Table 2.

Differential diagnosis table for right isomerism (continued on next page)

Disease	X-Ray	Echocardiography	USG	CT	MRI
Right Isomerism (asplenia syndrome)	Cardiac apex – right/left/midline, Aortic arch-right/left Major and minor fissures in both lungs Stomach-midline/right/left	Cardiac apex-right/left/midline Both atrium has right atrium morphology with or without ASD Common atrioventricular valve Transposition of great arteries Pulmonary stenosis Bilateral SVC TAPVC IVC & aorta on same side of spine	Absent spleen Symmetrical & midline liver & midline gall bladder Ipsilateral IVC & aorta Stomach-midline/right/left Gut malrotation Truncated pancreas	Cardiac apex-right/left/midline Transposition of great arteries Bilateral SVC TAPVC Piggy backed IVC Aortic arch-right/left Bilateral eparterial bronchi Major and minor fissures in both lungs Absent spleen Symmetrical & midline liver & midline gall bladder, Gut malrotation Truncated pancreas	Cardiac apex-right/left/midline Transposition of great arteries Bilateral SVC TAPVC Piggy backed IVC Aortic arch-right/left Bilateral eparterial bronchi Absent spleen Symmetrical & midline liver & midline gall bladder Gut malrotation Truncated pancreas
Left Isomerism (polysplenia syndrome)	Cardiac apex-right/left Aortic arch-right/left Bilateral hyparterial bronchi Absent bilateral minor fissure Stomach-right/left	Cardiac apex-right/left ASD Normal atrioventricular valve in most cases VSD Normal relationship of great arteries IVC & aorta relationship is normal	Multiple spleens Biliary atresia Liver-right/left/midline Interrupted IVC with double vessel sign Gut malrotation Truncated pancreas	Cardiac apex-right/left Aortic arch-right/left Normal relationship of great arteries IVC & aorta relationship is normal Bilateral hyparterial bronchi Absent bilateral minor fissure Multiple spleens Biliary atresia Liver-right/left/midline Interrupted IVC with double vessel sign Gut malrotation Truncated pancreas	Cardiac apex-right/left Aortic arch-right/left Normal relationship of great arteries IVC & aorta relationship is normal Bilateral hyparterial bronchi Multiple spleens Biliary atresia Liver-right/left/midline Interrupted IVC with double vessel sign Gut malrotation Truncated pancreas
Situs Inversus Totalis	Cardiac apex-right Aortic arch-right Right hyparterial & left eparterial bronchus Minor fissure on left side Stomach-right side	Cardiac apex-right Right atrium & ventricle on left side Left atrium & ventricle on right side Corrected transposition of great arteries Right side aorta & left side IVC	Right side spleen Left side liver Left side gall bladder Right side stomach	Cardiac apex-right Aortic arch-right Corrected transposition of great arteries Right side aorta & left side IVC Right hyparterial & left eparterial bronchus Minor fissure on left side Right side spleen Left side liver Left side gall bladder Right side stomach	Cardiac apex-right Aortic arch-right Corrected transposition of great arteries Right side aorta & left side IVC Right hyparterial & left eparterial bronchus Right side spleen Left side liver Left side gall bladder Right side stomach