Magnetic resonance quarterly最新文献

Update in shoulder magnetic resonance imaging. 肩部磁共振成像的更新。

Magnetic resonance quarterly Pub Date : 1995-03-01

D S Uri, J B Kneeland, M K Dalinka

{"title":"Update in shoulder magnetic resonance imaging.","authors":"D S Uri, J B Kneeland, M K Dalinka","doi":"","DOIUrl":"","url":null,"abstract":"The shoulder is capable of the largest range motion of any articulation in the human body. Because it is inherently unstable, the glenohumeral joint is dependent on the support given by surrounding muscular, ligamentous, and tendonous structures. A variety of disorders may involve these structural supports and lead to shoulder pain and dysfunction. Refinements in magnetic resonance (MR) imaging techniques have allowed improved characterization of these abnormalities and may permit earlier and more specific diagnoses in patients with shoulder pain. Theories as to the pathogenesis of rotator cuff disease include intrinsic and extrinsic impingement as well as overload tendinosis. MR is useful in the evaluation of rotator cuff impingement and tears. The classification and MR assessment of glenohumeral instability has recently received increased attention yet remains an area of difficulty. MR arthrography has been used with some success in the evaluation of instability demonstrating improved diagnostic sensitivities and specificities when compared with conventional MR. Relatively little attention has been paid to MR evaluation of the shoulder after surgery. Micrometallic artifact, distortion of soft-tissue planes, and persistent signal abnormalities within rotator cuff and capsulolabral structures may hinder assessment of recurrent tear or instability in the postoperative patient.","PeriodicalId":77248,"journal":{"name":"Magnetic resonance quarterly","volume":"11 1","pages":"21-44"},"PeriodicalIF":0.0,"publicationDate":"1995-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"18617901","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Functional magnetic resonance imaging with echo planar imaging. 功能磁共振成像与回波平面成像。

Magnetic resonance quarterly Pub Date : 1995-03-01

K K Kwong

引用次数: 0

Magnetic resonance imaging of the anal sphincter using an internal coil. 使用内部线圈的肛门括约肌磁共振成像。

Magnetic resonance quarterly Pub Date : 1995-03-01

N M deSouza, R Puni, D J Gilderdale, G M Bydder

{"title":"Magnetic resonance imaging of the anal sphincter using an internal coil.","authors":"N M deSouza, R Puni, D J Gilderdale, G M Bydder","doi":"","DOIUrl":"","url":null,"abstract":"A surface coil placed within the anal canal was used to image the anal sphincter and determine normal anatomy and contrast enhancement patterns as well as appearances in disease. Sixteen normal volunteers and 24 patients were examined. Imaging was performed on a 0.5-T Picker Asset and a 1.0-T Picker HPQ Vista MRI scanner. T1-weighted and T2-weighted spin-echo, T1-weighted gradient-echo, STIR images transverse to the sphincter, and T1-weighted spin-echo images parallel to the sphincter in the coronal oblique plane were obtained. Intravenous gadopentetate dimeglumine (0.1 mmol/kg) was given to two normal subjects and 10 patients. The coil was easy to insert and well-tolerated and provided high spatial resolution. The internal sphincter had a higher signal intensity than the external sphincter on all sequences but particularly on STIR images. Brisk contrast enhancement of the internal sphincter was seen. Sphincteric abscesses and fistulous tracks were identified in three patients and confirmed at surgery. Sphincter defects were seen in three patients with obstetric trauma, and these were confirmed at surgery. Sphincter atrophy was seen in four patients with idiopathic fecal soiling. High resolution magnetic resonance imaging with a dedicated endoanal coil provides excellent visualisation of normal anatomy and pathology in and around the anal sphincter and may be of considerable value in diagnosis.","PeriodicalId":77248,"journal":{"name":"Magnetic resonance quarterly","volume":"11 1","pages":"45-56"},"PeriodicalIF":0.0,"publicationDate":"1995-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"18617902","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Functional magnetic resonance imaging with echo planar imaging. 功能磁共振成像与回波平面成像。

Magnetic resonance quarterly Pub Date : 1995-01-01 DOI: 10.1007/978-88-470-2194-5_16

K. Kwong

引用次数: 191

Concepts of myocardial perfusion imaging in magnetic resonance imaging. 磁共振成像中心肌灌注成像的概念。

Magnetic resonance quarterly Pub Date : 1994-12-01

N Wilke, M Jerosch-Herold, A E Stillman, K Kroll, N Tsekos, H Merkle, T Parrish, X Hu, Y Wang, J Bassingthwaighte

