bluuebunny/crossref_metadata_2025_split huggingface dataset:
Three‐dimensional magnetic resonance imaging technique for myocardial‐delayed hyperenhancement: A comparison with the two‐dimensional technique
Authors: Tatli Servet , Zou Kelly H. , Fruitman Mark , Reynolds H. Glenn , Foo Thomas , Kwong Raymond , Yucel E. Kent 
Published: August 2004

AbstractPurposeTo compare two‐dimensional and three‐dimensional techniques in the detection of myocardial infarction (MI) and in the grading transmural extent (TE).Materials and MethodsTwelve patients with clinically proven MI were examined using two‐dimensional and three‐dimensional techniques with cardiac‐gated, breath‐hold, T1‐weighted gradient echo sequence with an inversion recovery pulse following gadopentetate dimeglumine (Gd‐DTPA) at 0.2 mmol/kg. Contrast‐to‐noise, signal‐to‐noise, and signal intensity ratios (CNR, SNR, and SIR, respectively) were derived and compared for each technique.ResultsFrom two‐dimensional to three‐dimensional, statistical significant difference was found in the mean CNR (11.65 vs. 56.59; P = 0.002), SNR (18.03 vs. 76.90; P < 0.001), and SIR (3.6 vs. 6.36; P = 0.05). Intraobserver agreement (kappa) between two‐dimensional and three‐dimensional were R1 = 74% and R2 = 90%. Interobserver agreements between the readers were two‐dimensional = 77% and three‐dimensional = 79%.ConclusionMean CNR, SNR, and SIR are significantly increased in the three‐dimensional technique compared to the conventional two‐dimensional technique. J. Magn. Reson. Imaging 2004;20:378–382. © 2004 Wiley‐Liss, Inc.
High‐resolution MR‐imaging of the liver with T2‐weighted sequences using integrated parallel imaging: Comparison of prospective motion correction and respiratory triggering
Authors: Zech Christoph J. , Herrmann Karin A. , Huber Armin , Dietrich Olaf , Stemmer Alto , Herzog Peter , Reiser Maximilian F. , Schoenberg Stefan O. 
Published: August 2004

AbstractPurposeTo compare high‐resolution T2‐weigthed images of the liver with and without integrated parallel acquisition techniques (iPAT) using either breath‐hold sequences in combination with prospective acquisition motion correction (PACE) or respiratory triggering.Materials and MethodsTen volunteers and 10 patients underwent each four different high‐resolution fast spin echo (FSE) T2‐weigthed sequences with 5 mm slice thickness and a full 320 matrix: a multi‐breath‐hold FSE sequence with and without iPAT and PACE and a respiratory‐triggered FSE sequence with and without iPAT. Image quality was rated with a five‐point scale by two independent readers. Signal intensity measurements were performed on a water phantom.ResultsThe sequences with iPAT required a substantially shorter acquisition time without loss of image quality. Overall image quality was rated equal for all sequences by both readers. Image time for nine slices with iPAT was 13 seconds (19 seconds without iPAT) with multi‐breath‐hold and on average 4:00 minutes (7:02 minutes without iPAT) with respiratory triggering. Imaging with the PACE technique resulted in more correct positioning of the image stacks.ConclusionT2‐weighted fast imaging with iPAT is feasible and results in high‐quality images within a short acquisition time. Overall image quality is not negatively affected by iPAT. J. Magn. Reson. Imaging 2004;20:443–450. © 2004 Wiley‐Liss, Inc.
Metabolites in ventricular cerebrospinal fluid detected by proton magnetic resonance spectroscopic imaging
Authors: Nagae‐Poetscher Lidia M. , McMahon Michael , Braverman Nancy , Lawrie William T. , Fatemi Ali , Degaonkar Mahaveer , Horská Alena , Pomper Martin G. , Chacko Vaddapuram P. , Barker Peter B. 
Published: August 2004

