in the article entitled use of a thin - section archive and enterprise 3d software for long - term storage of thin - slice ct datasets in a previous issue of the journal of digital imaging,1 the authors describe their view of a set - up in which a separate thin - section archive is located at the 3-dimensional server .
the crippling effect on current picture archiving and communication system ( pacs ) of the vast increase of data produced by the latest generation computed tomography ( ct ) devices is one of their major concerns .
they state that many institutions were forced to devise strategies for handling thin - slice ct data besides their normal data flow . in their solution
they also use this concept and only store the thin - slice data on a separate server with limited storage capacity .
the phased introduction of thin - slice ct data the authors propose is very interesting and provides a sound solution . at the university medical center groningen ,
groningen in the netherlands , an approach has been adopted from the start right after the first multidetector ct ( mdct ) was placed including one large pacs containing all data including the thin - slice ct data sets , a fully integrated 3d - server - based rendering system , and an enterprise webserver containing limited and nonpermanent data .
this shows that phase 3 as stated by meenan et al.1 could very well be the first step when one is able to employ the right tools .
in one step , we went to full usage and storage of all available thin - slice data from our ct systems , which would correspond with phase 3 as proposed by meenan et al.1 this means that every image acquired and reconstructed is actually stored on the pacs for review including all thin slices .
currently , a rox5 picture archiving and communication system ( pacs ) ( rogan delft , veenendaal , the netherlands ) is installed at our department .
this is an everything on - line ( eol ) pacs with 21 tb of harddisk storage and 20 tb of near - line backup storage on two dvd jukeboxes .
remaining dvds are now stored off - line , but transition to ultra density optical ( udo ) disks will be made soon providing a fully available near - line storage again .
the eol concept provides all data , including thin slices , on the direct available storage of the pacs .
the near - line storage on dvd is purely for backup and security reasons and will not be accessed for retrieval in normal working conditions of the pacs .
our 3d server is an aquariusnet server ( tera - recon , san mateo , ca ) with 0.7 tb of storage and two volpro rendering boards and allows the 3d rendering of a maximum of 3,500 ct slices at once . for distribution of patient image data throughout the hospital ,
an enterprise webserver is installed ( web-1000 , agfa , belgium ) with a short - term storage of 2 tb .
all ct modalities are configured such that they automatically reconstruct and store both thin - slice and thick - slice data sets and push them to the pacs .
our router ( rogrouter , rogan delft , veenendaal , the netherlands ) will automatically route the incoming data to different locations such as the institutional webserver .
only a series of less than 300 slices are stored in the institutional webserver , whereas all data , including thin - slices , are sent to the pacs ( fig .  1 ) . 

fig  1data acquired by the ct scanner , including thin slices , are sent to the pacs through the router .
all data are stored in the pacs and the near - line backup dvd . through the aquariusnet ,
the institution - wide webserver only receives series below the threshold of 300 images per series .
data acquired by the ct scanner , including thin slices , are sent to the pacs through the router .
all data are stored in the pacs and the near - line backup dvd . through the aquariusnet ,
the institution - wide webserver only receives series below the threshold of 300 images per series .
our pacs viewer ( hyperview pro , rogan delft , veenendaal , the netherlands ) is a basic viewer , which has only functionality to visualize and manipulate images , either acquired or reconstructed results ( secondary captures ) .
the thin - client post processing software used for integration into the radiological work stations is called aquariusnet ( terarecon , san mateo , ca ) .
this is a commercially available , server - based solution , which brings interactive 3d rendering and manipulation to the physician s desktop without the requirement of specialized hardware .
the rendering is performed on the processing server : all data remain at the server ( no transmission of large data sets throughout the hospital ) and only the rendered and  manipulated  images are displayed in the client software at the radiological work station ( fig .  2 ) .
the central server can be managed and controlled locally through a secure , password protected webpage .
after login to the server webpage , full control of the system is possible , even allowing a remote restart of the entire system . 

the pacs viewer is used to access images , which are retrieved to the work station from the pacs using digital imaging and communication in medicine ( dicom ) query / retrieve .
the thin - client postprocessing software thin - client application provides series information and user commands to the thin - client postprocessing software server , which actively queries the pacs and renders the data .
only resulting images are transferred to the work station and results can be stored into the pacs as dicom secondary capture .
the interaction between the pacs viewer and the thin - client postprocessing software thin - client application is established and information about the series , which should be retrieved , is communicated .
the pacs viewer is used to access images , which are retrieved to the work station from the pacs using digital imaging and communication in medicine ( dicom ) query / retrieve .
the thin - client postprocessing software thin - client application provides series information and user commands to the thin - client postprocessing software server , which actively queries the pacs and renders the data .
