Rigor mortis at the myocardium investigated by post-mortem magnetic resonance imaging

INTRODUCTION Post-mortem cardiac MR exams present with different contraction appearances of the left ventricle in cardiac short axis images. It was hypothesized that the grade of post-mortem contraction may be related to the post-mortem interval (PMI) or cause of death and a phenomenon caused by internal rigor mortis that may give further insights in the circumstances of death. METHOD AND MATERIALS The cardiac contraction grade was investigated in 71 post-mortem cardiac MR exams (mean age at death 52y, range 12-89y; 48 males, 23 females). In cardiac short axis images the left ventricular lumen volume as well as the left ventricular myocardial volume were assessed by manual segmentation. The quotient of both (LVQ) represents the grade of myocardial contraction. LVQ was correlated to the PMI, sex, age, cardiac weight, body mass and height, cause of death and pericardial tamponade when present. In cardiac causes of death a separate correlation was investigated for acute myocardial infarction cases and arrhythmic deaths. RESULTS LVQ values ranged from 1.99 (maximum dilatation) to 42.91 (maximum contraction) with a mean of 15.13. LVQ decreased slightly with increasing PMI, however without significant correlation. Pericardial tamponade positively correlated with higher LVQ values. Variables such as sex, age, body mass and height, cardiac weight and cause of death did not correlate with LVQ values. There was no difference in LVQ values for myocardial infarction without tamponade and arrhythmic deaths. CONCLUSION Based on the observation in our investigated cases, the phenomenon of post-mortem myocardial contraction cannot be explained by the influence of the investigated variables, except for pericardial tamponade cases. Further research addressing post-mortem myocardial contraction has to focus on other, less obvious factors, which may influence the early post-mortem phase too.

Postmortem magnetic resonance imaging: Reproducing typical autopsy heart measurements

PURPOSE The aim of this study was to evaluate the utility of cardiac postmortem magnetic resonance (PMMR) to perform routine measurements of the ventricular wall thicknesses and the heart valves and to assess if imaging measurements are consistent with traditional autopsy measurements. METHODS In this retrospective study, 25 cases with cardiac PMMR and subsequent autopsy were included. The thicknesses of the myocardial walls as well as the circumferences of all heart valves were measured on cardiac PMMR and compared to autopsy measurements. Paired samples T-test and the Wilcoxon-Signed rank test, were used to compare autopsy and cardiac PMMR measurements. For exploring correlations, the Pearson's Correlation coefficient and the Spearman's Rho test were used. RESULTS Cardiac PMMR measurements of the aortic and pulmonary valve circumferences showed no significant differences from autopsy measurements. The mitral and tricuspid valves circumferences differed significantly from autopsy measurements. Left myocardial and right myocardial wall thickness also differed significantly from autopsy measurements. Left and right myocardial wall thickness, and tricuspid valve circumference measurements on cardiac PMMR and autopsy, correlated strongly and significantly. CONCLUSION Several PMMR measurements of cardiac parameters differ significantly from corresponding autopsy measurements. However, there is a strong correlation between cardiac PMMR measurements and autopsy measurements in the majority of these parameters. It is important to note that myocardial walls are thicker when measured in situ on cardiac PMMR than when measured at autopsy. Investigators using post-mortem MR should be aware of these differences in order to avoid false diagnoses of cardiac pathology based on cardiac PMMR.

Short-term changes in magnetic resonance imaging and disease activity in response to infliximab

To characterise and quantify short-term changes in local inflammation using magnetic resonance imaging (MRI), and to correlate the findings with clinical disease activity in response to infliximab in patients with spondyloarthritis.

The effect of GH replacement therapy on different fat compartments: a whole-body magnetic resonance imaging study

Patients with GH deficiency (GHD) are insulin resistant with an increase in visceral fat mass (FM). Whether this holds true when sedentary control subjects (CS) are matched for waist has not been documented. GH replacement therapy (GHRT) results in a decrease in FM. Whether the decrease in FM is mainly related to a reduction in visceral FM remains to be proven. The aim was to separately assess visceral and subcutaneous FM in relation to insulin resistance (IR) in GHD patients before and after GHRT and in sedentary CS.

Magnetic resonance imaging in traumatic posterior hip dislocation

The objective was to report the ability of a magnetic resonance image to document the integrity of the obturator externus tendon after posterior hip dislocation as a potential predictor for preserved femoral head vascularity.

Intravenous versus intra-articular delayed gadolinium-enhanced magnetic resonance imaging in the hip joint: a comparative analysis

The purpose of this study was to investigate whether T1-mapping of hip joint with intra-articular delayed gadolinium-enhanced magnetic resonance imaging (MRI) of cartilage (ia-dGEMRIC) is comparable to the already established intravenous (iv)-technique for assessing different grades of cartilage degeneration.

