July 2018 Imaging Case of the Month

Michael B. Gotway, MD

Department of Radiology

Mayo Clinic Arizona

Scottsdale, AZ USA

Imaging Case of the Month CME Information  

Completion of an evaluation form is required to receive credit and a link is provided on the last panel of the activity.

0.25 AMA PRA Category 1 Credit(s)™

Estimated time to complete this activity: 0.75 hours

Lead Author(s): Michael B. Gotway, MD. All Faculty, CME Planning Committee Members, and the CME Office Reviewers have disclosed that they do not have any relevant financial relationships with commercial interests that would constitute a conflict of interest concerning this CME activity. 

Learning Objectives: As a result of completing this activity, participants will be better able to:

1. Interpret and identify clinical practices supported by the highest quality available evidence.
2. Establish the optimal evaluation leading to a correct diagnosis for patients with pulmonary, critical care and sleep disorders.
3. Translate the most current clinical information into the delivery of high quality care for patients.
4. Integrate new treatment options for patients with pulmonary, critical care and sleep related disorders.

Learning Format: Case-based, interactive online course, including mandatory assessment questions (number of questions varies by case). Please also read the Technical Requirements.

CME Sponsor: University of Arizona College of Medicine at the Arizona Health Sciences Center.

Current Approval Period: January 1, 2017-December 31, 2018

Clinical History: An 81–year old non-smoking woman presented with complaints of shortness of breath for one month, more so when laying down. The patient had a history of Sjögren syndrome established 13 years earlier. She notes a history of dryness of the eyes and upper airways. Her medications included 5 mg prednisone daily as well as various vitamins and supplements. While she complained of several medication “allergies,” none were serious and most appeared to represent side effects or untoward reactions to medications as opposed to true allergic reactions. Her past medical history included arthritis, possible obstructive sleep apnea, kidney stones, and orthostatic hypotension, the latter thought to be related to her Sjögren syndrome. Her surgical history included a sternotomy for thymoma resection years earlier.

Her physical examination was unremarkable except for diminished breath sounds at the left base; her vital signs were within normal limits.

Frontal and lateral chest radiography (Figure 1) was performed.

Figure 1. Frontal (A) & lateral (B) chest radiography.

Which of the following represents the most accurate assessment of the chest radiographic findings? (click on the correct answer to be directed to the second of eleven pages)

1. Chest radiography shows an elevated left hemidiaphragm
2. Chest radiography shows bibasilar fibrotic-appearing opacities
3. Chest radiography shows cavitary pulmonary lesions
4. Chest radiography shows multifocal bronchiectasis
5. Chest radiography shows small pulmonary nodules

Cite as: Gotway MB. July 2018 imaging case of the month. Southwest J Pulm Crit Care. 2018;17(1):15-27. doi: https://doi.org/10.13175/swjpcc086-18 PDF 

Medical Image of the Week: Saber Sheath Trachea

Figure 1. A: Narrowing in the mid and lower parts of the trachea on the scout film (arrow). B: Cross sectional image from chest computed tomography (CT) showing coronal narrowing of the trachea (arrow).  C: Cross sectional images from chest computed tomography (CT) showing sagittal widening of the trachea (arrow).  No mass or external compression seen.

Figure 2. Bronchoscopy image that shows the coronal narrowing and sagittal widening of the (A) proximal trachea, (b) mid trachea and (C) distal trachea.

A 79-year-old man with chronic obstructive pulmonary disease (COPD) and an active smoker was transferred for evaluation of tracheal narrowing and concerns of malignant external compression versus tracheobronchomalacia for possible stenting.

The patient underwent both chest computed tomography (Figure 1) and bronchoscopy (Figure 2) that confirmed the diagnosis of saber-sheath trachea and ruled out external compression. The airway was still adequately patent during inspiration and expiration with no clear dynamic collapse.

Saber-sheath trachea is commonly described as intra-thoracic coronal narrowing and sagittal widening of the trachea (like a sword sheath). Repetitive cartilaginous injury from excessive coughing and elevated intra-thoracic pressure causes degeneration and calcification of the trachea cartilage, leading to remodeling and bending of the tracheal cartilage (1). Presence of saber-sheath trachea is highly associated with obstructive lung disease, which is present in our patient (2). There is no known specific treatment for saber-sheath trachea, however if patient with saber-sheath trachea were to require intubation, air leak can be a concern due to the rigid deformity of the trachea (3).

