Medical Image of the Week: Traumatic Aortic Dissection

Figure 1. Chest x-ray demonstrating widened mediastinum with prominence of the aortic arch.

Figure 2. Contrast enhanced CT axial (A, left) and coronal (B, right) views demonstrate descending thoracic aortic dissection with mediastinal hematoma and intimal flap (arrow).

A 21-year-old gentleman with no significant past medical history presented to the emergency department following a highway speed motor vehicle collision. The patient was a restrained passenger in the back seat of the vehicle. On initial evaluation the patient was in stable condition and complaining of acute onset back pain. Physical exam was remarkable for facial contusions, tenderness to palpation about the thoracic and lumbar spine, and a normal neurologic exam.

Imaging with chest x-ray (CXR) revealed widening of the mediastinum with prominence of the aortic arch (Figure 1). Further investigation with contrast enhanced computed tomography (CT) of the chest, abdomen and pelvis showed descending thoracic aortic dissection with mediastinal hematoma (Figure 2). The patient underwent successful endovascular repair and was discharged in stable condition.

Acute traumatic aortic injury is a potentially life-threatening condition requiring prompt evaluation. Initial investigation in the trauma setting often includes CXR imaging (1). CXR findings which should raise suspicion for aortic injury in the appropriate clinical scenario include mediastinal widening, abnormality of the aortic silhouette, and right side tracheal deviation.

CT angiography (CTA) is considered the definitive diagnostic modality in most cases, with high sensitivity and specificity. Mediastinal, periaortic and retrocrural hematoma are findings suggestive of traumatic aortic injury. Definitive findings include contrast extravasation, irregularity of the aortic contour, contained rupture, intramural thrombus, and aortic dissection.

Justin S. Caskey, BS

University of Arizona

College of Medicine

Tucson, Arizona, USA

Reference

1. Nagpal P, Mullan BF, Sen I, Saboo SS, Khandelwal A. Advances in imaging and management trends of traumatic aortic injuries. Cardiovasc Intervent Radiol. 2017 May;40(5):643-54. [CrossRef] [PubMed]

Cite as: Caskey JS. Medical image of the week: traumatic aortic dissection. Southwest J Pulm Crit Care. 2018;16(2):94-5. doi: https://doi.org/10.13175/swjpcc016-18 PDF

Medical Image of the Week: Tortuosity of Thoracic Aorta Mimicking a Lung Mass

Figure 1. PA (A) and lateral (B) chest X-ray showing a 5x4 cm round mass with sharp margins in retrocardiac area.

Figure 2. A-C: Initial CT image showing thoracic aorta acutely angulated above the diaphragm and crossing to the right side of the chest. Then the aorta acutely angulates again and descends into the abdomen on the right. D: Follow-up CT image after 2 years showing saccular dilatation of transverse area of thoracic aorta.

An 83-year-old female presented with epigastric discomfort and nausea for 1 month. Her past medical history included hypertension and osteoarthritis. Her vital signs at were unremarkable. Her electrocardiogram revealed only atrial premature beats. Laboratory examination, including complete blood count, liver function test, blood urea nitrogen, creatinine, and electrolytes were normal.

Esophagogastroduodenoscopy revealed minimal changes of reflux esophagitis, erosive gastritis, and extrinsic compression of lower esophagus. Her chest x-ray (Figure 1) showed a 5x4 cm sized round retrocardiac mass with sharp margin. Chest CT was ordered to evaluate the lung mass and it revealed that acutely angulated lower thoracic aorta which crossed from left to right above the left diaphragm (Figure 2). After treatment with a proton pump inhibitor and a gastrointestinal pro-motility agent, her symptoms gradually decreased. Follow-up CT after 2 years shows saccular dilatation of the transverse area of thoracic aorta (Figure 2D), however, she has no specific symptoms.

Abnormal vascular structures like a severe tortuous thoracic aorta occasionally can be confused with a lung mass or neoplasm. The most common cause of aortic disease mimicking lung mass on CXR is an aortic aneurysm (1). Some cases have reported an intervention or even an operation being performed. The symptoms of tortuosity of thoracic aorta are varied from asymptomatic to dysphagia, gastroesophageal reflux, nausea and vomiting (2). Therefore, clinical symptom is not helpful to diagnose the underlying cause. As in this case, chest computed tomography (CT) can be beneficial for the differential diagnosis between vascular lesion and lung mass. Chest CT also gives additional information for communication of the aneurysm with the aorta, relationship of vascular structure to mediastinal organs. In children, Loeys-Dietz syndrome or arterial tortuosity syndrome should be considered (3). If aortic aneurysm or tortuosity of aorta is diagnosed as a cause in older age, close observation should be performed because of the possibility of progression to aortic aneurysm, dissection or compression of adjacent organs.

