bluuebunny/crossref_metadata_2025_split huggingface dataset:
Invited. Interactive MRI‐guided radiofrequency interstitial thermal ablation of abdominal tumors: Clinical trial for evaluation of safety and feasibility
Authors: Lewin Jonathan S. , Connell Cindy F. , Duerk Jeffrey L. , Chung Yiu‐Cho , Clampitt Mark E. , Spisak Julie , Gazelle G. Scott , Haaga John R. 
Published: March 2007

AbstractThis clinical trial was performed to evaluate the safety and feasibility of interactive MR‐guided radiofrequency (RF) interstitial thermal ablation (ITA) performed entirely within the MR imager. RF‐ITA was performed on 11 intra‐abdominal metastatic tumors during 13 sessions. The RF electrode was placed under MR guidance on a .2‐T system using rapid fast imaging with steady state precession (FISP) and true FISP images. A custom 17‐gauge electrode was used and was modified in four sessions to allow circulation of iced saline for cooling during ablation. Tissue necrosis monitoring and electrode repositioning were based on rapid T2‐weighted and short‐inversion‐time inversion recovery (STIR) sequences. Morbidity and toxicity were assessed by clinical and imaging criteria. The region of tissue destruction was visible in all 11 tumors treated, as confirmed on subsequent contrast‐enhanced images. No significant morbidity was noted, and patient discomfort was minimal. In conclusion, interactive MR‐guided RF‐ITA is feasible on a clinical .2‐T C‐arm system with supplemental interventional accessories with only minor patient morbidity. The ability to completely ablate tumors with RF‐ITA depends on tumor size and vascularity.
Treatment planning for MRI‐guided laser‐induced interstitial thermotherapy of brain tumors—The role of blood perfusion
Authors: Schwarzmaier Hans‐Joachim , Yaroslavsky Ilya V. , Yaroslavsky Anna N. , Fiedler Volkhard , Ulrich Frank , Kahn Thomas 
Published: March 2007

AbstractMR techniques have been demonstrated to allow a reliable monitoring of laser‐induced interstitial thermotherapy (LITT). However, an adequate on‐line control of this coagulation technique requires an exact therapy planning. The latter is mandatory to interpret the MR‐monitoring data correctly to guarantee a precise laser irradiation. Moreover, it is a prerequisite for online decisions if modifications of the therapeutic regimen are required. In this work, we present a new simulation technique for LITT planning. The model accounts for the specific geometry of the treatment site, the exact configuration of the applicator, and the optical and thermal properties of the tissue, including changes during the heating process. The simulation results were compared with MR scans of laser‐induced lesions in three patients with World Health Organization (WHO) grade II astrocytoma. Special interest was directed toward the role of blood perfusion, which was studied parametrically. Good agreement between the simulation results and the MR data was found if the appropriate blood perfusion rates were taken into account. Thus, the model can generate valid therapy plans allowing a precise on‐line control of laser irradiation using MR techniques. Neglecting adequate perfusion parameters resulted in substantial errors with respect to the prediction of the final laser lesion.
MRI monitoring of interstitial microwave‐induced heating and thermal lesions in rabbit brain in vivo
Authors: Moriarty John A. , Chen Julian C. , Purcell Carrie M. , Ang Lee C. , Hinks R. Scott , Peters Robert D. , Henkelman R. Mark , Plewes Donald B. , Bronskill Michael J. , Kucharczyk Walter 
Published: March 2007

AbstractThe purpose of this experiment was to use MRI to monitor microwave heating and thermal damage of brain tissue in vivo. Interstitial microwave antennas were implanted into the cerebral hemispheres of seven anesthetized rabbits. Variable power of 30 to 100 W was applied for periods of 5 to 15 minutes and tissue temperature was monitored continuously. MR images were obtained throughout the procedure at 20‐second intervals, using a spoiled gradient‐echo sequence, without significant artifact. Magnitude, phase, and complex difference images all demonstrated temperature‐related signal changes during heating. The findings were better visualized on the phase and complex difference images. Phase difference image analysis revealed an approximately linear relationship between phase change and temperature. Post‐treatment thermal lesions measured up to 2.0 cm in size on pathologic specimens and exhibited a zonal pattern on spin‐echo MR images.
Invited. In vivo MRI thermometry using a phase‐sensitive sequence: Preliminary experience during MRI‐guided laser‐induced interstitial thermotherapy of brain tumors
Authors: Kahn Thomas , Harth Thorsten , Kiwit Jürgen C. W. , Schwarzmaier Hans‐Joachim , Wald Christoph , Mödder Ulrich 
Published: March 2007