See-Wei Low, MD¹; Huthayfa Ateeli, MD²; James Knepler, MD²

¹ Department of Internal Medicine and ² Pulmonary, Allergy, Critical Care and Sleep Medicine

Banner University Medical Center Tucson

Tucson, AZ, USA

References

1. Ismail SA, Mehta AC. "Saber-sheath" trachea. J Bronchol Intervent Pulmonol 2003;10:296-7. [CrossRef]
2. Greene R. Saber-sheath trachea: relation to chronic obstructive pulmonary disease. AJR Am J Roentgenol. 1978;130:441-5. [CrossRef] [PubMed]
3. Wallace E, Chung F. General anesthesia in a patient with an enlarged saber-sheath trachea. Anesthesiology. 1998;88:527-9. [CrossRef] [PubMed] 

Cite as: Low S-W, Ateeli H, Knepler J. Medical image of the week: saber sheath trachea. Southwest J Pulm Crit Care. 2017;14(6):283-4. doi: https://doi.org/10.13175/swjpcc056-17 PDF 

Medical Image of the Week: Dynamic Collapse of the Trachea

Figures 1A (Inspiratory) and 1B (Expiratory). CTs showing greater than 50% reduction of the anterior-posterior diameter of the trachea (double-headed arrow in Panel A compared to single-headed arrow in Panel B) during expiration consistent with dynamic airway collapse.

A 61 year old man with a history of chronic obstructive pulmonary disease (COPD) requiring multiple intubations over the past 2 years as well as obstructive sleep apnea (OSA) presented with acute dyspnea, cough and difficulty expectorating sputum over the last 24 hours.  His physical exam was notable for expiratory and inspiratory wheezing.  ABG revealed a pH of 7.24, P_aCO₂ of 71, P_aO₂ of 103, and HCO₃ of 29 mMol consistent with an acute on chronic respiratory acidosis. In the Emergency Department, the patient was given multiple bronchodilators and eventually placed on BiPAP with gradual improvement. CT of the chest revealed the caliber of the trachea was narrowed greater than 50% during expiration (Figure 1B) consistent with dynamic airway collapse of tracheobronchomalacia. This often overlooked condition may be related to past intubations or COPD with chronic bronchitis and is often misdiagnosed as COPD or treatment resistant asthma. Stents are often entertained in these patients but are fraught with complications and when used a removable stent is chosen.

Prathima Guruguri MD, Varun Takyar MD, Janet Campion MD, Stephen Klotz MD, and Philip Factor DO

University of Arizona

Tucson,  AZ

Reference as: Guruguri P, Takyar V, Campion J, Klotz S, Factor P. Medical image of the week: collapse of the trachea. Southwest J Pulm Crit Care. 2013;7(1):40. doi: http://dx.doi.org/10.13175/swjpcc090-13 PDF

September 2012 Imaging Case of the Month

Michael B. Gotway, MD

Associate Editor Imaging

Department of Radiology

Mayo Clinic Arizona

Scottsdale, AZ

Clinical History: A 35-year-old non-smoking man presented with a history of slowly progressive shortness of breath preceded by cough and wheezing, previously presumptively diagnosed with asthma. He had a previous history of ulcerative colitis and a +PPD for which he received 6 month INH therapy. Frontal and lateral chest radiography (Figure 1) was performed.

Figure 1. Panel A: Frontal chest radiography. Panel B: Lateral chest radiography.

Which of the following statements regarding the chest radiograph is accurate?

1. The radiograph shows a diffuse interstitial abnormality
2. The radiograph appears normal
3. The radiograph shows cystic lung disease
4. The radiograph a mediastinal contour abnormality
5. The radiograph shows abnormal lung volumes

Reference as: Gotway MB. September 2012 imaging case of the month. Southwest J Pulm Crit Care 2012;5:126-34. (Click here for a PDF version)