staining was strongly positive in all tumors. Conclusions: BOLD MRI with oxygen challenge is well tolerated in patients and is a feasible noninvasive technique to study tissue oxygenation in tumors. Differential oxygenation patterns of prostates appear to correlate with pathological features. Further testing is needed to validate these findings.

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