diff --git a/js/main.js b/js/main.js
index e630fa1..f64e988 100644
--- a/js/main.js
+++ b/js/main.js
@@ -270,6 +270,7 @@ function loadPacketFromAjax(path) {
   })
     .done(function (data) {
       //setUpPacket(data, path.split("/").pop());
+      if (data.hasOwnProperty("cached") && data["cached"]) { console.log("loading cached packet")}
       setUpPacket(data, path);
       $("#options-panel").hide();
     })
@@ -378,6 +379,8 @@ cornerstoneWebImageLoader.external.cornerstone = cornerstone;
 
 cornerstoneWADOImageLoader.external.cornerstone = cornerstone;
 
+cornerstone.imageCache.setMaximumSizeBytes(52428800)
+
 // cornerstoneWADOImageLoader.configure({
 //  beforeSend: function(xhr) {
 //    // Add custom headers here (e.g. auth tokens)
@@ -462,6 +465,8 @@ function setUpPacket(data, path) {
         question_total
       );
 
+      if (question_json.hasOwnProperty("cached") && question_json["cached"]) { console.log("loading cached packet")}
+
       //requests.push(request)
       //request_numbers.push(n)
       data["questions"][n] = question_json;
@@ -644,6 +649,13 @@ function loadQuestion(n, section = 1, force_reload = false) {
     $(".canvas-panel").remove();
   }
 
+  // disable any further enabled elements
+  cornerstone.getEnabledElements().forEach((el) => {
+    cornerstone.disable(el.element);
+  })
+
+  cornerstone.imageCache.purgeCache();
+
   // Remove feedback images
   $(".feedback-image").remove();
 
@@ -656,6 +668,7 @@ function loadQuestion(n, section = 1, force_reload = false) {
     // TODO: figure captions (need to extend base json)
 
     current_question.images.forEach(function createThumbnail(image, id) {
+      console.log("create thumb", image);
       // For thumbnails we only want a single image
       if (Array.isArray(image)) {
         image = image[0]; // Do we want the middle image?
@@ -2018,5 +2031,3 @@ function saveSession() {
 
 window.saveSession = saveSession;
 
-// Register Key Event Listener
-window.addEventListener("keydown", viewer.keydown_handler);
diff --git a/js/viewer.js b/js/viewer.js
index fb46d44..fcda19c 100644
--- a/js/viewer.js
+++ b/js/viewer.js
@@ -44,6 +44,8 @@ export function loadMainImage(image, stack) {
   cornerstoneTools.setToolActive("Pan", { mouseButtonMask: 1 });
   cornerstoneTools.setToolEnabled("ArrowAnnotate");
 
+  //cornerstoneTools.keyboardInput.enable(element);
+
   element.addEventListener("cornerstoneimagerendered", onImageRendered);
 
   setDicomCanvasNonFullscreen(element);
@@ -78,6 +80,10 @@ export function loadMainImage(image, stack) {
     .addEventListener("change", function () {
       changeControlSelection();
     });
+
+
+  // Register Key Event Listener
+  document.addEventListener("keydown", keydown_handler);
 }
 
 /**
@@ -202,9 +208,6 @@ export function manualScrollDicom(n) {
   let dicom_element = document.getElementById("dicom-image");
   let c = cornerstone.getEnabledElement(dicom_element);
 
-  // Cancel if no active element
-  if (el == undefined) { return }
-
   let max = c.toolStateManager.toolState.stack.data[0].imageIds.length;
 
   if (max < 2) {
@@ -356,8 +359,13 @@ export function changeControlSelection() {
  * @param {*} event - KeyEvent
  */
 export function keydown_handler(event) {
+  console.log(event);
   const target_element = event.target.tagName;
 
+  // Cancel if no active element
+  let dicom_element = document.getElementById("dicom-image");
+  if (dicom_element == undefined) { return }
+
   // Catch all keypresses unless user is typing
   if (target_element == "INPUT" || target_element == "TEXTAREA") {
     return;