Image Quality

When considering to upload a case to Vetlucent, image quality is important as to enable a good user experience. Poor image quality, including non-adherence to patient confidentiality, will prevent your case from being published on Vetlucent. As a general rule, screenshots and photographs of screens will not be accepted - there is a strong preference for digitally exported images from your PACS. 

Quality

Radiology is all about image quality and as such it is crucial for the site as a whole and for your online contributions to be of high quality. We are not all blessed with state-of-the-art hardware, but we can still optimize our image.

Before uploading an image please ensure that: 

1. the images have appropriate window/level/contrast/brightness

2. are of sufficient resolution (see below)

3. are appropriate for teaching (slice thickness, views, etc.) 

Supported formats

• JPG: small size but degraded by compression; use quality of 80 or above to minimize image degradation 

• PNG: non-lossy, reasonable size, the preferred format for diagrams, as edges and text will be crisp

• DICOM: lossless, an original image format that is the standard for storing and transmitting medical images

  • Uploading DICOM images to Vetlucent directly (with full client-side anonymization) is available as an opt-in beta feature in the user settings

Size

Vetlucent accepts (essentially) any size and then resizes it to serve up to viewers. Thus uploading a larger size, particularly native modality resolution is recommended.

Never (except for plain films and mammography) upload images that are smaller than the size acquired: 

• CT: 512 x 512 pixels (px)

• MRI: sequence-specific ranging from 128 to 1024 px

• x-ray: variable but generally larger than 1600 x 1600 px

• ultrasound: 512 x 512 px

• mammography: 2048 x 2048 px

• angiography (DSA): 1600 x 1600 px

If in doubt upload a larger image. We keep all the original images and optimize the images for display on browsers. 

Cross-sectional images should have a square or slightly rectangular collimation. Radiographs should be collimated to the appropriate area.

Frequently asked questions

Can I combine multiple images into one image?

No. In general please have only one image/slice/projection per image. This is especially the case for cross-sectional imaging.

The one exception (sometimes) is long/thin x-rays (e.g. limbs) which can be better presented as side by side views. 

What image preparation software should I use?

A number of tools are useful to make sure your images are the best they can be (for Vetlucent and for publication).

Image editing software

• Adobe Photoshop

  • not-free... not even close

  • the 'gold standard' of photo editing software

  • (Windows and Mac)

• Krita

  • opensource Photoshop-like

  • krita.org/ (Windows, Linux and Mac) 

• Gimp

  • opensource alternative to photoshop

  • gimp.org/ (Windows, Linux and Mac) 

• Irfan viewer

  • free

  • powerful image converted (great for batch processing images)

  • http://www.irfanview.com/ (Windows only)

DICOM viewer and editor

• Horos

  • Free, open source DICOM viewer

  • Can be used to create and organize your own teaching library

  • Powerful DICOM editing tools and many export options 

  • horosproject.org (Mac)

Online image editing software

If you do not want to install software on the computer you are using you can use online browser-based programs of which there are dozens.

• Phixr.com

  • free

  • lets you crop and convert to greyscale

  • http://www.phixr.com

Tips for taking photos of printed film?

Taking photos of printed film is tricky, and generally discouraged. Some historical films are worth preserving and with a little practice, reasonable results can be obtained.

General tips

• camera settings

  • black/white (you can convert to greyscale later too)

  • macro

  • high-quality jpg (90 or 100)

    • you can convert .raw or .tiff image types to .png, but this is of limited utility as jpg image degradation is not the quality limiting step

• tripod ideal

Common problems

• glare from next to the film is horrible so you need to mask it out

  • for CT/MR which are the standard size a hole cut in card works fine

  • for odd shapes need to be more inventive

• reflections may not be apparent until you look at the image, so a pitch-black room except for the lightbox is best, and even then you may see a reflection of yourself

• autofocus often does not work (fluffy images) so focusing on a sheet of paper with lines drawn on it placed in front of the film works well; alternatively set your focus to the central dot, and aim initially at the patient demographics (remember to exclude these or edit them out later)

• it can be really hard to replicate a nice flat image when there is dense bone (when the film is completely transparent you get a lot of glare and can't see the rest)