diff --git a/supervision/metrics/detection.py b/supervision/metrics/detection.py
index 99a11322..bbbfa711 100644
--- a/supervision/metrics/detection.py
+++ b/supervision/metrics/detection.py
@@ -391,11 +391,10 @@ class ConfusionMatrix:
             ```
         """
         predictions, targets = [], []
-        for img_name, img in dataset.images.items():
-            predictions_batch = callback(img)
+        for _, image, annotation in dataset:
+            predictions_batch = callback(image)
             predictions.append(predictions_batch)
-            targets_batch = dataset.annotations[img_name]
-            targets.append(targets_batch)
+            targets.append(annotation)
         return cls.from_detections(
             predictions=predictions,
             targets=targets,
@@ -604,11 +603,10 @@ class MeanAveragePrecision:
             ```
         """
         predictions, targets = [], []
-        for img_name, img in dataset.images.items():
-            predictions_batch = callback(img)
+        for _, image, annotation in dataset:
+            predictions_batch = callback(image)
             predictions.append(predictions_batch)
-            targets_batch = dataset.annotations[img_name]
-            targets.append(targets_batch)
+            targets.append(annotation)
         return cls.from_detections(
             predictions=predictions,
             targets=targets,