Jong Seol Park, MD and Yong Sung Kim, MD, PhD

Department of Internal Medicine

Wonkwang University Sanbon Hospital

Gunpo, Korea

References

1. Wixson D, Baltaxe HA, Sos TA. Pitfalls in the plain film evaluation of the thoracic aorta: the mimicry of aneurysms and adjacent masses and the value of aortography. Part I. Transverse aortic arch. Cardiovasc Radiol. 1979 Apr 27;2(2):69-76. [CrossRef] [PubMed]
2. Badila E, Bartos D, Balahura C, Daraban AM. A rare cause of Dysphagia - Dysphagia aortica - complicated with intravascular disseminated coagulopathy. Maedica (Buchar). 2014 Mar;9(1):83-7. [PubMed]
3. Na KJ, Park KH. Multiple aortic operations in loeys-dietz syndrome: report of 2 cases. Korean J Thorac Cardiovasc Surg. 2014 Dec;47(6):536-40. [CrossRef] [PubMed] 

Cite as: Park JS, Kim YS. Medical image of the week: tortuosity of thoracic aorta mimicking a lung mass. Southwest J Pulm Crit Care. 2017;15(2):80-1. doi: https://doi.org/10.13175/swjpcc086-17 PDF 

Medical Image of the Week: Coral Reef Aorta

Figure 1. Coronal (A) and lateral (B) thoracic CT in soft tissue windows showing the coral reef calcification (arrows).

A 52-year-old woman with no past medical history presented to the emergency department with signs and symptoms concerning for pneumonia. Chest x-ray showed incidental findings of a calcified aortic mass. Subsequently, a follow up computed tomography scan (CT) was obtained which showed coral reef aorta (Figure 1). On physical examination, vital signs were only significant for mildly elevated blood pressure to 146/62 mmHg. She also had normal and equal pulses and pressures throughout all 4 extremities. In retrospect, patient had complaints of bilateral lower extremity claudication on strenuous exercise.

Coral reef aorta, a rare condition that was first described in 1984 by Qvarfordt et al. (1) is characterized by an eccentric, heavily calcified polypoid lesion and stenosis of the juxtarenal and suprarenal aorta. The rock-hard, irregular, gritty, whitish surface of the calcification strongly resembled a coral reef. The most common presentation is severe hypertension and intermittent claudication. Magnetic resonance angiogram (MRA) and CT have the ability to diagnose and appreciate the extent of this phenomenon (2).

Lance Eberson MS¹ and Sehem Ghazala MD²

¹College of Medicine and ²Department of Internal Medicine

University of Arizona

Tucson, Arizona, USA

References

1. Qvarfordt PG, Reilly LM, Sedwitz MM, Ehrenfeld WK, Stoney RJ. "Coral reef" atherosclerosis of the suprarenal aorta: a unique clinical entity. J Vasc Surg. 1984 Nov;1(6):903-9. [CrossRef] [PubMed]
2. Kopani K, Liao S, Shaffer K. The Coral Reef Aorta: Diagnosis and Treatment Following CT. Radiol Case Rep. 2016 Oct 4;4(1):209. eCollection 2009. [CrossRef] [PubMed] 

Cite as: Eberson L, Ghazala S. Medical image of the week: coral reef aorta. Southwest J Pulm Crit Care. 2017:15(1):49. doi: https://doi.org/10.13175/swjpcc080-17 PDF

Medical Image of the Week: Type A Aortic Dissection Extending Into Main Coronary Artery

Figure 1. Electrocardiogram at presentation showing ST segment elevation in anterior leads (arrows).

Figure 2. Coronary angiogram showing RAO caudal view of left main coronary artery after contrast injection with the smooth proximal linear irregularity suspicious for dissection flap into the left anterior descending artery (arrow).

Figure 3. Panel A: Computed tomography angiogram transverse view showing true lumen and false lumen of both ascending and descending aorta (arrow). Panel B: Computed tomography angiogram sagittal view showing dissection from root into abdominal aorta. 

