Monitoring of laser and freezinginduced ablation in the liver with T1‐weighted MR imaging

Matsumoto, Reiko; Oshio, Koichi; Jólesz, Ferenc A.

doi:10.1002/jmri.1880020513

Cited by 172 publications

(69 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Temperature dependence was found to be on the order of 1%/°C (22), with values of 1.4%/°C in bovine muscle (23), 1-2%/°C in liver (24), and 0.97%/°C in fat (25). The signal for both spin echo or gradient echo images can be expressed in terms of M 0 , the flip angle ␣, the relaxation time T 1 , and the repetition time TR as:…”

Section: T 1 Relaxation Time Of Water Protonsmentioning

confidence: 99%

MR thermometry

Rieke

Pauly

2008

Magnetic Resonance Imaging

1,019

952

View full text Add to dashboard Cite

Minimally invasive thermal therapy as local treatment of benign and malignant diseases has received increasing interest in recent years. Safety and efficacy of the treatment require accurate temperature measurement throughout the thermal procedure. Noninvasive temperature monitoring is feasible with magnetic resonance (MR) imaging based on temperature-sensitive MR parameters such as the proton resonance frequency (PRF), the diffusion coefficient (D), T 1 and T 2 relaxation times, magnetization transfer, the proton density, as well as temperature-sensitive contrast agents. In this article the principles of temperature measurements with these methods are reviewed and their usefulness for monitoring in vivo procedures is discussed. Whereas most measurements give a temperature change relative to a baseline condition, temperature-sensitive contrast agents and spectroscopic imaging can provide absolute temperature measurements. The excellent linearity and temperature dependence of the PRF and its near independence of tissue type have made PRF-based phase mapping methods the preferred choice for many in vivo applications. Accelerated MRI imaging techniques for real-time monitoring with the PRF method are discussed. Special attention is paid to acquisition and reconstruction methods for reducing temperature measurement artifacts introduced by tissue motion, which is often unavoidable during in vivo applications.

show abstract

Section: T 1 Relaxation Time Of Water Protonsmentioning

confidence: 99%

MR thermometry

Rieke

Pauly

2008

Magnetic Resonance Imaging

1,019

952

View full text Add to dashboard Cite

show abstract

“…This choice is in full agreement with the technical and clinical considerations outlined in a recent review (17). The PRF method is an alternative to T1-dependent temperature changes (18)(19)(20). This latter method was also studied (21) but discarded for real-time applications as its temporal resolution is limited to several seconds by the need to acquire and reconstruct a full inversion-recovery or saturation-recovery MRI experiment.…”

Section: Original Articlementioning

confidence: 99%

Towards MRI temperature mapping in real time—the proton resonance frequency method with undersampled radial MRI and nonlinear inverse reconstruction

Zhang

Michaelis

Frahm

2017

Quant. Imaging Med. Surg.

View full text Add to dashboard Cite

IntroductionRecent developments in MRI provide a new method for real-time imaging (1) which offers so far unsurpassed diagnostic capabilities in a large variety of clinical fields. Respective applications range from cardiac MRI without ECG synchronization and during free breathing (2) to real-time studies of blood flow (3), swallowing (4), dysphagia (5), esophageal functions (6), dynamics of the temporomandibular joint (7), respiration-induced flow of the cerebrospinal fluid (8,9) as well as movements of the articulators during normal speech (10) or brass playing of patients with embouchure dystonia (11). In a technical sense, the method is based on highly undersampled radial gradient-echo sequences in combination with iterative image reconstruction by nonlinear inversion (NLINV) and temporal regularization (1). These new possibilities are expected to vastly broaden the range of clinical MRI and, in particular, to stimulate renewed interest in "interventional MRI", i.e., the use of real-time MRI for monitoring and guiding minimally invasive procedures.In this sense, true "real-time" MRI not only refers to high-speed data acquisitions, but includes (I) online Original ArticleTowards MRI temperature mapping in real time-the proton resonance frequency method with undersampled radial MRI and nonlinear inverse reconstruction

show abstract

“…Computed tomography has also been used to guide cryotherapy 45,46 ; the iceball appears as a well-marginated low-attenuation area. Magnetic resonance imaging with an integrated guidance mechanism and MR-compatible cryoprobes can be used to show the iceball in its entirety 25,[47][48][49][50][51] and can provide a three-dimensional image of the developing iceball. Also, the area of an iceball will no longer enhance with gadolinium.…”

