bluuebunny/crossref_metadata_2025_split huggingface dataset:
MR‐monitored LITT as a palliative concept in patients with high grade gliomas: Preliminary clinical experience
Authors: Reimer Peter , Bremer Christoph , Horch Christoph , Morgenroth Carlo , Allkemper Thomas , Schuierer Gerhard 
Published: March 2007

AbstractThe purpose of this study was to evaluate the clinical utility of laser‐induced thermotherapy (LITT) as a palliative treatment for patients with high‐grade gliomas. Four consenting patients with recurrent high grade III/IV gliomas near the primary language or motor areas were palliatively treated with LITT (2–5 W, 3–13 minutes; Neodym YAG Laser, Dornier, Friedrichshafen, Germany). Temperature monitoring was performed by T1‐weighted turbo‐fast low‐angle shot (FLASH) imaging at 1.5 T (Siemens Magnetom SP 4000, Siemens, Erlangen, Germany). MRI studies before LITT included contrast‐enhanced conventional scans and functional activation studies to localize the primary motor cortex or language areas using an echoplanar imaging (EPI) spin‐echo (SE) sequence. Follow‐up studies consisted of contrast‐enhanced conventional scans as well as diffusion studies (contrast‐enhanced Fourier‐acquired steady‐state technique and EPI‐SE) and perfusion studies (EPI‐SE with .2 mmol of gadolinium (Gd)/kg body weight) to differentiate posttherapeutic effects from residual or recurrent tumor growth. Local tumor control was achieved in areas with laser energy deposition with clinically stable conditions ⩾ 6 months. Conventional contrast‐enhanced scans demonstrated strong enhancement surrounding ablated tumor components, which showed a reduction in CBV/CBF. Perfusion studies were useful to discriminate granulomatous tissue enhancement from residual or recurrent tumor growth. Careful application of LITT may evolve as an alternative palliative concept for patients with end‐stage high‐grade cerebral gliomas reducing clinical symptoms from circumscribed areas of pathology.
MR‐guided balloon angioplasty: In vitro demonstration of the potential of MRI for guiding, monitoring, and evaluating endovascular interventions
Authors: Bakker Chris J. , Smits Henk F. , Bos Clemens , van der Weide Remko , Zuiderveld Karel J. , van Vaals Joop J. , Hurtak Wenzel F. , Viergever Max A. , Mali Willem P. 
Published: March 2007

AbstractThe purpose of this study was to demonstrate the potential of MRI for guiding, monitoring, and evaluating endovascular interventions. This was done by investigating the feasibility of MR‐guided balloon angioplasty in a stenosed vessel model. Catheters and guidewires were prepared for susceptibility‐based MR visualization by incorporating paramagnetic markers into their walls. Near real‐time monitoring (up to 1 image/sec) of the interventional procedure was achieved by using a dynamic two‐dimensional gradient‐echo technique. Devices were localized by on‐the‐fly subtraction of a baseline image from consecutive dynamic images and by merging the subtraction images with a previously acquired road map. All steps involved in balloon angioplasty, from the introduction and placement of a guidewire to the positioning of a catheter across the stenosis, inflation of the balloon, and dilatation of the stenosis could adequately be monitored with MR fluoroscopy. The beneficial effect of dilatation could be substantiated by a reduction of stenosis‐related hypointensities and hyperintensities in the posttreatment MR angiogram as compared to the pretreatment angiogram and by a posttreatment increase of the volumetric flow rate.
Visualization of vascular guidewires using MR tracking
Authors: Ladd Mark E. , Zimmermann Gesine G. , McKinnon Graeme C. , von Schulthess Gustav K. , Dumoulin Charles L. , Darrow Robert D. , Hofmann Eugen , Debatin Jörg F. 
Published: March 2007

AbstractMR tracking of a vascular guidewire sized for a .035‐inch (.89‐mm) catheter lumen was performed. The guidewire was actively tracked by incorporation of a miniature radiofrequency (RF) receive coil built into its tip. After in vitro validation, simultaneous tracking of the guidewire and a catheter was performed in the aortic and abdominal vessels of a swine at 1.5 T. The ability to track such a small device and the ability to simultaneously track multiple devices are significant steps towards vascular interventions under MR guidance.
Invited III. New developments: 2. Virtual MR endoscopy in the central nervous system
Authors: Shigematsu Yoshinori , Korogi Yukunori , Hirai Toshinori , Okuda Tomoko , Sugahara Takeshi , Liang Luxia , Ge Yulin , Takahashi Mutsumasa 
Published: March 2007

