Perceived Sufficiency of Full-Field Digital Mammograms With and Without Irreversible Image Data Compression for Comparison with Next-Year Mammograms

Problems associated with the large file sizes of digital mammograms have impeded the integration of digital mammography with picture archiving and communications systems. Digital mammograms irreversibly compressed by the novel wavelet Access Over Network (AON) compression algorithm were compared with lossless-compressed digital mammograms in a blinded reader study to evaluate the perceived sufficiency of irreversibly compressed images for comparison with next-year mammograms. Fifteen radiologists compared the same 100 digital mammograms in three different comparison modes: lossless-compressed vs 20:1 irreversibly compressed images (mode 1), lossless-compressed vs 40:1 irreversibly compressed images (mode 2), and 20:1 irreversibly compressed images vs 40:1 irreversibly compressed images (mode 3). Compression levels were randomly assigned between monitors. For each mode, the less compressed of the two images was correctly identified no more frequently than would occur by chance if all images were identical in compression. Perceived sufficiency for comparison with next-year mammograms was achieved by 97.37% of the lossless-compressed images and 97.37% of the 20:1 irreversibly compressed images in mode 1, 97.67% of the lossless-compressed images and 97.67% of the 40:1 irreversibly compressed images in mode 2, and 99.33% of the 20:1 irreversibly compressed images and 99.19% of the 40:1 irreversibly compressed images in mode 3. In a random-effect analysis, the irreversibly compressed images were found to be noninferior to the lossless-compressed images. Digital mammograms irreversibly compressed by the wavelet AON compression algorithm were as frequently judged sufficient for comparison with next-year mammograms as lossless-compressed digital mammograms

Image toggling saves time in mammography

When two images are perfectly aligned, even subtle differences are readily detected when the images are "toggled" back and forth in the same location. However, substantial changes between two photographs can be missed if the images are misaligned ("change blindness"). Nevertheless, recent work from our lab, testing nonradiologists, suggests that toggling misaligned photographs leads to superior performance compared to side-by-side viewing (SBS). In order to determine if a benefit of toggling misaligned images may be observed in clinical mammography, we developed an image toggling technique where pairs of new and prior breast imaging exam images could be efficiently toggled back and forth. Twenty-three radiologists read 10 mammograms evenly divided in toggle and SBS modes. The toggle mode led to a 6-s benefit in reaching a decision [t(22)=5.11,

Computed Tomography-guided fine-needle aspiration and tissue-core biopsy of bone lesions in small animals

Nell'uomo, la biopsia TC-guidata a mano libera è un metodo accurato per ottenere dei campioni di tessuto. Ci sono pochi lavori di questa tecnica in medicina veterinaria. Nel presente studio, 21 cani e 2 gatti sono stati sottoposti a biopsia TC-guidata (17 animali) o ago aspirato fine TC-guidato (6 animali) di lesioni ossee. Due delle 17 biospie sono state anche sottoposta ad esame colturale. Tutte le 17 biospie erano diagnostiche (accuratezza 100%). Cinque dei sei aghi aspirati fini erano diagnostici (accuratezza 83.3%). L'accuratezza totale era 95.7%. In un aspirato, la qualità citologica è stata considerata insufficiente in quanto conteneva solo sangue. Non si sono evidenziate complicazioni maggiori. Sono state diagnosticate 14 lesioni neoplastiche, 2 infezioni, e 6 lesioni benigne. L'esame TC dopo somministrazione di mezzo di cotnrasto endovenoso ha aggiunto informazioni utili per evitare grossi vasi e per biopsare tessuto vitale. La bipsia e l'ago aspirato fine TC-guidati a mano libera sembra essere una tecnica sicura e molto accurata per la diagnosi di patologie ossee nei piccoli animaliIn humans, free-hand computed tomography (CT)-guided biopsy is an accurate method to obtain a tissue sample. There are only a few reports of this technique in veterinary medicine. In the present study, 21 dogs and two cats underwent a free-hand CT-guided tissue-core biopsy (17 animals) or fine-needle aspiration (six animals) of a bone lesion. Two out of 17 tissue-core samples were also cultured. All 17 tissue-core biopsy samples were diagnostic (accuracy of 100%). Five out of six aspirates were diagnostic (accuracy of 83.3%). The overall accuracy was 95.7%. In one aspirate, cytologic quality was insufficient containing only blood. No major complications were encountered. Fourteen neoplastic, two infectious and six benign lesions were diagnosed. CT examination after intravenous contrast medium added useful information to avoid large vessels and to biopsy-viable tissue. Free-hand CT-guided tissue-core biopsy and aspiration appears to be a safe and very accurate procedure for use in the diagnosis of bone-associated diseases in small animal