The purpose of this study was to determine if the size of ultrasound examinations was increasing over time.
The primary reasons for this are believed to be an increased number of images per study, the incorporation of "cine
loops", and increased use of color flow Doppler. The result of this study, if it supports the hypothesis that ultrasound
study size is increasing, would be directly applicable to planning for future expansion of storage in the Ultrasound
PACS. Data were obtained from the ultrasound PACS server for number of studies, number of images, and total
stored volume for sampled months (January and July of 2003 - 2006). The investigators believed that these months
would provide a reasonable sample of study size as examination types did not vary significantly from month to month
(based on Departmental statistics). The Radiology Department's information system (RIS) was used to determine total
yearly ultrasound examination volume to determine the trend over time. Because no protected health information (PHI)
was to be used in this study, the investigators believed that no IRB approval was necessary. The number of studies done per month was more variable than the investigators had believed. One month in
particular (July, 2003) had an anomalously large number of studies. However, despite this, computations of the number
of images per study, the total data volume per study, and the average amount of data per image did show an increasing
trend as expected. Also, the total volume of data stored showed an increasing trend over the study time period. The
investigators' hypothesis that examination size is increasing has been demonstrated to be true for the months sampled. From Departmental data, the investigators know that the most recent ultrasound yearly volume
increased approximately ten percent over the previous year, and that trend was also seen for the study period (from 7-10
percent per year increase in volume). With the information that the examination size is also increasing, the Department
can make better plans for future expansion of the Ultrasound PACS storage system. Ultrasound examination size is increasing, largely because of the increased use of cine loops. A change to
using more of these to replace single static images will further increase examination size.
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