Magnetic resonance imaging contrast agents: theory and application to the central nervous system

1990 ◽  
Vol 73 (6) ◽  
pp. 820-839 ◽  
Author(s):  
Richard A. Bronen ◽  
Gordon Sze
Keyword(s):  
Magnetic Resonance Imaging ◽  
Central Nervous System ◽  
Magnetic Resonance ◽  
Mr Imaging ◽  
Contrast Agents ◽  
Resonance Imaging ◽  
Content Type ◽  
Contrast Enhanced ◽  
The Central Nervous System ◽  
Fine Print

✓ The theoretical aspects of magnetic resonance (MR) imaging contrast agents are reviewed, and their current applications to the central nervous system (CNS) and their future applications are discussed. Profound differences exist between contrast agents used for MR imaging and computerized tomography (CT). In MR imaging, the contrast agents are not imaged directly but rather act on adjacent protons to shorten T1 and T2 relaxation times. This in turn results in signal intensity changes. The lanthanide metal, gadolinium, in the form of gadopentetate dimeglumine, has been found to be both safe and efficacious as the only currently approved contrast agent for MR imaging. Magnetic resonance imaging revolutionized the detection and treatment of disease affecting the brain and spine. Initially, it was thought that signal characteristics on MR imaging would allow differentiation of specific pathology. It was soon found that MR studies were able to detect more abnormalities but were less able to characterize them. The recent development of contrast agents for MR imaging has allowed this modality to surpass CT for the evaluation of most CNS lesions. At present, contrast-enhanced MR imaging is generally accepted as the study of choice for evaluating acoustic neurinomas, pituitary lesions, meningeal disease, primary and secondary brain tumors, active multiple sclerosis, intradural spinal neoplasms, intramedullary spinal disease, and postoperative states in both the spine and brain. Even when contrast-enhanced CT can detect the same abnormalities, evaluation of the lesions in multiple planes on MR imaging can sometimes yield invaluable information, especially prior to surgery. Future developments of contrast material for MR imaging include non-gadolinium compounds, intrathecal contrast media, cerebral blood flow and volume evaluation, and, possibly, antibody-labeled contrast agents.

Correlation of the relationships of brain—tumor interfaces, magnetic resonance imaging, and angiographic findings to predict cleavage of meningiomas

1999 ◽  
Vol 91 (3) ◽  
pp. 384-390 ◽  
Author(s):  
Faruk İldan ◽  
Metin Tuna ◽  
Alp İskender Göcer ◽  
Bülent Boyar ◽  
Hüseyin Bağdatoğlu ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Brain Tumor ◽  
Magnetic Resonance ◽  
Mr Imaging ◽  
Vascular Supply ◽  
Peritumoral Edema ◽  
Resonance Imaging ◽  
Content Type ◽  
Angiographic Findings ◽  
Fine Print

Object. The authors examined the relationships of brain—tumor interfaces, specific magnetic resonance (MR) imaging features, and angiographic findings in meningiomas to predict tumor cleavage and difficulty of resection.Methods. Magnetic resonance imaging studies, angiographic data, operative reports, clinical data, and histopathological findings were examined retrospectively in this series, which included 126 patients with intracranial meningiomas who underwent operations in which microsurgical techniques were used. The authors have identified three kinds of brain—tumor interfaces characterized by various difficulties in microsurgical dissection: smooth type, intermediate type, and invasive type. The signal intensity on T1-weighted MR images was very similar regardless of the type of brain—tumor interface (p > 0.1). However, on T2-weighted images the different interfaces seemed to correlate very precisely with the signal intensity and the amount of peritumoral edema (p < 0.01), allowing the prediction of microsurgical effort required during surgery. On angiographic studies, the pial—cortical arterial supply was seen to participate almost equally with the meningeal—dural arterial supply in vascularizing the tumor in 57.9% of patients. Meningiomas demonstrating hypervascularization on angiography, particularly those fed by the pial—cortical arteries, exhibited significantly more severe edema compared with those supplied only from meningeal arteries (p < 0.01). Indeed, a positive correlation was found between the vascular supply from pial—cortical arteries and the type of cleavage (p < 0.05).Conclusions. In this analysis the authors proved that there is a strong correlation between the amount of peritumoral edema, hyperintensity of the tumor on T2-weighted images, cortical penetration, vascular supply from pial—cortical arteries, and cleavage of the meningioma. Therefore, the consequent difficulty of microsurgical dissection can be predicted preoperatively by analyzing MR imaging and angiographic studies.

Magnetic resonance imaging and aneurysm clips

1989 ◽  
Vol 70 (3) ◽  
pp. 426-431 ◽  
Author(s):  
Bertil Romner ◽  
Magnus Olsson ◽  
Bengt Ljunggren ◽  
Stig Holtås ◽  
Hans Säveland ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Mr Imaging ◽  
Image Artifacts ◽  
Resonance Imaging ◽  
Content Type ◽  
Aneurysm Clip ◽  
Different Types ◽  
Mr Artifacts ◽  
Fine Print

✓ The magnetic properties of 12 different types of aneurysm clip were investigated in order to identify which clips allow postoperative magnetic resonance (MR) imaging without risk. Clip-induced MR artifacts were also quantitatively studied using a geometrical phantom. Nonferromagnetic aneurysm clips like the Yaşargil Phynox, Sugita Elgiloy, and Vari-Angle McFadden clips do not appear to contraindicate MR studies performed with a FONAR β-3000M imager. There is no clip movement upon introduction of the phantom into the MR imager, and the image artifacts caused by the clips are so limited that patients harboring such clips may well be considered for MR imaging. This examination may reveal information not obtainable by any other radiological modality.

