Window Dicom Element Freezes Webpage On iOS Devices (Blazor)

[allanhitch]

When displaying any dicom our webpage becomes unresponsive on all iOS devices (tested with an iPad10 and iPhone14pro) until the popup is closed. The viewer is responsive on android and desktop devices. This is being rendered on a Blazor window popup.

Code to display the dicom:

<div id="@($"dwv:{_fileName}{Index}")">
    <div id='layerGroup0'></div>
</div>

JS Invoke call:

var stream = new DotNetStreamReference(await response.Content.ReadAsStreamAsync());
await JS.InvokeVoidAsync("loadDicomFile", $"dwv:{_fileName}{Index}", stream);

loadDicomFile JS:

const arrayBuffer = await contentStreamRef.arrayBuffer();
const app = new dwv.App();

const viewConfig0 = new dwv.ViewConfig('layerGroup0');
const viewConfigs = { '*': [viewConfig0] };

const options = new dwv.AppOptions(viewConfigs);
options.tools = { WindowLevel: new dwv.ToolConfig() };

app.init(options);

app.addEventListener('load', function () {
    app.setTool('WindowLevel');
});

app.loadImageObject([{ name: "", filename: "", data: arrayBuffer }]);

[allanhitch]

• Using .Net 8

• Blazor

• DevExpress controls

• Seeing high CPU usage on PC when using any browser.

• Spikes from 1-3% to ~20% CPU usage for the tab when opening the windowed Dicom.

• Spike in CPU only starts once mouse click and drag to adjust contrast and opacity begins.

• CPU usage drops back to normal range once user stops adjusting

• Theory is the mobile/tablet devices can't handle the spike in resource usage.

• Similar popup windows do not spike CPU usage

[ivmartel]

Windowing can be costly, it gets worse with large data (high number of columns and rows). What size is the data you are loading? I mainly use Firefox and Chrome, it's been some time I did not test with Safari or Edge.

[allanhitch]

I just tested Firefox on the iPhone with the same results. The DCM files are all around 8-9 MB in size.