AbstractThe purpose of this study was the application of the proton‐resonance‐frequency method to monitor laser‐induced interstitial thermotherapy (LITT) in a patient with an astrocytoma WHO II. A phase‐sensitive two‐dimensional (2D) fast low‐angle shot (FLASH) sequence was used to determine the temperature‐related phase shifts during LITT. Temperature maps were displayed during therapy with a temporal resolution of 20 seconds. Irradiation was discontinued as soon as the 60 to 65°C isotherm reached the margin of the tumor. A contrast‐enhanced MRI study performed immediately after therapy showed a good correlation of the size of an enhancing rim around the lesion with the 60 to 65°C isotherm. The preliminary results of our study indicate that MRI guidance of LITT may be improved by temperature quantification based on the proton‐resonance‐frequency method.
Three‐dimensional monitoring of small temperature changes for therapeutic hyperthermia using MR
Authors: Wlodarczyk Waldemar , Boroschewski Ralf , Hentschel Michael , Wust Peter , Mönich Gerhard , Felix Roland 
Published: March 2007

AbstractRadiofrequency hyperthermia of deep‐seated pelvic tumors requires noninvasive monitoring of temperature distributions in patients. Methods of MR thermography were reported to be a promising tool in solving this problem. However, to be truly useful for monitoring hyperthermia treatments, MR thermography should be able to cover the entire pelvis in acquisition times no longer than for a breath‐hold (⩽15 seconds) and to resolve small temperature differences (< 1°C). Three methods exploiting the temperature dependence of spin‐lattice relaxation time (T1), of self‐diffusion coefficient (D), and of chemical shift of proton resonance frequency (PRF) were applied in phantom experiments; the pulse sequences were the T1‐weighted gradient echo, the pulsed diffusion gradient spin echo made faster through the keyhole technique, and the gradient echo with the phase reconstruction, respectively. The high planar resolution was compromised, and instead, coarse and more isotropic voxels were used. Experiments were performed in two consecutive steps, thus imitating a possible scenario for monitoring hyperthermia. In the first step, calibration curves were recorded, which were then used in the second step to obtain maps of temperature changes. The results show a clear superiority of the PRF method, followed by the D and the T1 methods. The uncertainty of temperature changes predicted both from calibration curves and from maps was less than 1°C only with the PRF and the D‐based methods.
Developing a multichannel temperature probe for interventional MRI
Authors: Shankaranarayanan Ajit , Duerk Jeffrey L. , Lewin Jonathan S. 
Published: March 2007

AbstractInterventional MRI (I‐MRI) guided thermal tissue ablation has been used for a variety of interventional cancer therapies. These would be further facilitated by temperature‐sensitive sequences on low magnetic field MR images. However, until these sequences have been reliably implemented at low fields, other methods of temperature measurement are required. This project describes the development of a low cost, reliable, MRI‐compatible temperature sensor array useful at a temperature range from 37°C to higher than 90°C. The device uses a three‐channel thermocouple sensor array connected to a variety of filtering and signal‐conditioning electronics, analog‐to‐digital (A/D) converters, and personal computers. The sensors induce negligible field distortion. Similarly, no MRI‐based measurement artifacts are observed. One‐dimensional temperature profiles are generated with thermocouple signal linearization performed by the software.
Interventional MRI at high‐field (1.5 T): Needle artifacts
Authors: Liu Haiying , Martin Alastair J. , Truwit Charles L. 
Published: March 2007

AbstractA better understanding of the appearance of a biopsy needle as well as its interaction with various sequence parameters in MRI is beneficial for its application in interventional MRI. As an extension of previous researchers' contributions, we investigate the specific characteristics of MR image artifacts associated with the tip of a biopsy needle when it is approximately parallel to the main magnetic field. The origin of the needle tip artifact, which exhibits as a blooming ball, was studied using MRI techniques and numerical simulation using the finite element method (FEM). Satisfactory agreement between theory and experiment has been achieved. Results showed that the image artifacts associated with biopsy needle are present and dependent on imaging parameters, but the artifacts can be reduced if optimal imaging parameters were used. Images of actual human brain tumor biopsies performed using the same needle under MRI guidance and monitoring demonstrated this artifact.
Neuroimaging in epilepsy
Authors: Sitoh Yih‐Yian , Tien Robert D. 
Published: March 2007

