I won't pretend to be an expert in DICOM - Digital Imaging and Communications in Medicine. But I do know that the Oracle Multimedia team are experts in this field, and they recently released a new packaged application which demonstrates the use of DICOM Medical Image Support in the Oracle Database 11g, all from within an Application Express application. This just further illustrates my point that Oracle Application Express, instead of insulating you from the database via multiple layers and stacks and tiers, enables you to readily exploit the native functionality of the Oracle Database, like Oracle Multimedia and the DICOM features.
From Melli, the Oracle Multimedia Product Manager:
The DICOM sample application shows how the database can be used to store and manage DICOM medical images and illustrates how quickly Oracle technology (DICOM functionality and Application Express) can be used to build an archive to manage medical images. With this archive application, clinicians can easily browse the images, share images with other clinicians, and search images.
The DICOM sample application is demonstrated in a browser. Because a DICOM viewer is not available, full-size JPEG images and JPEG thumbnail images are created using Oracle Multimedia DICOM features. These images are stored in a main archive table, along with the original DICOM images. Additionally, all the meta data from the DICOM images is extracted from the DICOM images to enable searching based on DICOM meta data.
The DICOM Image Archive Demonstration application can be downloaded from the Oracle Application Express Packaged Applications. You can also preview the DICOM Image Archive Demonstration as well as the DICOM Image Archive Administration applications, all running on (you guessed it) apex.oracle.com.