Diagnostic accuracy of mediastinal width measurement on posteroanterior and anteroposterior chest radiographs in the depiction of acute nontraumatic thoracic aortic dissection

Abstract

We aimed to explore the diagnostic accuracy of various mediastinal measurements in determining acute nontraumatic thoracic aortic dissection with respect to posteroanterior (PA) and anteroposterior (AP) chest radiographs, which had received little attention so far. We retrospectively reviewed 100 patients (50 PA and 50 AP chest radiographs) with confirmed acute thoracic aortic dissection and 120 patients (60 PA and 60 AP chest radiographs) with confirmed normal aorta. Those who had prior history of trauma or aortic disease were excluded. The maximal mediastinal width (MW) and maximal left mediastinal width (LMW) were measured by two independent radiologists and the mediastinal width ratio (MWR) was calculated. Statistical analysis was then performed with independent sample t test. PA projection was significantly more accurate than AP projection, achieving higher sensitivity and specificity. LMW and MW were the most powerful parameters on PA and AP chest radiographs, respectively. The optimal cutoff levels were LMW = 4.95 cm (sensitivity, 90 %; specificity, 90 %) and MW = 7.45 cm (sensitivity, 90 %; specificity, 88.3 %) for PA projection and LMW = 5.45 cm (sensitivity, 76 %; specificity, 65 %) and MW = 8.65 cm (sensitivity, 72 %; specificity, 80 %) for AP projection. MWR was found less useful and less reliable. The use of LMW alone in PA film would allow more accurate prediction of aortic dissection. PA chest radiograph has a higher diagnostic accuracy when compared with AP chest radiograph, with negative PA chest radiograph showing less probability for aortic dissection. Lower threshold for proceeding to computed tomography aortogram is recommended however, especially in the elderly and patients with widened mediastinum on AP chest radiograph.

Frequency and Detection of Stanford Type A Aortic Dissection in Hyperacute Stroke Management

“…Clinical background characteristics including cardiovascular risk factors were obtained, and routine blood biochemistry examinations, head magnetic resonance imaging, chest X-ray, and neck duplex ultrasonography were performed on admission. Mediastinal widening on the chest X-ray in this study was defined as >8.65 cm from the right lateral border to the left lateral border of the superior mediastinum at the level of the aortic knob [16] because almost all chest X-rays in this study were taken in a supine anteroposterior position. Stroke severity was assessed using the National Institutes of Health Stroke Scale (NIHSS), and functional outcome was evaluated by the modified Rankin scale score [17] at the time of discharge from the hospital.…”

Aortic dissection presenting an acute onset of neuroradicular syndrome complicated by coeliac and superior mesenteric artery embolism

“…Pulse differential or blood pressure differential is reported to account for approximately 38% in patients with AD . Mediastinal widening is one of the most important radiological findings, which could be easily diagnosed by chest X‐ray detection, especially by posteroanterior chest radiograph . Thus, aortic pain with immediate onset, a tearing or ripping character, or both; mediastinal widening, aortic widening, or both on chest radiography; and pulse differentials, blood pressure differentials, or both were identified as independent predictors of acute AD …”

Chest pain in a young patient: an unusual complication of Epstein-Barr virus

“…The D-dimer is usually raised in acute aortic dissection and values of less than 500 mg/mL have been shown to be a useful screening tool to identify patients who do not have an acute aortic dissection 1. The pain was not the typical central chest pain radiating to the back which is often described in association with aortic dissection and the chest radiograph did not show any mediastinal widening which is sometimes a radiological feature, although the diagnostic accuracy is higher for PA radiographs (sensitivity 90%) than AP radiographs (sensitivity 72%) 2. This patient also had a family history of aortic aneurysm which may represent a risk factor for dissection especially if in association with connective tissue disease, although there was no suggestion of this.…”