AbstractNeuroimaging techniques have improved the understanding, diagnosis, and management of epilepsy. By providing excellent structural information, MRI is the technique of choice in evaluating patients with epilepsy. Functional imaging techniques, including MR spectroscopy, functional MRI, positron emission tomography, and single photon emission CT, permit noninvasive assessment of the epileptic substrate, its functional status, and neuroreceptors. The MRI‐based techniques will potentially assume a greater role in the cost‐effective workup of the patient. Currently, newer techniques such as magnetoencephalography, magnetic source imaging, and optical imaging are research tools.
Invited. MRI of nasopharyngeal carcinoma with emphasis on relationship to radiotherapy
Authors: Ng Shu‐Hang , Wan Yung‐Liang , Ko Sheung‐Fat , Chang Joseph T. 
Published: March 2007

AbstractMRI has been used increasingly in the evaluation of nasopharyngeal carcinoma (NPC) because of its good tissue contrast and multiplanar capacity. Although there are some controversies in assessing skull base invasion and cervical metastatic adenopathy, recent reports demonstrate that MRI is currently better than or as good as CT in defining the extent of NPC. During follow‐up of patients with NPC after radiotherapy, MRI is also more effective than CT in demonstrating tumor recurrence and in detecting postradiation complications. However, the difficulty of using MRI to detect early mucosal recurrence and to differentiate postradiation tissue changes from local tumor recurrence should be recognized. This paper reviews the literature regarding MRI of NPC related to radiotherapy, with special emphasis on treatment planning, recurrence assessment, and complication detection.
Reproducibility study of left ventricular measurements with breath‐hold cine MRI using a semiautomated volumetric image analysis program
Authors: Butler S. Patrick , McKay Erin , Paszkowski Andrew L. , Quinn Richard J. , Shnier Ronald C. , Donovan Joanne T. 
Published: March 2007

AbstractThe reproducibility of a semiautomated method of volumetric analysis allowing estimates of left ventricular (LV) parameters in approximately 5 minutes of analysis time is reported. Twenty normal volunteers underwent cine breath‐hold cardiac MRI on two occasions with two observers using this new semiautomated method to estimate LV parameters. Reproducibility of this technique was comparable to published data with a variability of less than approximately 10% for all LV parameters calculated. Using this technique, the 95% confidence limits for change for left ventricular end diastolic volume (LVEDV) = ± 15 ml, left ventricular end systolic volume (LVESV) = ± 8 ml, LV mass = ± 24 g, and left ventricular ejection fraction (LVEF) = ± 6%. This new method also compared favorably to established manual methods. This new method permits estimation of LV parameters with acceptable reproducibility in a time that may permit routine quantitation of cardiac MR studies.
A novel MR angiography technique: SPEED acquisition using half‐Fourier RARE
Authors: Miyazaki Mitsue , Ichinose Nobuyasu , Sugiura Satoshi , Kanazawa Hitoshi , Machida Yoshio , Kassai Yoshimori 
Published: March 2007

AbstractA novel MR angiography (MRA) method, swap phase encode extended data (SPEED), was developed. Two one‐shot images with the phase‐encode directions swapped were collected within a single breath‐hold period and processed with a maximum intensity projection (MIP) to obtain an image. In this study, a long echo train two‐dimensional rapid acquisition with relaxation enhancement (RARE) sequence with half‐Fourier (half‐RARE) was used to obtain the pulmonary MRA images. The MIP image obtained using the SPEED technique presented promising results for pulmonary vessels.
Renal MR angiography: A comprehensive approach
Authors: Prince Martin R. 
Published: March 2007

AbstractRenal artery MR angiography has now emerged as a safe, accurate approach to renal arteriography. A comprehensive examination, including both three‐dimensional (3D) dynamic gadolinium‐enhanced and 3D phase contrast MRA techniques, allows evaluation of both the aorta‐renal and splanchnic arterial anatomy as well as the hemodynamic significance of any stenoses identified. The 3D gadolinium‐enhanced MRA technique produces a contrast arteriogram but without risks of iodinated contrast or ionizing radiation. The 3D phase contrast technique is a flow‐based technique, which may show dephasing in the presence of hemodynamically significant stenoses. A comprehensive examination should also include T1‐ and T2‐weighted imaging for the assessment of potential neoplastic masses and the ubiquitous renal cysts. Through trial and error over the course of over a thousand examinations, this comprehensive approach to the MR evaluation of renal vascular pathology has emerged.
Patterns of lingual tissue deformation associated with bolus containment and propulsion during deglutition as determined by echo‐planar MRI
Authors: Gilbert Richard J. , Daftary Shrenik , Campbell Terrence A. , Weisskoff Robert M. 
Published: March 2007

