BOLD MRI: a tool for predicting tumor therapy outcome based on tumor blood oxygenation and vascular function

2009 ◽  
Vol 1 (1) ◽  
pp. 11-13 ◽  
Author(s):  
Ralph P Mason
Keyword(s):  
Vascular Function ◽  
Tumor Therapy ◽  
Blood Oxygenation ◽  
Therapy Outcome ◽  
Bold Mri

scholarly journals BOLD MRI to evaluate early development of renal injury in a rat model of diabetes

2018 ◽  
Vol 46 (4) ◽  
pp. 1391-1403 ◽  
Author(s):  
Qidong Wang ◽  
Chuangen Guo ◽  
Lan Zhang ◽  
Rui Zhang ◽  
Zhaoming Wang ◽  
...  
Keyword(s):  
Renal Injury ◽  
Diabetic Rats ◽  
Blood Oxygenation ◽  
Dynamic Changes ◽  
Bold Mri ◽  
Oxygenation Level ◽  
Mri Scans ◽  
Streptozotocin Induced Diabetes ◽  
Magnetic Resonance Imaging Mri ◽  
Diabetes Induction

Objective To investigate changes in renal oxygenation levels by blood-oxygenation-level dependent (BOLD)-magnetic resonance imaging (MRI), and to evaluate BOLD-MRI for detecting early diabetic renal injury. Methods Seventy-five rats, with unilateral nephrectomy, were randomly divided into streptozotocin-induced diabetes mellitus (DM, n = 65) and normal control (NC, n = 10) groups. BOLD-MRI scans were performed at baseline (both groups) and at 3, 7, 14, 21, 28, 35, 42, 49, 56, 63 and 70 days (DM only). Renal cortical (C) and medullary (M) R2* signals were measured and R2* medulla/cortex ratio (MCR) was calculated. Results DM-group CR2* and MR2* values were significantly higher than NC values following diabetes induction. R2* values increased gradually and peaked at day 35 (CR2*, 33.95 ± 0.34 s–1; MR2*, 43.79 ± 1.46 s–1), then dropped gradually (CR2*, 33.17 ± 0.69 s–1; MR2*, 41.61 ± 0.95 s–1 at day 70). DM-group MCR rose gradually from 1.12 to 1.32 at day 42, then decreased to 1.25 by day 70. Conclusions BOLD-MRI can be used to non-invasively evaluate renal hypoxia and early diabetic renal injury in diabetic rats. MCR may be adopted to reflect dynamic changes in renal hypoxia.

scholarly journals The Cumulative Influence of Hyperoxia and Hypercapnia on Blood Oxygenation and R2*

2015 ◽  
Vol 35 (12) ◽  
pp. 2032-2042 ◽  
Author(s):  
Carlos C Faraco ◽  
Megan K Strother ◽  
Jeroen CW Siero ◽  
Daniel F Arteaga ◽  
Allison O Scott ◽  
...  
Keyword(s):  
Venous Blood ◽  
Quantitative Information ◽  
Blood Oxygenation ◽  
Cerebrovascular Reactivity ◽  
Resonance Imaging ◽  
Tissue Water ◽  
Bold Mri ◽  
Bold Imaging ◽  
Complex Interactions ◽  
Oxygenation Level

