CASE 14137 Published on 15.10.2016

Pulmonary AVM with 3D reconstruction images

Section

Chest imaging

Case Type

Clinical Cases

Authors

Jason S. Chu, Zain Badar, Ernest Scalzetti.

SUNY Upstate Medical University Hospital,
SUNY Upstate Medical University,
Department of Radiology;
750 East Adams Street
13210 Syracuse, NY,
United States of America

Patient

40 years, female

Categories

Area of Interest Lung ; Imaging Technique CT, Catheter arteriography

Procedure Contrast agent-intravenous, Embolisation ; Special Focus Arteriovenous malformations ;

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Clinical History

A 40-year-old female patient presented for evaluation of dyspnoea. The patient had previous work up at an outside institution, and prior history is unavailable.

Imaging Findings

Contrast-enhanced CT of the thorax was obtained following intravenous contrast administration. Multiplanar reformatted and 3D-reconstructed images were also available for review. The examination demonstrated a solitary serpiginous enhancing lesion in the left costophrenic angle arising from the left interlobar pulmonary artery.

Discussion

Background
Pulmonary Arteriovenous Malformation (pAVM) refers to the abnormal communication between a pulmonary artery branch and pulmonary vein branch, bypassing the pulmonary capillary bed. These communications are usually congenital in nature. Risk factors include family history of Hereditary Heamorrhagic Telangiectasia (HHT), female sex, hepatopulmonary shunt, schistosomiasis, actinomycosis, and Fanconi syndrome [1]. Of these, HHT (also known as Osler-Weber-Rendu syndrome) has the strongest association with pAVM. 30 to 50% of HHT patients have pulmonary AVMs and roughly 90% of pAVM patients have HHT [1, 2, 3]. These lesions have predilection for the lower lobes, with the left side more commonly affected than the right [1]. The malformation can be classified as simple or complex, depending on the feeding artery’s structure. A simple pAVM has a single feeding segmental artery, while a complex pAVM is fed by more than one segmental artery. A subset of complex AVM includes diffuse pAVM, in which innumerable feeding arteries are present and is in particular difficult to treat [2].

Clinical Perspective
Although many patients may remain asymptomatic, symptoms often are the result of right to left shunting, which may be associated with dyspnoea, migraine headache and cyanosis. Major complications of pAVM include TIA, stroke, and brain abscess due to paradoxical embolism. [4, 5] The prevalence of neurologic manifestations becomes greater for patients with multiple pAVM [6].

Imaging Perspective
The modality of choice is contrast enhanced helical CT, and the most common finding is a simple AVM located in the lower lobes. Catheter-based pulmonary angiography, which is usually reserved for treatment after primary diagnosis was made, also can show the relationship between the pAVM and its feeding artery. Limitations of CT include the possibility of “steal phenomenon”, resulting in non-enhancement of some accessory feeding vessels. Additionally, measurement of feeding vessel calibre for the purposes of choosing the embolic device should be confirmed on catheter-based pulmonary angiography, as the feeding artery may be under-distended during the time of CT examination [2].

Outcome
The treatment of choice for pAVM is percutaneous transcatheter embolization, with a size cut-off of less than 3 mm for the feeding artery [2]. Surgery is indicated to control bleed or for lesions not amenable to catheter embolization [1, 2]. Lifelong follow up contrast-enhanced chest CT is necessary due to the potential for growth of new pAVM or recanalization of treated pAVMs [1, 2].

Take Home Message
Pulmonary AVM may be incidentally discovered. Treatment is required because of the risk of paradoxical embolism.

Differential Diagnosis List

Pulmonary arteriovenous malformation.

Abnormal systemic vessels

Highly vascular parenchymal mass

Final Diagnosis

Pulmonary arteriovenous malformation.

References

[1] Cartin-Ceba, R. Swanson, K. L., Krowka, M. J. (2013) Pulmonary Arteriovenous Malformations. Chest Journal 144(3): 1033-1044 (PMID: 24008954)

[2] Narsinh, K. H, Ramaswamy, R., and Kinney, T. B. (2013) Management of Pulmonary Arteriovenous Malformation in Hereditary Hemorrhagic Telangiectasia Patients. Semin Intervent Radiol 30(4): 408-412 (PMID: 24436569)

[3] Gossage, J. R. and Kanj, G. (1998) Pulmonary Arteriovenous Malformations. Am J Respir Crit Care Med 158(2): 643-661 (PMID: 9700146)

[4] Khurshid, I. Downie, G. H. (2002) Pulmonary Arteriovenous Malformation. Postgrad Med J 78(918): 191-197 (PMID: 11930021)

[5] Shovlin, C. L. (2014) Pulmonary Arteriovenous Malformations. American Journal of Respiratory and Critical Care Medicine 190 (11): 1217-1228 (PMID: 25420112)

[6] Moussouttas, M. Fayad, P. Rosenblatt, M. Hashimoto, M. Pollak, J. Henderson, K. Ma T.Y., White, R.I. (2000) Pulmonary Arteriovenous Malformation: Cerebral Ischemia and Neurologic Manifestations. Neurology 10;55(7): 959-64 (PMID: 11061251)

Case information

URL:	https://www.eurorad.org/case/14137
DOI:	10.1594/EURORAD/CASE.14137
ISSN:	1563-4086

License

This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

Figure 1

CT images

Axial contrast enhanced CT of the thorax shows an enhancing serpiginous lesion in the left costophrenic angle (red arrow).

Left image: Sagittal view of the same lesion (red arrow). Right image: Magnified view of lesion.

Left image: Coronal view of the same lesion (red arrow). Right image: Magnified view of lesion.

Figure 2

3D reconstruction.

3D reconstructed images from source CECT images (red arrow).

Magnified and oblique view of the same lesion (red arrow).

Figure 3

CT Angiography

Left image: Pulmonary angiography demonstrating vascular lesion and its relation to the supplying vessels. Right image: Occlusion of feeding vessel after embolization.