Dysfunction of the diaphragm: imaging as a diagnostic tool

This review summarizes the utility and efficacy of different imaging modalities in the diagnosis of diaphragmatic dysfunction.

Dynamic MRI of the diaphragm has been recently described in the literature as a tool allowing more detailed study of diaphragmatic dysfunction.

The diaphragm is the primary muscle of ventilation. Diaphragmatic dysfunction can be partial or complete, unilateral or bilateral. The diagnosis is difficult to establish at certain times due to diversity of presentations and severity of symptoms. There are several causes of diaphragmatic dysfunction, which adds to the complexity of diagnostic workup. In this review, the basic anatomy and function of the diaphragm and the different pathologic processes that may affect its function will be presented. These processes may originate in the brain, spinal cord, phrenic nerve or the diaphragm itself. Furthermore, this article will review the utility and efficacy of different diagnostic modalities in the diagnosis of diaphragmatic dysfunction. Most of these imaging tools have been well known for several years, including plain chest radiographs, fluoroscopy and ultrasound. An emerging mode is magnetic resonance dynamic imaging, which is another potentially effective way of functional diaphragmatic imaging that is still not part of routine clinical practice.