Cerebrovascular reactivity (CVR)-weighted blood-oxygenation-level-dependent magnetic resonance imaging (BOLD-MRI) experiments are frequently used in conjunction with hyperoxia. Owing to complex interactions between hyperoxia and hypercapnia, quantitative effects of these gas mixtures on BOLD responses, blood and tissue R2∗, and blood oxygenation are incompletely understood. Here we performed BOLD imaging (3T; TE/TR = 35/2,000 ms; spatial resolution = 3×3×3.5 mm3) in healthy volunteers ( n = 12; age = 29±4.1 years) breathing (i) room air (RA), (ii) normocapnic-hyperoxia (95% O2/5% N2, HO), (iii) hypercapnic-normoxia (5% CO2/21% O2/74% N2, HC-NO), and (iv) hypercapnic-hyperoxia (5% CO2/95% O2, HC-HO). For HC-HO, experiments were performed with separate RA and HO baselines to control for changes in O2. T2-relaxation-under-spin-tagging MRI was used to calculate basal venous oxygenation. Signal changes were quantified and established hemodynamic models were applied to quantify vasoactive blood oxygenation, blood–water R∗2, and tissue-water R∗2. In the cortex, fractional BOLD changes (stimulus/baseline) were HO/RA = 0.011 ± 0.007; HC-NO/RA = 0.014±0.004; HC-HO/HO = 0.020±0.008; and HC-HO/RA = 0.035 ±0.010; for the measured basal venous oxygenation level of 0.632, this led to venous blood oxygenation levels of 0.660 (HO), 0.665 (HC-NO), and 0.712 (HC-HO). Interleaving a HC-HO stimulus with HO baseline provided a smaller but significantly elevated BOLD response compared with a HC-NO stimulus. Results provide an outline for how blood oxygenation differs for several gas stimuli and provides quantitative information on how hypercapnic BOLD CVR and R∗2 are altered during hyperoxia.

Abstract 2240: T2-Prepared Steady-State Free-Precession Blood Oxygenation Level-Dependent MRI in Patients with Coronary Artery Disease and Normal Volunteers: Validation against PET

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Theodoros D Karamitsos ◽  
Alejandro Recio-Mayoral ◽  
Jayanth R Arnold ◽  
Lucia Leccisotti ◽  
Paul Bhamra-Ariza ◽  
...  
Keyword(s):  
Gold Standard ◽  
Blood Oxygenation Level Dependent ◽  
Blood Oxygenation ◽  
Short Axis ◽  
Normal Volunteers ◽  
Bold Mri ◽  
Blood Oxygenation Level ◽  
Oxygenation Level ◽  
Artery Disease ◽  
Perfusion Measurements

Blood oxygenation level-dependent (BOLD) MRI clinical studies at 1.5 Tesla (T) have been principally limited by low signal to noise. We sought to apply this method at 3T in patients with coronary artery disease (CAD) and normal volunteers, and validated it against perfusion measurements by PET. Twenty-two patients (age 62±8 yrs, 16 men) with CAD (at least 1 stenosis > 50% on quantitative coronary angiography-QCA) and 10 normal volunteers (age 52±7 yrs, 7 men) underwent 3T BOLD MRI and PET. For BOLD MRI a mid-ventricular slice was acquired every 30sec at rest and during adenosine stress (140 μg/kg/min). A set of 6 images was acquired at rest and at peak stress. Using PET with oxygen-15 labelled water, myocardial blood flow (MBF) was measured at baseline and during adenosine hyperemia. The BOLD short-axis view was divided into 6 segments, according to the mid-ventricular segments of the 17-AHA segment model, and mean signal intensities (SI) were calculated using QMass (Medis) software. PET images were analyzed with MATLAB software (MathWorks Inc.) and registered with the BOLD short-axis image using anatomical landmarks. Taking QCA as the gold standard, cut-off values for stress MBF (< 2.57ml/min/g - AUC 0.79) and BOLD SI change (< 4.75% -AUC 0.78) were determined to define ischemic segments. Rest MBF, stress MBF, coronary flow reserve and BOLD-SI change of ischemic (n=69), remote to ischemia (n=73) and normal segments (n=60) are shown in table . BOLD MRI and PET agreed on the presence or absence of ischemia in 18 of the 22 patients (82%), and in all normals. With regards to per segment analysis: taking PET as the gold standard and by applying the cut-off values for stress MBF and BOLD SI, BOLD MRI had only moderate sensitivity (61%) but good specificity (88%) for the identification of ischemia. T2-prepared SSFP 3T BOLD imaging is feasible in the clinical setting and has good agreement with PET perfusion measurements for the detection of myocardial ischemia.

