Magnetic resonance quarterly最新文献_第2页

Contrast-enhanced magnetic resonance imaging of the abdomen. 腹部对比增强磁共振成像。

Magnetic resonance quarterly Pub Date : 1994-06-01

E D Brown, R C Semelka

{"title":"Contrast-enhanced magnetic resonance imaging of the abdomen.","authors":"E D Brown, R C Semelka","doi":"","DOIUrl":"","url":null,"abstract":"The use of intravenous gadolinium chelates in imaging of the abdomen is helpful in the detection and characterization of disease entities. It is well recognized that magnetic resonance (MR) imaging is more sensitive to the presence or absence of gadolinium chelates than computed tomography is to iodine. By exploiting this strength of gadolinium and MR sequences that reduce artifacts, the usefulness of abdominal MR examinations can be maximized. As a nonspecific extracellular contrast agent, the enhancement of gadolinium chelates reflect blood delivery (capillary phase imaging), capillary permeability (interstitial enhancement), and venous drainage (late interstitial/washout enhancement). In general terms, MR evaluation of abdominal organs is benefited by imaging in both capillary and interstitial phases of enhancement since these separate phases reflect different physiological aspects of disease processes. In this review, optimized investigation using intravenous gadolinium chelates is described for diseases of the kidney, gastrointestinal tract, liver, gallbladder, pancreas, spleen, and adrenal glands. The use of newer intravenous and oral contrast agents, particularly relating to the investigation of bowel and liver diseases, is also discussed.","PeriodicalId":77248,"journal":{"name":"Magnetic resonance quarterly","volume":"10 2","pages":"97-124"},"PeriodicalIF":0.0,"publicationDate":"1994-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"18981502","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

Interventional use of magnetic resonance imaging. 磁共振成像的介入应用。

Magnetic resonance quarterly Pub Date : 1994-06-01

F A Jolesz, S M Blumenfeld

引用次数: 0

Controversies in breast MRI. 乳腺MRI的争议。

Magnetic resonance quarterly Pub Date : 1994-06-01

J C Weinreb, G Newstead

引用次数: 0

Quantitative interpretation of bioenergetic data from 31P and 1H magnetic resonance spectroscopic studies of skeletal muscle: an analytical review. 骨骼肌31P和1H磁共振光谱研究生物能量数据的定量解释:分析综述。

Magnetic resonance quarterly Pub Date : 1994-03-01

G J Kemp, G K Radda

{"title":"Quantitative interpretation of bioenergetic data from 31P and 1H magnetic resonance spectroscopic studies of skeletal muscle: an analytical review.","authors":"G J Kemp, G K Radda","doi":"","DOIUrl":"","url":null,"abstract":"In the study of skeletal muscle bioenergetics, 31P magnetic resonance spectroscopy (MRS) allows frequent measurement of the cytosolic pH and the concentrations of phosphocreatine, inorganic phosphate, and adenosine diphosphate (ADP) during exercise and recovery, which can be supplemented by 1H MRS (or biopsy) measurements of muscle lactate content and 13C MRS (or biopsy) measurements of muscle glycogen. We review the many methods now described by which 31P MRS measurements can be made to yield quantitative estimates of adenosine triphosphate (ATP) turnover, oxidative capacity, and proton handling in skeletal muscle. In particular, we describe how to estimate the rates of glycogenolytic and aerobic ATP synthesis during exercise and oxidative ATP synthesis and proton efflux during recovery from exercise and how to assess oxidative capacity using data from steady-state exercise, work jumps, or recovery. We discuss the metabolic relationships that make these methods possible and the assumptions (e.g., about cytosolic buffer capacity and mitochondrial control mechanisms) on which they depend. We show how these methods, although sometimes based on apparently conflicting metabolic models, can be analysed in a common framework. Finally, we discuss some examples of the current and potential applications of these methods in clinical and experimental studies of skeletal muscle.","PeriodicalId":77248,"journal":{"name":"Magnetic resonance quarterly","volume":"10 1","pages":"43-63"},"PeriodicalIF":0.0,"publicationDate":"1994-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19153173","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 imaging in cervical carcinoma: diagnosis, staging, and follow-up. 宫颈癌的磁共振成像:诊断、分期和随访。

