MRI units, CT scanners

Remarks

MRI is an imaging technique designed to visualize internal structures of the body. MRI is based on the principles of NMR, a spectroscopic technique used by scientists to obtain microscopic chemical and physical information about molecules. As the human body consists primarily of fat and water, it is affluent with hydrogen atoms. Hydrogen nuclei contain a single proton, which possesses a property called spin. The spin can be thought of as a small magnetic field, causing the nucleus to produce an NMR signal. The visualization of the internal structures of the body is made using these magnetic and electromagnetic fields which induce a resonance effect of hydrogen atoms. The electromagnetic emission created by these atoms is registered and processed by a dedicated computer to produce the images of the body structures.

The data shown in the above presentation was retrieved from OECD Health Data. The OECD aims to collect aggregate data on the availability of medical equipments in all health care facilities, including the hospital sector and the ambulatory sector.

When interpreting the above figure, the following comparability limitations should be taken into account. The 2005 increase in the numbers of MRI units in Greece is due to the partial recording of medical equipment in the private sector prior to 2005. The figure recorded for the Netherlands for 2005 represents the number of hospitals reporting to have an MRI unit. Figures of medical technology in Slovakia were recalculated according to the OECD recommendation and definition. Figures were recalculated according to the revision of data within the register in 2003. Therefore the data are submitted only for the period 2003 – 2005. In Spain the data relate only to devices available in hospitals, they do not include equipment in other health care facilities. Therefore, the numbers presented for this country may be under-estimated. The data shown for the United Kingdom might be influenced by the changes to the reported area: prior to 2002 the reported area only included England; in 2002 and 2003 it included all of Great Britain; in 2004, 2005, 2006 it included the United Kingdom. For more detailed information about the sources and methods used see OECD Health Data.

Remarks

A CT or CAT scanner is used to obtain two- or three-dimensional images of the internal organs and structures of the body. The three-dimensional image of the internal parts of an object is generated as a result of a large series of two-dimensional x-ray images that are taken around a single axis of rotation. A CT scanner is used as a diagnostic tool and as a guide for interventional procedures. In order to increase the quality of the image (especially with abdominal scans, imaging of soft tissues, blood vessels, and hollow body organs) a contrast material (e.g., barium sulphate) is sometimes used.

The data shown in the above presentation was retrieved from OECD Health Data. The OECD aims to collect aggregate data on the availability of medical equipment in all health care facilities, including the hospital sector and the ambulatory sector.

When interpreting the above figure, the following comparability limitations should be taken into account. The 2005 increase in the numbers of CT scanners in Greece is due to the partial recording of medical equipment in the private sector prior to 2005. The figure recorded for the Netherlands for 2005 represents the number of hospitals possessing a CT scanner. Figures of medical technology in Slovakia were recalculated according to the OECD recommendation and definition. Figures were recalculated according to the revision of data within the register in 2003. Therefore the data are submitted only for the period 2003 – 2005. In Spain the data relate only to devices available in hospitals, they do not include equipment in other health care facilities. Therefore, numbers can be under-estimated. The data shown for the United Kingdom might be influenced by changes to reported area: prior to 2002 the reported area only included England; in 2002 and 2003 it included all of Great Britain; in 2004, 2005, and 2006 it included the United Kingdom.. For more detailed information about the sources and methods used see OECD Health Data.