Rewriting human surface anatomy using crosssectional imaging.

Accurate surface anatomy and awareness of variations are essential for safe clinical practice. Our knowledge of surface anatomy is largely derived from cadaver studies. Numerous inconsistencies in clinically important surface markings exist between and within anatomical reference texts. The aim of this study was to reassess clinically important surface landmarks in vivo using modern imaging techniques. Patients with pathology were excluded. 50 healthy volunteers (mean age 37 years) underwent ultrasound scans. 52 CT scans of the neck (mean age 63 years), 153 thoracic CT scans (mean age 63 years), 52 thoracoabdominal CT scans (mean age 61 years), 108 abdominal CT scans (mean age 60 years), and 45 MR scans of the head (mean age 56 years) were analyzed. All scans were from supine adults with a standardized position. Some surface landmarks in contemporary anatomical reference texts accurately reflect in vivo findings (e.g. cardiac apex). In contrast, others are inaccurate and unreliable (e.g. central sulcus, spleen, kidneys). Whilst the surface anatomy of some structures are accurately described in modern texts, others are inaccurate and must be revised using modern imaging techniques in living subjects. Potential variations associated with ethnicity and other variables need further exploration.