SET T0007 -
Emergency Department

1). These two radiographs are normal.

2). Assessment of the C1 and C2 vertebrae and their alignment is essential when evaluating every lateral radiograph. The " Coffee Bean " shadow is a good starting point for those who are unfamiliar with the normal and abnormal appearances.

Coffee Bean shadow??

See : Accident & Emergency Radiology : A Survival Guide (3rd edition) : Pages 174-175

3). On the open mouth peg view it is crucial that you always assess the " lining up of the lateral masses ". But . . . be aware of the occasional anatomical and positional variants.

See : Accident & Emergency Radiology : A Survival Guide (3rd edition) : Pages 186-187

NB. The 3rd edition will be published in July 2014.

• The open mouth Peg view of the patient on our left is normal.
• The open mouth Peg view of the patient on our right is abnormal. The lateral masses of C1 and C2 do not align on the right side. The alignment on the left side is more difficult to visualise. Nevertheless, the malalignment on the right side indicates that additional assessment is indicated (eg CT). Impression: strong suspicion that there has been ligamentous rupture at the C1/C2 articulation resulting in subluxation.

PS On our courses we often refer to the open mouth Peg view as " the lining up of the lateral masses view " because this is the important assessment.

See : Accident & Emergency Radiology : A Survival Guide (3rd edition) : Pages 186-187

NB. The 3rd edition will be published in July 2014.

This is a normal PA chest X-ray. Note that the hila and both descending pulmonary arteries are easy to identify.

On a normal PA CXR :

1. The right hilum is never higher than the left hilum.
2. The right descending pulmonary artery is visible in approximately 93% of patients (ie in nearly all patients).
3. The left descending pulmonary artery is sometimes more difficult to detect / outline. It will be visible in approximately 61% of patients.
4. The " little finger " appearance refers to the size and shape of a descending pulmonary artery. Hila position and lower lobe pulmonary artery identification is crucial on all CXRs. Understanding their importance and normal appearances . . .

See : The Chest X-Ray : A Survival Guide : Pages 70-79

1. This is a normal AP chest radiograph.
2. The heart size cannot be evaluated because this is clearly identified as a Supine CXR (ie it is an AP CXR). An AP CXR will magnify the heart because the radiograph has been obtained with the patient lying supine or sitting up and facing the X-ray tube. Consequently the mediastinal shadows are magnified. The CTR assessment of heart size only applies to:

• a PA CXR
• a PA CXR that is obtained in full inspiration.

For these explanations . . .

See : The Chest X-Ray : A Survival Guide : Pages 2-6