Y H Lee

Publications (20)57.89 Total impact

• Article: Measurement of compensatory hyperplasia of the contralateral kidney: usefulness for differential diagnosis of fetal unilateral empty renal fossa.

  J Y Cho, M H Moon, Y H Lee, K W Kim, S H Kim
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  ABSTRACT: To assess the usefulness of sonographic evaluation of compensatory hyperplasia of the contralateral kidney for the differential diagnosis of fetal unilateral empty renal fossa (ERF). We retrospectively measured the ratio of the anteroposterior (AP) and transverse (TR) diameters of the contralateral kidney in 24 fetuses with unilateral ERF including 12 cases of unilateral renal agenesis, six cases of a unilateral pelvic kidney and six cases of a unilateral ectopic multicystic dysplastic kidney (MCDK). For the normal reference value, we calculated the AP : TR diameter ratios of both kidneys in 20 normal fetuses in the second and third trimesters. We calculated the accuracy of the AP : TR ratio to detect contralateral compensatory hyperplasia. The median (range) AP : TR diameter ratios of the normal kidneys were 0.84 (0.72-0.89) in the second trimester and 0.81 (0.65-0.89) in the third trimester. All cases of unilateral renal agenesis and ectopic MCDK showed the presence of compensatory hyperplasia, while no case of renal ectopy was seen with compensatory hyperplasia. The median (range) ratios for unilateral renal agenesis and ectopic MCDK were 1.0 (0.95-1.02) and 1.1 (1-1.25) in the second and third trimesters, respectively. The median ratios for a unilateral pelvic kidney were 0.8 (0.74-0.85) and 0.77 (0.74-0.84) in the second and third trimesters, respectively. Using 0.9 as the discriminating value, the sensitivity, specificity, and accuracy of the AP : TR diameter ratio for the prenatal diagnosis of compensatory renal hyperplasia was 100%. Sonographic evaluation of compensatory hyperplasia of the contralateral kidney may be useful for the differential diagnosis of a fetal unilateral ERF. Prospective studies are warranted.
  Ultrasound in Obstetrics and Gynecology 11/2009; 34(5):515-20. · 3.01 Impact Factor
• Article: P31.10: First‐trimester screening for Down syndrome: the role of nasal bone assessment in the Korean population

  M. H. Moon, J. Y. Cho, Y. H. Lee, J. Y. Min, J. A. Kim, S. I. Jung
  Ultrasound in Obstetrics and Gynecology 09/2007; 30(4):571 - 571. · 3.01 Impact Factor
• Article: P26.17: Evaluation of the fetal urinary bladder and associated genitourinary anomalies

  J. Y. Cho, S. H. Kim, Y. H. Lee, M. H. Moon, M. Y. Kim
  Ultrasound in Obstetrics and Gynecology 09/2007; 30(4):551 - 551. · 3.01 Impact Factor
• Article: OC104: Isolated gallbladder abnormality in utero: clinical significance as a screen for fetal anomaly

  M. H. Moon, J. Y. Cho, Y. H. Lee, M. J. Song, M. S. Lee, H. J. Cho
  Ultrasound in Obstetrics and Gynecology 09/2007; 30(4):399 - 399. · 3.01 Impact Factor
• Article: Diameter of the normal fetal thymus on ultrasound.

  J Y Cho, J Y Min, Y-H Lee, B McCrindle, L K Hornberger, S-J Yoo
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  ABSTRACT: To present the normative data of the transverse diameter of the developing fetal thymus. In this prospective study, the maximum transverse diameter of the thymus was measured by one sonologist in 376 normal fetuses between 19 and 38 weeks of gestation. We assessed the relationship of the transverse thymic diameter with gestational age (GA), biparietal diameter, femur length and abdominal circumference using general linear regression modeling. The predicted mean and 95% reference range of thymic diameter at each GA were calculated from the regression equation. Measurements of the transverse diameter were possible in 352 of the 376 (94%) fetuses. The transverse diameter of the fetal thymus increased with increasing GA and fetal size parameters in a linear manner. The regression equation for transverse diameter of the thymus as a function of GA was: thymic diameter (cm) = 0.15 x GA (weeks) - 1.59 (r(2) = 0.86, P < 0.001). The transverse diameter of the fetal thymus is easy to measure; this study presents normative data.
  Ultrasound in Obstetrics and Gynecology 07/2007; 29(6):634-8. · 3.01 Impact Factor
• Article: P02.68: Various prenatal sonographic findings of normal and abnormal fetal genitalia

  S. I. Jung, J. Y. Cho, M. H. Moon, Y. H. Lee, J. A. Kim, J. Y. Min
  Ultrasound in Obstetrics and Gynecology 08/2006; 28(4):539 - 539. · 3.01 Impact Factor
• Article: P02.57: Compensatory hyperplasia of the contralateral kidney: usefulness in the differential diagnosis of invisible single kidney in the fetus

