Clinical MR imaging of degenerative spinal disease: Pulse sequences, gradient-echo techniques, and contrast agents

1991 ◽  
Vol 1 (1) ◽  
pp. 29-37 ◽  
Author(s):  
Jeffrey S. Ross ◽  
Jean Tkach ◽  
Carolyn VanDyke ◽  
Michael T. Modic
Keyword(s):  
Mr Imaging ◽  
Contrast Agents ◽  
Pulse Sequences ◽  
Gradient Echo ◽  
Spinal Disease ◽  
Degenerative Spinal Disease

Experimental intracerebral and subarachnoid/intraventricular haemorrhages: MR detectability at 0.5 T and 1.5 T

2002 ◽  
Vol 43 (5) ◽  
pp. 464-473
Author(s):  
M. Alemany Ripoll ◽  
R. Raininko
Keyword(s):  
Cerebrospinal Fluid ◽  
Mr Imaging ◽  
Spin Echo ◽  
Autologous Blood ◽  
Pulse Sequences ◽  
Proton Density ◽  
Gradient Echo ◽  
The Brain ◽  
Formalin Fixed

Purpose: To compare the detectability of small experimental intracranial haemorrhages on MR imaging at 0.5 T and 1.5 T, from hyperacute to subacute stages. Material and Methods: 1 ml of autologous blood was injected into the brain of 15 rabbits to create intraparenchymal haematomas. Since the blood partially escaped into the cerebrospinal fluid (CSF) spaces, detectability of subarachnoid and intraventricular blood was also evaluated. MR imaging at 0.5 T and at 1.5 T was repeated up to 14 days, including T1-, proton density- and T2-weighted (w) spin-echo (SE), FLAIR and T2*-w gradient echo (GE) pulse sequences. The last MR investigation was compared to the formalin-fixed brain sections in 7 animals. Results: The intraparenchymal haematomas were best revealed with T2*-w GE sequences, with 100% of sensitivity at 1.5 T and 90–95% at 0.5 T. Blood in the CSF spaces was significantly ( p < 0.05) better detected at 1.5 T with T2*-w GE sequences and detected best during the first 2 days. The next most sensitive sequence for intracranial blood was FLAIR. SE sequences were rather insensitive. Conclusion: 1.5 T equipment is superior to 0.5 T in the detection of intracranial haemorrhages from acute to subacute stages. T2*-w GE sequences account for this result but other sequences are also needed for a complete examination.

OPTIMAL CONCENTRATIONS OF GADOVIST IN T1-WEIGHTED MAGNETIC RESONANCE IMAGING: PHANTOM STUDY AND COMPUTER SIMULATION

2011 ◽  
Vol 23 (03) ◽  
pp. 237-244 ◽  
Author(s):  
Chia-Chi Hsiao ◽  
Po-Chou Chen ◽  
Huay-Ben Pan ◽  
Jo-Chi Jao
Keyword(s):  
Magnetic Resonance Imaging ◽  
Computer Simulation ◽  
Magnetic Resonance ◽  
Contrast Agents ◽  
Pulse Sequence ◽  
Pulse Sequences ◽  
Phantom Study ◽  
Resonance Imaging ◽  
Gradient Echo ◽  
Spoiled Gradient Echo

