Morphomics Data Dictionary
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  • Most measures are taken "per vertebra" at each vertebral level visible in the CT scan, allowing morphomics to be reported as a function of body region.

  • A number of measures of muscle density are reported in Hounseld Units (HU), and often separated into Normal Density Muscle (NDM) and Low Density Muscle (LDM). The thresholds for these come from the paper Goodpaster BH, Kelley DE, Wing RR, Meier A, Thaete FL. Effects of weight loss on regional fat distribution and insulin sensitivity in obesity. Diabetes. 1999;48(4):839-47.

  • The "lean psoas" is a mathematical combination of measures of psoas cross sectional area (mm2) and psoas density (in HU) inside the muscle boundary. The formula for lean psoas is then:

  • Data dictionary equation
  • This can be thought of as "normalizing a muscle's density between -85 HU (very fatty and low density) and +85 HU (very dense)". The values of ±85 were chosen by inspection of some of our sickest and healthiest individuals' data points.


Sven Holcombe, Binu Enchakalody, Peng Zhang, Stewart Wang

  • By using our Analytic Morphomics data, you can compare your patient's inner measurements to that of a control population. This page describes some of the measurements you can compare your patients to.

Body Measures (central plane depths)

central plane depths

Fascia to Skin (mm)

Linear distance from fascia to skin (central sub-cutaneous size)

Vertebral Body to Fascia (mm)

Front of vertebral body to fascia (central visceral size)

Spine to Back Skin (mm)

Posterior tip of spine to back skin


Body Measures (shapes & sizes)

shapes & sizes

Total Body Area (mm2)

Cross-sectional area of the body (inside purple line)

Fascia Area (mm2)

Cross-sectional area of fascia (inside yellow line)

Body Depth (mm)

Front-to-back body distance (aligned to body habitus)

Body Width (mm)

Left-to-right body distance (aligned to body habitus)

Fascia Eccentricity (ratio)

Eccentricity of an ellipse having the same second-moments of the fascia region. (Ratio of major-axis length to the distance between ellipse foci). A circle has eccentricity of 0, while a line has eccentricity of 1.


Fat Measures

Fat measures

Visceral Fat Area (mm2)

Area inside the fascia (yellow line) meeting fat density thresholds (-205 to 51 HU)

Subcutaneous Fat Area (mm2)

Area between skin and fascia meeting fat density thresholds (-205 to -51 HU)

Subcutaneous Fat (HU)

Median pixel intensity of fat-intensity pixels (-205 to -51 HU) in the subcutaneous region. Not computed when fewer than 200 pixels of fat exist.

Visceral Fat (HU)

Median pixel intensity of fat-intensity pixels (-205 to -51 HU) inside the visceral cavity. Not computed when fewer than 200 pixels of fat exist.


Muscle (psoas)

Muscle (psoas)

Total Psoas Area (mm2)

Total area of the left/right psoas at L4 (region inside blue lines)

Psoas (HU)

Average pixel intensity inside blue lines

Weighted Lean Psoas (HU x mm2)

Psoas HU normalized between -85 and +85, multiplied by Total Psoas Area.


Muscle (dorsal muscle group)

Dorsal muscle Group

DMG Volume Within VB (mm3)

Volume of the dorsal muscle group between this vertebra and its superior neighbor

DMG Boundary Area (mm2)

Cross sectional area of the DMG perimeter boundary. Boundary is built from triangle between spinal canal and left/right lateral seams, connected by nearest location to the posterior fascial envelope irrespective of bone/muscle/air contents.

DMG Low Density Area (mm2)

Cross sectional area of the DMG falling in a low density muscle HU range (0 to 30)

DMG Normal Density Area (mm2)

Cross sectional area of the DMG falling in a normal density muscle HU range (31 to 100)

DMG Mean (HU)

Mean pixel intensity within the DMG boundary.

DMG Median (HU)

Median pixel intensity within the DMG boundary.

DMG Low Density Mean (HU)

Mean pixel intensity within Low Density Muscle (0 to 30) pixels inside the DMG boundary.

DMG Low Density Median (HU)

Median pixel intensity within Low Density Muscle (0 to 30) pixels inside the DMG boundary.

DMG Normal Density Mean (HU)

Mean pixel intensity within Normal Density Muscle (31 to 100) pixels inside the DMG boundary.

DMG Normal Density Median (HU)

Median pixel intensity within Normal Density Muscle (31 to 100) pixels inside the DMG boundary.


Pelvis (sizes)

Pelvis (sizes)

Pelvis Distance (mm)

Distance across full pelvis (shown in orange)

ASIS Distance (mm)

Distance across ASIS (where the seatbelt goes, shown blue)

Pubis to ASIS Distance (mm)

Distance from pubis to ASIS (shown green)

Pubis to ASIS Angle (deg)

Angle between two green arrows

Pelvis Height (mm)

Height of pelvis (vertical arrow, shown grey)


Spinal Measures (angles & sizes)

Spinal Measures (angles & sizes)

Vertebral Depth (mm)

Distance from anterior vertebral body point to posterior vertebral body point.

Vertebral Height at the Spinal Canal (mm)

Distance from inferior spinal canal point to superior spinal canal point.

Vertebral Height at the Anterior of the Body (mm)

Distance from inferior anterior vertebral body point to superior anterior body point (inclusive of disc)

Angle Y WRT INFVB (deg)

Verteral angle (forward/backwards or flex/extension) with respect to the inferior vertebra (illustrated above)

Angle X WRT INFVB (deg)

Verteral angle (side-to-side) with respect to the inferior vertebra (not shown above, will be zero for a laterally symmetric spine)

Angle Y WRT YZ (deg)

Verteral "pose" (forward/backwards or flex/extension) with respect to the scanning table


Spinal Measures (cortical bone)

Spinal Measures (cortical bone)

Anterior Cortical Half-Maximum (HU)

HU level at half-max of the bone signal peak

Anterior Cortical Full-Width x Half-Maximum (HU*mm)

The "Full-width-multiplied-by-half-max" of the avg. cortical bone signal (Newman - 1998, Prevrhal - 1999)

Anterior Cortical Full-Width x Half-Maximum Standard Deviation (HU*mm)

Std. Dev. from all 60 "Full-width-by-half-max" measurements (at 1° increments in the 60° wedge)


Spinal Measures (trabecular bone)

Spinal Measures (trabecular bone)

Bone Mineral Density VB Aligned (HU)

Average pixel intensity (in CT Hounsfield Units) inside central bone core sample

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