R. Slaughter

MR Findings in Cardiac Amyloidosis

OBJECTIVE The objective of our study was to describe a combination of features on MRI specific to cardiac amyloidosis. CONCLUSION Cardiac amyloidosis is a common cause of infiltrative heart disease. The combination of subtle widespread heterogeneous myocardial enhancement on delayed postcontrast inversion recovery T1-weighted images, which may initially be dismissed as a technical error, with ancillary features of restrictive cardiac disease is highly suggestive of cardiac amyloidosis.

Modified RV Short Axis Series—A New Method for Cardiac MRI Measurement of Right Ventricular Volumes

PURPOSE The current standard image orientation employed in the MRI assessment of right ventricular volumes uses a series of short axis cine acquisitions located with respect to a horizontal long axis view with the first slice placed across the atrio-ventricular valve plane at end diastole. Inherent inaccuracies are encountered with the use of this image orientation due to difficulty in defining the tricuspid valve and the border between atrium and ventricle on the resultant images. Our experience indicates that because the tricuspid valve is usually not in-plane in the slice the atrio-ventricular margin is difficult to distinguish. This leads to inaccuracies in measurements at the base of the RV and miscalculation of the RV volume. The purpose of this study was to assess an alternative method of image orientation aimed at increasing the accuracy of RV volume measurements using current commercially available CMRI sequences. This technique, the modified RV short axis series, is oriented to the outflow tract of the right ventricle. METHOD We undertook a prospective study of 50 post cardiac transplant patients. A series of LV short axis multi-slice cine acquisition FIESTA images was acquired using the current standard technique. From this data set, LV and RV stroke volumes were derived on an Advantage Windows workstation using planimetry of the endocardial and epicardial borders in end systole and end diastole. Our new technique involved obtaining a set of multi-slice cine acquisition FIESTA images in a plane perpendicular to a line from the centre of the pulmonary valve to the apex of the RV. Planimetry of the RV was then performed and a stroke volume calculated using the same method of analysis. RV stroke volumes obtained from both techniques were compared with LV stroke volumes. Three operators independently derived RV data sets. RESULTS On the images acquired with the new technique, the tricuspid valve was easier to define leading to more accurate and reproducible planimetry of ventricular borders. RV stroke volumes calculated from the new method showed better agreement with LV stroke volumes than with the current method. These results were consistent across the three operators. CONCLUSIONS This new method improves visualisation of the tricuspid valve and makes analysis easier and less prone to operator error than the current standard technique for MRI assessment of RV volumes.

Improvement after angioplasty and stenting of pulmonary arteries due to sarcoid mediastinal fibrosis.

We describe a series of cases referred to our institution with working diagnoses of chronic thrombo-embolic pulmonary hypertension (CTEPH) for consideration of surgical pulmonary thrombo-endarterectomy (PTE). Investigations in two cases revealed extrinsic compression of the pulmonary arteries from massive mediastinal lymphadenopathy (mediastinal fibrosis) due to underlying sarcoidosis. Angioplasty and stenting of the pulmonary arteries were performed in all cases with sustained haemodynamic and functional improvement. This highlights the value of new imaging modalities in delineating causes of pulmonary hypertension, and demonstrates an interventional approach for selected cases.

The value of dual-source 64-slice CT coronary angiography in the assessment of patients presenting to an acute chest pain service.

BACKGROUND The absence of radiological evidence of plaque on computed tomographic coronary angiography (CTCA) reliably excludes obstructive coronary artery disease. METHODS We studied patients who presented to our emergency department with chest pain and were admitted to our chest pain assessment service. If they were free of pain and without high-risk features of myocardial ischaemia including elevation of serum biomarkers they underwent CTCA and performed a standard treadmill exercise test. RESULTS Eighty-nine patients aged 56.3+/-8.6 years were admitted. Eleven of them had selective angiography; CTCA identified all who had obstructive disease. More than half of the 85 patients who had normal values of cardiac troponin and of the 75 with a negative exercise test had radiological evidence of disease. During follow-up for 355+/-72 days none died, suffered myocardial infarction or required coronary artery surgery: two with obstructive disease underwent percutaneous coronary intervention 1 and 7 days after the index study. CONCLUSIONS The CTCA findings were significantly correlated with those of selective angiography and with troponin status and increased the ascertainment of coronary artery disease in a cohort of patients at low risk for clinically significant ischaemic heart disease.

Subendocardial Late Gadolinium Enhancement in Two Patients with Anthracycline Cardiotoxicity Following Treatment for Ewing's Sarcoma

Cardiotoxicity is a well-known consequence of anthracycline chemotherapy. We report CMR findings not previously described in two patients with anthracycline cardiotoxicity following treatment for Ewings sarcoma. Subendocardial enhancement on late gadolinium contrast-enhanced CMR was present in both cases, with histological correlation in one case.

