Vertebrae at the thoracolumbar junction: A quantitative assessment using CT scans.

The thoracolumbar junction is often associated with traumatic injuries, due to its biomechanical instability. Reasons for this instability are currently still under debate; however, contributing factors such as the rapid change in spinal curvature and facet orientation from the thoracic to lumbar transition have been implicated. Normally, the superior facet orientation in the thoracic region is angled in a coronal plane, whereas vertebrae in the lumbar region have facets angled in the sagittal plane. Distinguishing between thoracic, lumbar, and transitional vertebrae at the thoracolumbar junction based on articular facet angles, using quantitative methods on CT scans has, to the authors' knowledge, not yet been reported in the literature. Therefore, this study aimed to evaluate whether quantitative measurements can be clinically applied and used to differentiate vertebrae at the thoracolumbar junction using CT scans and, additionally, to record possible cases of congenital defects or variations observed in the spine. A sample (n = 173) of CT scans representative of the Windhoek population in Namibia was retrospectively assessed using radio-imaging software. Measurements of the angle formed by the superior facets of the vertebrae at the thoracolumbar junction (T11-L1) were recorded. Based on the results of this study, quantitative morphometry of the superior facet of vertebrae can differentiate between thoracic, lumbar,. and transitional vertebrae at the thoracolumbar junction. All individuals with identified thoracolumbar transitional vertebrae (TLTV) in this sample had at least one other congenital anomaly of the spine.

Delayed enhancement imaging in a contemporary patient cohort following correction of tetralogy of Fallot.

OBJECTIVE: To test the hypothesis that myocardial scars after repair of tetralogy of Fallot are related to impaired cardiac function and adverse clinical outcome. METHODS: A total of 53 patients were retrospectively analysed after repair of tetralogy of Fallot. The median patient age was 20 years (range 2-48). Cardiac MRI with a 1.5 T magnet included cine sequences to obtain volumes and function, phase-sensitive inversion recovery delayed enhancement imaging to detect myocardial scars, and flow measurements to determine pulmonary regurgitation fraction. In addition, clinical parameters were obtained. RESULTS: An overall 83% of patients were in NYHA class I. All patients with the exception of 2 (96%) had pulmonary insufficiency. Mean ejection fraction and end-diastolic volume index were 46% and 128 ml/m2 for the right ventricle and 54% and 82 ml/m² for the left ventricle, respectively. Excluding enhancement of the septal insertion and prosthetic patches, delayed enhancement was seen in 11/53 cases (21%). Delayed enhancement of the right ventricle was detected in 6/53 patients (11%) and of the left ventricle in 5/53 patients (9%). The patient group with delayed enhancement was significantly older (p=0.003), had later repair (p=0.007), and higher left ventricular myocardial mass index (p=0.009) compared with the group without delayed enhancement. CONCLUSIONS: This study reveals that scarring is common in patients after surgical repair of tetralogy of Fallot and is associated with older age and late repair. However, there was no difference in right ventricular function, NYHA class, or occurrence of clinically relevant arrhythmias between patients with and those without myocardial scars.

Systemic right ventricles rarely show myocardial scars in cardiac magnetic resonance delayed-enhancement imaging.

OBJECTIVES: To test the hypothesis that myocardial scars cause systolic dysfunction in patients with transposition of the great arteries and a systemic right ventricle. METHODS: We retrospectively analyzed 20 consecutive patients (10 male, mean age 27.3 years) with a systemic right ventricle who underwent cardiac magnetic resonance imaging with 1.5 T. Cine steady-state free-precession sequences were performed to obtain volumes and function. Phase-sensitive inversion-recovery (PSIR) delayed-enhancement imaging was performed to detect myocardial scars. Tricuspid insufficiency was detected with echocardiography. Furthermore, the presence of arrhythmias and New York Heart Association (NYHA) class were assessed. RESULTS: Mean ejection fraction of systemic right ventricles was 43 ± 11 %, mean end-diastolic volume index was 111 ± 37 ml/m(2). Delayed-enhancement imaging revealed only one myocardial scar in the wall of a right ventricular aneurysm. All patients but one (95 %) presented with tricuspid insufficiency. Clinically relevant arrhythmias were present in 13/20 patients (65 %). The majority of patients (90 %) were NYHA class I or II. Arrhythmias, tricuspid insufficiency and NYHA class were not associated with right ventricular ejection fraction. CONCLUSIONS: Although right ventricular function was clearly impaired in our patient cohort, there was only one myocardial scar. Our results show that myocardial scarring assessed by PSIR delayed-enhancement imaging is not the underlying pathology of systemic right ventricular failure.