diff --git a/celldetection_scripts/cpn_inference.py b/celldetection_scripts/cpn_inference.py
index c7b9aea..6313843 100644
--- a/celldetection_scripts/cpn_inference.py
+++ b/celldetection_scripts/cpn_inference.py
@@ -14,12 +14,10 @@
 from collections import OrderedDict
 from PIL import ImageFile
 import cv2
-from torch.distributed import is_available, all_gather_object, get_world_size, is_initialized, get_rank
-from itertools import chain
+from torch.distributed import is_available, get_world_size, is_initialized, get_rank, gather_object
 import albumentations.augmentations.functional as F
 from typing import Union, List, Optional, Dict, Any
 from warnings import warn
-from skimage import img_as_float, img_as_ubyte
 
 
 def dict_collate_fn(batch, check_padding=True, img_min_ndim=2) -> Union[OrderedDict, None]:
@@ -271,42 +269,48 @@ def apply_model(img, models, trainer, mask=None, point_mask=None, crop_size=(768
         y = trainer.predict(model, data_loader)
 
         is_dist = is_available() and is_initialized()
-        if is_dist:
-            o = ([None] * get_world_size())
-            all_gather_object(obj=y, object_list=o)  # give every rank access to results
-            y = list(chain.from_iterable(o))
+        rank = get_rank()
+        ranks = get_world_size()
 
-        if (is_dist and get_rank() == 0) or not is_dist:
+        pre_results = {}
+        for y_idx, y_ in enumerate(y):
+
+            if y_ is None or y_ is ...:  # skip
+                continue
+
+            # Iterate batch
+            keeps = []
+            for n in range(len(y_['contours'])):
+                # Determine window position
+                h_i, w_i = np.unravel_index(y_['slice_idx'][n], tile_loader.num_slices_per_axis)
+
+                # Remove partial contours
+                top, bottom = h_i > 0, h_i < (h_tiles - 1)
+                right, left = w_i < (w_tiles - 1), w_i > 0
+                keep = cd.ops.cpn.remove_border_contours(y_['contours'][n], tile_loader.crop_size[:2],
+                                                         border_removal,
+                                                         top=top, right=right, bottom=bottom, left=left,
+                                                         offsets=-y_['offsets'][n])
+
+                if stitching_rule != 'nms':
+                    keep = cd.ops.filter_contours_by_stitching_rule(y_['contours'][n], tile_loader.crop_size[:2],
+                                                                    y_['overlaps'][n], rule=stitching_rule,
+                                                                    offsets=-y_['offsets'][n]) & keep
+
+                keeps.append(keep)
+            apply_keep_indices_(y_, keeps, ['offsets', 'overlaps'])
+            concat_results_(pre_results, y_)
+
+        if is_dist:
+            pre_results_ = [None] * ranks if rank == 0 else None
+            gather_object(pre_results, pre_results_, dst=0)
+            pre_results = pre_results_
 
+        if (is_dist and rank == 0) or not is_dist:
             results_ = {}
-            for y_idx, y_ in enumerate(y):
-
-                if y_ is None or y_ is ...:  # skip
-                    continue
-
-                # Iterate batch
-                keeps = []
-
-                for n in range(len(y_['contours'])):
-                    # Determine window position
-                    h_i, w_i = np.unravel_index(y_['slice_idx'][n], tile_loader.num_slices_per_axis)
-
-                    # Remove partial contours
-                    top, bottom = h_i > 0, h_i < (h_tiles - 1)
-                    right, left = w_i < (w_tiles - 1), w_i > 0
-                    keep = cd.ops.cpn.remove_border_contours(y_['contours'][n], tile_loader.crop_size[:2],
-                                                             border_removal,
-                                                             top=top, right=right, bottom=bottom, left=left,
-                                                             offsets=-y_['offsets'][n])
-
-                    if stitching_rule != 'nms':
-                        keep = cd.ops.filter_contours_by_stitching_rule(y_['contours'][n], tile_loader.crop_size[:2],
-                                                                        y_['overlaps'][n], rule=stitching_rule,
-                                                                        offsets=-y_['offsets'][n]) & keep
-
-                    keeps.append(keep)
-                apply_keep_indices_(y_, keeps, ['offsets', 'overlaps'])
-                concat_results_(results_, y_)
+            for r_idx, r in enumerate(pre_results):
+                assert isinstance(r, dict)
+                concat_results_flat_(results_, r)
 
             # Remove duplicates from tiling
             if 'nms' in stitching_rule.split(','):