Imaging

Those who care for patients with pulmonary, critical care or sleep disorders rely heavily on chest radiology and pathology to determine diagnoses. The Southwest Journal of Pulmonary, Critical Care & Sleep publishes case-based articles with characteristic chest imaging and related pathology.

The editor of this section will oversee and coordinate the publication of a core of the most important chest imaging topics. In doing so, they encourage the submission of unsolicited manuscripts. It cannot be overemphasized that both radiologic and pathologic images must be of excellent quality. As a rule, 600 DPI is sufficient for radiographic and pathologic images. Taking pictures of plain chest radiographs and CT scans with a digital camera is strongly discouraged. The figures should be cited in the text and numbered consecutively. The stain used for pathology specimens and magnification should be mentioned in the figure legend. Those who care for patients with pulmonary, critical care or sleep disorders rely heavily on chest radiology and pathology to determine diagnoses. The Southwest Journal of Pulmonary, Critical Care & Sleep publishes case-based articles with characteristic chest imaging and related pathology. The editor of this section will oversee and coordinate the publication of a core of the most important chest imaging topics. In doing so, they encourage the submission of unsolicited manuscripts. It cannot be overemphasized that both radiologic and pathologic images must be of excellent quality. As a rule, 600 DPI is sufficient for radiographic and pathologic images. Taking pictures of plain chest radiographs and CT scans with a digital camera is strongly discouraged. The figures should be cited in the text and numbered consecutively. The stain used for pathology specimens and magnification should be mentioned in the figure legend.

Rick Robbins, M.D. 3/4/15 Rick Robbins, M.D. 3/4/15

Medical Image Of The Week: Westermark Sign

Figure 1. Chest x-ray showing decrease pulmonary vasculature on the right upper lobe (red circle, Westermark sign).

Figure 2. Coronal section of the CT angiogram showing occlusive thrombosis on the right pulmonary artery.

A 71 year old man was evaluated in the Emergency Department for acute onset of dyspnea. On exam he was tachypneic, tachycardic and hypoxemic requiring 6 L/min of oxygen. He had recently underwent prostatectomy for prostate cancer. Past medical history was also significant for coronary artery disease treated with coronary bypass.

The chest x-ray (Figure 1) shows unilateral oligemia concerning for a pulmonary embolus and the CT angiogram of the chest (Figure 2) confirms the diagnosis.

While the chest radiograph is normal in the majority of pulmonary emboli, the ‘Westermark sign’ may be seen in up to 2% of the cases (1). It represents a focus of oligemia seen distal to a pulmonary embolism. The finding is a result of a combination of dilation of the pulmonary artery proximal to the thrombus and the collapse of the distal vasculature.

Muna Omar MD¹, Tammer Elaini MD² and Bhupinder Natt MD¹

¹Division of Pulmonary, Allergy , Critical Care and Sleep Medicine

²Department of Internal Medicine

University of Arizona Medical Center

Tucson, AZ

Reference

Worsley DF, Alavi A, Aronchick JM, Chen JT, Greenspan RH, Ravin CE. Chest radiographic findings in patients with acute pulmonary embolism: observations from the PIOPED Study. Radiology. 1993;189(1):133-6. [CrossRef] [PubMed]

Reference as: Omar M, Elaini T, Natt B. Medical image of the week: Westermark sign. Southwest J Pulm Crit Care. 2015;10(3):125-6. doi: http://dx.doi.org/10.13175/swjpcc015-15 PDF

Rick Robbins, M.D. 1/15/14 Rick Robbins, M.D. 1/15/14

Medical Image of the Week: Oligemic Lung Field

A Sinister Sign of Acute Pulmonary Embolism?

Figure 1. Panel A: The chest x-ray showed decreased vascular markings in the right lung field (oligemic right lung field) and reduced prominence of right pulmonary artery. There is also a small opacity in right lower lung field possibly a pulmonary infarct. Panel B: A Coronal section of the computed tomographic pulmonary angiography showing a large thrombus in the right pulmonary artery (white arrow). Panel C: A 12-lead EKG shows sinus tachycardia, right bundle branch block, deep S wave in lead I (black arrow), deep q wave (orange arrow) and inverted T-wave (green arrow) in lead III. Panel D: A computed tomographic pulmonary angiography showing an enlarged right ventricle (blue arrow) compressing the left ventricle (red arrow).

A 67 year-old woman presented with pleuritic, non-radiating chest pain of sudden onset. She was anxious, diaphoretic, and tachycardic.

The chest radiograph (Figure 1A) showed decreased vascular markings in the entire right lung field (oligemic right lung field) and reduced prominence of the right pulmonary artery. A small opacity in right lower lung field was suspicious for a pulmonary infarct. A follow-up computed tomographic pulmonary angiography (CTA) showed a large embolus in right pulmonary artery and a smaller embolus in the subsegmental left pulmonary artery (Figure 1B). Twelve-lead electrocardiogram (EKG) findings were notable for a new onset right bundle branch pattern, deep S wave in lead I, with a q-wave and inverted T-wave in Lead III (Figure 1C). A 2-Dimentional echocardiogram showed a massively dilated and hypokinetic right ventricle. The CTA also revealed that the massively distended right ventricle with a deviated interventricular septum was compressing the left ventricle (Figure 1D). Venous duplex study of lower extremities showed an acute thrombosis of the right popliteal vein.

The patient showed marked clinical improvement after the infusion of tissue plasminogen activator (tPA) and heparin. A chest x-ray obtained 2 days later showed resolution of right sided oligemia. On Day 6, the right bundle branch block had resolved.

Radiographic findings in acute pulmonary embolism (PE) are uncommon. The Westermark sign (oligemia), Hampton hump and prominent central pulmonary artery are infrequently seen in acute PE. Westermark sign of an entire side lung field is rare, sinister sign of a large burden pulmonary embolism. If identified early, this sign can be invaluable in early recognition and management.

Suman B. Thapamagar MBBS, Ramya Mallareddy MD, Ilya Lantsberg MD

Easton Hospital, Drexel University, Department of Internal Medicine, 250 S. 21st Street, Easton, PA 18042

Reference

Agnelli G, Becattini C. Acute pulmonary embolism. N Engl J Med. 2010;363(3):266-74. [CrossRef] [PubMed]

Reference as: Thapamagar SB, Mallareddy R, Lantsberg I. Medical image of the week: oligemic lung field. Southwest J Pulm Crit Care. 2014:8(1):48-9. doi: http://dx.doi.org/10.13175/swjpcc163-13 PDF