Scan time reduction in 23Na-Magnetic Resonance Imaging using the chemical shift imaging sequence: Evaluation of an iterative reconstruction method

2015 ◽  
Vol 25 (3) ◽  
pp. 275-286 ◽  
Author(s):  
Sebastian Weingärtner ◽  
Friedrich Wetterling ◽  
Simon Konstandin ◽  
Marc Fatar ◽  
Eva Neumaier-Probst ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Chemical Shift ◽  
Iterative Reconstruction ◽  
Chemical Shift Imaging ◽  
Reconstruction Method ◽  
Resonance Imaging ◽  
Scan Time ◽  
Imaging Sequence ◽  
23Na Magnetic Resonance Imaging

scholarly journals Chemical shift magnetic resonance imaging in differentiation of benign from malignant vertebral collapse in a rural tertiary care hospital in North India

2016 ◽  
Vol 7 (04) ◽  
pp. 489-492 ◽  
Author(s):  
Puneet Mittal ◽  
Ranjana Gupta ◽  
Amit Mittal ◽  
Sandeep Joshi
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Chemical Shift ◽  
Signal Intensity ◽  
Chemical Shift Imaging ◽  
Care Hospital ◽  
Resonance Imaging ◽  
Vertebral Collapse ◽  
Phase Images ◽  
Phase Out

ABSTRACT Introduction: Magnetic resonance imaging (MRI) is the modality of the first choice for evaluation of vertebral compression/collapse. Many MRI qualitative features help to differentiate benign from malignant collapse. We conducted this study to look for a quantitative difference in chemical shift values in benign and malignant collapse using dual-echo gradient echo in-phase/out-phase imaging. Materials and Methods: MRI examinations of a total of 38 patients were retrospectively included in the study who had vertebral compression/collapse with marrow edema in which final diagnosis was available at the time of imaging/follow-up. Signal intensity value in the region of abnormal marrow signal and adjacent normal vertebra was measured on in phase/out phase images. Signal intensity ratio (SIR) was measured by dividing signal intensity value on opposite phase images to that on in phase images. SIR was compared in normal vertebrae and benign and malignant vertebral collapse. Results: There were 21 males and 17 females with mean age of 52.4 years (range 28–76 years). Out of total 38 patients, 18 were of benign vertebral collapse and 20 of malignant vertebral collapse. SIR in normal vertebrae was 0.30 ± 0.14, 0.67 ± 0.18 in benign vertebral collapse, and 1.20 ± 0.27 in malignant vertebral collapse with significant difference in SIR of normal vertebrae versus benign collapse (P < 0.01) and in benign collapse versus malignant collapse (P < 0.01). Assuming a cutoff of <0.95 for benign collapse and ≥0.95 for malignant collapse, chemical shift imaging had a sensitivity of 90% and specificity of 94.4%. Conclusion: Chemical shift imaging is a rapid and useful sequence in differentiating benign from malignant vertebral collapse with good specificity and sensitivity.

Phase contrast in magnetic resonance imaging perspectives for chemical shift imaging

1986 ◽  
Vol 4 (5) ◽  
pp. 431-433
Author(s):  
André Briguet ◽  
Jean Chankji ◽  
Gilles Desorbay ◽  
Danielle Graveron-Demilly ◽  
Emile Hiltbrand
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Chemical Shift ◽  
Phase Contrast ◽  
Chemical Shift Imaging ◽  
Resonance Imaging

scholarly journals Role of Diffusion-Weighted and Chemical Shift Magnetic Resonance Imaging in Differentiation of Benign and Malignant Spinal Fractures

2020 ◽  
Vol 27 (3) ◽  
pp. E202037
Author(s):  
Waseem Ahmed Sheikh ◽  
Feroze A Shaheen ◽  
Nasir Ahmad Lone ◽  
Srabjit S Chhiber ◽  
Rumana Hamid Makhdoomi
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Chemical Shift ◽  
Diffusion Weighted Imaging ◽  
Chemical Shift Imaging ◽  
Resonance Imaging ◽  
Post Contrast ◽  
Compression Fractures ◽  
Diffusion Weighted ◽  
Spinal Compression

Atraumatic spinal compression fractures are common clinical problem. Differentiating benign osteoporotic fractures from pathological fractures due to malignant/metastatic lesions affects the management and prognoses in patients with known extraspinal malignancy.    The objective of the research was to assess the role of conventional magnetic resonance imaging sequences with diffusion-weighted imaging and chemical-shift imaging in differentiating benign and malignant acute spinal compression fractures. Materials and Methods. The study included 40 patients with acute spinal compression fractures. Patients were evaluated using magnetic resonance imaging with diffusion-weighted imaging and chemical-shift imaging to differentiate benign etiology from malignant one. The results obtained were compared with histopathological follow-up for 6 months for definite clinical diagnoses. Results. No significant difference was noted in signal characteristics of benign and malignant fractures on T1, T2 and short-tau inversion recovery. However, posterior element involvement, soft tissue component and post-contrast enhancement were seen more frequently in malignant fractures (p<0.05). On diffusion-weighted images, 77.8% of malignant fractures were hyperintense and 59.1% of benign fractures were hypointense (p<0.05). The mean apparent diffusion coefficient value was 0.81 ± 0.19 for malignant and 1.24 ± 0.24 for benign fractures (p<0.5). The mean signal intensity ratio for malignant fractures was 0.91 ± 0.125, whereas the signal intensity ratio for benign fractures was 0.64 ± 0.096 (p<0.001). Conclusions. Signal characteristics on T1, T2 and short-tau inversion recovery sequences do not differentiate benign from malignant fractures; however, posterior element involvement, soft tissue and post contrast enhancement help in differentiating the etiology. Diffusion-weighted imaging and apparent diffusion coefficient values, as well as using chemical shift imaging further improve the diagnostic accuracy of magnetic resonance imaging.

Ocular biometry through fully refocused steady-state magnetic resonance imaging sequence: reliability and agreement with the IOLMaster® 500

2021 ◽  
Author(s):  
Lorenzo Ismael Perez-Sanchez ◽  
Julia Gutierrez-Vazquez ◽  
Maria Satrustegui-Lapetra ◽  
Francisco Ferreira-Manuel ◽  
Juan Jose Arevalo-Manso ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Steady State ◽  
Magnetic Resonance ◽  
Resonance Imaging ◽  
Magnetic Resonance Imaging Sequence ◽  
Ocular Biometry ◽  
Imaging Sequence

Contrast-agent free evaluation of cardiomyopathies with T1 mapping and the new fast strain-encoded (fSENC) magnetic resonance imaging

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
K Hirschberg ◽  
O Paul ◽  
J Salatzki ◽  
F Andre ◽  
J Riffel ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Contrast Agent ◽  
T1 Mapping ◽  
Hypertensive Heart Disease ◽  
Study Groups ◽  
Resonance Imaging ◽  
Gadolinium Enhancement ◽  
Scan Time ◽  
Normal Individuals

Abstract Background Cardiomyopathies (CMP) may cause impairment of cardiac function and structure. Cardiac Magnetic Resonance Imaging (CMR) is used for analysis and risk stratification of CMP by Late Gadolinium Enhancement (LGE). However, T1 mapping (T1) and fast strain encoded (f-SENC) sequences allow contrast-free and faster exams. The aim of this study was to characterize CMP by T1 and f-SENC to develop a faster and safer CMR protocol (fast-CMR). Methods CMP scans from our CMR database were retrospectively analyzed. All patients were scanned at 1.5T/3T scanner. Study groups were divided as follows: Patients with normal findings, dilated cardiomyopathy (DCM), hypertrophic cardiomyopathy (HCM), hypertensive heart disease (HHD) and cardiac amyloidosis. Global T1 times, longitudinal (GLS) and circumferential (GCS) strain using f-SENC of study groups were compared to healthy individuals (controls). Scan time and amount of gadolinium-based contrast agent (CA) in CMR-protocol with LGE were compared to fast-CMR. Results 174 patients and 31 controls were recruited. T1 times, GLS and GCS were similar between controls and normal individuals. T1 times were significantly increased (p&lt;0.05), while GLS and GCS were significantly reduced (p&lt;0.05) in all CMR study groups compared to controls (Table 1). Using fast-CMR 21 (±6) min of scan time were saved, about 47%, and 9 (±2) ml of CA were saved per patient. Conclusion Normal findings could be identified by fast-CMR without contrast agent. Fast CMR might also be a useful tool to identify different forms of CMP. Funding Acknowledgement Type of funding source: None

Could we assess the functional status, of hormone secreting, or non-secreting of the adrenal masses regarding their Magnetic Resonance Imaging (MRI) characteristics?

2021 ◽  
Vol 22 ◽  
Author(s):  
Gamze Akkus ◽  
Ferhat Piskin ◽  
Barış Karagun ◽  
Murat Sert ◽  
Mehtap Evran ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Chemical Shift ◽  
Functional Status ◽  
Signal Intensity ◽  
Adrenal Mass ◽  
Resonance Imaging ◽  
Intensity Index ◽  
Adrenal Masses ◽  
Magnetic Resonance Imaging Mri

Background: Diagnostic imaging techniques including magnetic resonance imaging (MRI) should also perform on all patients with incidentalomas. However, there is a limited study whether the quantitative measurements (signal intensity index, adrenal to spleen ratio) in MRI could predict the functional status of adrenal adenomas. Material-Method: Between 2015-2020; 404 patients (265 females, 139 males) with adrenal mass who were referred to the university hospital for further investigation were included. After detailed diagnostic hormonal evaluation, all patients underwent MRI 1.5 T device (Signa, GE Medical Systems; Milwaukee, USA). The signal intensities of the adrenal lesions on T2W images were qualitatively evaluated and noted as homogenous or heterogeneous in comparison with the liver signal intensity (SI). A chemical-shift SI index and chemical shift adrenal-to-spleen SI ratio were also calculated. Results: While 331(81.9%) of the patients had nonfunctional adrenal mass, the rest of them (n=73, 18.1%) were patients with functional (autonomous cortisol secretion-ACS, cushing syndrome-CS, pheochromocytoma, primary hyperaldosteronism-PA) adrenal masses. In phase vs phase values of patients with NFAI, Pheo(n=17), ACS (n=30), CS (n=11), and PA (n=15) were 474.04±126.7 vs 226.6±132.4, 495.3±182.8 vs 282.17±189.1, 445.2±134.8 vs 203.3±76.2, 506.8±126.5 vs 212.2±73.6 and 496.2±147.5 vs 246.6±102.1, respectively. Mean signal intensity index (SII) and adrenal to spleen ratio (ASR) of all groups (NFAI, Pheo, ACS, CS, PA) were 52.0±24.8 and 0.51, 44.9±22.5 and 0.55, 49.5±24.5 and 0.53, 56.2±16.4 and 0.43, 47.6±25.1 and 0.54, respectively. Based the current accepted measurements in the case of ASR and SII, all lesions were similar and shown as fat rich adenomas (p*= 0.552, p** = 0.45). Conclusion: The quantitative assessment (SII, ASR) of intracellular lipids in an incidentally discovered adrenal tumour could only help distinguish adrenal masses in case of adenomas or non-adenomas As initial diagnostic evaluation, clinical and laboratory assessment ,to distinguish hormone secretion, should be taken in all patients with adrenal incidentalomas.

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