Thick soft tissue may obscure underlying structures
Black within soft tissue may represent gas
Whenever you look at a chest X-ray, have a look at the soft tissues, especially around the neck, the thoracic wall, and the breasts.
If a patient has very thick soft tissue due to obesity, underlying structures such as the lung markings may be obscured. Large breasts may obscure the costophrenic angles, giving the impression of the presence of pleural effusions.
The nipples are clearly seen on this chest X-ray, but care is needed whenever there is a chance that the markings may represent underlying lung nodules. If there is any doubt then a repeat chest X-ray should be performed, with metallic markers used to indicate the position of the nipples.
At first glance the left costophrenic angle appears blunt. This is because the patient was in a rotated position when the X-ray was taken. This has resulted in a greater thickness of breast overlying the costophrenic angle on the left, compared to the right.
If you are not careful you may be misled into thinking there is a pleural effusion or other pathology causing costophrenic angle blunting.