Quantitative Methods in Abdominal MRI

Madhuranthakam, Ananth J.; Yuan, Qing; Pedrosa, Iván

doi:10.1097/rmr.0000000000000145

Cited by 14 publications

(8 citation statements)

References 46 publications

(57 reference statements)

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“…Presently, the early detection of liver fibrosis is unclear, and hence, finding a method for the diagnosis of the disease is an urgent requisite. Perfusion-weighted imaging (PWI) is a noninvasive method for assessing microvascular tissue distribution, viability, and function via tissue microcirculation hemodynamics, which is superior to traditional magnetic resonance imaging (MRI) [5,6]. Previously, the clinical application of PWI in thoracic and abdominal organs was limited due to physiological movements [5,7].…”

Section: Introductionmentioning

confidence: 99%

“…Perfusion-weighted imaging (PWI) is a noninvasive method for assessing microvascular tissue distribution, viability, and function via tissue microcirculation hemodynamics, which is superior to traditional magnetic resonance imaging (MRI) [5,6]. Previously, the clinical application of PWI in thoracic and abdominal organs was limited due to physiological movements [5,7]. In recent years, with the development and application of echo-planar imaging (EPI), the influence of physiological activity on signal acquisition is greatly reduced, which lays a foundation for the widespread application of PWI in liver lesions.…”

Section: Introductionmentioning

confidence: 99%

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Application Value of Magnetic Resonance Perfusion Imaging in the Early Diagnosis of Rat Hepatic Fibrosis

Fan

Yang

et al. 2019

BioMed Research International

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Objective. To assess the application value of perfusion-weighted imaging (PWI) in early diagnosis, quantitation, and hepatic fibrosis staging by analyzing the related parameters in hepatic fibrosis. Methods. A total of 60 rats were randomly divided into the hepatic fibrosis and control groups, and carbon tetrachloride (CCL4) was used to establish the liver fibrosis model. All rats underwent PWI examination, and the trend of the time-signal intensity curve (TIC, automatically generated by the software) was observed. Also, the perfusion parameters, maximum signal reduction ratio (SRRmax), time to peak (TTP), and mean transit time (MTT), were analyzed and compared with pathological staging. Results. The TIC curve was characterized by slow wash-in and wash-out with a low and wide peak. The PWI perfusion parameters were statistically significant in specific groups (P<0.05): SRRmax values (control group and F3, F4), TTP, and MTT values (control group and F2–F4, F1 and F3, F1 and F4, and F2 and F4 in addition to TTP values for F1 and F2). Pearson’s correlation analysis showed a negative correlation of SRRmax with hepatic fibrosis stage (r = −0.439, P<0.05), while TTP and MTT values were positively correlated with hepatic fibrosis stage (TTP, r = 0.798; MTT, r = 0.647; all P<0.001). Conclusions. PWI perfusion parameters reflect the degree of hepatic fibrosis, especially TTP and MTT, and PWI is recommended for the early diagnosis of liver fibrosis for timely intervention and treatment of the disease and delaying its progression.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Application Value of Magnetic Resonance Perfusion Imaging in the Early Diagnosis of Rat Hepatic Fibrosis

Fan

Yang

et al. 2019

BioMed Research International

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“…The results of our research indicate that the use of drugs allows the limitation of the cooling effect by shrinking the tumor. While conducting further research, it is worth considering the use of quantitative tissue perfusion analysis methods currently used in the assessment of malignant neoplasms [ 54 ]. Our results allow us to consider conducting research in patients with Funaki group III UFs, who have been completely disqualified so far.…”

Section: Discussionmentioning

confidence: 99%

Magnetic Resonance-Guided High-Intensity Focused Ultrasound Ablation of Uterine Fibroids—Efficiency Assessment with the Use of Dynamic Contrast-Enhanced Magnetic Resonance Imaging and the Potential Role of the Administration of Uterotonic Drugs

