diff --git a/.env b/.env
index 23a96aa..9b6f2c9 100644
--- a/.env
+++ b/.env
@@ -24,12 +24,15 @@ IDENTIFIERFIELD=IDSTUDY
 
 # ImViewer4
 # Si es 1, se usa imViewer4, si es 0 se usa el viewer viejo
-imViewer4=0
+imViewer4=1
 # Si usa ImViewer4, se debe agregar el dominio sin https://
 # Ejemplo: imViewer4_host=informesmedicos.apross.gov.ar
-# imViewer4_host=informesmedicos.apross.gov.ar
+imViewer4_host=informesmedicos.apross.gov.ar
 # Si usa ImViewer4, se debe agregar el uid del cliente
-# imViewer4_uid=aab2741a-6b94-4c72-ad29-bf0ca8e492f7
+imViewer4_uid=aab2741a-6b94-4c72-ad29-bf0ca8e492f7
+# Si usa ImViewer4, se debe agregar el gethash
+# Ejemplo: imViewer4_gethash=https://informesmedicos.apross.gov.ar
+imViewer4_gethash=https://informesmedicos.apross.gov.ar/viewer_api/gethash/
 
 # Datos SMTP/Mailer
 #SMTP_USER=informes@ciem.com.ar
diff --git a/lib/api_web/live/index_live.ex b/lib/api_web/live/index_live.ex
index c0d173b..c4cf447 100644
--- a/lib/api_web/live/index_live.ex
+++ b/lib/api_web/live/index_live.ex
@@ -28,6 +28,7 @@ defmodule ApiWeb.IndexLive do
       |> assign(logo: Envar.get("LOGO"))
       |> assign(logo_sm: Envar.get("LOGO_SM"))
       |> assign(idstudyfield: idstudyfield)
+      |> assign(idstudy: nil)
     {:ok, socket}
   end
 
@@ -175,36 +176,6 @@ defmodule ApiWeb.IndexLive do
     token
   end
 
-
-  def generate_token_imv4(studyidentifier_type, studyidentifier, username) do
-    idstudy = if studyidentifier_type == "IDSTUDY" do
-      # El tipo es IDSTUDY
-      studyidentifier
-    else
-      # El tipo es ACCESSIONNUMBER
-      query = from s in "study",
-        where: s.accessionnumber == ^studyidentifier,
-        select: s.idstudy
-
-      case Repo.one(query) do
-        nil -> {:error, "No se encontró idstudy para el acccessionnumer: #{studyidentifier}"}
-        idstudy -> Logger.info("idstudy encontrado: #{idstudy}")
-      end
-    end
-
-    json =  %{
-      idstudy: Integer.to_string(idstudy),
-      username: username,
-      vencimiento: DateTime.add(DateTime.utc_now(), 2 * 24 * 60 * 60, :second)
-    }
-
-    json_string_64 = Jason.encode!(json) |> Base.encode64()
-    query_json = "select encrypt('#{json_string_64}'::bytea, '1nf0rm3', 'aes')::text"
-    token = Repo.query!(query_json).rows |> hd() |> hd()
-    token = String.replace_prefix(token, "\\x", "")
-    token
-  end
-
   def open_viewer(idstudy, accessionnumber, patientid, assigns) do
     Envar.load(".env")
     Envar.require_env_file(".env")
@@ -212,6 +183,7 @@ defmodule ApiWeb.IndexLive do
     viewer = Envar.get("imViewer4")
     viewer_host = Envar.get("imViewer4_host")
     viewer_uid = Envar.get("imViewer4_uid")
+    gethash = Envar.get("imViewer4_gethash")
 
     studyidentifier = if studyidentifier_ed == "IDSTUDY" do
       idstudy
@@ -226,14 +198,51 @@ defmodule ApiWeb.IndexLive do
         },
         limit: 1
 
-    username = Repo.one(query)
-
+    viewer_config = %{
+        client_uuid: viewer_uid,
+        gethash: gethash,
+        imviewer4_domain: viewer_host
+    }
     case viewer do
-      "1" -> "https://#{viewer_host}/imviewer4/viewer/#{viewer_uid}/#{generate_token_imv4(studyidentifier_ed, studyidentifier, username)}"
+      "1" ->
+        case open_imviewer4(viewer_config, studyidentifier, 172800, assigns) do
+          {:ok, hash} ->
+            "https://#{viewer_host}/imviewer4/viewer/#{viewer_uid}/#{hash}"
+
+          {:error, reason} ->
+            Logger.error("No se pudo obtener el hash para ImViewer4: #{inspect(reason)}")
+        end
       "0" -> "https://estudio.informemedico.com.ar/#/#{assigns.idsite}/#{generate_token(studyidentifier_ed, studyidentifier, patientid)}"
     end
   end
 
+  def open_imviewer4(v, access_study, expiration, assigns) do
+    url = v.gethash <> v.client_uuid
+    if access_study == assigns.idstudy do
+      case Req.post(url, json: %{"idstudy" => access_study, "expiration"  => expiration}) do
+        {:ok, %Req.Response{status: 200, body: %{"hash" => hash}}} ->
+          {:ok, hash}
+
+        {:ok, %Req.Response{status: status, body: body}} ->
+          {:error, {:unexpected_response, status, body}}
+
+        {:error, reason} ->
+          {:error, {:request_failed, reason}}
+      end
+    else
+      case Req.post(url, json: %{"accessionnumber" => access_study, "expiration"  => expiration}) do
+        {:ok, %Req.Response{status: 200, body: %{"hash" => hash}}} ->
+          {:ok, hash}
+
+        {:ok, %Req.Response{status: status, body: body}} ->
+          {:error, {:unexpected_response, status, body}}
+
+        {:error, reason} ->
+          {:error, {:request_failed, reason}}
+      end
+    end
+  end
+
   def render(assigns) do
     ~H"""
     <body class="m-0 p-0 bg-[rgb(228, 228, 228)]">