Magnetic resonance imaging findings in ossification of the posterior longitudinal ligament of the cervical spine

1998 ◽  
Vol 88 (2) ◽  
pp. 247-254 ◽  
Author(s):  
Izumi Koyanagi ◽  
Yoshinobu Iwasaki ◽  
Kazutoshi Hida ◽  
Hiroyuki Imamura ◽  
Hiroshi Abe
Keyword(s):  
Magnetic Resonance Imaging ◽  
Spinal Cord ◽  
Magnetic Resonance ◽  
Mr Imaging ◽  
Posterior Longitudinal Ligament ◽  
Imaging Findings ◽  
Resonance Imaging ◽  
Disc Protrusion ◽  
Content Type ◽  
Fine Print

Object. Because of the lack of magnetic resonance (MR) signal from cortical bones, MR imaging is inadequate for diagnosing ossified lesions in the spinal canal. However, MR imaging provides important information on spinal cord morphology and associated soft-tissue abnormality. The purpose of this study is to determine the role of MR imaging in the diagnosis and treatment of patients with ossification of the posterior longitudinal ligament (OPLL) of the cervical spine. Methods. The authors reviewed MR imaging findings in 42 patients with cervical OPLL who were examined with a superconducting MR imaging system. The types of OPLL reviewed included eight cases of continuous, 21 cases of segmental, and 13 cases of the mixed type. All patients were treated surgically either by anterior (26 cases) or posterior decompression (16 cases). Conclusions. The T1-weighted images clearly demonstrated the spinal cord deformity caused by OPLL. Associated disc protrusion was found to be present at the maximum compression level in 60% of the patients in this series. The highest incidence of disc protrusion (81%) was found in patients with segmental OPLL. Intramedullary hyperintensity on T2*-weighted imaging was noted in 18 patients (43%). The neurological deficits observed in these 18 patients were significantly more severe than those observed in the other 24 patients. Postoperative MR imaging revealed improvement in the spinal cord deformity, although the intramedullary hyperintensity was still observed in most cases. The present study demonstrates the importance of associated disc protrusion in the development of myelopathy in patients with cervical OPLL. Magnetic resonance imaging findings may be used to help determine the actual levels of spinal cord compression and to suggest the method of surgical treatment.

Transient dystonia following magnetic resonance imaging in a patient with deep brain stimulation electrodes for the treatment of Parkinson disease

2003 ◽  
Vol 99 (4) ◽  
pp. 772-774 ◽  
Author(s):  
Jörg Spiegel ◽  
Gerhard Fuss ◽  
Martin Backens ◽  
Wolfgang Reith ◽  
Tim Magnus ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Deep Brain Stimulation ◽  
Magnetic Resonance ◽  
Mr Imaging ◽  
Parkinson Disease ◽  
Resonance Imaging ◽  
Content Type ◽  
Ballistic Movements ◽  
Fine Print ◽  
Deep Brain

✓ Data from previous studies have shown that magnetic resonance (MR) imaging of the head can be performed safely in patients with deep brain stimulators. The authors report on a 73-year-old patient with bilaterally implanted deep brain electrodes for the treatment of Parkinson disease, who exhibited dystonic and partially ballistic movements of the left leg immediately after an MR imaging session. Such dystonic or ballistic movements had not been previously observed in this patient. In the following months, this focal movement disorder resolved completely. This case demonstrates the possible risks of MR imaging in patients with deep brain stimulators.

Can magnetic resonance imaging alone accurately define the arteriovenous nidus for gamma knife radiosurgery?

2002 ◽  
Vol 97 ◽  
pp. 464-470 ◽  
Author(s):  
E. J. St. George ◽  
P. Butler ◽  
P. N. Plowman
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Mr Imaging ◽  
Gamma Knife ◽  
Gamma Knife Radiosurgery ◽  
Resonance Imaging ◽  
Systemic Complications ◽  
Content Type ◽  
Weighted Sequences ◽  
Fine Print

Object. Current radiosurgical treatment of arteriovenous malformations (AVMs) relies on planning protocols that integrate data from both magnetic resonance (MR) imaging and stereotactic angiography studies. Angiography, however, is invasive and associated with a small but well-defined risk of neurological and systemic complications. Magnetic resonance imaging, on the other hand, is noninvasive with multiplanar capability, demonstrates good anatomical detail, and has been shown to be superior to angiography in the delineation of selected AVMs. Methods. In this study, MR imaging—related accuracy of defining the AVM nidus in gamma knife radiosurgery is investigated using only T1- and T2-weighted sequences. Conclusions. Little interobserver variability was observed and AVM nidi, as demonstrated on T1- and T2-weighted MR images, were well correlated in terms of size. The displacement of the new target, however, from the original nidus, was not predictable and occasionally was significant, thus precluding safe radiosurgical planning.

MR Imaging of Congenital and Acquired Malformation of the Eye and Orbit

1997 ◽  
Vol 10 (4) ◽  
pp. 423-430 ◽  
Author(s):  
L. Manfrè ◽  
A. Banco ◽  
M. Accardi ◽  
V. D'Antonio ◽  
A. Caronia ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Central Nervous System ◽  
Nervous System ◽  
Magnetic Resonance ◽  
Mr Imaging ◽  
Imaging Modality ◽  
Resonance Imaging ◽  
The Central Nervous System ◽  
Cns Malformations ◽  
Teratogenic Factor

As for all the central nervous system (CNS) defects, the severity of eye malformations is related to the time a teratogenic factor occurs: the earlier the insult, the more serious the eye abnormalities are. Magnetic resonance imaging perfectly depicts most eye defects. Considering that several CNS malformations have been described to occur simultaneously in the case of eye abnormalities, MRI is considered the imaging modality of choice nowadays.

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