diff --git a/AFQ/tasks/data.py b/AFQ/tasks/data.py
index b05f4e833..d30fcedeb 100644
--- a/AFQ/tasks/data.py
+++ b/AFQ/tasks/data.py
@@ -280,6 +280,24 @@ def dti_fa(dti_tf):
     return dti_tf.fa
 
 
+@pimms.calc("dti_lt0", "dti_lt1", "dti_lt2", "dti_lt3", "dti_lt4", "dti_lt5")
+def dti_lt(dti_tf, dwi_affine):
+    """
+    Image of first element in the DTI tensor,
+    Image of second element in the DTI tensor,
+    Image of third element in the DTI tensor,
+    Image of fourth element in the DTI tensor,
+    Image of fifth element in the DTI tensor,
+    Image of sixth element in the DTI tensor
+    """
+    dti_lt_dict = {}
+    for ii in range(6):
+        dti_lt_dict[f"dti_lt{ii}"] = nib.Nifti1Image(
+            dti_tf.lower_triangular()[..., ii],
+            dwi_affine)
+    return dti_lt_dict
+
+
 @pimms.calc("dti_cfa")
 @as_file(suffix='_model-DTI_desc-DEC_FA.nii.gz')
 @as_fit_deriv('DTI')
@@ -605,9 +623,9 @@ def get_data_plan(kwargs):
     data_tasks = with_name([
         get_data_gtab, b0, b0_mask, brain_mask,
         dti_fit, dki_fit, anisotropic_power_map,
-        dti_fa, dti_cfa, dti_pdd, dti_md, dki_fa, dki_md, dki_awf, dki_mk,
-        dti_ga, dti_rd, dti_ad, dki_ga, dki_rd, dki_ad, dki_rk, dki_ak,
-        dti_params, dki_params, csd_params, get_bundle_dict])
+        dti_fa, dti_lt, dti_cfa, dti_pdd, dti_md, dki_fa, dki_md, dki_awf,
+        dki_mk, dti_ga, dti_rd, dti_ad, dki_ga, dki_rd, dki_ad, dki_rk,
+        dki_ak, dti_params, dki_params, csd_params, get_bundle_dict])
 
     if "scalars" not in kwargs:
         kwargs["scalars"] = ["dti_fa", "dti_md"]
diff --git a/AFQ/tasks/segmentation.py b/AFQ/tasks/segmentation.py
index 7a2ea9e5f..58e71666a 100644
--- a/AFQ/tasks/segmentation.py
+++ b/AFQ/tasks/segmentation.py
@@ -304,11 +304,16 @@ def tract_profiles(clean_bundles, data_imap,
         this_sl = seg_sft.get_bundle(bundle_name).streamlines
         if len(this_sl) == 0:
             continue
+        if profile_weights == "gauss":
+            # calculate only once per bundle
+            bundle_profile_weights = gaussian_weights(this_sl)
         for ii, (scalar, scalar_file) in enumerate(scalar_dict.items()):
-            scalar_data = nib.load(scalar_file).get_fdata()
+            if isinstance(scalar_file, str):
+                scalar_file = nib.load(scalar_file)
+            scalar_data = scalar_file.get_fdata()
             if isinstance(profile_weights, str):
                 if profile_weights == "gauss":
-                    this_prof_weights = gaussian_weights(this_sl)
+                    this_prof_weights = bundle_profile_weights
                 elif profile_weights == "median":
                     # weights bundle to only return the mean
                     def _median_weight(bundle):
diff --git a/AFQ/tasks/viz.py b/AFQ/tasks/viz.py
index 260522f10..b8bb226df 100644
--- a/AFQ/tasks/viz.py
+++ b/AFQ/tasks/viz.py
@@ -22,7 +22,10 @@
 
 def _viz_prepare_vol(vol, xform, mapping, scalar_dict):
     if vol in scalar_dict.keys():
-        vol = nib.load(scalar_dict[vol]).get_fdata()
+        vol = scalar_dict[vol]
+        if isinstance(vol, str):
+            vol = nib.load(vol)
+        vol = vol.get_fdata()
     if isinstance(vol, str):
         vol = nib.load(vol).get_fdata()
     if xform:
diff --git a/AFQ/tests/test_api.py b/AFQ/tests/test_api.py
index bfbe464d8..cfa72cc68 100644
--- a/AFQ/tests/test_api.py
+++ b/AFQ/tests/test_api.py
@@ -724,6 +724,7 @@ def test_AFQ_data_waypoint():
             "dti_FA",
             "dti_MD",
             "dti_GA",
+            "dti_lt2",
             ImageFile(path=t1_path_other),
             TemplateImage(t1_path)],
         robust_tensor_fitting=True,
@@ -772,7 +773,7 @@ def test_AFQ_data_waypoint():
     tract_profiles = pd.read_csv(tract_profile_fname)
 
     assert tract_profiles.select_dtypes(include=[np.number]).sum().sum() != 0
-    assert tract_profiles.shape == (500, 8)
+    assert tract_profiles.shape == (500, 9)
 
     myafq.export("indiv_bundles_figures")
     assert op.exists(op.join(
@@ -821,6 +822,7 @@ def test_AFQ_data_waypoint():
                 "dti_fa",
                 "dti_md",
                 "dti_ga",
+                "dti_lt2",
                 f"ImageFile('{t1_path_other}')",
                 f"TemplateImage('{t1_path}')"]),
         VIZ=dict(
@@ -843,7 +845,7 @@ def test_AFQ_data_waypoint():
     # The tract profiles should already exist from the CLI Run:
     from_file = pd.read_csv(tract_profile_fname)
 
-    assert from_file.shape == (500, 8)
+    assert from_file.shape == (500, 9)
     assert_series_equal(tract_profiles['dti_fa'], from_file['dti_fa'])
 
     # Make sure the CLI did indeed generate these: