MyMedR

Displaying all 5 publications

Abstract:

Sort:

Fulltext Feasibility of vocal fold abduction and adduction assessment using cine-MRI

Baki MM, Menys A, Atkinson D, Bassett P, Morley S, Beale T, et al.

Eur Radiol, 2017 Feb;27(2):598-606.
PMID: 27085701 DOI: 10.1007/s00330-016-4341-3

OBJECTIVE: Determine feasibility of vocal fold (VF) abduction and adduction assessment by cine magnetic resonance imaging (cine-MRI) METHODS: Cine-MRI of the VF was performed on five healthy and nine unilateral VF paralysis (UVFP) participants using an axial gradient echo acquisition with temporal resolution of 0.7 s. VFs were continuously imaged with cine-MRI during a 10-s period of quiet respiration and phonation. Scanning was repeated twice within an individual session and then once again at a 1-week interval. Asymmetry of VF position during phonation (VF phonation asymmetry, VFPa) and respiration (VF respiration asymmetry, VFRa) was determined. Percentage reduction in total glottal area between respiration and phonation (VF abduction potential, VFAP) was derived to measure overall mobility. An un-paired t-test was used to compare differences between groups. Intra-session, inter-session and inter-reader repeatability of the quantitative metrics was evaluated using intraclass correlation coefficient (ICC).
RESULTS: VF position asymmetry (VFPa and VFRa) was greater (p=0.012; p=0.001) and overall mobility (VFAP) was lower (p=0.008) in UVFP patients compared with healthy participants. ICC of repeatability of all metrics was good, ranged from 0.82 to 0.95 except for the inter-session VFPa (0.44).
CONCLUSION: Cine-MRI is feasible for assessing VF abduction and adduction. Derived quantitative metrics have good repeatability.
KEY POINTS: • Cine-MRI is used to assess vocal folds (VFs) mobility: abduction and adduction. • New quantitative metrics are derived from VF position and abduction potential. • Cine-MRI able to depict the difference between normal and abnormal VF mobility. • Cine-MRI derived quantitative metrics have good repeatability.

Matched MeSH terms: Magnetic Resonance Imaging, Cine/methods*
Harmonic phase interference for the detection of tag line crossings and beyond in homogeneous strain analysis of cardiac tagged MRI data

Bilgen M

Australas Phys Eng Sci Med, 2010 Dec;33(4):357-66.
PMID: 21110236 DOI: 10.1007/s13246-010-0039-z

Homogenous strain analysis (HSA) was developed to evaluate regional cardiac function using tagged cine magnetic resonance images of heart. Current cardiac applications of HSA are however limited in accurately detecting tag intersections within the myocardial wall, producing consistent triangulation of tag cells throughout the image series and achieving optimal spatial resolution due to the large size of the triangles. To address these issues, this article introduces a harmonic phase (HARP) interference method. In principle, as in the standard HARP analysis, the method uses harmonic phases associated with the two of the four fundamental peaks in the spectrum of a tagged image. However, the phase associated with each peak is wrapped when estimated digitally. This article shows that special combination of wrapped phases results in an image with unique intensity pattern that can be exploited to automatically detect tag intersections and to produce reliable triangulation with regularly organized partitioning of the mesh for HSA. In addition, the method offers new opportunities and freedom for evaluating myocardial function when the power and angle of the complex filtered spectra are mathematically modified prior to computing the phase. For example, the triangular elements can be shifted spatially by changing the angle and/or their sizes can be reduced by changing the power. Interference patterns obtained under a variety of power and angle conditions were presented and specific features observed in the results were explained. Together, the advanced processing capabilities increase the power of HSA by making the analysis less prone to errors from human interactions. It also allows strain measurements at higher spatial resolution and multi-scale, thereby improving the display methods for better interpretation of the analysis results.

Matched MeSH terms: Magnetic Resonance Imaging, Cine/methods*
Motion corrected LV quantification based on 3D modelling for improved functional assessment in cardiac MRI

Liew YM, McLaughlin RA, Chan BT, Abdul Aziz YF, Chee KH, Ung NM, et al.

Phys Med Biol, 2015 Apr 7;60(7):2715-33.
PMID: 25768708 DOI: 10.1088/0031-9155/60/7/2715

Cine MRI is a clinical reference standard for the quantitative assessment of cardiac function, but reproducibility is confounded by motion artefacts. We explore the feasibility of a motion corrected 3D left ventricle (LV) quantification method, incorporating multislice image registration into the 3D model reconstruction, to improve reproducibility of 3D LV functional quantification. Multi-breath-hold short-axis and radial long-axis images were acquired from 10 patients and 10 healthy subjects. The proposed framework reduced misalignment between slices to subpixel accuracy (2.88 to 1.21 mm), and improved interstudy reproducibility for 5 important clinical functional measures, i.e. end-diastolic volume, end-systolic volume, ejection fraction, myocardial mass and 3D-sphericity index, as reflected in a reduction in the sample size required to detect statistically significant cardiac changes: a reduction of 21-66%. Our investigation on the optimum registration parameters, including both cardiac time frames and number of long-axis (LA) slices, suggested that a single time frame is adequate for motion correction whereas integrating more LA slices can improve registration and model reconstruction accuracy for improved functional quantification especially on datasets with severe motion artefacts.

Matched MeSH terms: Magnetic Resonance Imaging, Cine/methods*
Acute myocarditis mimicking ST-elevation myocardial infarction: A diagnostic challenge for frontline clinicians

Ang KP, Quek ZQ, Lee CY, Lu HT

Med J Malaysia, 2019 12;74(6):561-563.
PMID: 31929492

The clinical presentation of acute myocarditis is highly variable ranging from no symptoms to cardiogenic shock. Despite considerable progress, it remains a challenge for frontline physicians to discriminate between acute myocarditis and myocardial infarction, especially in the early phase. Our case serves as a reminder that acute presentation of myocarditis could resemble ST elevation myocardial infarction potentially misdirecting the therapeutic decision. The clinical presentation, electrocardiographic and laboratory findings of the patient are not specific enough to distinguish acute myocarditis from myocardial infarction. The gold standard tests such coronary angiography and cardiovascular magnetic resonance (CMR) can reliably differentiate the two entities.

Matched MeSH terms: Magnetic Resonance Imaging, Cine/methods
CMR imaging biosignature of cardiac involvement due to cancer-related treatment by T1 and T2 mapping

Haslbauer JD, Lindner S, Valbuena-Lopez S, Zainal H, Zhou H, D'Angelo T, et al.

Int J Cardiol, 2019 Jan 15;275:179-186.
PMID: 30360992 DOI: 10.1016/j.ijcard.2018.10.023

BACKGROUND: Cancer-related treatment is associated with development of heart failure and poor outcome in cancer-survivors. T1 and T2 mapping by cardiovascular magnetic resonance (CMR) may detect myocardial injury due to cancer-related treatment.
METHODS: Patients receiving cancer-related treatment regimes underwent screening of cardiac involvement with CMR, either within 3 months (early Tx) or >12 months (late Tx) post-treatment. T1 and T2 mapping, cardiac function, strain, ischaemia-testing, scar-imaging and serological cardiac biomarkers were obtained.
RESULTS: Compared to age/gender matched controls (n = 57), patients (n = 115, age (yrs): median(IQR) 48(28-60), females, n = 60(52%) had reduced left ventricular ejection fraction (LV-EF) and strain, and higher native T1 and T2. The early Tx group (n = 52) had significantly higher native T1, T2 and troponin levels compared to the late Tx group, indicating myocardial inflammation and oedema (p 

Matched MeSH terms: Magnetic Resonance Imaging, Cine/methods*