Contrast-Enhanced Magnetic Resonance Imaging (CE-MRI) has been widely used in the diagnosis of lesions. Many contrast agents with various chemical and pharmacokinetic properties have been developed for clinical use. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) after the contrast agent administration depend on many factors, e.g. category and injected dosage of contrast agents, field strength of magnetic resonance (MR) scanner, slew rate of gradient, type of radiofrequency coil, reconstruction algorithm, pulse sequences, and so on. Gadovist is a newly developed contrast agent with high formulation of 1.0 M. It has been used in MR angiography and perfusion studies. The aim of this study is to investigate the optimal concentrations of Gadovist in MR T1-weighted (T1W) images from phantom study and computer simulation. A phantom made of 21 test tubes with various concentrations of Gadovist (0–160 mM) was investigated. All the studies were performed on a 1.5-T clinical whole-body scanner. Four T1W pulse sequences, including two-dimensional spoiled gradient echo (2DSPGR), three-dimensional fast spoiled gradient echo (3DFSPGR), conventional spin echo (CSE), and inversion recovery (IR) were employed to produce T1W images. The CNR values were calculated from regions of interest (ROIs) of all test tubes and the optimal concentration for each pulse sequence was determined. The T1 and T2 values of the phantom were also measured to obtain the relaxivities (r1 and r2). Afterward, the optimal concentration for each pulse sequence could be obtained from computer simulation by using the r1 and r2 values. The results showed that the measured optimal concentrations for 2DSPGR, 3DFSPGR, CSE and IR are 10, 20, 2.5, and 2.5 mM, respectively. The r1 and r2 values of the Gadovist phantom are 4.1 and 5.7 mM-1s-1, respectively. The optimal concentrations obtained from computer simulation are 13.5, 22.8, 2.0, and 2.7 mM for 2DSPGR, 3DFSPGR, CSE, and IR, respectively. The optimal concentrations obtained from computer simulation and phantom study are in good agreement.

Relationship between pulse sequences and signal intensity of joint fluid in the gradient-echo MR imaging

1997 ◽  
Vol 15 (5) ◽  
pp. 597-603 ◽  
Author(s):  
Motoyuki Horri ◽  
Toshikazu Kubo ◽  
Shoji Naruse ◽  
Yasusuke Hirasawa
Keyword(s):  
Mr Imaging ◽  
Signal Intensity ◽  
Pulse Sequences ◽  
Joint Fluid ◽  
Gradient Echo

Contrast agents for MR imaging of the liver: a clinical overview

1997 ◽  
Vol 7 (4) ◽  
pp. 507-513 ◽  
Author(s):  
A.-E. Mahfouz ◽  
B. Hamm ◽  
M. Taupitz
Keyword(s):  
Mr Imaging ◽  
Contrast Agents ◽  
Clinical Overview

scholarly journals Acute bilateral foot drop with or without cauda equina syndrome—a case series

2021 ◽  
Vol 163 (4) ◽  
pp. 1191-1198
Author(s):  
Andreas K. Demetriades ◽  
Marco Mancuso-Marcello ◽  
Asfand Baig Mirza ◽  
Joseph Frantzias ◽  
David A. Bell ◽  
...  
Keyword(s):  
Cauda Equina Syndrome ◽  
Cauda Equina ◽  
Case Series ◽  
Foot Drop ◽  
Spinal Disease ◽  
Full Resolution ◽  
Degenerative Spinal Disease ◽  
The Mean ◽  
The One

Abstract Introduction Isolated acute bilateral foot drop due to degenerative spine disease is an extremely rare neurosurgical presentation, whilst the literature is rich with accounts of chronic bilateral foot drop occurring as a sequela of systemic illnesses. We present, to our knowledge, the largest case series of acute bilateral foot drop, with trauma and relevant systemic illness excluded. Methods Data from three different centres had been collected at the time of historic treatment, and records were subsequently reviewed retrospectively, documenting the clinical presentation, radiological level of compression, timing of surgery, and degree of neurological recovery. Results Seven patients are presented. The mean age at presentation was 52.1 years (range 41–66). All patients but one were male. All had a painful radiculopathic presentation. Relevant discopathy was observed from L2/3 to L5/S1, the commonest level being L3/4. Five were treated within 24 h of presentation, and two within 48 h. Three had concomitant cauda equina syndrome; of these, the first two made a full motor recovery, one by 6 weeks follow-up and the second on the same-day post-op evaluation. Overall, five out of seven cases had full resolution of their ankle dorsiflexion pareses. One patient with 1/5 power has not improved. Another with 1/5 weakness improved to normal on the one side and to 3/5 on the other. Conclusion When bilateral foot drop occurs acutely, we encourage the consideration of degenerative spinal disease. Relevant discopathy was observed from L2/3 to L5/S1; aberrant innervation may be at play. Cauda equina syndrome is not necessarily associated with acute bilateral foot drop. The prognosis seems to be pretty good with respect to recovery of the foot drop, especially if partial at presentation and if treated within 48 h.

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