A 58-year-old woman with no significant past medical history, presented to the emergency department with complains of sudden onset, severe , non-radiating epigastric pain associated with nausea and vomiting. An electrocardiogram (EKG) done in emergency department showed ST segment elevation in the anterior leads (Figure 1). Blood pressure at presentation was 141/79, and she had symmetrical bilateral pulses of the upper extremities, no diastolic murmur, and no neurologic deficit. The patient was taken to catherization laboratory, for ST segment elevated myocardial infarction (STEMI). She was found have aortic dissection extending to the left main coronary artery (Figure 2). Cardiothoracic surgery was called immediately. Computed tomography angiogram (CTA) of the thoracic and abdominal aorta revealed Debakey type 1 aortic dissection. (Figure 3). The patient was taken to the operating room. Unfortunately, the patient suffered pulseless electrical activity (PEA) arrest during anesthesia induction from which she could not be revived.

Aortic dissection is a critical compromise in the lining of the main arterial outflow from the heart (1).  Two theories have been proposed to explain the pathogenesis. A tear in the tunica intima, of the aorta, leads to blood from the aortic lumen surging into the tunica media (2). In contrast, the second theory holds that the vasa vasorum in the more outer portions of the tunica media hemorrhage first and then cause the rupture of the tunica intima (2). The pressure of the pulsatile blood flow extends the dissection, typically in an anterograde fashion (2). Anatomically aortic dissection is classified as Debakey 1,2, and 3 and Stanford A and B (1). Rarely aortic dissections can also extend in a retrograde fashion to reach the coronary ostia (3). Signs of myocardial ischemia including ST segment changes, adversely affect survival outcomes in patients with type A aortic dissection extending to the coronary arteries (4).

Ali Osama Malik MD¹, Oliver Abela MD², Chowdhury Ahsan MD², and Jimmy Diep MD²

¹Department of Internal Medicine

²Department of Cardiovascular Medicine

University of Nevada School of Medicine

Las Vegas, NV USA

References

1. Golledge J, Eagle KA. Acute aortic dissection. Lancet. 2008 Jul 5;372(9632):55-66. [CrossRef] [PubMed]
2. Patel AY, Eagle KA, Vaishnava P. Acute type B aortic dissection: insights from the International Registry of Acute Aortic Dissection. Ann Cardiothorac Surg. 2014 Jul;3(4):368-74. [CrossRef] [PubMed]
3. Neri E, Toscano T, Papalia U, Frati G, Massetti M, Capannini G, et al. Proximal aortic dissection with coronary malperfusion: presentation, management, and outcome. J Thorac Cardiovasc Surg. 2001 Mar;121(3):552-60. [CrossRef] [PubMed]
4. Imoto K, Uchida K, Karube N, Yasutsune T, Cho T, Kimura K, et al. Risk analysis and improvement of strategies in patients who have acute type A aortic dissection with coronary artery dissection. Eur J Cardiothorac Surg. Sep;44(3):419-24; discussion 24-5. [CrossRef] [PubMed]

Cite as: Malik AO, Abela O, Ahsan C, Diep J. Medical image of the week: type A aortic dissection extending into main coronary artery. Southwest J Pulm Crit Care. 2017;14(5):238-9. doi: https://doi.org/10.13175/swjpcc044-17 PDF 

Medical Image of the Week: Pneumomediastinum

Figure 1. Chest X-ray PA view.

Figure 2. CT scan of chest.

A 38-year-old gentleman was flown to the emergency room after being involved in a motor vehicle accident. In the field, he had a Glasgow Coma Scale of about 7 and cricothyrotomy was performed to establish an airway. He sustained severe head and chest injuries, with extensive subcutaneous emphysema.  Chest X-ray (Figure 1) and CT scan (Figure 2) revealed pneumomediastinum with classical “continuous diaphragm sign” (red arrows), lucent streaks outlining the ascending aorta (blue arrows) and extensive subcutaneous emphysema (block arrows). Subdural and subarachnoid hemorrhage was detected on CT scan of head. His neurological status worsened over next 24 hours and he was confirmed brain dead.

Ramasubramanian Baalachandran MD, Naser Mahmoud MD, and Laura Meinke MD

Department of Medicine

University of Arizona

Tucson, Arizona

References

1. Bejvan SM, Godwin JD. Pneumomediastinum: old signs and new signs. AJR Am J Roentgenol. 1996;166:1041-8. [CrossRef] [PubMed]
2. Levin B. The continuous diaphragm sign. A newly-recognized sign of pneumomediastinum. Clin Radiol.1973;24(3):337-8. [CrossRef] [PubMed]

Reference as: Baalachandran R, Mahmoud N, Meinke L. Medical image of the week: pneumomediastinum. Southwest J Pulm Crit Care. 2014;9(3):189-90. doi: http://dx.doi.org/10.13175/swjpcc123-14 PDF