  J. Y. Cho, M. H. Moon, S. I. Jung, Y. H. Lee, K. W. Kim, M. Y. Kim, J. H. Jung, S. H. Kim
  Ultrasound in Obstetrics and Gynecology 08/2006; 28(4):536 - 537. · 3.01 Impact Factor
• Article: P04.21: Broad spectrum of ultrasound (US) findings of hydatidiform mole and molar mimicker

  S. I. Jung, J. Y. Cho, M. H. Moon, M. J. Song, J. A. Kim, J. Y. Min, Y. H. Lee
  Ultrasound in Obstetrics and Gynecology 09/2005; 26(4):401 - 402. · 3.01 Impact Factor
• Article: P04.20: Pre & postnatal imaging findings of fetal neoplasms

  J. Y. Cho, S. I. Jung, M. H. Moon, M. J. Song, J. A. Kim, J. Y. Min, Y. H. Lee, M. Y. Kim, Y. K. Chun
  Ultrasound in Obstetrics and Gynecology 09/2005; 26(4):401 - 401. · 3.01 Impact Factor
• Article: P04.30: Ultrasound findings of venous anomalies in the fetal liver

  J. Y. Cho, S. I. Jung, M. H. Moon, M. J. Song, J. A. Kim, J. Y. Min, Y. H. Lee, M. Y. Kim
  Ultrasound in Obstetrics and Gynecology 09/2005; 26(4):404 - 404. · 3.01 Impact Factor
• Article: Prenatal diagnosis of horseshoe kidney by measurement of the renal pelvic angle.

  J Y Cho, Y-H Lee, A Toi, B Macdonald
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  ABSTRACT: The aim of this study was to evaluate the usefulness of measurement of the angle between bilateral renal pelves on axial views in the prenatal ultrasonographic diagnosis of horseshoe kidney. We retrospectively measured the renal pelvic angle in 19 fetuses with horseshoe and 20 fetuses with normal kidneys in the second and third trimesters. Renal pelvic angle was defined as the angle between the long axis of the renal pelves on the axial view of the abdomen. We compared the renal pelvic angles of horseshoe and normal kidneys with unpaired t-test. Taking 140 degrees as a cut-off value, we calculated the sensitivity, specificity and accuracy of pelvic angle measurement for the prenatal diagnosis of horseshoe kidney. The mean pelvic angles in the fetuses with horseshoe kidney were 116 degrees and 110 degrees in the second and third trimester, respectively. In the normal fetuses, the equivalent angles were 172 degrees and 161 degrees. The difference between the two groups was statistically significant (P < 0.01). Using 140 degrees as the discriminating criterion, the sensitivity, specificity and accuracy of renal pelvic angle measurement for the prenatal diagnosis of horseshoe kidney were all 100%. Fifteen of 19 fetuses with horseshoe kidney had no other abnormality. Four (21%) fetuses had severe complex abnormalities which were associated with trisomy 18 in three cases. Observation and measurement of the renal pelvic angle is a simple and useful method in the prenatal diagnosis of the horseshoe kidney.
  Ultrasound in Obstetrics and Gynecology 06/2005; 25(6):554-8. · 3.01 Impact Factor
• Article: Measurement of nuchal skin fold thickness in the second trimester: influence of imaging angle and fetal presentation.

  J Y Cho, K W Kim, Y H Lee, A Toi
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  ABSTRACT: To assess the effect of imaging angle and fetal presentation on the measurement of nuchal skin fold thickness (NFT) in the second trimester. Fetal NFT was prospectively measured in 921 women at 18-21 weeks' gestation. The population was divided into two groups according to fetal presentation. Group A comprised 643 fetuses in cephalic or transverse presentation and Group B comprised 278 fetuses in breech presentation. To determine whether there was a difference in NFT depending on imaging angle, in Group A the NFT was measured on the standard axial horizontal images and then on images obtained after moving the transducer about 30 degrees toward the occiput. In Group B an assessment was made as to whether NFT changed with fetal presentation. Initial measurements were made with the fetuses in breech presentation. Repeat NFT measurements were made after 15 min in 64 fetuses that had converted to cephalic or transverse presentation. Statistical analysis was performed using a paired t-test. The mean NFT on the standard horizontal image was 5.2 mm, while that on the 30 degrees occiput image was 4.0 mm. The difference was significant (P < 0.001). One hundred and twenty-three (19.1%) fetuses had a NFT greater than 6 mm on the standard image, but only two (0.3%) had an NFT of > 6 mm on the 30 degrees occiput image. There were no chromosomal or structural abnormalities in the 123 fetuses in which the NFT was > 6 mm. The mean NFT of 64 fetuses in the breech presentation was 4.4 mm, while it was 3.9 mm when they had converted to other presentations. The difference was statistically significant (P = 0.001). In breech presentation, 13/64 (20.3%) fetuses had a NFT greater than 6 mm compared to only one (1.6%) fetus in the other presentations. There were no structural or chromosomal abnormalities in any fetus with a NFT > 6 mm in either group. In this study the NFT measurement varied with scan direction and fetal presentation. To avoid falsely thickened NFT measurements the scan should be directed to image the posterior surface of the occipital bone. This can be achieved by scanning from a 30 degrees occipital direction. Also, NFT is greater in fetuses in a breech presentation. Attention to these details can reduce false-positive NFT measurements.
  Ultrasound in Obstetrics and Gynecology 04/2005; 25(3):253-7. · 3.01 Impact Factor
• Article: Congenital curly toe of the fetus.

