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Topic

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Right hemidiaphragm

The right hemidiaphragm is the muscular dome-shaped half of the diaphragm that separates the right thoracic cavity from the abdominal cavity. It arises from the xiphoid process, lower six costal cartilages, and upper lumbar vertebrae via the right crus, and inserts centrally into the central tendon. The right hemidiaphragm lies higher than the left, due to the underlying liver, and plays a major role in respiration by contracting and flattening to increase thoracic volume during inspiration.

Synonyms

  • Right dome of diaphragm

  • Right diaphragmatic dome

  • Right half of diaphragm

Function

  • Principal muscle of respiration (contracts to expand thoracic cavity during inspiration)

  • Provides barrier between thoracic and abdominal cavities

  • Assists in venous return by generating negative intrathoracic pressure

  • Contributes to coughing, sneezing, defecation, and vomiting by increasing intra-abdominal pressure

Arterial Supply

  • Inferior phrenic arteries (primary supply)

  • Contributions from the superior phrenic arteries, musculophrenic arteries, and pericardiacophrenic arteries

Venous Drainage

  • Drains into the inferior phrenic veins → inferior vena cava (IVC) on the right

  • Additional venous drainage via brachiocephalic and azygos systems

Nerve Supply

  • Supplied by the right phrenic nerve (C3–C5)

  • Provides motor innervation to the diaphragm and sensory fibers to the diaphragmatic pleura, pericardium, and peritoneum

MRI Appearance

T1-weighted images:

  • Right hemidiaphragm appears as a thin hypointense muscular layer separating thoracic and abdominal cavities

  • Liver provides intermediate-to-high signal background, enhancing diaphragm contrast

T2-weighted images:

  • Hemidiaphragm remains low signal (hypointense) compared to adjacent lungs (high signal air interface) and liver (intermediate signal)

  • Useful for detecting muscle discontinuity (hernia, rupture) or thinning

STIR (Short Tau Inversion Recovery):

  • Normal diaphragm appears low signal

  • Edema, inflammation, or denervation changes appear hyperintense, highlighting pathology

T1 Post-Contrast (Gadolinium-enhanced):

  • Diaphragmatic muscle may show mild homogeneous enhancement

  • Pathology (tumor, metastasis, or inflammatory thickening) demonstrates asymmetric or heterogeneous enhancement

CT Appearance

Non-contrast CT:

  • Seen as a thin, curvilinear soft tissue structure separating right lung base and liver

  • Right hemidiaphragm is elevated compared to the left due to the liver

Contrast-enhanced CT (CECT):

  • Better delineation of diaphragm against enhancing liver and thoracic structures

  • Detects diaphragmatic hernias, ruptures, tumors, or eventration

  • Multiplanar reconstructions (coronal, sagittal) are excellent for defining continuity and defects

MRI image

right hemidiaphragm MRI coronal image -img-00000-00000

CT image

right hemidiaphragm CT coronal image -img-00000-00000

X Ray image

Right hemidiaphragm x ray Anatomy, Location and Imaging Appearance CT anatomy image -img-00000-00000