Feasibility of texture analysis for the assessment of biochemical changes in meniscal tissue on T1 maps calculated from delayed gadolinium-enhanced magnetic resonance imaging of cartilage data: comparison with conventional relaxation time measurements

To (1) establish the feasibility of texture analysis for the in vivo assessment of biochemical changes in meniscal tissue on delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC), and (2) compare textural with conventional T1 relaxation time measurements calculated from dGEMRIC data ("T1(Gd) relaxation times").

Delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC), after slipped capital femoral epiphysis

OBJECTIVE: The aim of this study was to assess the glycosaminoglycan (GAG) content in hip joint cartilage in mature hips with a history of slipped capital femoral epiphysis (SCFE) using delayed gadolinium-enhanced MRI of cartilage (dGEMRIC). METHODS: 28 young-adult subjects (32 hips) with a mean age of 23.8+/-4.0 years (range: 18.1-30.5 years) who were treated for mild or moderate SCFE in adolescence were included into the study. Hip function and clinical symptoms were evaluated with the Harris hip score (HHS) system at the time of MRI. Plain radiographic evaluation included Tonnis grading, measurement of the minimal joint space width (JSW) and alpha-angle measurement. The alpha-angle values were used to classify three sub-groups: group 1=subjects with normal femoral head-neck offset (alpha-angle <50 degrees ), group 2=subjects with mild offset decrease (alpha-angle 50 degrees -60 degrees ), and group 3=subjects with severe offset decrease (alpha-angle >60 degrees ). RESULTS: There was statistically significant difference noted for the T1(Gd) values, lateral and central, between group 1 and group 3 (p-values=0.038 and 0.041). The T1(Gd) values measured within the lateral portion were slightly lower compared with the T1(Gd) values measured within the central portion that was at a statistically significance level (p-value <0.001). HHS, Tonnis grades and JSW revealed no statistically significant difference. CONCLUSION: By using dGEMRIC in the mid-term follow-up of SCFE we were able to reveal degenerative changes even in the absence of joint space narrowing that seem to be related to the degree of offset pathology. The dGEMRIC technique may be a potential diagnostic modality in the follow-up evaluation of SCFE.

Delayed gadolinium-enhanced magnetic resonance imaging of cartilage in the long-term follow-up after Perthes disease

Aim of this study was to assess the glycosaminoglycan content in hip joint cartilage in mature hips with a history of Legg-Calvé-Perthes (LCPD) disease using delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC).

Prevalence of cam-type deformity on hip magnetic resonance imaging in young males: a cross-sectional study

Objective To determine the prevalence of cam-type deformities on hip magnetic resonance imaging (MRI) in young males. Methods This was a population-based cross-sectional study in young asymptomatic male individuals who underwent clinical examination and completed a self-report questionnaire. A random sample of participants was invited for MRI of the hip. We graded the maximal offset at the femoral head–neck junction on radial sequences using grades from 0 to 3, where 0 = normal, 1 = possible, 2 = definite, and 3 = severe deformity. The prespecified main analyses were based on definite cam-type deformity grades 2 or 3. We estimated the prevalence of the cam-type deformity adjusted for the sampling process overall and according to the extent of internal rotation. Then we determined the location of the deformity on radial MRI sequences. Results A total of 1,080 subjects were included in the study and 244 asymptomatic males with a mean age of 19.9 years attended MRI. Sixty-seven definite cam-type deformities were detected. The adjusted overall prevalence was 24% (95% confidence interval [95% CI] 19–30%). The prevalence increased with decreasing internal rotation (P < 0.001 for trend). Among those with a clinically decreased internal rotation of <30°, the estimated prevalence was 48% (95% CI 37–59%). Sixty-one of 67 cam-type deformities were located in an anterosuperior position. Conclusion Cam-type deformities can be found on MRI in every fourth young asymptomatic male individual and in every second male with decreased internal rotation. The majority of deformities are located in an anterosuperior position.

Noninvasive assessment of exercise-related intramyocellular acetylcarnitine in euglycemia and hyperglycemia in patients with type 1 diabetes using ¹H magnetic resonance spectroscopy: a randomized single-blind crossover study

Intramyocellular acetylcarnitine (IMAC) is involved in exercise-related fuel metabolism. It is not known whether levels of systemic glucose influence IMAC levels in type 1 diabetes.

Two-dimensional linear-combination model fitting of magnetic resonance spectra to define the macromolecule baseline using FiTAID, a Fitting Tool for Arrays of Interrelated Datasets

To propose the determination of the macromolecular baseline (MMBL) in clinical 1H MR spectra based on T(1) and T(2) differentiation using 2D fitting in FiTAID, a general Fitting Tool for Arrays of Interrelated Datasets.

Anatomic study of the quadrigeminal cistern in patients with 3-dimensional magnetic resonance cisternography

The aim of this study was to demonstrate the anatomy of the quadrigeminal cistern, define the anatomic landmarks, and measure the extension of the cistern in the living by using magnetic resonance (MR) cisternography with 3-dimensional reconstruction.