AbstractRecent advances in three‐dimensional (3D) data acquisition and postprocessing technologies have been playing a important role in widening the potential applications of 3D display. The authors described new applications of a virtual endoscopic algorithm for 3D display of high resolution MR images: (a) intracranial intravascular virtual MR endoscopy using the 3D fast imaging with steady state precession (FISP) sequence, and (b) virtual MR endoscopy of the cerebrospinal fluid (CSF) spaces using the constructive interference in steady state (CISS) three‐dimensional Fourier transform (3DFT) sequence. The virtual endoscopic images were displayed with use of a commercially available perspective volume‐rendering algorithm. Our initial experience showed that virtual MR endoscopy can be performed to observe the intracranial arteries and CSF spaces from the viewpoints within themselves. Although the clinical use of the intracranial virtual MR endoscopy has not been established yet, the images obtained are very attractive and further investigations in this field will be expected.
Invited. MRI of CNS parasitic diseases
Authors: Chang Kee‐Hyun , Han Moon Hee 
Published: March 2007

AbstractThis article reviews MRI findings of parasitic diseases of the central nervous system (CNS), with emphasis on neurocysticercosis, which is by far the most common CNS parasitic infection worldwide. MRI findings of neurocysticercosis are various, depending on the location (parenchymal, cisternal, ventricular, and spinal forms), and temporal evolutional stages (vesicular, colloid vesicular, granular nodular, and nodular calcified stages) of the worm. Classical findings of each location and stage are presented. Characteristic MRI findings of cerebral toxoplasmosis frequently seen in patients with acquired immunodeficiency syndrome (AIDS), paragonimiasis, and sparganosis that have most commonly been reported in East Asia are also illustrated. MRI is superior to CT scan in the evaluation of most CNS parasitic infections and is nearly diagnostic, particularly in endemic areas. Contrast‐enhanced study is essential not only for specific diagnosis of the disease, but also for assessment of the inflammatory activity.
Invited. Fukuyama congenital muscular dystrophy: A neuroradiologic review
Authors: Aida Noriko 
Published: March 2007

AbstractWe reviewed neuroradiologic findings of Fukuyama congenital muscular dystrophy (FCMD) and correlated them with the known neuropathology. All patients showed thick and bumpy cortices with shallow sulci corresponding to polymicrogyria, and approximately half of the patients showed pachygyric cortex with smooth surface corresponding to type II lissencephaly. The two types of cortical dysplasias presented characteristic distributions: the former demonstrated frontal lobe involvement in all and parietotemporal lobe involvement in some, whereas the latter involved the temporo‐occipital lobes. Most patients showed prolonged T1 and T2 signal in the white matter, which was indistinct in neonates and infrequently seen in adolescents. Cerebellar polymicrogyria depicted as disorganized cerebellar foliation accompanying cysts were found more than 90% of the patients. In conclusion, brain MRI demonstrates findings consistent with the known neuropathology of FCMD. The detection of the two types of cerebral cortical dysplasia with characteristic distribution and cerebellar abnormalities is helpful in the differential and early diagnosis.
Invited MRI of the liver
Authors: Laing Andrew D. P. , Gibson Robert N. 
Published: March 2007

AbstractMRI of the liver is a powerful imaging modality for detection and characterization of liver pathology. MRI technology continues to evolve with developments in scanner hardware performance and refinements in imaging sequences, particularly in respect to fast imaging techniques, improving the quality of images that can be routinely achieved. Fast imaging techniques allow dynamic contrast‐enhanced scanning to assist in lesion detection and characterization. An array of tissue‐specific contrast agents are also becoming available; the clinical utility of some of these agents is yet to be fully established. An overview of scanning technique, contrast media, and the role of MRI in liver lesion detection and characterization is presented, with a review of the typical imaging characteristics of common focal and diffuse hepatic diseases. Where possible, emphasis has been placed on features that allow distinction between the various pathologic entities described.
Invited. MRI of Clonorchiasis and Cholagiocarcinoma
Authors: Choi Byung Ihn , Kin Tea Kyoung , Han Joon Koo 
Published: March 2007