AbstractNormally, ventricular cerebrospinal fluid (CSF) contains low levels of all metabolite signals on proton magnetic resonance spectroscopic imaging (MRSI). We present here three cases (two with seizure disorders, one with a central nervous system lymphoma) who presented with unusually elevated CSF signals on MRSI. Based on chemical shifts and in vitro studies (in one case), the signals were assigned to propan‐1,2‐diol (PD), acetone, and lactate, respectively. These compounds were either exclusively, or more readily, detected in CSF than in brain. Proton MRSI conveniently screens both brain and CSF for abnormal metabolism simultaneously. J. Magn. Reson. Imaging 2004;20:496–500. © 2004 Wiley‐Liss, Inc.
Reliability in detection of hemorrhage in acute stroke by a new three‐dimensional gradient recalled echo susceptibility‐weighted imaging technique compared to computed tomography: A retrospective study
Authors: Wycliffe Nathaniel D. , Choe Judy , Holshouser Barbara , Oyoyo Udo E. , Haacke E. Mark , Kido Daniel K. 
Published: August 2004

AbstractPurposeTo compare the sensitivity of magnetic resonance (MR) susceptibility‐weighted imaging (SWI) with conventional MR sequences and computed tomography (CT) in the detection of hemorrhage in an acute infarct.Materials and MethodsA series of 84 patients suspected of having acute strokes had both CT and MR imaging (MRI) scans with diffusion‐weighted imaging (DWI) and SWI. The SWI sequence is a new high‐resolution three‐dimensional (3D) imaging technique that amplifies phase to enhance the magnitude contrast.ResultsThirty‐eight of 84 cases showed abnormal DWI consistent with acute infarct. Of the 38, SWI showed evidence of hemorrhage in 16 cases, compared to eight cases with spin echo (SE) T2, seven cases with fluid attentuated inversion recovery (FLAIR), and only five cases with CT. In a subset of 17 cases of acute infarct who had both two‐dimensional gradient recalled echo (2D‐GRE) T2*‐weighted imaging and SWI, in addition to conventional MRI, evidence of hemorrhage was seen in 10 cases using SWI, compared to seven cases with 2D‐GRE T2*.ConclusionSWI proved to be a powerful new approach for visualizing hemorrhage in acute stroke compared to CT and conventional MRI methods. J. Magn. Reson. Imaging 2004;20:372–377. © 2004 Wiley‐Liss, Inc.
Adnexal torsion: Magnetic resonance findings in the viable adnexa with emphasis on stromal ovarian appearance
Authors: Ghossain Michel A. , Hachem Kamal , Buy Jean‐Noël , Hourany‐Rizk Roula G. , Aoun Noël J. , Haddad‐Zebouni Soha , Mansour Fersan , Attieh Elie , Abboud Joseph 
Published: August 2004

AbstractPurposeTo evaluate ultrasound (US) and magnetic resonance (MR) findings in the viable twisted adnexa.Materials and MethodsTen patients underwent US and MR studies before surgical detorsion. Corrected cross‐sectional area of the ovary was defined as cross‐sectional area minus areas of cysts and follicles superior to 1 cm. On T2‐weighted images, signal intensity of the stroma was graded as type 1 when it was equal to that of urine and type 2 when it was less than that of urine but markedly more than the contralateral side.ResultsThe tube was twisted in six cases and the ovary in nine cases. All adnexa were viable. The largest ovarian cross‐sectional area and the largest corrected ovarian cross‐sectional area of the twisted ovary were significantly larger than those of the contralateral ovary (P = 0.043 for US; P = 0.012 and 0.017, respectively, for MR). These ovaries contained types 1 and 2 hyperintensity in six cases and only type 2 hyperintensity in three cases. Tubal thickening was seen on MR in five cases.ConclusionTubal thickening, enlargement of ovarian stroma as reflected by the corrected cross‐sectional area, and hyperintensity of this stroma on T2‐weighted images probably related to edema were useful findings in these viable torsions. J. Magn. Reson. Imaging 2004;20:451–462. © 2004 Wiley‐Liss, Inc.
Recurrent coronary artery stenosis: Assessment with three‐dimensional MR imaging
Authors: Müller Markus F. , Fleisch Martin 
Published: August 2004