Queensland Lung Cancer Screening Study: rationale, design and methods

Lung cancer is the leading cause of cancer‐related mortality in Australia. Screening using low‐dose computed tomography (LDCT) can reduce lung cancer mortality. The feasibility of screening in Australia is unknown. This paper describes the rationale, design and methods of the Queensland Lung Cancer Screening Study.

Coronary artery calcification on computed tomography correlates with mortality in chronic obstructive pulmonary disease.

Objective This cross-sectional study assessed the prognostic implications of computed tomography (CT) coronary artery calcification (CAC), independent of emphysema, in patients with chronic obstructive pulmonary disease (COPD). Materials and Methods Coronary artery calcification and emphysema were assessed on noncontrast, ungated chest CT scans of patients with COPD using the validated CAC ordinal visual scale (CAC OVS; range, 0–12) and visual CT emphysema index. Results A total of 200 CT images were analyzed. All-cause mortality was associated with CAC OVS greater than 4 (hazard ratio, 2.03; 95% confidence interval, 1.08–3.82; P = 0.028) and with moderate to severe CT emphysema index (hazard ratio, 4.34; 95% confidence interval, 1.53–12.33; P = 0.006). Increased emphysema severity, myocardial infarction, hypertension, and male sex independently correlated with CAC OVS greater than 4. Conclusions Coronary artery calcification severity and emphysema severity on CT images are related and are strongly as well as independently associated with prognosis in patients with moderate to severe COPD. The potential to use CAC OVS on unenhanced nongated CT as a screening tool for coronary artery disease and as a prognostic marker in patients with COPD needs further investigation in prospective studies.

Positron emission tomography combined with computed tomography as an integral component in evaluation of primary cardiac lymphoma.

We present a case of primary cardiac lymphoma (PCL) that was initially manifest through syncopal episodes. In the diagnostic evaluation, positron emission tomography combined with computed tomography (PET‐CT) made a significant contribution—beyond that which would have been possible if only conventional imaging modalities such as magnetic resonance imaging (MRI) and transthoracic echocardiography (TTE) were utilized—and played a major role in follow‐up. Copyright

Effect of cardiac motion on body surface electrocardiographic potentials: an MRI-based simulation study

This paper describes an electrical model of cardiac ventricles incorporating real geometry and motion. The heart anatomy and its motion through the cardiac cycle are obtained from segmentations of multiple-slice MRI time sequences; the special conduction system is constructed using an automated mapping procedure from an existing static heart model. The heart model is mounted in an anatomically realistic voxel model of the human body. The cardiac electrical source and surface potentials are determined numerically using both a finite-difference scheme and a boundary-element method with the incorporation of the motion of the heart. The electrocardiograms (ECG) and body surface potential maps are calculated and compared to the static simulation in the resting heart. The simulations demonstrate that introducing motion into the cardiac model modifies the ECG signals, with the most obvious change occurring during the T-wave at peak contraction of the ventricles. Body surface potential maps differ in some local positions during the T-wave, which may be of importance to a number of cardiac models, including those incorporating inverse methods.

Screen-detected subsolid pulmonary nodules: long-term follow-up and application of the PanCan lung cancer risk prediction model

OBJECTIVE To report the long-term follow-up of subsolid nodules (SSNs) detected in participants of a prospective low-dose CT lung cancer screening cohort, and to investigate the utility of the PanCan model in stratifying risk in baseline SSNs. METHODS Participants underwent a baseline scan, two annual incidence scans and further follow-up scans for the detected nodules. All SSNs underwent a minimum of 2 years of follow-up (unless resolved or resected). Risk of malignancy was estimated using the PanCan model; discrimination [area under the receiver-operating characteristic curve (AUC)] and calibration (Hosmer-Lemeshow goodness-of-fit test) were assessed. The Mann-Whitney U-Wilcoxon test was used to compare estimated risk between groups. RESULTS 70 SSNs were detected in 41 (16.0%) out of 256 total participants. Median follow-up period was 25.5 months (range 2.0-74.0 months). 29 (41.4%) SSNs were transient. Five (7.1%) SSNs were resected, all found to be Stage I lung adenocarcinoma, including one SSN stable in size for 3.0 years before growth was detected. The PanCan model had good discrimination for the 52 baseline SSNs (AUC = 0.89; 95% confidence interval 0.76-1); the Hosmer-Lemeshow goodness-of-fit test was non-significant (p = 0.27). Estimated risk was significantly higher in the baseline SSNs found to be cancer vs those not found to be cancer after 2-6 years of follow-up (p < 0.01). CONCLUSION Our findings support a long-term follow-up approach for screen-detected SSNs for 3 years or longer. The PanCan model appeared discriminatory and well calibrated in this cohort. ADVANCES IN KNOWLEDGE The PanCan model may have utility in identifying low-risk SSNs which could be followed with less frequent CT scans.