Section: Cryotherapy and Imagingmentioning

confidence: 99%

Needle-Based Ablation of Renal Parenchyma Using Microwave, Cryoablation, Impedance- and Temperature-Based Monopolar and Bipolar Radiofrequency, and Liquid and Gel Chemoablation: Laboratory Studies and Review of the Literature

Rehman

Landman

Lee

et al. 2004

Journal of Endourology

View full text Add to dashboard Cite

"Needle-based ablation of renal parenchyma using microwave, cryoablation, impedance-and temperature-based monopolar and bipolar radiofrequency, and liquid and gel chemoablation: Laboratory studies and review of the literature." Journal of Endourology.18,1. 83-104. (2004 ABSTRACTBackground and Purpose: Small renal tumors are often serendipitously detected during the screening of patients for renal or other disease entities. Rather than perform a radical or partial nephrectomy for these diminutive lesions, several centers have begun to explore a variety of ablative energy sources that could be applied directly via a percutaneously placed needle-like probe. To evaluate the utility of such treatment for small renal tumors/masses, we compared the feasibility, regularity (consistency in size and shape), and reproducibility of necrosis produced in normal porcine kidneys by different modes of tissue ablation: microwaves, cold impedance-based and temperature-based radiofrequency (RF) energy (monopolar and bipolar), and chemical. Chemoablation was accomplished using ethanol gel, hypertonic saline gel, and acetic acid gel either alone or with simultaneous application of monopolar or bipolar RF energy. Materials and Methods: A total of 107 renal lesions were created laparoscopically in 33 domestic pigs. Microwave thermoablation (N 5 12) was done using a Targis T3 (Urologix) 10F antenna. Cryoablation (N 5 16) was done using a single 1.5-mm probe or three 17F microprobes (17F SeedNet™ system; Galil Medical) (N 5 10 single probe and N 5 6 three probes); a double freeze cycle with a passive thaw was employed under ultrasound guidance. Dry RF lesions were created using custom-made 18-gauge single-needle monopolar probe with two or three exposed metal tips (GelTx) (N 5 12) or a single-needle bipolar probe (N 5 6) at 50 W of 510 kHz RF energy for 5 minutes. In addition, a multitine RF probe (RITA Medical Systems) was used in one set of studies (N 5 6). Both impedance-and temperature-based RF were evaluated. Chemoablation was performed with 95% ethanol (4 mL), 24% hypertonic saline (4 mL), and 50% acetic acid (4 mL) as single injections. In addition, chemoablation was tested with monopolar and bipolar RF (wet RF). Tissues were harvested 1 week after ablation for light microscopy.Results: In 11 of the 15 ablation techniques, there was complete necrosis in all lesions; however, three ethanol gel lesions had skip areas, three hypertonic saline gel lesions showed no necrosis or injury, and one monopolar RF and one bipolar RF lesion showed skip areas. In contrast to impedance-based RF, heat-based RF (RITA) caused complete necrosis without skip areas. All cryolesions resulted in complete tissue necrosis, and cryotherapy was the only modality for which lesion size could be effectively monitored using ultrasound imaging.

show abstract

Monitoring of laser and freezinginduced ablation in the liver with T1‐weighted MR imaging

Cited by 172 publications

References 16 publications

MR thermometry

MR thermometry

Towards MRI temperature mapping in real time—the proton resonance frequency method with undersampled radial MRI and nonlinear inverse reconstruction

Needle-Based Ablation of Renal Parenchyma Using Microwave, Cryoablation, Impedance- and Temperature-Based Monopolar and Bipolar Radiofrequency, and Liquid and Gel Chemoablation: Laboratory Studies and Review of the Literature

Contact Info

Product

Resources

About