AbstractPurposeTo assess the diagnostic value of three‐dimensional coronary magnetic resonance (MR) angiography with fat saturation and navigator echo in the setting of restenosis after percutaneous transluminal coronary angioplasty (PTCA).Materials and MethodsThirty consecutive patients who had PTCA and were referred for elective coronary reangiography underwent MR imaging and coronary angiography. The pulse sequence was a cardiac triggered, single‐slab, three‐dimensional, gradient‐echo sequence, employing a spin‐echo navigator echo measurement to track the variation of the diaphragm during the scan. The following segments of the coronary arteries were included in this prospective study: left main coronary artery, proximal and middle left anterior descending, proximal and middle left circumflex, proximal and middle right coronary artery, and intermediate branch, if present. The quality of the MR images was graded from 0 to 5.ResultsIn total, 221 coronary artery segments could be identified. Mean image quality was 3.3. Overall accuracy for segments with an image quality of grade 2 or more was 90%. To achieve a positive predictive value >70% for a significant stenosis/restenosis, only segments with quality ≥3 could be assessed, whereas an acceptable negative predictive value could be achieved for nearly all segments.ConclusionOur preliminary data suggest that MR coronary angiography may be most helpful as a screening test in selected patients to exclude clinically relevant stenoses or to assess restenoses after PTCA or in patients in whose coronary angiography is relatively contraindicated. J. Magn. Reson. Imaging 2004;20:383–389. © 2004 Wiley‐Liss, Inc.
Nitrate‐induced coronary vasodilation by stress‐magnetic resonance imaging: A novel noninvasive test of coronary vasomotion
Authors: Pepe Alessia , Lombardi Massimo , Takacs Imola , Positano Vincenzo , Panzarella Gaetano , Picano Eugenio 
Published: August 2004

AbstractPurposeTo evaluate the feasibility of assessing coronary vasodilation following exogenous nitrates, using magnetic resonance angiography (MRA). The assessment of coronary response to exogenous nitrovasodilators may have a diagnostic and prognostic impact in patients with coronary artery disease. To date, stress imaging of coronary artery vasomotion has been confined to the catheterization laboratory. MRA is emerging as a noninvasive tool for coronary artery imaging.Materials and MethodsCoronary MRA was performed in 20 healthy volunteers (12 males, age = 33 ± 8). We used spiral spoiled gradient echo (SSGE) sequences for imaging of coronary artery lumen. After the baseline short‐axis view of the coronary artery was obtained, sublingual nitroglycerin (NTG) (0.3 mg) was administered. In all subjects, short‐axis views of the coronary artery were acquired repetitively (8–10 times) from 1 up to 10 minutes after NTG administration. Measurements were obtained by two independent investigators.ResultsInterpretable short‐axis view of left anterior descending artery (LAD) was obtained in 15 subjects (75%); in the remaining five subjects the right coronary artery (RCA) was examined. The interobserver variability was 15%, and the intraobserver variability 4%. The NTG‐induced maximal vasodilation was 43 ± 22%. The vasodilator response over time after NTG was maximal on average at 279 ± 112 seconds, but with substantial heterogeneity.ConclusionEntity and time course of nitrate‐induced coronary vasodilation in the left anterior descending and/or RCA can be assessed using MRA with high feasibility and reproducibility. Coronary MRA has potential for dynamic imaging of coronary vasomotion. J. Magn. Reson. Imaging 2004;20:390–394. © 2004 Wiley‐Liss, Inc.
Quantitative assessment of regional pulmonary perfusion in the entire lung using three‐dimensional ultrafast dynamic contrast‐enhanced magnetic resonance imaging: Preliminary experience in 40 subjects
Authors: Ohno Yoshiharu , Hatabu Hiroto , Murase Kenya , Higashino Takanori , Kawamitsu Hideaki , Watanabe Hirokazu , Takenaka Daisuke , Fujii Masahiko , Sugimura Kazuro 
Published: August 2004