Magnetic resonance quarterly Pub Date : 1994-03-01

F Ebner, K Tamussino, H Y Kressel

引用次数: 0

Magnetic resonance imaging of the kidneys: current status. 肾脏磁共振成像:现状。

Magnetic resonance quarterly Pub Date : 1994-03-01

G P Krestin

{"title":"Magnetic resonance imaging of the kidneys: current status.","authors":"G P Krestin","doi":"","DOIUrl":"","url":null,"abstract":"Magnetic resonance imaging (MRI) differs fundamentally from other imaging techniques, since for the first time one method permits simultaneous assessment of macroscopic changes in the kidneys and evaluation of renal functional derangements. To provide morphological information that may compete with the results of computed tomography (CT) and ultrasonography (US), special techniques like artifact compensation, fast imaging, and fat suppression have to be employed. The additional use of a renally eliminated paramagnetic contrast agent permits assessment of parenchymal perfusion and visualization of the passage of the contrast medium, providing information about renal excretory function. Results and clinical utility of state of the art MRI can be summarized as follows: (a) MR is not a screening method; sensitivity is, however, similar to CT when fat suppression and contrast agents are used. (b) Classification of renal masses is almost restricted to the differentiation of cystic, fat-containing, and solid lesions. (c) Contrast-enhanced MRI helps to assess large retroperitoneal masses and to classify them as intra- or extrarenal. (d) Accurate staging of renal cancers is possible; thus, MRI is a good alternative when CT yields uncertain findings and for patients with known contraindications to the administration of iodinated contrast agents. (e) Contrast-enhanced dynamic MRI studies provide semiquantitative evaluation of global and segmental renal function. (f) MR angiography offers the possibility to evaluate renal arteries and veins.","PeriodicalId":77248,"journal":{"name":"Magnetic resonance quarterly","volume":"10 1","pages":"2-21"},"PeriodicalIF":0.0,"publicationDate":"1994-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19153169","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 imaging of urinary bladder cancer: an overview and new developments. 膀胱癌磁共振成像研究综述及新进展。

Magnetic resonance quarterly Pub Date : 1993-12-01

J O Barentsz, S H Ruijs, L J van Erning

引用次数: 0

Magnetic resonance imaging of the foot and ankle. 脚和脚踝的磁共振成像。

Magnetic resonance quarterly Pub Date : 1993-12-01

M E Schweitzer

{"title":"Magnetic resonance imaging of the foot and ankle.","authors":"M E Schweitzer","doi":"","DOIUrl":"","url":null,"abstract":"Magnetic resonance imaging (MRI) of the foot and ankle is useful for the diagnosis and staging as well as the surgical planning of multiple disorders: first, for osseous injury, particularly stress fractures and occult fractures, which appear like bone bruises but behave more like fractures. Then, for the Achilles tendon, MR is useful for staging the chronicity and extent of damage, as well as whether the tendon can be surgically repaired or reconstructed. For the diagnosis of posterior tibialis tendon tears and injuries, MR is an important tool in surgical planning. Often, MR is helpful for the diagnosis of peroneal tendon injury, including dislocations and peroneal splits, two entities that are seen to affect only the peroneal tendons. MR helps in the evaluation of avascular necrosis in any bone secondary to various systemic causes, particularly following talus fractures. MR has also been utilized to assess ankle sprains with complications, such as the ankle impingement syndrome, the sinus tarsi syndrome, and chronic instability, and to diagnose osteomyelitis (since the typical patient also has neuropathic disease bone, scintigraphy is invariably abnormal). MR is promising for the evaluation of reflex sympathetic dystrophy and is as useful for the evaluation of bone and soft tissue tumors as it is elsewhere in the skeleton. MR helps to characterize the biological aggressiveness of the tumor as well as its extent and therefore aids in surgical planning.","PeriodicalId":77248,"journal":{"name":"Magnetic resonance quarterly","volume":"9 4","pages":"214-34"},"PeriodicalIF":0.0,"publicationDate":"1993-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19262682","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

Imaging at high magnetic fields: initial experiences at 4 T. 高磁场成像:4度的初步经验。

Magnetic resonance quarterly Pub Date : 1993-12-01

K Uğurbil, M Garwood, J Ellermann, K Hendrich, R Hinke, X Hu, S G Kim, R Menon, H Merkle, S Ogawa

{"title":"Imaging at high magnetic fields: initial experiences at 4 T.","authors":"K Uğurbil, M Garwood, J Ellermann, K Hendrich, R Hinke, X Hu, S G Kim, R Menon, H Merkle, S Ogawa","doi":"","DOIUrl":"","url":null,"abstract":"This article reviews the preliminary experiences and the results obtained on the human brain at 4 T at the University of Minnesota. Anatomical and functional images are presented. Contrary to initial expectations and the early results, it is possible to obtain high-resolution images of the human brain with exquisite T1 contrast, delineating structures especially in the basal ganglia and thalamus, which were not observed clearly in 1.5-T images until now. These 4-T images are possible using a new approach that achieves maximal contrast for different T1 values at approximately the same repetition time and has built-in tolerance to variations in B1 magnitude. For functional images, the high field provides increased contribution from the venuoles and the capillary bed because the susceptibility-induced alterations in 1/T2* from these small-diameter vessels increase quadratically with the magnitude of the main field. Images obtained with short echo times at 4 T, and by implication at lower fields with correspondingly longer echo times, are expected to be dominated by contributions from large venous vessel or in-flow effects from the large arteries; such images are undesirable because of their poor spatial correspondence with actual sites of neuronal activity.","PeriodicalId":77248,"journal":{"name":"Magnetic resonance quarterly","volume":"9 4","pages":"259-77"},"PeriodicalIF":0.0,"publicationDate":"1993-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19262684","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 arteriography of the pelvis and lower extremities. 骨盆和下肢的磁共振动脉造影。

Magnetic resonance quarterly Pub Date : 1993-09-01

M L Schiebler, J Listerud, R A Baum, J Carpenter, J Weigele, G Holland, M D Schnall, R S Owen, C Cope, M Pentecost

引用次数: 0