AbstractIntrahepatic cholangiocarcinomas are usully categorized as peripheral cholangiocarcinoma or hilar cholangiocarcinoma on the basis of the site of origin. Clonorchiasis is a trematodiasis caused by chronic infestation of liver flukes, Which are largely confined to the Orient, from Japan to Vietnam. The close relationship between clonorchiasis and cholangiocarcinoma has long been emphasized. This paper discusses the effecacy and possible roles of MRI for imaging clonorchiasis and cholangiocarcinoma of the liver. Although sonography, CT, and direct cholangiography have been used traditionally to diagnose these diseases, the role of MRI has been increasing rapidly with dramtic progress of the MRI has been increasing rapidly with dramatic progress of the MRI tecniques. We review MRU findings of clonorcjhiaiss na cholangiocarcinoma and discuss the potential usefulness of MRI.
Invited. Ossification of posterior longitudinal ligaments: Evaluation with MRI
Authors: Hirai Toshinori , Korogi Yukunori , Yamashita Yasuyuki , Takahashi Mutsumasa , Shimomura Osamu , Sakae Terumi 
Published: March 2007

AbstractOssification of the posterior longitudinal ligament is a special subcategory of degenerative disease responsible for compression of the spinal cord. On MR images, T2‐weighted sequences are the most effective to evaluate both spinal cord compression due to the ossification and abnormal signal intensity of the cord. Although ossification of the ligaments is well demonstrated on CT and plain radiographs, MRI noninvasively provides useful information about the degree and extent of spinal cord compression, as well as the character of the ossification.
Standard dose Gd‐DTPA dynamic MR of renal arteries
Authors: Tello Richard , Thomson Ken R. , Witte David , Becker Gary J. , Tress Brian M. 
Published: March 2007

AbstractRenal MR contrast enhancement depends on the timing of image acquisition. Limited human trials have demonstrated efficacy of renal artery stents on salvage of renal function. This study assessed the ability of dynamic gadolinium‐diethylenetriamine pentaacetic acid (Gd‐DTPA) administration to demonstrate renal artery stenosis and renal stent patency compared to conventional angiography as the gold standard. Twenty subjects referred for renal angiography underwent 22 dynamic MR studies, including 7 with renal artery stenting (Palmaz P204 or P201, Johnson & Johnson, Sydney, Australia). All were examined with conventional angiography and after dynamic Gd‐DTPA infusion. Coronal MR images of the kidneys were acquired using a GE Signa 1.5‐T magnet (General Electric Medical Systems, Milwaukee, WI) (fast spoiled gradient echo [FSPGR]; TE = 4.2 msec, TR = 68–150 msec, flip angle = 75°) 0 to 600 seconds after iv bolus injection of 15 ml of Gd‐DTPA during sequential breath‐hold acquisitions, 13 to 32 seconds each. All 51 renal arteries (13 stenosed, 38 normal) were detected with dynamic MRI. Severity of renal artery stenosis was classified correctly with an accuracy of 98% (95% confidence interval [CI]: 85–100), yielding 98% specificity and 100% sensitivity. All nine renal stents were visualized with 100% accurate patency documentation. FSPGR MRI with bolus Gd‐DTPA administration can provide adequate time and spatial resolution to demonstrate renal artery stenosis.
The value of detection of flow voids between the uterus and the leiomyoma with MRI
Authors: Torashima Miyuki , Yamashita Yasuyuki , Matsuno Yasuhara , Takahashi Mutsumasa , Nakahara Kazuhiko , Onitsuka Yoshio , Ohtake Hideyuki , Tanaka Nobuyuki , Okamura Hitoshi 
Published: March 2007

AbstractFlow voids are occasionally seen between the uterus and the leiomyoma. This study was performed to determine the prevalence of this sign and its relation to tumor size and location, internal signal intensity of the leiomyomas, and the ease of detectability using different MR sequences. Also, to understand the pathologic causes for the phenomenon of flow voids. The MR images of the pelvis in 92 females with 359 uterine leiomyomas were analyzed. Flow voids located between the uterus and the leiomyomas were seen in 32 lesions on T1‐weighted images and in 12 on T2‐weighted images. Flow void was seen exclusively in leiomyomas of 3‐cm diameter of larger. In five pedunculated subserous leiomyomas, flow voids were seen within the pedicle of the tumor. Large lieomyomas and leiomyomas with irregular signal intensity on T2‐weighted images showed significantly greater frequency of signal void than other leiomyomas (P < .01). The sign was not seen in any other pelvic tumors. On pathologic evaluation, the flow voids were found to correspond to dilated feeding arteries located outside the capsule of the leiomyoma.
Comparison of breath‐hold multishot echo‐planar and respiratory triggered fast‐spin‐echo sequences for T2‐weighted MRI of liver lesions
Authors: Yamakado Koichiro , Sakuma Hajime , Murashima Shuichi , Nakatsuka Atsuhiro , Matsumura Kaname , Takeda Kan 
Published: March 2007

