Update app.py

app.py

@@ -325,8 +325,8 @@ class DicomAnalyzer:
             cell1.font = red_font
             cell1.alignment = openpyxl.styles.Alignment(horizontal='center')
             
-            # CNR Formula for second row
-            formula2 = f"=IF(OR({std_col}{row2}=0,{base_col}{row1}=0,{base_col}{row2}=0),0,({base_col}{row1}-{base_col}{row2})/{std_col}{row2})"
+            # CNR Formula for second row with zero handling
+            formula2 = f"=IF(OR({std_col}{row2}=0,{base_col}{row1}=0,{base_col}{row2}=0),\"\",({base_col}{row1}-{base_col}{row2})/{std_col}{row2})"
             cell2 = ws[f"{formula_col}{row2}"]
             cell2.value = formula2
             cell2.font = red_font
@@ -456,35 +456,34 @@ class DicomAnalyzer:
             # Calculate CNR averages for each row pair
             for i, size in enumerate(phantom_sizes):
                 row_number = row_pairs[i][1]  # Second row for CNR
-                cnr_references = []
+                valid_cnr_refs = []
                 
-                # Get all CNR formula references
                 for cols in column_groups:
                     formula_col = get_column_letter(column_index_from_string(cols[-1]) + 1)
-                    cnr_cell = f"{formula_col}{row_number}"
+                    mean_col = cols[1]
+                    std_col = cols[2]
                     
-                    # Check if the cell would have a valid CNR value
-                    mean_col = cols[1]  # Mean column
-                    mean1 = ws[f"{mean_col}{row_pairs[i][0]}"].value  # First row mean
-                    mean2 = ws[f"{mean_col}{row_pairs[i][1]}"].value  # Second row mean
-                    stddev2 = ws[f"{cols[2]}{row_pairs[i][1]}"].value  # Second row StdDev
+                    # Check if the values used in CNR calculation are valid
+                    mean1 = ws[f"{mean_col}{row_pairs[i][0]}"].value
+                    mean2 = ws[f"{mean_col}{row_pairs[i][1]}"].value
+                    std2 = ws[f"{std_col}{row_pairs[i][1]}"].value
                     
-                    # Only add to references if values are valid
                     if (mean1 not in [0, None, ''] and 
                         mean2 not in [0, None, ''] and 
-                        stddev2 not in [0, None, '']):
-                        cnr_references.append(cnr_cell)
+                        std2 not in [0, None, '']):
+                        valid_cnr_refs.append(f"{formula_col}{row_number}")
                 
-                if cnr_references:
-                    # Create AVERAGE formula excluding zero values
-                    formula = f"=AVERAGEIF({','.join(cnr_references)},\"<>0\")"
-                    size_cell = ws.cell(row=current_row, column=1, value=size)
-                    size_cell.alignment = center_alignment
-                    
-                    avg_cell = ws.cell(row=current_row, column=2)
-                    avg_cell.value = formula
+                # Add row to the averages table
+                size_cell = ws.cell(row=current_row, column=1, value=size)
+                size_cell.alignment = center_alignment
+                
+                avg_cell = ws.cell(row=current_row, column=2)
+                if valid_cnr_refs:
+                    # Create average formula that ignores blank cells
+                    refs = ",".join(valid_cnr_refs)
+                    avg_cell.value = f'=AVERAGE(IF(LEN({refs})>0,{refs}))'
                     avg_cell.number_format = '0.000'
-                    avg_cell.alignment = center_alignment
+                avg_cell.alignment = center_alignment
                 
                 current_row += 1
 
@@ -517,7 +516,7 @@ class DicomAnalyzer:
         
         for i, (header, key) in enumerate(value_mapping.items()):
             cell = ws[f"{cols[i]}{row}"]
-            cell.value = float(result[key])
+            cell.value = float(result[key]) if result[key] != '' else ''
             cell.alignment = center_alignment
 
     def format_results(self):