Find a way to resolve System.OutOfMemoryException for In-memory cache c# web application

We have our c# web application which use in-memory to store data using multi threading, our application work till 14-15 days after that it start to throw OutOfMemoryException for thread and for reading cache due to which our application get crash we need to give hard reset to start application properly. I want a way to catch which cache code is taking large memory or cache is get created repeat for same or any other problem is causing this, below is some code which start to throws:
Thread

System.OutOfMemoryException: Exception of type 'System.OutOfMemoryException' was thrown. at System.Threading.Thread.StartInternal(IPrincipal principal, StackCrawlMark& stackMark) at System.Threading.Thread.Start(StackCrawlMark& stackMark) at System.Threading.Thread.Start()

Code snippet from where it is throwing above exception:

public void PreloadSavedCartsFor(LoggedInUser loggedinUser)
    {
        System.Web.HttpContext ctx = System.Web.HttpContext.Current;
        System.Threading.Thread preloadcustomercarts = new System.Threading.Thread(
            delegate()
            {
                System.Web.HttpContext.Current = ctx;
                try
                {
                    if (System.Web.HttpContext.Current != null && System.Web.HttpContext.Current.Session != null)
                    {
                        System.Web.HttpContext.Current.Session["SavedCarts"] = LoadCustomerSavedCarts(loggedinUser);
                    }
                }
                catch
                {
                    //TODO LOg Exception
                }
            });
        preloadcustomercarts.Start();
    }

System.OutOfMemoryException: Out of memory. at System.Drawing.Image.FromFile(String filename, Boolean useEmbeddedColorManagement) at ImageService.FileImageProvider.RetrieveImage(String name, Boolean checkCacheExpiration) in c:\Builds\22\ImageService\FileImageProvider.cs:line 215 at CreateResizedImageFromOriginalImage(String ImageName, String ImageDimension, String newsizename, String& returnName, String& contentType) in Store\Inetpub\wwwroot\ViewHelper\Product.cs:line 680

Below is code snippet we use to read and save image :
ImageService dll code:

public override Image RetrieveImage(string name, bool checkCacheExpiration = true)
    {
        lock (_Sync)
        {
            if (checkCacheExpiration ? Exists(name) : this.FileExists(name))
                return Image.FromFile(ResolvePath(name));
            else
                return null;
        }
    }

code from where above method is getting called :

private static void CreateResizedImageFromOriginalImage(string ImageName, string ImageDimension, string newsizename, ref string returnName, ref string contentType)
    {
        using (System.Drawing.Image originalImage = ImageService.RetrieveImage(ImageName, false))
        {
            if (originalImage != null)
            {
                contentType = ImageService.RetriveImageContentType(ImageName);
                System.IO.MemoryStream ms = new System.IO.MemoryStream();
                originalImage.Save(ms, originalImage.RawFormat);
                Byte[] data = ms.ToArray();

                // Create the stream of image & generate new image with specified width & height
                int imageheight = 0;
                int imagewidth = 0;
                if (!string.IsNullOrEmpty(ImageDimension.Split('X')[0]))
                    imagewidth = Convert.ToInt32(ImageDimension.Split('X')[0], System.Globalization.CultureInfo.InvariantCulture);
                if (!string.IsNullOrEmpty(ImageDimension.Split('X')[1]))
                    imageheight = Convert.ToInt32(ImageDimension.Split('X')[1], System.Globalization.CultureInfo.InvariantCulture);

                byte[] newdata = ImageGenerator.CreateImageThumbnail(data, contentType, imageheight, imagewidth, false);

                if (newdata.Length > 0)
                {
                    ImageService.SaveImage(newsizename, newdata, contentType);
                    returnName = ImageService.RetrieveImageUrl(newsizename);
                }
            }
        }
    }

We have written FromFile method in using, so object of FromFile will get dispose after use.

Can anyone tell me if this error occur how to handle it so it should not break our application and way to find reason behind start throwing this error.

Thanks,
Sandy