{"title":"Concepts of myocardial perfusion imaging in magnetic resonance imaging.","authors":"N Wilke, M Jerosch-Herold, A E Stillman, K Kroll, N Tsekos, H Merkle, T Parrish, X Hu, Y Wang, J Bassingthwaighte","doi":"","DOIUrl":"","url":null,"abstract":"Based on the major innovations in ultrafast magnetic resonance (MR) imaging in recent years, myocardial perfusion imaging with MR has become the focus of many investigators. Two major approaches to myocardial perfusion imaging involve either exogenous or endogenous contrast agents. For the first category of perfusion experiments, we review the characteristics of the common contrast agents and MR techniques for experimental and clinical first-pass studies and in particular address the question of extracting quantitative estimates for myocardial blood flow (milliliters per minute per gram) and volume (milliliters per gram). We demonstrated quantitative perfusion analysis using intravascular relaxation agents and heavily T1-weighted ultrafast gradient echo sequences. Signal time curves need to be transformed to content time curves and the resulting residue functions were analyzed with a multiple-pathway, axially distributed perfusion model. These preliminary results suggest that quantitative assessment of myocardial perfusion is feasible, but additional studies should provide further confidence for this novel MR approach. The exact sensitivity and specificity of MR first-pass imaging in conjunction with extracellular contrast agents in patient studies and its diagnostic accuracy as judged against coronary angiography and scintigraphic perfusion imaging remain yet undefined. The second category of perfusion experiments does not require exogenous contrast agents and has not yet been tested in patient studies. Progress is reported on several MR perfusion-sensitive methods that use the tissue water as an endogenous contrast agent in combination with magnetization transfer techniques as well as paramagnetic deoxyhemoglobin for measuring tissue oxygenation using heavily T2*-weighted sequences for blood oxygen-level-dependent contrast. Possible future directions and developments toward further improvements for MR myocardial perfusion measurements and contraction-perfusion matching are also addressed.","PeriodicalId":77248,"journal":{"name":"Magnetic resonance quarterly","volume":"10 4","pages":"249-86"},"PeriodicalIF":0.0,"publicationDate":"1994-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"18871828","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Clinical applications of magnetic resonance spectroscopy. 磁共振波谱的临床应用。

Magnetic resonance quarterly Pub Date : 1994-12-01

B Ross, T Michaelis

引用次数: 0

MRI of degenerative disease of the lumbar spine. 腰椎退行性疾病的MRI。

Magnetic resonance quarterly Pub Date : 1994-09-01

M C Jensen, A P Kelly, M N Brant-Zawadzki

引用次数: 0

Magnetic resonance angiography. 磁共振血管造影。

Magnetic resonance quarterly Pub Date : 1994-09-01

D Atkinson, L Teresi

引用次数: 0

Quantitative magnetic resonance flow imaging. 定量磁共振血流成像。

Magnetic resonance quarterly Pub Date : 1994-09-01

N J Pelc, F G Sommer, K C Li, T J Brosnan, R J Herfkens, D R Enzmann

{"title":"Quantitative magnetic resonance flow imaging.","authors":"N J Pelc, F G Sommer, K C Li, T J Brosnan, R J Herfkens, D R Enzmann","doi":"","DOIUrl":"","url":null,"abstract":"Time-of-flight and phase shift methods have both been used for vascular imaging with magnetic resonance. Phase methods, and phase contrast in particular, are well suited to quantitative measurements of velocity and volume flow rate. The most robust methods for measuring flow encode through-plane velocity into phase shift and compute flow by integrating the measured velocity over the vessel lumen. The accuracy of the flow data can be degraded by the effects of acceleration and eddy currents and by partial volume effects, including the effects of finite slice thickness and resolution, pulsatile waveforms, motion, and chemical shift. The reproducibility depends on the signal-to-noise of the data and the strength of the flow encoding and can be degraded by inconsistent definition of the vessel boundary. The adjustable flow sensitivity inherent in this method is a particular asset, allowing phase contrast flow measurement to operate over a dynamic range exceeding 10(5). Recently developed rapid imaging methods are helpful in applications that would be compromised by respiratory motion. With care, excellent quantitative data can be quickly obtained in vivo, and the resulting flow information is valuable for the diagnosis and management of a variety of conditions.","PeriodicalId":77248,"journal":{"name":"Magnetic resonance quarterly","volume":"10 3","pages":"125-47"},"PeriodicalIF":0.0,"publicationDate":"1994-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"18812145","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Magnetic resonance angiography. 磁共振血管造影。

Magnetic resonance quarterly Pub Date : 1994-09-01 DOI: 10.1201/b11379-20

David Atkinson, L. Teresi

引用次数: 11