Quiz #9: Where is the tip of the PA line?

Question: Based on the CXR and PA line pressure trace, what is the location of the PA line tip? (Clue: The PA pressure trace holds the answer. Chest Xray helps to corroborate.)

Answer: RV outflow tract.

Rationale: PA pressure has a ventricular trace with a pressure of 55/1. If you enlarge and see, pressure trace is typical of a ventricular pattern. So, the line tip is in the RV. But, in the CXR, it is high up in the RV. Combining the two findings, the line tip has to be below the valve i.e. RVOT.

Of course, this patient has elevated PA pressure at ~50% systemic level.

Quiz #8: Barium Swallow

Question 1: What are the salient findings on Barium Swallow?
Answer 1: Bilateral indentation of the esophagus.
(Indentation on the right side is at a higher level than the left side which is usual in this condition)


Question 2: What is the diagnosis?
Answer 2: Double aortic arch (MRI from the same patient is given below).

Quiz #7: Barium Swallow Study

Question 1: Describe the findings in PA view?

Answer 1: Oblique impression in the upper esophagus (going left to right, from below upwards). However, in addition, there is a subtle compression of both side of the trachea.

Question 2: Describe the finding in Lateral view?

Answer 2: Posterior indentation of esophagus in the upper esophagus.

Question 3: What is the diagnosis?

Answer 3: Anomalous origin of right subclavian artery. In addition, this baby also has a possibility of double aortic arch (with patent right side arch giving off all the branches and ligamentous representation of left side arch. Left side arch is a presumption based on the the following findings: Right aortic arch with left descending aorta - associated with a Kommerell's diverticulum). See the rule in "Moss & Adams" - Vascular ring chapter by Dr. Paul Weinberg. Click here for link to a blog posting about the "rule". Briefly, the rule states that presence of 3 Ds in the opposite side from the ascending aorta, there is a vascular ring. The 3 Ds are Diverticulum, Dimple or Descending aorta.

Quiz #6: Barium Swallow Answers

Link to the question

Question 1: What is salient finding?
Answer: Anterior indentation of the esophagus. This means, the structure is passing inbetween the trachea and esophagus. The indentation in this condition is usually at the level of carina.

Question 2: What is the diagnosis?
Answer: "Pulmonary sling". This term refers to anomalous origin of LPA from RPA. The LPA courses inbetween trachea and esophagus to reach the left side.

2 bonus questions:
Question 3: What is the tracheal anomaly associated with pulmonary sling?
Answer: Complete rings in distal trachea - that may need additional surgical treatment (apart from correcting vascular anomaly)

Question 4: What cardiac anomaly is commonly associated with pulmonary sling?
Answer: Usually occurs by itself. Common associated cardiac lesion is Tetralogy of Fallot.
(Ref: Moss & Adams Fifth edition. p. 833. Chapter by Dr. Paul Weinberg)

7 out of 7 fellows responded. One fellow needed some "proding". But, ultimately everyone got the answer right. Dr. Agu sent a great article on this subject (Thorax 1969;24:295-306) with very illustrative figures.

The 2 MRI images are from one of our patients (Black arrow - Trachea. White arrow - Esophagus with NG tube). This patient did not have a barium swallow. Such is the trend these days! Barium swallow is still a good, straight forward study to demonstrate esophageal compression. Sometimes, this is unclear in MRI images.