update imports

Signed-off-by: Wenqi Li <[email protected]>

Author: wyli

model_zoo/TCIA_PROSTATEx_Prostate_MRI_Anatomy_Model.ipynb

@@ -113,10 +113,10 @@
     "#   which are critical to image processing and display.\n",
     "\n",
     "# installations required for monai\n",
-    "!{sys.executable} -m pip install --upgrade -q \"monai[nibabel,itk,tqdm,pandas,skimage]\"\n",
+    "!python -c \"import monai\" || pip install -q \"monai[nibabel,itk,tqdm,pandas,skimage]\"\n",
     "\n",
     "# These are the libraries used to read DICOM Seg objects.\n",
-    "!{sys.executable} -m pip install --upgrade -q pydicom pydicom-seg\n",
+    "!{sys.executable} -m pip install -q pydicom pydicom-seg\n",
     "\n",
     "# Install tcia_utils to download the datasets.\n",
     "!{sys.executable} -m pip install --upgrade -q tcia_utils\n",