only resulting images are transferred to the work station and results can be stored into the pacs as dicom secondary capture .
the interaction between the pacs viewer and the thin - client postprocessing software thin - client application is established and information about the series , which should be retrieved , is communicated .
the integration of the standard pacs viewer and the thin - client post processing viewer was developed using a simple executable call from within the pacs viewer . with this call ,
the instanceuid of the current series displayed in the pacs viewer is transmitted to the thin - client postprocessing viewer after which the same series is actively requested by the thin - client post processing viewer from the pacs through the post processing server ( fig .  2 ) .
all integrations were established by the vendors of our pacs ( rogandelft , veenendaal , the netherlands ) and the thin - client post processing software ( terarecon , san mateo , ca ) .
postprocessing results are not archived as a default , but upon request of the radiologist any image or image sequence can be stored in digital imaging and communication in medicine ( dicom ) secondary capture format into the pacs system ( fig .  2 ) .
the system was evaluated by presenting a small questionnaire to our ct and mr radiologists . in this questionnaire
the following questions were asked : 
 are you using aquariusnet?if yes , for which modality ( ct / mr ) and how often per day?has the use of aquariusnet increased the use of 3d in daily practice when compared with dedicated work stations in terms of 
 a lower threshold to use 3da higher frequency of 3d usedo you still use dedicated 3d work stations ? if yes , for what reason?which grade would you give on a 110 scale ( in which 1 is very bad and 10 is very good ) for 
 ease of usequality of images / rendering are you using aquariusnet ?
if yes , for which modality ( ct / mr ) and how often per day ? has the use of aquariusnet increased the use of 3d in daily practice when compared with dedicated work stations in terms of 
 a lower threshold to use 3da higher frequency of 3d use a lower threshold to use 3d a higher frequency of 3d use do you still use dedicated 3d work stations ?
which grade would you give on a 110 scale ( in which 1 is very bad and 10 is very good ) for 
 ease of usequality of images / rendering quality of images / rendering the results of the questionnaire were collected and evaluated using excel ( microsoft corporation , redmond , wa , usa ) .
our pacs viewer ( hyperview pro , rogan delft , veenendaal , the netherlands ) is a basic viewer , which has only functionality to visualize and manipulate images , either acquired or reconstructed results ( secondary captures ) .
the thin - client post processing software used for integration into the radiological work stations is called aquariusnet ( terarecon , san mateo , ca ) . this is a commercially available , server - based solution , which brings interactive 3d rendering and manipulation to the physician s desktop without the requirement of specialized hardware .
the rendering is performed on the processing server : all data remain at the server ( no transmission of large data sets throughout the hospital ) and only the rendered and  manipulated  images are displayed in the client software at the radiological work station ( fig .  2 ) .
the central server can be managed and controlled locally through a secure , password protected webpage .
after login to the server webpage , full control of the system is possible , even allowing a remote restart of the entire system . 

the pacs viewer is used to access images , which are retrieved to the work station from the pacs using digital imaging and communication in medicine ( dicom ) query / retrieve .
the thin - client postprocessing software thin - client application provides series information and user commands to the thin - client postprocessing software server , which actively queries the pacs and renders the data .
only resulting images are transferred to the work station and results can be stored into the pacs as dicom secondary capture .
the interaction between the pacs viewer and the thin - client postprocessing software thin - client application is established and information about the series , which should be retrieved , is communicated .
the pacs viewer is used to access images , which are retrieved to the work station from the pacs using digital imaging and communication in medicine ( dicom ) query / retrieve .
the thin - client postprocessing software thin - client application provides series information and user commands to the thin - client postprocessing software server , which actively queries the pacs and renders the data .
only resulting images are transferred to the work station and results can be stored into the pacs as dicom secondary capture .
the interaction between the pacs viewer and the thin - client postprocessing software thin - client application is established and information about the series , which should be retrieved , is communicated .
the integration of the standard pacs viewer and the thin - client post processing viewer was developed using a simple executable call from within the pacs viewer . with this call ,
the instanceuid of the current series displayed in the pacs viewer is transmitted to the thin - client postprocessing viewer after which the same series is actively requested by the thin - client post processing viewer from the pacs through the post processing server ( fig .  2 ) .
all integrations were established by the vendors of our pacs ( rogandelft , veenendaal , the netherlands ) and the thin - client post processing software ( terarecon , san mateo , ca ) .
postprocessing results are not archived as a default , but upon request of the radiologist any image or image sequence can be stored in digital imaging and communication in medicine ( dicom ) secondary capture format into the pacs system ( fig . 
