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Detection of low-grade gliomas by NMR imaging
240
Magnetic Resonance Imaging 0 Volume 2, Number 3, 1984
detecting IN in asymptomatic joints, in femoral heads during the reperfusion stage when the BS appears normal, and can be used to evaluate IN following surgical procedures. Improved NMR Evaluation of the Head Using Calculated T,, T2 and Estimated Images
K. R. Maravilla, J. C. Weinreb, and R. Nunnally Department of Radiology, The University of Texas Health Science Center, Dallas, Texas 75235
Proton magnetic resonance imaging of the head is very sensitive in detecting intracranial abnormalities. Since most abnormalities which occur in the brain have a prolonged T2 measurement, the most common pulse sequence used for evaluation of the head is a Tzweighted spin-echo image with a long TR value ( 1.5-2 s). Although this sequence results in enhancement of the NMR signal for abnormalities with long T2 on the delayed spin-echoes, there are limitations encountered using this single pulse sequence. This is especially true in abnormalities related to the basal cisterns including the suprasella region, brainstem, and upper cervical cord. Small intraaxial or extraaxial mass lesions in these regions can be missed due to poor contrast between the CSF in the cisterns and the brain. Additional limitations are encountered in evaluating abnormalities which show very little contrast or have a very slight T2 difference relative to the surrounding brain tissue or when compared to the CSF in the ventricles and cisterns. In these cases we use a protocol which consists of two spin-echo imaging sequences which use different repetition rates and which are obtained without moving the patient. This protocol has resulted in improved detection and characterization of lesions with slight changes in T, or T2 compared with using any single pulse sequence. The short TR sequence which weights T, information allows for better definition of structures bordering the basal cisterns. The dual pulse sequence protocol also permits determination of calculated image maps of T, values as well as interpolated images which are computer-generated images which allow for retrospectively varying TR and TE parameters independently. These combined techniques have allowed for better detection and characterization of subtle lesions. Clinical cases which illustrate the value of this technique include small intracranial cysts, cystic astrocytomas, small lesions related to the suprasella cistern and a small lesion in the thalamus. Using the dual pulse sequence and calculated images in select cases has enabled us to improve our specificity of diagnosis and the index of certainty.
Detection of Low-Grade Gliomas by NMR Imaging
A. C. Price, V. M. Runge, J. H. Allen, C. L. Partain, A. E. James Department of Radiology, Vanderbilt University Medical Center, Nashville, Tennessee 37232
Utilizing a Technicare 0.5 T superconducting NMR imager, four patients with symptomatology suggestive of a low-grade cerebral neoplastic process were examined. The patients’ clinical history was significant for progressive headaches over several months. Highresolution CT scans were equivocal in all cases. Sagittal, coronal, and axial sections were obtained using spin-echo (30/ 500 and 120/ 1000) and inversion recovery techniques. With spin-echo technique (30/250 and 120/ 1000) use was also made of volume anisotropic acquisitions in the transverse plane, which generated 32 sequential slices from the cervical region to the top of the skull. Soft tissue masses were visualized in all cases with prolonged T, and T2 relaxation times, high signal intensity on T,-weighted sequences and low signal intensity on inversion recovery. Slight mass effects were also demonstrated optimally by NMR while the results of CT examinations were equivocal or subtle. Two of the four patients have proceeded to surgery with pathology confirming the presence of a low grade glioma. In four cases with clinical symptoms suggestive of neoplastic disease, NMR examination of the head detected an area of tissue pathology, confirmed by surgery in two cases, when CT examination was equivocal. These .areas of abnormality were best seen using spin-echo technique (120/ 1000) with a long time to echo and pulse repetition rate. Coronal and sagittal images provided exquisite anatomical detail and localization for surgical approach. Magnetic Resonance Imaging of Demyelinating ease
Dis-
V. M. Runge, A. C. Price, H. S. Kirshner, J. H. Allen, C. L. Partain, A. E. James, Jr. Department of Radiology, Vanderbilt University Medical Center, Nashville, Tennessee 37232
Forty-nine patients with demyelinating disease have been studied by magnetic resonance (MR) at 0.5 T. 42 of the patients had a confirmed diagnosis of multiple sclerosis, 6 were diagnosed by CT to have deep white matter infarcts, and 1 pediatric patient presented with a presumed course of postinfectious leukoencephalopathy. Proton density (TE = 30 ms, TR = 250-500 ms), T,-weighted (TE = 30, TI = 400, TR = 1250 ms), and T,-weighted (TE = 60-120 ms, TR = l-2 s) images were constructed primarily.in the transverse plane (for comparison with CT) in all patients. Recently acquired
