MRI Assessment of Hippocampal Sclerosis

2005 ◽  
Vol 18 (3) ◽  
pp. 357-363
Author(s):  
A. Lefkopoulos ◽  
A. Tzinas ◽  
E. Papadopoulou ◽  
A. Haritanti ◽  
D. Karanikolas ◽  
...  
Keyword(s):  
Temporal Lobe ◽  
Signal Intensity ◽  
Hippocampal Formation ◽  
Spin Echo ◽  
Hippocampal Sclerosis ◽  
High Sensitivity ◽  
Cost Effective ◽  
Inversion Recovery ◽  
Fast Spin Echo ◽  
Transverse Spin

Hippocampal Sclerosis (HS) is the most common cause of refractory temporal lobe epilepsy in adults. The aim of our study was to evaluate the diagnostic accuracy of conventional MRI sequences in HS and devise a cost-effective protocol of choice. Forty-eight patients, 26 men and 22 women, aged 16–55 years (mean age 29 years) with seizures refractory to medical treatment were evaluated by MR imaging. Hippocampal formation was assessed by transverse spin-echo (SE) T1-weighted (WI) and fast spin-echo (FSE) T2-WI sequences and by coronal Fluid Attenuated Inversion Recovery (FLAIR) and Inversion Recovery (IR) images. Increased signal intensity in FLAIR (93.2%), hippocampal atrophy (84.8%) and decreased signal intensity in IR images (72.7%) were the most common pathological findings of HS, while loss of the ipsilateral temporal lobe gray/white matter demarcation (66,7%) and amygdala sclerosis (15.1%) were encountered less frequently. FLAIR sequence was found to be more sensitive than FSE T2-WI in detecting HS. Thin coronal images were particularly helpful in assessing hippocampal formation, while IR images were additionally useful for the detection of possible co-existent cortical abnormalities. A brief review of the imaging findings of HS in more recent MR sequences is also made, though emphasizing that conventional SE T1-WI, FSE T2-WI, FLAIR and IR sequences, with a total examination duration of less than eight minutes, provide high sensitivity and specificity in the assessment of HS.

Comparison between Conventional and Fast Spin-Echo Stir Sequences

1996 ◽  
Vol 37 (3P2) ◽  
pp. 943-949 ◽  
Author(s):  
K. Hittmair ◽  
S. Trattnig ◽  
C. J. Herold ◽  
M. Breitenseher ◽  
J. Kramer
Keyword(s):  
Spin Echo ◽  
High Sensitivity ◽  
Fat Suppression ◽  
Inversion Recovery ◽  
Fast Spin Echo ◽  
T1 Relaxation ◽  
Scan Time ◽  
Musculoskeletal Abnormalities ◽  
Pork Fat ◽  
Fast Spin

Purpose: To evaluate the common characteristics and differences in contrast behavior of short-TI-inversion-recovery (STIR) and short-TI-inversion-recovery fast spin-echo (TurboSTIR) sequences. Material and Methods: Phantoms doped with increasing doses of Gd-DTPA and a pork-fat phantom were used to evaluate the dependence of the STIR and TurboSTIR signals on the T1 relaxation time. Clinical TurboSTIR images were obtained from 30 patients with musculoskeletal abnormalities and compared to conventional STIR images in 15 cases and to postcontrast TurboSTIR images in another 15 cases. Results: In the phantom measurements, a significantly shorter inversion time (TI) was needed to achieve fat suppression on TurboSTIR images, and, with an identical number of signal averages, contrast-to-noise ratios were lower on TurboSTIR images. These differences between STIR and TurboSTIR can be attributed to the contribution of stimulated echoes to overall TurboSTIR signal and can be compensated by a shorter TI and a higher number of signal averages for TurboSTIR, respectively. With these adaptations, clinical TurboSTIR and STIR images showed an identical contrast behavior with fat suppression and a high sensitivity to pathological lesions but TurboSTIR saved a significant amount of scan time and reduced some types of artifacts. Contrast uptake impaired lesion conspicuity on TurboSTIR images. Conclusion: TurboSTIR sequences should replace conventional STIR sequences and should be performed before contrast administration.