AbstractPurposeTo assess regional differences in quantitative pulmonary perfusion parameters, i.e., pulmonary blood flow (PBF), mean transit time (MTT), and pulmonary blood volume (PBV) in the entire lung on a pixel‐by‐pixel basis in normal volunteers and pulmonary hypertension patients.Materials and MethodsThree‐dimensional ultrafast dynamic contrast‐enhanced MR imaging was performed in 15 normal volunteers and 25 patients with pulmonary hypertension. From the signal intensity–time course curves, PBF, MTT and PBV maps were generated using deconvolution analysis, indicator dilution theories, and the central volume principle, on a pixel‐by‐pixel basis. From pulmonary perfusion parameter maps of normal volunteers and pulmonary hypertension patients, regional PBF, MTT, and PBV were statistically evaluated.ResultsRegional PBF, MTT, and PBV showed significant differences in the gravitational and isogravitational directions (P < 0.05). The quantitative pulmonary perfusion parameter maps demonstrated significant differences between normal volunteers and pulmonary hypertension patients (P < 0.05).ConclusionThree‐dimensional ultrafast dynamic contrast‐enhanced MR imaging is feasible for the assessment of regional quantitative pulmonary perfusion parameters in the entire lung on a pixel‐by‐pixel basis in normal volunteers and pulmonary hypertension patients. J. Magn. Reson. Imaging 2004;20:353–365. © 2004 Wiley‐Liss, Inc.
Comparison of matched‐filtered two‐dimensional projection and elliptical centric‐ordered three‐dimensional contrast‐enhanced magnetic resonance angiography
Authors: Huang Yuexi , Merchant Naeem , Wright Graham A. 
Published: August 2004

AbstractPurposeTo compare the image quality of matched‐filtered two‐dimensional projection magnetic resonance angiography (MRA) and elliptical centric‐ordered (EC) three‐dimensional MRA.Materials and MethodsSignal‐to‐noise ratios (SNRs) of matched‐filtered two‐dimensional projection and EC three‐dimensional MRA are developed theoretically and compared by clinical studies, in which 10–20 mL of gadolinium (Gd) was injected at 1.5 mL/second. The artery‐vein contrast in two‐dimensional projection MRA was managed by manually selecting specific templates for the matched filters.ResultsThe SNR of matched‐filtered two‐dimensional projection MRA is superior to that of EC three‐dimensional MRA for vessels wider than one pixel due to the integral effect. The artery–vein contrast can be managed flexibly in two‐dimensional projection MRA by choosing different templates for the matched filter, while the artery–vein contrast in EC three‐dimensional MRA is solely determined by the timing to start the acquisition.ConclusionMatched‐filtered two‐dimensional projection MRA provides comparable image quality and is a flexible alternative to EC three‐dimensional MRA in applications where contrast timing is difficult and temporal information is of interest. J. Magn. Reson. Imaging 2004;20:435–442. © 2004 Wiley‐Liss, Inc.
Evaluation of heart perfusion in patients with acute myocardial infarction using dynamic contrast‐enhanced magnetic resonance imaging
Authors: Nielsen Gitte , Fritz‐Hansen Thomas , Dirks Christina G. , Jensen Gorm B. , Larsson Henrik B.W. 
Published: August 2004

AbstractPurposeTo investigate the diagnostic ability of quantitative magnetic resonance imaging (MRI) heart perfusion in acute heart patients, a fast, multislice dynamic contrast‐enhanced MRI sequence was applied to patients with acute myocardial infarction.Materials and MethodsSeven patients with acute transmural myocardial infarction were studied using a Turbo‐fast low angle shot (FLASH) MRI sequence to monitor the first pass of an extravascular contrast agent (CA), gadolinium diethylene triamine pentaacetic acid (Gd‐DTPA). Quantitation of perfusion, expressed as Ki (mL/100 g/minute), in five slices, each having 60 sectors, provided an estimation of the severity and extent of the perfusion deficiency. Reperfusion was assessed both by noninvasive criteria and by coronary angiography (CAG).ResultsThe Ki maps clearly delineated the infarction in all patients. Thrombolytic treatment was clearly beneficial in one case, but had no effect in the two other cases. Over the time‐course of the study, normal perfusion values were not reestablished following thrombolytic treatment in all cases investigated.ConclusionThis study shows that quantitative MRI perfusion values can be obtained from acutely ill patients following acute myocardial infarction. The technique provides information on both the volume and severity of affected myocardial tissue, enabling the power of treatment regimes to be assessed objectively, and this approach should aid individual patient stratification and prognosis. J. Magn. Reson. Imaging 2004;20:403–410. © 2004 Wiley‐Liss, Inc.
Radiofrequency thermal ablation: Correlation of hyperacute MR lesion images with tissue response
Authors: Breen Michael S. , Lazebnik Roee S. , Fitzmaurice Maryann , Nour Sherif G. , Lewin Jonathan S. , Wilson David L. 
Published: August 2004