Magnetic Resonance Imaging 0 Volume 2, Number 3, 1984
detecting IN in asymptomatic joints, in femoral heads during the reperfusion stage when the BS appears normal, and can be used to evaluate IN following surgical procedures. Improved NMR Evaluation of the Head Using Calculated T,, T2 and Estimated Images
K. R. Maravilla, J. C. Weinreb, and R. Nunnally Department of Radiology, The University of Texas Health Science Center, Dallas, Texas 75235
Proton magnetic resonance imaging of the head is very sensitive in detecting intracranial abnormalities. Since most abnormalities which occur in the brain have a prolonged T2 measurement, the most common pulse sequence used for evaluation of the head is a Tzweighted spin-echo image with a long TR value ( 1.5-2 s). Although this sequence results in enhancement of the NMR signal for abnormalities with long T2 on the delayed spin-echoes, there are limitations encountered using this single pulse sequence. This is especially true in abnormalities related to the basal cisterns including the suprasella region, brainstem, and upper cervical cord. Small intraaxial or extraaxial mass lesions in these regions can be missed due to poor contrast between the CSF in the cisterns and the brain. Additional limitations are encountered in evaluating abnormalities which show very little contrast or have a very slight T2 difference relative to the surrounding brain tissue or when compared to the CSF in the ventricles and cisterns. In these cases we use a protocol which consists of two spin-echo imaging sequences which use different repetition rates and which are obtained without moving the patient. This protocol has resulted in improved detection and characterization of lesions with slight changes in T, or T2 compared with using any single pulse sequence. The short TR sequence which weights T, information allows for better definition of structures bordering the basal cisterns. The dual pulse sequence protocol also permits determination of calculated image maps of T, values as well as interpolated images which are computer-generated images which allow for retrospectively varying TR and TE parameters independently. These combined techniques have allowed for better detection and characterization of subtle lesions. Clinical cases which illustrate the value of this technique include small intracranial cysts, cystic astrocytomas, small lesions related to the suprasella cistern and a small lesion in the thalamus. Using the dual pulse sequence and calculated images in select cases has enabled us to improve our specificity of diagnosis and the index of certainty.
Detection of Low-Grade Gliomas by NMR Imaging
A. C. Price, V. M. Runge, J. H. Allen, C. L. Partain, A. E. James Department of Radiology, Vanderbilt University Medical Center, Nashville, Tennessee 37232
Utilizing a Technicare 0.5 T superconducting NMR imager, four patients with symptomatology suggestive of a low-grade cerebral neoplastic process were examined. The patients’ clinical history was significant for progressive headaches over several months. Highresolution CT scans were equivocal in all cases. Sagittal, coronal, and axial sections were obtained using spin-echo (30/ 500 and 120/ 1000) and inversion recovery techniques. With spin-echo technique (30/250 and 120/ 1000) use was also made of volume anisotropic acquisitions in the transverse plane, which generated 32 sequential slices from the cervical region to the top of the skull. Soft tissue masses were visualized in all cases with prolonged T, and T2 relaxation times, high signal intensity on T,-weighted sequences and low signal intensity on inversion recovery. Slight mass effects were also demonstrated optimally by NMR while the results of CT examinations were equivocal or subtle. Two of the four patients have proceeded to surgery with pathology confirming the presence of a low grade glioma. In four cases with clinical symptoms suggestive of neoplastic disease, NMR examination of the head detected an area of tissue pathology, confirmed by surgery in two cases, when CT examination was equivocal. These .areas of abnormality were best seen using spin-echo technique (120/ 1000) with a long time to echo and pulse repetition rate. Coronal and sagittal images provided exquisite anatomical detail and localization for surgical approach. Magnetic Resonance Imaging of Demyelinating ease
Dis-
V. M. Runge, A. C. Price, H. S. Kirshner, J. H. Allen, C. L. Partain, A. E. James, Jr. Department of Radiology, Vanderbilt University Medical Center, Nashville, Tennessee 37232
Forty-nine patients with demyelinating disease have been studied by magnetic resonance (MR) at 0.5 T. 42 of the patients had a confirmed diagnosis of multiple sclerosis, 6 were diagnosed by CT to have deep white matter infarcts, and 1 pediatric patient presented with a presumed course of postinfectious leukoencephalopathy. Proton density (TE = 30 ms, TR = 250-500 ms), T,-weighted (TE = 30, TI = 400, TR = 1250 ms), and T,-weighted (TE = 60-120 ms, TR = l-2 s) images were constructed primarily.in the transverse plane (for comparison with CT) in all patients. Recently acquired