Łoziński¹,

Ciebiera

Łuczyńska

et al. 2021

Diagnostics

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Objective: The assessment of the usefulness of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) when qualifying patients with uterine fibroids (UFs) for magnetic resonance-guided high-intensity ultrasound (MR-HIFU). Material and methods: This retrospective, single center study included 283 women who underwent DCE-MRI and were treated with MR-HIFU. The patients were divided according to non-perfused volume (NPV) as well as by the type of curve for patients with a washout curve in the DCE-MRI study and patients without a washout curve. The studied women were assessed in three groups according to the type of uterotonics administered. Group A (57 patients) received one dose of misoprostol/diclofenac transvaginally and group B (71 patients) received oxytocin intravenously prior to the MR-HIFU procedure. The remaining 155 women (group C) were treated with the traditional non-drug enhanced MR-HIFU procedure. Results: The average NPV value was higher in no washout group, and depended on the uterotonics used. Conclusions: We demonstrated a correlation between dynamic contrast enhancement curve types and the therapeutic efficacy of MR-HIFU. Our results suggest that DCE-MRI has the potential to assess treatment outcomes among patients with UFs, and patients with UFs that present with a washout curve may benefit from the use of uterotonic drugs. More studies are required to draw final conclusions.

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“…Using BGS is especially important for applications in which the ASL signal is subject to large temporal fluctuations. This is the case for most 3D ASL scans, where temporal fluctuations are introduced by the multishot nature of the acquisition process, 5,6 as well as in abdominal imaging, where motion is much more dominant than in the brain 7,8 …”

Section: Introductionmentioning

confidence: 99%

“…This is the case for most 3D ASL scans, where temporal fluctuations are introduced by the multishot nature of the acquisition process, 5,6 as well as in abdominal imaging, where motion is much more dominant than in the brain. 7,8 BGS is obtained by applying multiple inversion pulses before and during the postlabel delay (PLD). If the pulses are applied at the right timings, the reduction in background signal can be of the order of 99%.…”

Section: Introductionmentioning

confidence: 99%

Subject‐specific optimization of background suppression for arterial spin labeling magnetic resonance imaging using a feedback loop on the scanner

et al. 2022

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Background suppression (BGS) in arterial spin labeling (ASL) magnetic resonance imaging leads to a higher temporal signal-to-noise ratio (tSNR) of the perfusion images compared with ASL without BGS. The performance of the BGS, however, depends on the tissue relaxation times and on inhomogeneities of the scanner's magnetic fields, which differ between subjects and are unknown at the moment of scanning. Therefore, we developed a feedback loop (FBL) mechanism that optimizes the BGS for each subject in the scanner during acquisition. We implemented the FBL for 2D pseudo-continuous ASL scans with an echo-planar imaging readout. After each dynamic scan, the acquired ASL images were automatically sent to an external computer and processed with a Python processing tool. Inversion times were optimized on the fly using 80 iterations of the Nelder-Mead method, by minimizing the signal intensity in the label image while maximizing the signal intensity in the perfusion image. The performance of this method was first tested in a four-component phantom. The regularization parameter was then tuned in six healthy subjects (three males, three females, age 24-62 years) and set as λ = 4 for all other experiments. The resulting ASL images, perfusion images, and tSNR maps obtained from the last 20 iterations of the FBL scan were compared with those obtained without BGS and with standard BGS in 12 healthy volunteers (five males, seven females, age 24-62 years) (including the six volunteers used for tuning of λ). The FBL resulted in perfusion images with a statistically significantly higher tSNR (2.20) compared with standard BGS (1.96) (p < 5 x 10 À3 , two-sided paired t-test). Minimizing signal in the label image furthermore resulted in control images, from which approximate changes in perfusion signal can directly be appreciated. This could be relevant to ASL applications that require a high temporal resolution. Future work is needed to minimize the Abbreviations used: ASL, arterial spin labeling; BGS, background suppression; EPI, echo-planar imaging; FBL, feedback loop; FLAIR, fluid-attenuated inversion recovery; TSE, turbo-spin-echo; tSNR, temporal signal-to-noise ratio; XTC, eXTernal Control.

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Quantitative Methods in Abdominal MRI

Cited by 14 publications

References 46 publications

Application Value of Magnetic Resonance Perfusion Imaging in the Early Diagnosis of Rat Hepatic Fibrosis

Application Value of Magnetic Resonance Perfusion Imaging in the Early Diagnosis of Rat Hepatic Fibrosis

Magnetic Resonance-Guided High-Intensity Focused Ultrasound Ablation of Uterine Fibroids—Efficiency Assessment with the Use of Dynamic Contrast-Enhanced Magnetic Resonance Imaging and the Potential Role of the Administration of Uterotonic Drugs

Subject‐specific optimization of background suppression for arterial spin labeling magnetic resonance imaging using a feedback loop on the scanner

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