AbstractPurposeTo investigate the hypothesis that the outer boundary of the hyperintense region observed in hyperacute (several minutes post‐ablation) T2 and gadolinium contrast‐enhanced (CE) T1‐weighted magnetic resonance (MR) lesion images is an accurate predictor of eventual cell death from radiofrequency (RF) thermal ablation.Materials and MethodsA low‐field, open MR imaging system was used to guide an ablation electrode into a thigh muscle of five rabbits and acquire in vivo T2 and CE T1‐weighted MR volumes. Ablation occurred by applying RF current for two minutes with the electrode's temperature maintained at 90° ± 2°C. After fixation, we sliced and photographed the tissue at 3 mm intervals, using a specially designed apparatus, to obtain a volume of tissue images. Digital images of hematoxylin and eosin (H&E) and Masson trichrome–stained histologic samples were obtained, and distinct regions of tissue damage were labeled using a video microscopy system. After the MR and histology images were aligned using a three‐dimensional registration method, we compared tissue damage boundaries identified in histology with boundaries marked in MR images.ResultsThe lesions have distinct zones of tissue damage histologically: a central zone of necrotic cells surrounded by an outer zone with cells that appeared non‐viable and associated with marked interstitial edema. In 14 histology images from five lesions, the inner and outer boundaries of the outer zone were compared with the boundaries of a hyperintense rim that surrounds a central hypointense region in the T2 and CE T1‐weighted MR images. For T2 and CE T1‐weighted MR images, respectively, the mean absolute distance was 1.04 ± 0.30 mm (mean ± SD) and 1.00 ± 0.34 mm for the inner boundaries, and 0.96 ± 0.34 mm and 0.94 ± 0.44 mm for the outer boundaries. The mean absolute distances for T2 and CE T1‐weighted MR images were not sufficiently different to achieve statistical significance (P = 0.745, 0.818, for the inner and outer boundary, respectively).ConclusionIn hyperacute T2 and CE T1‐weighted MR lesion images, observations strongly suggest that the outer boundary of the hyperintense rim corresponds to the region of eventual cell necrosis within a distance comparable to our ability to measure. This is good evidence that during RF ablation procedures, MR lesion images can be used to accurately localize the zone of irreversible tissue damage at the lesion margin. J. Magn. Reson. Imaging 2004;20:475–486. © 2004 Wiley‐Liss, Inc.
Quantitative evaluation of metal artifact reduction techniques
Authors: Kolind Shannon H. , MacKay Alex L. , Munk Peter L. , Xiang Qing‐San 
Published: August 2004

