日本産科婦人科学会香川地方部会雑誌 vo1.9，No.，lpp.35 -37， 2007(平19.9月)
- Case Reportー
Department ofPerinatology and Gyneclogy
，Kagawa University School ofMedicine
We present herein a case of tetralogy of Fallot diagnosed by conventional two-dimensional fetal echocardiography and real-time three同dimensionalfetal echocardiography prenatally. Conventional two-dimensional fetal echocardiography
revealed a subaortic ventricular septal defect and an overriding aorta. These findings were visualized clearly by real -time three-dimensional fetal echocardiography with instantaneous volume-rendered displays. In conclusion
，real-time 3D echocardiography is a novel modality for prenatal diagnosis of congenital heart disease， although i rtemains to be improved. Key words:Tetralogy of Fallot， realイ的7ethree-dimensional fetal echocardiography， prenatal diagnosis
Tetralogy of Fallot (TOF) is one of the main caus巴S
of cyanotic cong巴nitalheart disease among newborns
which was described as the combination of pulmonary artery st巴nosis
，high ventricular septal defect (VSD)
，and overriding ofthe aorta ofboth ventricles1 ). Ithas an incidence of approximately 0.5 in 1，000 live births (5-7 per cent of congenital heart 1巴sions). Untreated
，25 per cent of patients die in the first year of life; however
，surgical repair has conveyed巴xcellent
resu1ts with most of patients have a favorable early and late outcome2， 3).Prenatal diagnosis of TOF may have its
great impact on the neonatal management. W巴present
herein a case of TOF diagnosed by conv巴ntiona
ltwo-dimensional (2D) fetal echocardiography and real-time three-dimensional (3D) fetal echocardiography prenatally.
A 31-year-old pregnant woman
for routine antenatal care at 32 weeks' gestation. The sonographic examination revealed that the f巴，tal
biometry was consistent with menstrual age and th巴
volume of amniotic fluid was normal.Conventional 2D fetal巴chocardiographyof the long-axis view revealed
a subaortic VSD and an overriding aorta (Figure l). A slightly small pulmonary trunk was also noted.
Figure 1 Conventional two-dimensional echocardiography in fetus with tetralogy of Fallot.Long-axis view rev巴aleda subaortic ventricular septal defect (VSD， *) and an overriding aorta (Ao). LV
，left ventricle; RV， right ventricle. 35
36 Real-time Three-Dimensional Fetal Echocardiographic Featurωes ofTetralogy ofFallot 産婦香川会誌9巻 1号
Figure 2 Volume-rend巴redimag巴of1'eal-time th1'ee-dimensional echocardiography in
fetus with tetralogy of Fallo VSD (t. *) and overriding aorta (Ao) w巴1'eclearly visualized.
，left ventricle; RV
Cardiac size and axis were no1'mal. Real-tim巴3Dfetal
echoca1'diography with instantaneous volume-rendered
displays (Philips Sonos 7500
，Philips Medical Systems
，USA) showed beating hea1't with thre巴
spatial dimensions， and VSD and overriding aorta were clearly visualized (Figure 2). Accordingly， the prenatal diagnosis of TOF was made and the patient attended the high-risk prenatal care clinic. Spontaneous vaginal deliveηr occUlTed at 41 weeks of gestation. The infant was female，
weighing 3，275g and the Apgar scores were both 8 at lmin and 5min. A neonatal echocardiographic examination confirmed the p1'enatal findings. The infant was doing well and then was transferred to the neonatal int巴nsivecare unit for further treatrnen.t
Conventional 2D fetal echoca1'diography is
currently the most widely used modality in sc1'eening for fetal cardiac disord巴1's.The main prenatal sonographic findings of TOF have been summarized by several study groups4-7).However， because of1'estriction to 2D images， it is difficult to gain precise evaluation of fetal heart
，which has complex stmc印reand dynamic activity. In addition
，the acquisition during examination is time-consuming and considerable expertise is required. Interobserver variation also exists due to subjectivity and incomplete information obtained from the flat 2D images.
With the technical advances in transduc巴1'sand
computational processor spe巴dand capacity， 3D
echocardiography emerged and has undergone the equivalent of a “quantum leap" with resp巳ctto image quality and ease of acquisition8 ). Real-time 3D echocardiography is the latest technique that acquires a volume of data vI1iually instantaneously， without the need for any form of reconstmction. It has a clea1'advantage ove1'2D echocardiography that images p1'ovided by real -time 3D echocardiography are tmly volumetric and this may allow a mo1'e objective and quantitative assessment of cardiac anatomy and function during a single cardiac cycle. Many efforts have been done to apply this technology to clinical cardiology， including analysis of cardiac volumes and mass
，congenital heart disease
，and the assessment of valvular pathology9). Moreove1'， it has been1'eported to be a feasible， safe and effectiv巴 modality in treatment of atrial septal defectslO ). Compare to adults， the study on f巴，talheart is relatively difficult due to the fast b巳ating
and fetal movement during examination. The rapidity and accuracy of1'eal-time 3D巳chocardiographyh巴lped us to resolve thes巴problems.F巴asibilityof using real -time 3D echocardiography to evaluate the fetal heart has been identified by sev巴ralstudy groupsll -14). Acar et al. inv巴stigatedboth normal fetuses and fl巴tuseswith congenital heart disease by this method， and found that real-time 3D imaging was useful in identify fetal heart morphologic abnormalities， including in evaluating ventricular septal defect and pulmonary obstruction of
2007年9月 Shu-Yan Dai， et al.
TOF12l. Anothe1'study has demonst1'ated the potentia1 of 1'ea1-time 3D to se1've as a screening too1 fo1'feta1 hea1't
disease. The sensitivity fo1'detecting congenita1 hea1't
dis巴asewas as high as 93 pe1'cene3l. Our prelimina1'y
study has a1so shown t白ha抗tre巴a1.ト'凹問但勾引.
was a nov 巴e1means fo1'eva1uation of feta1 h 号伺ar吋ti泊ntぬh巴
∞ond and thi1'd 凶trimesはt巴創1's
，without t血h巴n 巴ed f臼ol'ca1'diac gating
，and with 1巴sspotentia1 fo1'a1'tifact1'e1ated to D巴ta1 motion during the acquisition14l. In the p1'esent1'epo1't
，th巴 patient was diagnosed with TOF by both conventiona1 2D and rea1-time 3D巴choca1'diog1'aphy
，and the 1ater showed a more comprehensive visualization of feta1 hea1't on a beat -to開beatbasis. A1though1'ea1-time 3D is a feasib1e and a significant too1 fo1'p1'enata1 hea1't assessment
，some limitations have been a1so pointed outll-14l. The size of rea1“time 3D vo1ume is restricted by a narrow d巴finedregion of int巴rest of 200 ang1e. Moreover
，in cont 1 'ast to high sensitivity for f巴ta1heart disease
，the technique's specificity is re1ativ巴1y 10w (45 per cent). Artifacts re1ated to ang1e of acquisition shou1d be recognized and minimized. In conclusion
provide new insights into feta1 cardiac morpho10gy and function fo1'prenata1 medicine. Itwill be deve10ped into a wid巴1yused clinica1 too1 in the near fuれlre.
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