AbstractThe purpose of this study was to evaluate the usefulness of multishot echo‐planar imaging in detecting liver tumors in comparison with respiratory triggered T2‐weighted fast‐spin‐echo (FSE) imaging. Thirty‐two patients with 70 focal liver lesions were imaged using a 1.5‐T high speed MR imager. Eight‐shot echo‐planar images covering the whole liver were acquired during a single breath‐hold period. FSE images were acquired with respiratory triggering in approximately 4 minutes. Lesion detectability and image quality of the two pulse sequences were analyzed qualitatively. Quantitative analysis was performed by means of signal‐to‐noise and tumor‐liver contrast‐to‐noise analysis. Lesion detectability was comparable in both solid (86.3% vs 90.2%: .3 < P < .5) and nonsolid lesions (89.5% vs 100%: .3 < P < .5) between echo‐planar and FSE images. Echo‐planar imaging provided significantly reduced image artifact, better lesion conspicuity, and anatomic detail compared with FSE imaging. The signal‐to‐noise and contrast‐to‐noise ratios of echo‐planar images were significantly higher than those of FSE images. Breath‐hold eight‐shot echo‐planar imaging can be an alternative to T2‐weighted FSE imaging because it can provide comparable image quality in a substantially decreased acquisition time.
Microwave coagulation therapy on hepatomas: CT and MR appearance after therapy
Authors: Hyodoh Hideki , Hyodoh Kazusa , Takahashi Koji , Furuse Makoto , Kawamoto Chiaki , Isoda Norio , Hozumi Masanori , Ido Kenichi , Hirota Norio 
Published: March 2007

AbstractLaparoscopic microwave coagulation (LMC) for hepatocellular carcinomas (HCCs) was performed on 26 HCCs in 17 patients. Contrast‐enhanced CT (CECT) and MR images (T1‐weighted imaging [T1WI], T2WI, gadolinium‐diethylenetriamine pentaacetic acid [Gd‐DTPA] T1WI) were obtained to determine changes over time. The irradiated center exhibited low to moderate intensity with surrounded high intensity (HI) on T2WI and Gd‐DTPA T1WI. On T1WI, lesions showed four patterns of intensity: uniform HI (30.8%), arcuate HI (26.9%), mainly low with spot HI (30.8%), and isointensity to hypointensity (11.5%). Follow‐up imaging at more than 170 days revealed isointensity to hypointensity on T1WI (96.2%) and reduced HI on T2‐weighted imaging (T2WI) and Gd‐DTPA T1WI. All lesions became less conspicuous and were reduced in volume. HCC shows time‐related changes in signals and size after LMC. Identifying the irradiated lesion is necessary to estimate the adequacy of treatment by comparison with the pretherapeutic image.
Tissue temperature monitoring with multiple gradient‐echo imaging sequences
Authors: Mulkern Robert V. , Panych Lawrence P. , Hynynen Kullervo , Jolesz Ferenc A. , McDannold Nathan J. 
Published: March 2007

AbstractThe inherent sensitivity of multiple gradient‐echo sequences to the chemical shift is exploited to rapidly map muscle water frequency shifts caused by ultrasonic heating. The use of multiple echoes is shown to offer several advantages over single gradient‐echo approaches previously proposed for temperature measurement. An increase in the effective bandwidth significantly reduces aliasing problems observed with single gradient‐echo methods in high temperature applications. Of greater significance is the improved immunity to intrascan motion found for multi‐echo versus single echo gradient methods, making the former more attractive for clinical applications. Finally, a sensitivity to the presence of multiple spectral components unavailable with single gradient‐echo methods is obtained.
Biliary cystadenoma with mesenchymal stroma of the liver: Correlation between unusual MR appearance and pathologic findings
Authors: Gabata Toshifumi , Kadoya Masumi , Matsui Osamu , Yamashiro Masashi , Takashima Tsutomu , Mitchell Donald G. , Nakamura Yasutaka , Takeuchi Kazuo , Nakanuma Yasuni 
Published: March 2007

AbstractWe reported a case of the biliary cystadenoma of the liver. The cystic mass had labulation and septation and showed marked hyperintensity on T1‐weighted images and hypointensity on T2‐weighted images; MR findings were very unusual for cystadenoma. The content of the cystic mass was jelly‐like, thick mucinous fluid without intracystic hemorrhage. We concluded that these unusual signal intensities of the cyst were due to hyperproteinous mucinous fluid.
Dynamic MRI of transcorneal dispersion of oxygen into the anterior chamber of human eye
Authors: Obata Takayuki , Saito Kimihiko , Iwasawa Tae , Hirono Keishi , Yoshida Tetsuo , Matsubara Sho 
Published: March 2007