AbstractDisordered lingual function is a common clinical attribute of patients with oropharyngeal dysphagia. To determine physiologic patterns of lingual tissue motion during swallowing, we imaged the actively deforming tongue during water bolus swallows with sequential single‐slice sagittal orientation echo‐planar imaging. At rest, with the bolus contained in the oral cavity before swallow initiation, the tongue displayed a characteristic curved configuration consisting of a convex surface (anterior to the bolus) in continuity with a concave surface (containing the bolus) and a posterior‐located convex surface (comprising the tongue base). With swallow initiation, the previously deformed tongue underwent rapid biphasic displacement: (a) superior displacement of the anterior tongue and deepening of the midposterior‐located bolus‐containing concavity, resulting in a laterally beveled surface encompassing the bolus; and (b) retrograde displacement of the configured tissue, resulting in clearance of the bolus from the oral cavity to the oropharynx. These findings indicate that deglutitive tongue action can be depicted by echo‐planar imaging as a series of deformative surface modifications, which are related to the activity of intrinsic and extrinsic lingual muscles.
Hepatic T2‐weighted MRI: A prospective comparison of sequences, including breath‐hold, half‐Fourier turbo spin echo (HASTE)
Authors: Coates G. Glenn , Borrello Joseph A. , McFarland Elizabeth G. , Mirowitz Scott A. , Brown Jeffrey J. 
Published: March 2007

AbstractThe purpose of this study was to quantitatively compare the hepatic contrast characteristics of conventional spin‐echo (CSE) and fast spin‐echo (FSE) sequences with breath‐hold T2‐weighted images acquired with half‐Fourier turbo spin echo (HASTE). Forty‐five patients were examined with a phased‐array surface coil. Nineteen patients had focal hepatic lesions, including eight malignant tumors, 10 cavernous hemangiomas, and one hepatic adenoma. Twenty‐six patients had no focal hepatic lesions. T2‐weighted images with comparable TE were acquired with CSE, FSE, and HASTE pulse sequences. Signal‐to‐noise ratio (SNR) and contrast‐to‐noise ratio (CNR) for liver, spleen, and lesions were measured. FSE demonstrated significantly better quantitative performance than CSE for liver‐spleen CNR (P = .0084). No statistically significant difference was demonstrated between FSE and CSE for liver or spleen SNR. FSE demonstrated clear scan time and resolution advantages over CSE. HASTE performed significantly poorer than CSE and FSE for liver‐spleen CNR (P < .0001), liver SNR (P = .0002 for CSE and P < .0001 for FSE), and spleen SNR (P < .0001). Optimized FSE images with a short echo train length performed comparably to CSE images of equivalent TE. Liver‐lesion CNR was suppressed on HASTE images, suggesting that long echo train length FSE sequences could diminish solid lesion detection compared to CSE and short echo train length FSE.
Assessment of hepatic portal perfusion using T2* measurements of Gd‐DTPA
Authors: Uematsu Hidemasa , Yamada Hiroki , Sadato Norihiro , Muramoto Satoshi , Inoue Hiroshi , Hayashi Koji , Yonekura Yoshiharu , Kimura Hirohiko , Sakuma Hajime , Matsuda Tetsuya , Hayashi Nobushige , Yamamoto Kazutaka , Ishii Yasushi 
Published: March 2007

AbstractRecently, perfusion imaging has been of increasing interest in MRI. We applied this method for semiquantitative evaluation of hepatic parenchymal portal blood flow in patients with diffuse liver damage. Twenty patients with diffuse hepatic damage were divided according to the Child's Classification and studied. Gadolinium‐diethylenetriamine pentaacetic acid (Gd‐DTPA) was administered into the superior mesenteric artery (SMA), and a dynamic series of T2*‐weighted fast low angle shot (FLASH) images was obtained. We evaluated relative regional portal blood volume (rrPBV), mean transit time (MTT), and relative regional portal blood flow (rrPBF). The relationship between the rrPBV, rrPBF, and plasma indocyanine green retention rate test at 15 minutes (ICGR15) was also evaluated in 12 patients. Both rrPBF and rrPBV are significantly decreased in Child B & C patients compared with Child A patients. On the other hand, the MTT is significantly prolonged in Child B & C patients compared with Child A patients. Significant correlations were also noted between rrPBV and ICGR15 and between rrPBF and ICGR15. By means of selective catheterization into the SMA, we were able to estimate rrPBV, rrPBF, and MTT. This method may play a clinical role for assessment of regional portal perfusion in various diseases with diffuse liver damage.
Whole body turbo STIR MRI in unknown primary tumor detection
Authors: Eustace Stephen , Tello Richard , Decarvalho Victor , Carey John , Melhem Elias , Yucel E. Kent 
Published: March 2007

