Da. Clunie et al., DETECTION OF DISCRETE WHITE-MATTER LESIONS AFTER IRREVERSIBLE COMPRESSION OF MR-IMAGES, American journal of neuroradiology, 16(7), 1995, pp. 1435-1440
Citations number
12
Categorie Soggetti
Neurosciences,"Radiology,Nuclear Medicine & Medical Imaging
PURPOSE: To validate the use of techniques of irreversible compression
of images, which can be performed using a block-based discrete cosine
transform technique as defined by the Joint Photographic Experts Grou
p, before they can be used in clinical applications, by evaluating the
effect of compression on the ability of observers to detect discrete
white matter lesions on MR images of the brain, METHODS: Sixty T2- and
intermediate-weighted spin-echo images were compressed with varying d
egrees of coefficient quantization with compression ratios from 1:1 to
more than 40:1, randomized, and evaluated by three observers blinded
to the degree of compression. RESULTS: No significant difference in th
e number of lesions detected was apparent until compression ratios rea
ched 40:1, despite a significant subjective loss in perceived image qu
ality at 20:1, Only small (less than or equal to 5-mm) lesions were mi
ssed at the highest degree of compression. No significant differences
were observed in the detection of confluent periventricular white matt
er disease at any degree of compression tested. CONCLUSIONS: The use o
f high degrees of irreversible compression of MR images may be accepta
ble for diagnostic tasks.