AbstractPurposeTo develop a technique to quantify artifact, and to use it to compare the effectiveness of several approaches to metal artifact reduction, including view angle tilting and increasing the slice select and image bandwidths (BWs), in terms of metal artifact reduction, noise, and blur.Materials and MethodsNonmetallic replicas of two metal implants (stainless steel and titanium/chromium‐cobalt femoral prostheses) were fabricated from wax, and MR images were obtained of each component immersed in water. The differences between the images of each metal prosthesis and its wax counterpart were measured. The contributions from noise and blur were isolated, resulting in a measure of the metal artifact. Several off‐resonance artifact reduction techniques were assessed in terms of metal artifact reduction capability, as well as signal to noise ratio and blur.ResultsIncreasing the image BW from ±16 kHz to ±64 kHz was found to reduce the artifact by an average of 60%, while employing view angle tilting (VAT) alone was found to reduce the artifact by an average of 63%. The metal artifact reduction sequence (MARS), which combines several susceptibility artifact reduction techniques, resulted in the least amount of image distortion, reducing the artifact by an average of 79%.ConclusionThe results indicate that while VAT alone (with an image BW of ±16 kHz) resulted in the smallest amount of total energy and no reduction in the signal‐to‐noise ratio compared to a conventional spin‐echo pulse sequence, MARS resulted in significantly less artifact and dramatically less blur. J. Magn. Reson. Imaging 2004;20:487–495. © 2004 Wiley‐Liss, Inc.
3D breath‐held cardiac function with projection reconstruction in steady state free precession validated using 2D cine MRI
Authors: Peters Dana C. , Ennis Daniel B. , Rohatgi Pratik , Syed Mushabbar A. , McVeigh Elliot R. , Arai Andrew E. 
Published: August 2004

AbstractPurposeTo develop and validate a three‐dimensional (3D) single breath‐hold, projection reconstruction (PR), balanced steady state free precession (SSFP) method for cardiac function evaluation against a two‐dimensional (2D) multislice Fourier (Cartesian) transform (FT) SSFP method.Materials and MethodsThe 3D PR SSFP sequence used projections in the x‐y plane and partitions in z, providing 70–80 msec temporal resolution and 1.7 × 1.7 × 8–10 mm in a 24‐heartbeat breath hold. A total of 10 volunteers were imaged with both methods, and the measurements of global cardiac function were compared.ResultsMean signal‐to‐noise ratios (SNRs) for the blood and myocardium were 114 and 42 (2D) and 59 and 21 (3D). Bland‐Altman analysis comparing the 2D and 3D ejection fraction (EF), left ventricular end diastolic volume (LVEDV) and end systolic volume (LVESV), and end diastolic myocardial mass (LVEDM) provided values of bias ±2 SD of 0.6% ± 7.7 % for LVEF, 5.9 mL ± 20 mL for LVEDV, −2.8 mL ± 12 mL for LVESV, and −0.61 g ± 13 g for LVEDM. 3D interobserver variability was greater than 2D for LVEDM and LVESV.ConclusionIn a single breath hold, the 3D PR method provides comparable information to the standard 2D FT method, which employs 10–12 breath holds. J. Magn. Reson. Imaging 2004;20:411–416. Published 2004 Wiley‐Liss, Inc.
Polyamine dendrimer‐based MRI contrast agents for functional kidney imaging to diagnose acute renal failure
Authors: Kobayashi Hisataka , Jo Sang‐Kyung , Kawamoto Satomi , Yasuda Hideo , Hu Xuzhen , Knopp Michael V. , Brechbiel Martin W. , Choyke Peter L. , Star Robert A. 
Published: August 2004

AbstractPurposeTo choose an efficacious renal functional MRI contrast agent to image early renal tubular damage. We synthesized and compared smaller polyamine dendrimer‐based MRI contrast agents (<60 kD) that, unlike Gd‐[DTPA], transiently accumulate in renal tubules and can be used to visualize renal structural and functional damage.Materials and MethodsSix dendrimer‐based MRI contrast agents smaller than 60 kD were studied by high resolution dynamic micro‐MRI and compared to Gd‐[DTPA]‐dimeglumine and Gadomer‐17. The best agent, DAB‐G2, was further tested in a mouse ischemia/reperfusion model to validate its efficacy.ResultsDespite unequal renal clearance rates, all polyamine dendrimer agents visualized the renal functional anatomy of the mice better than Gd‐[DTPA]‐dimeglumine and Gadomer‐17. DAB‐G2 was excreted most rapidly, yet was able to visualize mild renal tubular injury very early after injury.ConclusionDAB‐G2 was found to be the best candidate for functional kidney imaging and enabled early diagnosis of acute renal injury. J. Magn. Reson. Imaging 2004;20:512–518. Published 2004 Wiley‐Liss, Inc.