Most commonly used sequences and clinical protocols for brain and spine magnetic resonance imaging allowing better identification of pathological changes in dogs

2013 ◽  
Vol 16 (1) ◽  
pp. 157-163 ◽  
Author(s):  
Y. Zhalniarovich ◽  
Z. Adamiak ◽  
A. Pomianowski ◽  
M. Jaskólska
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Imaging Modality ◽  
Spin Echo ◽  
Inversion Recovery ◽  
Fast Spin Echo ◽  
Single Shot ◽  
Turbo Spin Echo ◽  
Resonance Imaging ◽  
Turbo Spin

Abstract Magnetic resonance imaging is the best imaging modality for the brain and spine. Quality of the received images depends on many technical factors. The most significant factors are: positioning the patient, proper coil selection, selection of appropriate sequences and image planes. The present contrast between different tissues provides an opportunity to diagnose various lesions. In many clinics magnetic resonance imaging has replaced myelography because of its noninvasive modality and because it provides excellent anatomic detail. There are many different combinations of sequences possible for spinal and brain MR imaging. Most frequently used are: T2-weighted fast spin echo (FSE), T1- and T2-weighted turbo spin echo, Fluid Attenuation Inversion Recovery (FLAIR), T1-weighted gradient echo (GE) and spin echo (SE), high-resolution three-dimensional (3D) sequences, fat-suppressing short tau inversion recovery (STIR) and half-Fourier acquisition single-shot turbo spin echo (HASTE). Magnetic resonance imaging reveals neurologic lesions which were previously hard to diagnose antemortem.

scholarly journals High Signal Intensity of Fat on Fast Spin Echo Imaging

2000 ◽  
Vol 56 (10) ◽  
pp. 1269-1275
Author(s):  
Akio OGURA ◽  
Masaru YAMAZAKI ◽  
Takaharu HONGOH ◽  
Hiroshi INOUE ◽  
Akihiro ISHIKURO
Keyword(s):  
Signal Intensity ◽  
Spin Echo ◽  
High Signal Intensity ◽  
Fast Spin Echo ◽  
High Signal ◽  
Fast Spin

Quantitative analysis of unruptured intracranial aneurysm wall thickness and enhancement using 7T high resolution, black blood magnetic resonance imaging

2021 ◽  
pp. neurintsurg-2021-017688
Author(s):  
Xinke Liu ◽  
Junqiang Feng ◽  
Zhixin Li ◽  
Zihao Zhang ◽  
Qiang Zhang ◽  
...  
Keyword(s):  
Intracranial Aneurysm ◽  
Wall Thickness ◽  
Signal Intensity ◽  
Spin Echo ◽  
Fast Spin Echo ◽  
Black Blood ◽  
Post Contrast ◽  
Isotropic Resolution ◽  
Aneurysm Size ◽  
Aneurysm Wall

BackgroundThis study was performed to quantify intracranial aneurysm wall thickness (AWT) and enhancement using 7T MRI, and their relationship with aneurysm size and type.Methods27 patients with 29 intracranial aneurysms were included. Three-dimensional T1 weighted pre‐ and post-contrast fast spin echo with 0.4 mm isotropic resolution was used. AWT was defined as the full width at half maximum on profiles of signal intensity across the aneurysm wall on pre-contrast images. Enhancement ratio (ER) was defined as the signal intensity of the aneurysm wall over that of the brain parenchyma. The relationships between AWT, ER, and aneurysm size and type were investigated.Results7T MRI revealed large variations in AWT (range 0.11–1.24 mm). Large aneurysms (>7 mm) had thicker walls than small aneurysms (≤7 mm) (0.49±0.05 vs 0.41±0.05 mm, p<0.001). AWT was similar between saccular and fusiform aneurysms (p=0.546). Within each aneurysm, a thicker aneurysm wall was associated with increased enhancement in 28 of 29 aneurysms (average r=0.65, p<0.05). Thicker walls were observed in enhanced segments (ER >1) than in non-enhanced segments (0.53±0.09 vs 0.38±0.07 mm, p<0.001).ConclusionImproved image quality at 7T allowed quantification of intracranial AWT and enhancement. A thicker aneurysm wall was observed in larger aneurysms and was associated with stronger enhancement.

