diff --git a/nibabel/_compression.py b/nibabel/_compression.py
index f697fa54c..871be2629 100644
--- a/nibabel/_compression.py
+++ b/nibabel/_compression.py
@@ -12,12 +12,13 @@
 
 import bz2
 import gzip
-import io
 import typing as ty
 
 from .optpkg import optional_package
 
 if ty.TYPE_CHECKING:
+    import io
+
     import indexed_gzip  # type: ignore[import]
     import pyzstd
 
diff --git a/nibabel/dataobj_images.py b/nibabel/dataobj_images.py
index 685059901..565a22879 100644
--- a/nibabel/dataobj_images.py
+++ b/nibabel/dataobj_images.py
@@ -14,14 +14,14 @@
 
 import numpy as np
 
-from .arrayproxy import ArrayLike
 from .deprecated import deprecate_with_version
 from .filebasedimages import FileBasedHeader, FileBasedImage
-from .fileholders import FileMap
 
 if ty.TYPE_CHECKING:
     import numpy.typing as npt
 
+    from .arrayproxy import ArrayLike
+    from .fileholders import FileMap
     from .filename_parser import FileSpec
 
 ArrayImgT = ty.TypeVar('ArrayImgT', bound='DataobjImage')
diff --git a/nibabel/fileholders.py b/nibabel/fileholders.py
index 3db4c62a9..df7c34af6 100644
--- a/nibabel/fileholders.py
+++ b/nibabel/fileholders.py
@@ -10,12 +10,14 @@
 
 from __future__ import annotations
 
-import io
 import typing as ty
 from copy import copy
 
 from .openers import ImageOpener
 
+if ty.TYPE_CHECKING:
+    import io
+
 
 class FileHolderError(Exception):
     pass
diff --git a/nibabel/imageclasses.py b/nibabel/imageclasses.py
index 20cf1cac9..66f984e26 100644
--- a/nibabel/imageclasses.py
+++ b/nibabel/imageclasses.py
@@ -10,11 +10,11 @@
 
 from __future__ import annotations
 
+from typing import TYPE_CHECKING
+
 from .analyze import AnalyzeImage
 from .brikhead import AFNIImage
 from .cifti2 import Cifti2Image
-from .dataobj_images import DataobjImage
-from .filebasedimages import FileBasedImage
 from .freesurfer import MGHImage
 from .gifti import GiftiImage
 from .minc1 import Minc1Image
@@ -25,6 +25,10 @@
 from .spm2analyze import Spm2AnalyzeImage
 from .spm99analyze import Spm99AnalyzeImage
 
+if TYPE_CHECKING:
+    from .dataobj_images import DataobjImage
+    from .filebasedimages import FileBasedImage
+
 # Ordered by the load/save priority.
 all_image_classes: list[type[FileBasedImage]] = [
     Nifti1Pair,
diff --git a/nibabel/optpkg.py b/nibabel/optpkg.py
index bfe6a629c..90b8ded51 100644
--- a/nibabel/optpkg.py
+++ b/nibabel/optpkg.py
@@ -3,12 +3,14 @@
 from __future__ import annotations
 
 import typing as ty
-from types import ModuleType
 
 from packaging.version import Version
 
 from .tripwire import TripWire
 
+if ty.TYPE_CHECKING:
+    from types import ModuleType
+
 
 def _check_pkg_version(min_version: str | Version) -> ty.Callable[[ModuleType], bool]:
     min_ver = Version(min_version) if isinstance(min_version, str) else min_version
diff --git a/nibabel/spatialimages.py b/nibabel/spatialimages.py
index f4d27791b..ce8ee3c6e 100644
--- a/nibabel/spatialimages.py
+++ b/nibabel/spatialimages.py
@@ -132,18 +132,14 @@
 
 from __future__ import annotations
 
-import io
 import typing as ty
-from collections.abc import Sequence
 from typing import Literal
 
 import numpy as np
 
-from .arrayproxy import ArrayLike
 from .casting import sctypes_aliases
 from .dataobj_images import DataobjImage
 from .filebasedimages import FileBasedHeader, FileBasedImage
-from .fileholders import FileMap
 from .fileslice import canonical_slicers
 from .orientations import apply_orientation, inv_ornt_aff
 from .viewers import OrthoSlicer3D
@@ -155,8 +151,14 @@
     from functools import lru_cache as cache
 
 if ty.TYPE_CHECKING:
+    import io
+    from collections.abc import Sequence
+
     import numpy.typing as npt
 
+    from .arrayproxy import ArrayLike
+    from .fileholders import FileMap
+
 SpatialImgT = ty.TypeVar('SpatialImgT', bound='SpatialImage')
 SpatialHdrT = ty.TypeVar('SpatialHdrT', bound='SpatialHeader')
 
diff --git a/nibabel/testing/__init__.py b/nibabel/testing/__init__.py
index 992ef2ead..be111747b 100644
--- a/nibabel/testing/__init__.py
+++ b/nibabel/testing/__init__.py
@@ -26,12 +26,13 @@
 from .helpers import assert_data_similar, bytesio_filemap, bytesio_round_trip
 from .np_features import memmap_after_ufunc
 
+if ty.TYPE_CHECKING:
+    from importlib.resources.abc import Traversable
+
 try:
     from importlib.resources import as_file, files
-    from importlib.resources.abc import Traversable
 except ImportError:  # PY38
     from importlib_resources import as_file, files
-    from importlib_resources.abc import Traversable
 
 
 def get_test_data(
diff --git a/nibabel/volumeutils.py b/nibabel/volumeutils.py
index c2387f094..6e43f7918 100644
--- a/nibabel/volumeutils.py
+++ b/nibabel/volumeutils.py
@@ -10,7 +10,6 @@
 
 from __future__ import annotations
 
-import io
 import sys
 import typing as ty
 import warnings
@@ -25,6 +24,8 @@
 from .externals.oset import OrderedSet
 
 if ty.TYPE_CHECKING:
+    import io
+
     import numpy.typing as npt
 
     Scalar = np.number | float
diff --git a/pyproject.toml b/pyproject.toml
index f7d116ea9..d45c4e19f 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -122,6 +122,7 @@ select = [
     "PLE",
     "Q",
     "RSE",
+    "TCH",
     "UP",
 ]
 ignore = [