diff --git a/src/PartSeg_smfish/__init__.py b/src/PartSeg_smfish/__init__.py
index 44e7504..74e43ad 100644
--- a/src/PartSeg_smfish/__init__.py
+++ b/src/PartSeg_smfish/__init__.py
@@ -22,6 +22,10 @@ def register():
         segmentation.LayerRangeThresholdFlow,
         RegisterEnum.roi_mask_segmentation_algorithm,
     )
+    register_fun(
+        segmentation.ThresholdFlowAlgorithmWithDilation,
+        RegisterEnum.roi_mask_segmentation_algorithm,
+    )
     register_fun(measurement.ComponentType, RegisterEnum.analysis_measurement)
 
     if getattr(sys, "frozen", False):
diff --git a/src/PartSeg_smfish/segmentation.py b/src/PartSeg_smfish/segmentation.py
index 0e559c1..3e26fcd 100644
--- a/src/PartSeg_smfish/segmentation.py
+++ b/src/PartSeg_smfish/segmentation.py
@@ -30,6 +30,8 @@
 from PartSegCore.segmentation.segmentation_algorithm import (
     CellFromNucleusFlow,
     StackAlgorithm,
+    ThresholdFlowAlgorithm,
+    ThresholdFlowAlgorithmParameters,
 )
 from PartSegCore.segmentation.threshold import (
     BaseThreshold,
@@ -626,3 +628,56 @@ def maximum_projection(
             },
         )
     )
+
+
+class ThresholdFlowAlgorithmParametersWithDilation(
+    ThresholdFlowAlgorithmParameters
+):
+    dilation_radius: int = Field(
+        0,
+        title="Dilation radius",
+        description="Radius of dilation applied to the mask",
+        ge=0,
+        le=100,
+    )
+
+
+class ThresholdFlowAlgorithmWithDilation(ThresholdFlowAlgorithm):
+    new_parameters: ThresholdFlowAlgorithmParametersWithDilation
+    __argument_class__ = ThresholdFlowAlgorithmParametersWithDilation
+
+    @classmethod
+    def get_name(cls) -> str:
+        return "Threshold Flow with Dilation"
+
+    @classmethod
+    def get_steps_num(cls) -> int:
+        return ThresholdFlowAlgorithm.get_steps_num() + 1
+
+    def calculation_run(
+        self, report_fun: Callable[[str, int], None]
+    ) -> ROIExtractionResult:
+        res = super().calculation_run(report_fun)
+        if self.new_parameters.dilation_radius == 0:
+            return res
+
+        report_fun("Dilate ROI", self.get_steps_num() - 1)
+
+        from PartSegCore.image_operations import dilate
+
+        rad = self.new_parameters.dilation_radius
+        roi = dilate(res.roi, [rad, rad], True)
+
+        roi[res.roi > 0] = res.roi[res.roi > 0]
+
+        res2 = ROIExtractionResult(
+            roi=roi,
+            parameters=self.get_segmentation_profile(),
+            additional_layers=deepcopy(res.additional_layers),
+        )
+
+        res2.additional_layers["dilated roi"] = AdditionalLayerDescription(
+            res.roi, "labels", "Dilated ROI"
+        )
+        report_fun("Calculation done", self.get_steps_num())
+        return res2