Blood oxygenation level-dependent MRI at 3T for differentiating prostate cancer from benign tissue: a preliminary experience

2021 ◽  
pp. 20210461
Author(s):  
Yongtae Kim ◽  
Jung Jae Park ◽  
Chan Kyo Kim
Keyword(s):  
Prostate Cancer ◽  
Regional Distribution ◽  
Specific Antigen ◽  
Blood Oxygenation Level Dependent ◽  
Blood Oxygenation ◽  
Bold Mri ◽  
Benign Tissue ◽  
Blood Oxygenation Level ◽  
Oxygenation Level ◽  
Mean Differences

Objective: Blood oxygenation-level dependent (BOLD) MRI may identify or quantify the regional distribution of hypoxia within a tumor. We aimed to evaluate the feasibility of BOLD MRI at 3 T in differentiating prostate cancer from benign tissue. Methods: A total of 145 patients with biopsy-proven prostate cancer underwent BOLD MRI at 3 T. BOLD MRI was performed using a multiple fast field echo sequence to acquire 12 T2*-weighted images. The R2* value (rate of relaxation, s−1) was measured in the index tumor, and benign peripheral (PZ) and transition zone (TZ), and the results were compared. The variability of R2* measurements was evaluated. Results: Tumor R2* values (25.95 s−1) were significantly different from the benign PZ (27.83 s−1) and benign TZ (21.66 s−1) (p < 0.001). For identifying the tumor, the area under the receiver operating characteristic of R2* was 0.606, with an optimal cut-off value of 22.8 s−1 resulting in 73.8% sensitivity and 52% specificity. In the Bland–Altman test, the mean differences in R2* values were 8.5% for tumors, 13.3% for benign PZ, and 6.8% for benign TZ. No associations between tumor R2* value and Gleason score, age, prostate volume, prostate-specific antigen, or tumor size. Conclusion: BOLD MRI at 3 T appears to be a feasible tool for differentiating between prostate cancer and benign tissue. However, further studies are required for a direct clinical application. Advances in knowledge: The R2* values are significantly different among prostate cancer, benign PZ, and benign TZ.

scholarly journals Oxygenation in cervical cancer and normal uterine cervix assessed using blood oxygenation level-dependent (BOLD) MRI at 3T

2012 ◽  
Vol 25 (12) ◽  
pp. 1321-1330 ◽  
Author(s):  
Rami R. Hallac ◽  
Yao Ding ◽  
Qing Yuan ◽  
Roderick W. McColl ◽  
Jayanthi Lea ◽  
...  
Keyword(s):  
Cervical Cancer ◽  
Uterine Cervix ◽  
Blood Oxygenation Level Dependent ◽  
Blood Oxygenation ◽  
Bold Mri ◽  
Blood Oxygenation Level ◽  
Oxygenation Level

scholarly journals MRI Mapping of the Blood Oxygenation Sensitive Parameter T2* in the Kidney: Basic Concept

2021 ◽  
pp. 171-185
Author(s):  
Lu-Ping Li ◽  
Bradley Hack ◽  
Erdmann Seeliger ◽  
Pottumarthi V. Prasad
Keyword(s):  
Data Acquisition ◽  
Blood Oxygenation ◽  
The European Union ◽  
Noninvasive Method ◽  
Bold Mri ◽  
Oxygenation Level ◽  
Technical Issues ◽  
Renal Mri ◽  
The Cost