Improved Sensitivity of Bone Marrow Magnetic Resonance Imaging (BM-MRI) in Quantifying the Extent of Bone Marrow Involvement in Patients with Multiple Myeloma (MM).

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 4776-4776 ◽  
Author(s):  
Sikander Ailawadhi ◽  
Lyudmyla Derby ◽  
Kena C. Miller ◽  
Terry L. Mashtare ◽  
Gregory Wilding ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Bone Marrow ◽  
Correlation Coefficient ◽  
Spin Echo ◽  
Staging System ◽  
Inversion Recovery ◽  
Fast Spin Echo ◽  
Statistical Relationship ◽  
Spearman Correlation ◽  
Fast Spin

Abstract Background: Traditionally, bone marrow aspirate/biopsy (BM-Bx) has been used for diagnosis and quantification of the extent of disease as well as response to therapy in MM patients. This information is used to make decision for treatment initiation. Since MM is not a contiguous disease, marrow involvement can be patchy and BM-Bx may be misleading in assessing the true extent of the disease. BM-MRI is a non-invasive technique that can evaluate a large amount of marrow for tumor infiltration. We prospectively investigated the sensitivity of BM-MRI and compared its results with those obtained by BM-Bx as well as with the clinical stage of disease. Methods: All patients with the diagnosis of MM who had BM-MRI at our center were evaluable. Patients must have received a BM-Bx within 4 weeks of the BM-MRI. In these patients sagittal T1 and fast spin echo inversion recovery sequences of the cervical, thoracic and lumbosacral spine and coronal T1 and fast spin echo inversion recovery sequences of the sacrum and pelvic bones were reviewed on the MRI. Durie-Salmon (DS) staging criteria were used for correlation. To study the statistical relationship between pairs of ordinal variables the test corresponding to the Spearman correlation was used. To study the statistical relationship between nominal and ordinal variables, the Wilcoxon or Kruskal-Wallis test was used. A 0.05 nominal significance level was used in all testing. Following staging system was defined for evaluation of the involvement of the marrow by BM-MRI: A (0%), B (< 10%), C (10%–25%), D (26%–50%), E (> 50%). Results of this were then compared with the extent of involvement reported on histological evaluation of the BM-Bx. Results: A total of 50 patients (23 females and 27 males) were identified. Median age was 61.5 years (range 35–82 years) with 23 (46%) having stage IIIA disease. As per the staging system defined above, 6%, 10%, 10%, 22% and 52% of the patients had categories A, B, C, D and E involvement as per BM-MRI, respectively. Similarly, involvement observed on the BM-Bx was 8%, 24%, 22%, 16% and 30%, respectively. Categories of marrow involvement on BM-Bx and BM-MRI were concordant in 23 (46%) and discordant in 27 (54%) patients. Of the patients that showed discordance, 89% had a more extensive BM involvement detected by the BM-MRI and 11% had a higher reading on BM-Bx. The estimated Spearman correlation coefficient between MRI involvement and MM stage was 0.4849 (95% CI; 0.2494, 0.7205), showing a significant association between BM-MRI involvement and MM stage (p =0.0002). The estimated Spearman correlation coefficient between BM-Bx involvement and MM stage was 0.1775 (95% CI; −0.1406, 0.4956), showing no significant association between BM-Bx involvement and MM stage (p = 0.2764). Conclusions: We demonstrate for the first time that BM-MRI is a more sensitive technique to assess the true disease burden in MM and is significantly better than BM-Bx. We also observe that the extent of marrow infiltration noted on the BM-MRI correlates significantly with other prognostic characteristics like DS stage. Based on this observation we recommend that BM-MRI should be considered as part of the pre-treatment evaluation of patients with multiple myeloma.

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