AbstractTo measure the transcorneal dispersion of oxygen into the anterior chamber, dynamic T1‐weighted fast‐spin‐echo MRI (TR = 2 seconds, TE = 15 msec, 5‐mm slice) of the human eye was performed both before and during oxygen supply to a full goggle placed on the face. During the course of the imaging, a significant increase in the signals in the anterior chamber occurred. This indicated that transcorneal dispersion of oxygen into the anterior chamber can be evaluated by this procedure, suggesting that this method may be useful for diagnosing dysfunction of the cornea or aqueous flow.
Implementation and evaluation of a new pulse sequence for rapid acquisition of double inversion recovery images for simultaneous suppression of white matter and CSF
Authors: Bedell Barry J. , Narayana Ponnada A. 
Published: March 2007

AbstractWe describe a fast double inversion recovery (DIR) imaging sequence that effectively attenuates signal from both white matter and cerebrospinal fluid (CSF). The pulse sequence uses a novel inversion/excitation scheme and fast spin‐echo readout to maximize scan efficiency. The white matter/CSF suppressed images can be acquired from the entire brain in ∼6 minutes. Evaluation of the fast DIR sequence on patients with multiple sclerosis (MS) demonstrates high lesion conspicuity.
Flip angle dependence of experimentally determined T1sat and apparent magnetization transfer rate constants
Authors: Finelli Daniel A. , Reed Damon R. 
Published: March 2007

AbstractThe purpose of this work was to develop a method for determining the T1sat and magnetization transfer (MT) rate constants by analyzing the slice‐select flip angle dependent MT behavior of normal white and gray matter. The technique uses a high MT power, three‐dimensional (3D) gradient‐recalled echo (GRE) sequence, with a well chosen MT pulse frequency offset, such that the experimental conditions closely satisfy requisite assumptions for invoking a first order rate process for MT. Integral to this method is that the T1sat and MT ratio values are obtained under explicitly identical MT saturation conditions. The T1sat of white matter was found to be approximately 300 msec, and the MT rate constant was approximately 2.0 sec−1. The T1sat of gray matter was approximately 500 msec, and the MT rate constant was 1.1 sec−1. We also found a strong dependence of the MT rate constant on the slice‐select flip angle used for the imaging sequence, independent of the MT saturation parameters. Strongly T1‐weighted imaging sequences can result in the underestimation of the MT rate constant by 50%. Practical technical suggestions for quantitative MT experiments are put forth.
Histologic confirmation of microvascular hyperpermeability to macromolecular MR contrast medium in reperfused myocardial infarction
Authors: Saeed Maythem , van Dijke Cornelis F. , Mann Jeffrey S. , Wendland Michael F. , Rosenau Werner , Higgins Charles B. , Brasch Robert C. 
Published: March 2007

AbstractA macromolecular MR contrast medium (MMCM) designed to permit histochemical staining and specific tissue localization, albumin‐(biotin)10‐(Gd‐DTPA)25 (Bio‐Alb‐Gd), was used in a rat model of reperfused myocardial infarction to confirm the presence and distribution of microvascular hyperpermeability. T1‐weighted spin‐echo images were acquired before and after administration of Bio‐Alb‐Gd. An avidin‐biotin‐complex (ABC) stain, specific for the biotinylated MR contrast medium, was used to define the MMCM distribution and to detect any regional change in micro‐vascular permeability related to infarction. Immediately after Bio‐Alb‐Gd administration, the infarcted region was enhanced, with greatest signal intensity noted at the rim and less at the center. There was a gradual increase in signal intensity of the initially hypointense central region. The steady increase in signal intensity of the central region suggested convection transport of MMCM through the interstitial space and its influx into cellular compartment after leakage from the vascular compartment. Histologic findings confirmed regional microvascular hyperpermeability corresponding to the site of infarction and a predominant rim distribution of the MMCM. Bio‐Alb‐Gd was identified at high microscopic power in the intravascular, interstitial, and intracellular spaces at the periphery of reperfused infarcted myocardium. Bio‐Alb‐Gd can be used as an MR contrast medium in reperfused infarcted myocardium to confirm the existence and to localize altered microvascular permeability to macromolecules. Bio‐Alb‐Gd contrast technique removes all the ambiguity between the distribution of the MR or other imaging contrast agent and the distribution of the substrate for histochemical staining.