AbstractThis brief report outlines the novel use of whole body coronal turbo short tau inversion recovery (STIR) imaging to localize a primary tumor in patients with known metastatic disease without a previously identified source.
Invited. MRI and MR angiography in moyamoya disease
Authors: Hasuo Kanehiro , Mihara Futoshi , Matsushima Toshio 
Published: March 2007

AbstractThe role of radiological imaging in moyamoya disease includes screening of the disease based on clinical findings, evaluation of the changes in vasculature and brain parenchyma, and clinical follow‐up. The imaging findings in moyamoya disease are classified as primary and secondary. The primary findings essentially consist of occlusion of the circle of Willis and collateral formation, including moyamoya vessel formation. The secondary findings include cerebral infarction, white matter lesions, atrophy, and hemorrhage. For the visualization of the primary and secondary findings as well as postoperative results, MRI and MR angiography are the most reliable methods and play important roles because of their excellent diagnostic yield and noninvasiveness.
Evaluation of intracranial cysts by intraoperative MR
Authors: Schwartz Richard B. , Hsu Liangge , Black Peter McL , Iii Eben Alexander , Wong Terence Z. , Klufas Roman A. , Moriarty Thomas , Martin Claudia , Isbister Holly G. , Cahill Cheryl D. , Spaulding Sharon A. , Kanan Angela R. , Jolesz Ferenc A. 
Published: March 2007

AbstractEleven patients with intracranial cystic collections were evaluated in the open‐bore intraoperative MR system. In each case, the cystic collection or the surrounding cerebrospinal fluid (CSF) space was injected with .02 to .5 cc of .5 mol/1 gadopentetate dimeglumine. Serial Imaging was performed using T1‐weighted imaging. In seven patients, free communication was demonstrated between the cystic collection and the surrounding CSF spaces. In four cases, the cyst did not communicate with the CSF; two of these were drained in the intraoperative MR system with reduction in symptoms. One patient developed an aseptic meningitis 10 days after the study, which was successfully treated with steroids; no other complications were noted. We conclude that the communication of intracranial cystic collections with the cisterns and ventricies can be safely and effectively elucidated with gadolinium injection in the intraoperative MR system.
GC/MS‐positive ion chemical ionization and MS/MS study of volatile benzene compounds in five different woods used in barrel making
Authors: Flamini Riccardo , Vedova Antonio Dalla , Cancian Davide , Panighel Annarita , De Rosso Mirko 
Published: March 2007

AbstractExtracts from acacia, chestnut, cherry, mulberry, and oak wood, used in making barrels for aging wine and spirits were studied by GC/MS positive ion chemical ionization (PICI). Wood chips were extracted by a 50% water/ethanol solution and a tartrate buffer pH 3.2–12% ethanol (model wine) solution. The principal compounds identified in extracts were guaiacol‐containing aldehydes and alcohols, such as benzaldehyde and derivatives, vanillin and syringaldehyde, cinnamaldehyde and coniferaldehyde, eugenol and methoxyeugenol, guaiacol and methoxyguaiacol derivatives. PICI using methane as reagent gas produced a high yield of the protonated molecular ion of volatile phenols, compound identification was confirmed by collision‐induced‐dissociation (CID) experiments on [M + H]+ species. MS/MS fragmentation patterns were studied with standard compounds: guaiacol‐containing molecules were characterized by neutral methyl and methanol losses, benzaldehyde derivatives by CO loss. Acacia wood extracts contained significant syringaldehyde and anisaldehyde, but no eugenol and methoxyeugenol. Significant syringaldehyde, eugenol and methoxyeugenol, and high vanillin were found in chestnut and oak wood extracts; low presence of volatile benzene compounds was found in mulberry wood extracts. Cherry wood extracts were characterized by the presence of several benzaldehyde derivatives and high trimethoxyphenol. Copyright © 2007 John Wiley & Sons, Ltd.