the system was evaluated by presenting a small questionnaire to our ct and mr radiologists . in this questionnaire
the following questions were asked : 
 are you using aquariusnet?if yes , for which modality ( ct / mr ) and how often per day?has the use of aquariusnet increased the use of 3d in daily practice when compared with dedicated work stations in terms of 
 a lower threshold to use 3da higher frequency of 3d usedo you still use dedicated 3d work stations ? if yes , for what reason?which grade would you give on a 110 scale ( in which 1 is very bad and 10 is very good ) for 
 ease of usequality of images / rendering are you using aquariusnet ? if yes , for which modality ( ct / mr ) and how often per day ? has the use of aquariusnet increased the use of 3d in daily practice when compared with dedicated work stations in terms of 
 a lower threshold to use 3da higher frequency of 3d use a lower threshold to use 3d a higher frequency of 3d use do you still use dedicated 3d work stations ?
which grade would you give on a 110 scale ( in which 1 is very bad and 10 is very good ) for 
 ease of usequality of images / rendering quality of images / rendering the results of the questionnaire were collected and evaluated using excel ( microsoft corporation , redmond , wa , usa ) .
the thin - client postprocessing software s rendering capabilities are used by our radiologists both for magnetic resonance imaging ( mri ) and ct .
after the patient data acquisition is complete , the study is available on the main pacs archive within minutes .
the radiologist selects the series , which should be viewed in the thin - client postprocessing software viewer in the pacs viewer window and ( simply ) presses the thin - client postprocessing software button .
hereafter , the data are actively requested by the thin - client postprocessing software server from the pacs and transferred . within a very short time
( if available on the thin - client postprocessing software server < 2  sec ; if retrieved from the pacs < 2  min ) the default 3d rendering and multi planar reformation ( mpr ) is displayed for the selected data set .
of these , 92% ( n  =  12 ) uses the postprocessing capabilities frequently and 8% ( n  =  1 ) uses it every now and then .
most respondents use it for ct only ( 69% ) , whereas the others use it for both ct and mr ( 31% ) .
the mean of the usage results is 12 times per day , in which five of the respondents indicate that they use it for every ct study they read .
according to 92% ( n  =  12 ) of the respondents , the threshold for using 3d is graded lower and the frequency of use higher compared to using dedicated 3d ( stand alone ) work stations .
dedicated 3d work stations are still used frequently by 38% ( n  =  5 ) , rarely by 15% ( n  =  2 ) , and never by 46% ( n  =  6 ) .
the main reason for using a dedicated 3d work station is to apply more specialized software packages ( eg , mr mammography evaluation ) or to use more enhanced capabilities ( eg , better and more automated segmentation algorithms ) .
both the ease of use and the 3d quality of the thin - client post processing software were graded very high at 8 out of 10 .
in the background portion , meenan et al.1 pose a number of challenges of clinical use of thin - slice data sets .
first , the storage space required and cost - effective storage are mentioned . in our experience ,
the storage of all data is easily possible as long as you are capable of purchasing your storage space cost - effectively without high markup of the pacs vendor because of the dedicated use of the storage space .
these requirements are high , but by having a dedicated radiology network segment with a 1-gb / s network speed the storage of the data and review within radiology is not a problem . for 3d processing , the use of a thin - client solution effectively decreases the required network bandwidth and the limitation to series with a maximum of 300 slices of the forward to the enterprise web - server further decreases the required bandwidth outside radiology .
furthermore , the transition of pacs viewers from thick to thin client solutions using wavelet compression techniques will further decrease the bandwidth requirements .
the advantage of using one pacs storage system that includes all available data with a dedicated and fast network eliminates the requirement for workflow strategies .
the value of applying 3d rendering techniques to ct and mri data has been described frequently . although discussion has started on the integration of these techniques into the normal workflow , the main drawback of most current implementations remains that the rendering is performed on dedicated , stand alone , 3d work stations . especially with the arrival of digital reporting , rendering must be integrated into the normal radiological workflow .
using this set - up , the availability of thin - slice data sets is transparent to the users .
because all data are stored in one archive permanently and readily available everywhere , only one work station is required for both normal pacs viewing and advanced 3d viewing , and workflow strategies do not have to be implemented .
 current developments in storage solutions , pacs , and client - server systems allow for 3d imaging at the desktop . this can be achieved together with full storage into pacs of all slices , including the very large thin - section ct datasets . 
 this paper describes a possible setup , which has been in operation for several years now , in response to an article by meenan et al . 
 previously published in this journal ( 1 ) . 
INTRODUCTION
OUR CURRENT SETUP
PACS Viewer
Post Processing Software Package
Usage Evaluation
RESULTS
DISCUSSION
CONCLUSION