Nils Westermark

Biography

• Born 9 September 1892 in Stockholm, Sweden
• 1912 – Represented Sweden (silver medal) at the Fifth Olympic Games in Stockholm, sailing in the 8 metre class on Sans Atout (boat)
• 1919 – Graduated with MD degree from Karolinska Institutet Medical School, Sweden
• 1920-29 – Radiologist at Sabbatsbergs Hospital (1920-21); Karolinska Radium Hospital (1922-23); and St Eriks Hospital (1923-29)
• 1928-57 – Board member on the Swedish Society of Medical Radiology
• 1928-53 – Member of the Nordic Society of Medical Radiology
• 1930-57 – St. Göran’s Hospital
• 1930 – Awarded PhD in medicine (radiology)
• 1930 – Appointed Dozent (associate professor) at Karolinska Institutet
• 1930-57 – Radiologist at Saint Göran Hospital, Stockholm
• 1955 – Professor of radiology at Karolinska Institutet
• 1946 – Presented first Rigler lecture at the University of Minnesota
• Died 24 January 1980 in Stockholm, Sweden

Medical Eponyms

Westermark sign (1938)

Westermark sign describes chest x-ray findings in pulmonary embolism of a clarified area distal to a large vessel that is occluded by an embolus. The focal area of increased translucency (oligaemia), occurs due to impaired vascularisation of the lung from primary mechanical obstruction or reflex vasoconstriction.

Westermark identified these chest radiograph features after examining 28 cases of autopsy proven pulmonary embolism, and published his findings in a 1938 paper.

In embolism of the pulmonary artery without infarction we get ischaemia of the branches of the pulmonary artery on the peripheral side of the embolus. On the radiogram this ischaemia appears as a clarified area with diminished vascular design corresponding to the extent of the embolised artery. The vascularisation is however maintained in the central parts of the lung. The vascularisation takes however a rapid end to pass over into the above mentioned area of non-vascularisation.

Westermark 1938

This sign has been described to have 14% sensitivity; 92% specificity; 38% PPV; and 76% NPV (PIOPED 1993).

Major Publications

• Westermark N. On the roentgen diagnosis of lung embolism: brief review of the incidence, pathology and clinical symptoms of lung embolism. Acta Radiologica 1938; 19(4) :357-372. [Westermark sign
• Westermark N. On Tuberculosis of Bronchial Lymph-Glands: A Roentgenological Investigation. Acta Radiologica. 1940; 21(4): 399–422.
• Westermark N. A Simple Method of Localising Foreign Bodies. 1941; 22(4): 490-492.
• Westermark N. On epituberculosis and lung atelectasis. Acta Radiologica. 1941; 22(4): 501-510.

References

• Olympic Sailing: Nils Westermark. Sports-Reference.com
• Olympic Sailing: Nils Westermark. Olympic.org
• Maizlin ZV, Cooperberg PL, Clement JJ, Vos PM, Coblentz CL. People Behind Exclusive Eponyms of Radiologic Signs (Part II) Can Assoc Radiol J. 2010; 61(1): 44-53.
• Bibliography. Westermark, Nils Johan Hugo. WorldCat Identities
• Cadogan M. CXR eponyms in pulmonary embolism. LITFL