## Xray Evaluation Of Cardiac Size

1. How is determination of cardiac size by X-ray usually calculated?

ANS: By cardiothoracic (C/T) ratios. Fifty percent is considered by most radiologists to be the upper limit of normal.

2. How can we overcome the falsely normal C/T ratios in subjects who are short and underweight, or the falsely high C/T ratios in subjects who are overweight?

ANS: By the use of the height and weight tables of Ungerleider and Clark [4].

3. How can you measure cardiac volume to derive a more accurate cardiac size than by any other X-ray method?

ANS: The cardiac volume uses the lateral chest film and body surface area. The length dimension (L) is measured in centimeters from the junction of the superior vena cave and right atrium to the cardiac apex. The broad diameter (B) is measured from the junction of the right atrium and diaphragm to the junction of the pulmonary artery and left atrial appendage. The lateral dimension (D) is the greatest horizontal cardiac lateral diameter where BSA = body surface area. The 0.42 is the correction factor for a 6-ft distance of the heart from the film [5].

Instead of using the tables (see p. 102), one may use the formula

Weight x 25 = + 70 for males Height + 62 for females

The answer is in mm and 10% above the average may be normal or slightly enlarged. If kilos and mm are used, multiply the weight by 2.2 and divide the height by 2.5.

Cardiac volume =

PA view

Lateral view

The upper normal values are 490 (cm3) for females and 540 (cm3) for males.

PA view

Lateral view

The upper normal values are 490 (cm3) for females and 540 (cm3) for males.

Theoretical transverse diameters of heart Table for determining percent for various heights and weights deviation from average

 Jf MBtBfBlllBBtHIBIllB||miliHilBl^ ^QQQQ^ ÜBHHIBlIk 13 15 17 II 16 II 91 93 9\$ 91 101 100 102 (Light figures represent weights) 77 77 71 11 •3 >2 •3 16 17 II II 94 104 114 116 117 111 120 120 »21 122 124 >25 130 100 102 104 100 >02 104 106 101 103 105 107 >01 103 105 107 109 104 106 >01 110 10« 106 >01 110 112 106 101 no 1 14 i ii 113 115 117 79 10 10 11 12 16 16 17 93 104 114 116 >17 >11 >19 120 >21 122 131 101 110 113 106 101 no 112 114 101 109 111 113 115 111 113 115 117 111 113 115 117 119 113 115 117 119 121 114 1 16 111 121 123 116 111 120 123 135 126 121 121 123 125 121 130 >25 127 129 »32 139 131 133 133 >35 137 16 91 97 100 101 102 103 137 131 t39 »40 141 143 116 til 120 114 116 11* 120 123 116 11« 120 122 124 117 120 122 124 126 119 121 >24 126 131 121 123 125 121 130 131 134 127 129 131 133 136 131 133 I3S >31 130 133 135 137 140 132 134 137 139 142 134 »36 139 141 >43 136 131 141 143 145 19 100 101 106 107 no 111 112 >13 131 137 149 120 122 124 126 121 124 126 I» 130 124 126 ■ 31 130 133 126 121 130 132 134 137 141 134 136 131 141 (43 >31 140 143 147 149 151 153 151 150 157 155 157 160 152 >54 157 160 162 154 156 159 162 164 156 159 161 164 166 93 97 91 91 99 105 105 110 111 >12 116 117 111 120 121 122 121 124 136 141 143 154 »55 130 132 134 136 139 132 134 137 139 141 137 139 141 143 137 139 141 HI 146 150 152 145 141 150 152 155 157 159 157 159 162 >54 >56 159 161 164 156 159 161 164 166 151 »6» »63 166 »69 160 163 166 »61 171 163 165 161 171 173 171 172 175 177 >10 97 100 101 102 »02 103 106 107 101 109 Ito 115 1 16 120 121 127 173 135 126 127 121 129 134 >35 147 141 160 161 141 143 145 147 »50 153 141 150 157 153 157 150 152 155 157 160 152 155 157 160 162 155 157 160 162 164 157 160 162 165 167 173 177 179 171 >74 177 179 112 174 176 179 112 114 176 >79 HI 114 117 171 111 »14 117 119 111 113 116 >19 192 100 101 120 121 174 124 135 176 137 141 154 157 151 160 161 164 »65 166 161 152 154 156 159 161 157 159 161 164 157 159 162 164 166 159 162 164 167 169 162 164 167 169 172 172 174 177 172 175 177 110 172175 177 110 112 175 177 110 112 IIS 177 110 112 115 111 190 193 »17 190 !93 196 117 loo 193 196 >91 190 193 195 191 701 195 191 201 204 »95 191 201 204 206 104 104 125 131 133 1 3S 134 137 13« 139 146 160 164 166 167 174 163 166 161 170 173 166 161 171 173 176 171 174 176 »71 174 176 179 111 174 177 179 112 114 177 179 113 IM 117 110 112 115 117 190 190 193 196 190 193 196 199 190 193 196 199 201 707 704 707 199 201 204 207 310 201 204 207 210 213 704 207 210 213 216 207 210 213 216 319 209 212 216 219 222 212 215 211 221 224 130 137 142 14} 144 151 173 176 >71 179 110 175 171 110 »12 lis 194 191 200 30t 204 206 201 204 207 210 216 207 210 213 216 219 710 713 716 219 277 213 216 219 222 225 216 219 227 225 221 219 222 225 221 231 237 221 231 234 237 240 111 119 124 >25 »76 137 133 »34 141 143 145 144 147 14« 14» 176 171 179 116 117 190 192 195 >91 191 193 196 191 201 194 196 199 201 204 197 199 202 205 207 200 203 205 201 211 203 206 201 211 214 206 209 212 214 217 209 212 215 211 331 212 215 211 221 234 215 211 221 224 237 219 22? 224 22 7 230 722 225 221 231 234 237 247 250 740 744 747 750 253 243 247 250 253 257 113 113 1 t4 >15 116 131 137 131 139 146 153 114 160 161 162 166 167 161 169 177 115 119 190 »91 193 200 203 206 207 210 210 213 216 213 216 219 217 220 222 225 220 223 226 229 224 327 229 232 235 237 230 233 236 239 243 246 237 240 743 246 749 ?40 243 246 249 253 243 347 250 353 256 347 750 753 256 260 250 254 J57 260 263 753 257 260 763 767 2J7 260 263 767 270 260 264 767 270 779 116 117 111 119 119 176 176 127 135 151 155 154 157 15« 159 166 167 175 171 179 1«! 113 113 196 191 199 34\$ 249 757 755 759 256 259 262 259 263 266 769 273 763 766 770 773 776 766 770 773 277 210 291 | 131 137 131 139 139 156 144 no 116 117 1«9 Actual Predicted Actual Diameter (mm) The heart is usually enlarged if the width is 10% greater than the average prediction, which is shown in the boldface vertical column on the right. Subtract 8 mm for women, since this table was derived from thousands of male insurance applicants. (Personal communication from Dr. H. E. Ungerleider.)