AbstractThe role of hypoxia in renal disease and injury has long been suggested but much work still remains, especially as it relates to human translation. Invasive pO2 probes are feasible in animal models but not for human use. In addition, they only provide localized measurements. Histological methods can identify hypoxic tissue and provide a spatial distribution, but are invasive and allow only one-time point. Blood oxygenation level dependent (BOLD) MRI is a noninvasive method that can monitor relative oxygen availability across the kidney. It is based on the inherent differences in magnetic properties of oxygenated vs. deoxygenated hemoglobin. Presence of deoxyhemoglobin enhances the spin–spin relaxation rate measured using a gradient echo sequence, known as R2* (= 1/T2*). While the key interest of BOLD MRI is in the application to humans, use in preclinical models is necessary primarily to validate the measurement against invasive methods, to better understand physiology and pathophysiology, and to evaluate novel interventions. Application of MRI acquisitions in preclinical settings involves several challenges both in terms of logistics and data acquisition. This section will introduce the concept of BOLD MRI and provide some illustrative applications. The following sections will discuss the technical issues associated with data acquisition and analysis.This chapter is based upon work from the COST Action PARENCHIMA, a community-driven network funded by the European Cooperation in Science and Technology (COST) program of the European Union, which aims to improve the reproducibility and standardization of renal MRI biomarkers. This introduction chapter is complemented by two separate chapters describing the experimental procedure and data analysis.

scholarly journals A Reperfusion BOLD-MRI Tissue Perfusion Protocol Reliably Differentiate Patients with Peripheral Arterial Occlusive Disease from Healthy Controls

2021 ◽  
Vol 10 (16) ◽  
pp. 3643
Author(s):  
Kristina Törngren ◽  
Stefanie Eriksson ◽  
Jonathan Arvidsson ◽  
Mårten Falkenberg ◽  
Åse A. Johnsson ◽  
...  
Keyword(s):  
Lower Limb ◽  
Peripheral Arterial Occlusive Disease ◽  
Reactive Hyperemia ◽  
Tissue Perfusion ◽  
Arterial Occlusive Disease ◽  
Blood Oxygenation ◽  
Occlusive Disease ◽  
Healthy Controls ◽  
Bold Mri ◽  
Peripheral Arterial

There is no established technique that directly quantifies lower limb tissue perfusion. Blood oxygenation level-dependent magnetic resonance imaging (BOLD-MRI) is an MRI technique that can determine skeletal muscle perfusion. BOLD-MRI relies on magnetic differences of oxygenated and deoxygenated hemoglobin, and regional changes in oxy/deoxyhemoglobin ratio can be recorded by T2* weighted MRI sequences. We aimed to test whether BOLD-MRI can differentiate lower limb tissue perfusion in peripheral arterial occlusive disease (PAOD) patients and healthy controls. Twenty-two PAOD patients and ten healthy elderly volunteers underwent lower limb BOLD-MRI. Reactive hyperemia was provoked by transient cuff compression and images of the gastrocnemius and soleus muscles were continuously acquired at rest, during ischemia and reperfusion. Key BOLD parameters were baseline T2* absolute value and time to T2* peak value after cuff deflation (TTP). Correlations between imaging parameters and ankle-brachial index (ABI) was investigated. The mean TTP was considerably prolonged in PAOD patients compared to healthy controls (m. gastrocnemius: 111 ± 46 versus 48 ± 22 s, p = 0.000253; m. soleus: 100 ± 42 versus 41 ± 30 s, p = 0.000216). Both gastrocnemius and soleus TTP values correlated strongly with ABI (−0.82 and −0.78, p < 0.01). BOLD-MRI during reactive hyperemia differentiated most PAOD patients from healthy controls. TTP was the most decisive parameter and strongly correlated with the ABI.

Abstract 167: Noninvasive MRI Measurement of Cerebrovascular Reactivity Enables Evaluation of Surgical Revascularization Response in Moyamoya

Stroke ◽  
2014 ◽  
Vol 45 (suppl_1) ◽  
Author(s):  
Travis R Ladner ◽  
Carlos Faraco ◽  
Manus J Donahue ◽  
Daniel Arteaga ◽  
Lori C Jordan ◽  
...  
Keyword(s):  
Tissue Level ◽  
Blood Oxygenation ◽  
Cerebrovascular Reactivity ◽  
Clinical Severity ◽  
Atmospheric Air ◽  
Bold Mri ◽  
Oxygenation Level ◽  
Hemodynamic Improvement ◽  
Mri Changes ◽  
Mri Measurements

Introduction: Frequent dissociation between clinical severity and angiographic grading of moyamoya supports a role for alternative tissue-level hemodynamic measures. Here, angiography is complemented with noninvasive MRI measurements of parenchymal impairment to assess changes in cerebrovascular reactivity (CVR) after extracranial-intracranial bypass in moyamoya. Hypothesis: CVR is regionally impaired pre-operatively, yet increases after surgery. This can be visualized noninvasively by assessing blood oxygenation level-dependent (BOLD) MRI changes with safe, mildly hypercarbic gas. Methods: Using a block MRI paradigm, carbogen (5% CO 2 ; 95% O 2 3 min) was interleaved with atmospheric air (<1% CO 2 ; 3 min) administration during BOLD MRI in intracranial stenosis patients (n=70), a subset of which (n=9; age=35.7+/-10.8; 7F/2M) underwent indirect (n=8) or direct (n=1) revascularization for moyamoya. Five patients had both pre-operative and post-operative hemodynamic imaging, with post-operative scans performed after 7.3+/-4.1 months. CVR, calculated as a z-statistic in response to hypercarbia vs. atmospheric air, was compared (two-tailed t-test) for each patient between the two time points to correlate CVR changes with surgery. Results: Fig. 1 shows BOLD MRI on a patient scanned before and 2 years after right-sided indirect bypass, with significant (t=79.29, p<0.01) right-sided hemodynamic improvement. Cohort analyses of patients with pre/post-operative scans revealed significant interhemispheric CVR differences prior to surgery (t=3.48, p<0.01), which resolved after bypass (t=0.88, p=0.20). Additionally, CVR increased significantly in the operative hemisphere (t=4.50, p<0.01). Conclusions: CVR-weighted hemodynamic MRI can be implemented into routine clinical protocols, corresponds well with revascularization response, and has potential as a noninvasive complement to angiography for serial monitoring of moyamoya patients.

scholarly journals Validation of multiparametric MRI by histopathology after nephrectomy: a case study

2020 ◽  
Author(s):  
Anneloes de Boer ◽  
Tobias T. Pieters ◽  
Anita A. Harteveld ◽  
Peter J. Blankestijn ◽  
Clemens Bos ◽  
...  
Keyword(s):  
Renal Perfusion ◽  
Multiparametric Mri ◽  
Blood Oxygenation ◽  
Histological Evaluation ◽  
Normative Values ◽  
Bold Mri ◽  
Promising Tool ◽  
Oxygenation Level ◽  
Transplant Failure ◽  
Global Increase

Abstract Objectives Renal multiparametric MRI (mpMRI) is a promising tool to monitor renal allograft health to enable timely treatment of chronic allograft nephropathy. This study aims to validate mpMRI by whole-kidney histology following transplantectomy. Materials and methods A patient with kidney transplant failure underwent mpMRI prior to transplantectomy. The mpMRI included blood oxygenation level-dependent (BOLD) MRI, T1 and T2 mapping, diffusion-weighted imaging (DWI), 2D phase contrast (2DPC) and arterial spin labeling (ASL). Parenchymal mpMRI measures were compared to normative values obtained in 19 healthy controls. Differences were expressed in standard deviations (SD) of normative values. The mpMRI measures were compared qualitatively to histology. Results The mpMRI showed a heterogeneous parenchyma consistent with extensive interstitial hemorrhage on histology. A global increase in T1 (+ 3.0 SD) and restricted diffusivity (− 3.6 SD) were consistent with inflammation and fibrosis. Decreased T2 (− 1.8 SD) indicated fibrosis or hemorrhage. ASL showed diminished cortical perfusion (− 2.9 SD) with patent proximal arteries. 2DPC revealed a 69% decrease in renal perfusion. Histological evaluation showed a dense inflammatory infiltrate and fibrotic changes, consistent with mpMRI results. Most interlobular arteries were obliterated while proximal arteries were patent, consistent with ASL findings. Discussion mpMRI findings correlated well with histology both globally as well as locally.

Sign in / Sign up

Export Citation Format

Share Document