  J Y Cho, J H Park, J H Kim, Y H Lee
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  ABSTRACT: To assess the prevalence, prenatal detection rate, and associated anomalies of congenital curly toe in an unselected obstetric population. Between September 2001 and July 2002, 1167 singleton fetuses in the second and third trimesters underwent routine prenatal ultrasound at our hospital. Congenital curly toe was diagnosed when the fourth or fifth toe was not fully delineated on the axial image with medial and plantar flexion on the coronal image. All neonates underwent a physical examination within 3 days after delivery. Radiography was performed on those infants with curly toe. We assessed the prevalence, prenatal detection rate, and associated anomalies of the condition. There were 38 congenital curly toes among the 1167 neonates, yielding a total prevalence of 32.6 per 1000. In 26 of the 38 the fourth toe was curly and in 12 the fifth toe was curly. Of those in which the fourth toe was curly, 26.9% involved the right toe, 65.4% the left, and 7.7% involved both toes. For a curly fifth toe, these values were 25.0%, 16.7% and 58.3%, respectively. There was no associated structural anomaly, chromosomal abnormality, or syndrome in any case. Sixteen of the 38 curly toes were detected on prenatal ultrasound, including 13 of 26 with the fourth toe being curly and three of 12 with the fifth being curly. Congenital curly toe is not an uncommon condition, and can be detected on the prenatal ultrasound. Although it usually appears as an isolated finding without clinical significance, thorough ultrasound examination of the fetus should be recommended.
  Ultrasound in Obstetrics and Gynecology 10/2004; 24(4):417-20. · 3.01 Impact Factor
• Article: Fetal sonographic diagnosis of aortic arch anomalies.

  S-J Yoo, J-Y Min, Y-H Lee, K Roman, E Jaeggi, J Smallhorn
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  ABSTRACT: Aortic arch anomalies refer to congenital abnormalities of the position or branching pattern, or both of the aortic arch. Although aortic arch anomalies are not uncommon, reports on their prenatal diagnosis are scarce. Insight into the hypothetical arch model is crucial to understanding anomalies of the aortic arch in the fetus. Recognition of the trachea, three major vessels, ductus arteriosus and descending aorta in the axial views of the upper mediastinum is necessary for a complete fetal cardiac assessment. Clues to aortic arch anomalies include abnormal position of the descending aorta, absence of the normal 'V'-shaped confluence of the ductal and aortic arches, a gap between the ascending aorta and main pulmonary artery in the three-vessel view, and an abnormal vessel behind the trachea with or without a vascular loop or ring around the trachea. Meticulous attention to anatomic landmarks will lead to successful prenatal diagnosis of important vascular rings making early postnatal management possible.
  Ultrasound in Obstetrics and Gynecology 12/2003; 22(5):535-46. · 3.01 Impact Factor
• Article: P075: Prenatal sonographic diagnosis of omphalocele: the significance of the omphalocele contents

  J. Ryu, J. Y. Cho, Y. H. Lee, M. J. Song, B. H. Yi, M. H. Moon, J. A. Kim
  Ultrasound in Obstetrics and Gynecology 08/2003; 22(S1):91 - 91. · 3.01 Impact Factor
• Article: P072: Focal limb anomalies in fetuses; prenatal sonographic diagnosis with pathologic correlation

  J. Ryu, J. Y. Cho, Y. H. Lee, M. J. Song, B. H. Yi, M. D. Moon, M. D. Chun
  Ultrasound in Obstetrics and Gynecology 08/2003; 22(S1):90 - 90. · 3.01 Impact Factor
• Article: P363: Serial sonographic findings of complete hydatidiform mole coexisting with a live fetus

  J. Ryu, J. Y. Cho, Y. H. Lee, M. J. Song, B. H. Yi, M. H. Moon
  Ultrasound in Obstetrics and Gynecology 08/2003; 22(S1):168 - 168. · 3.01 Impact Factor
• Article: P153: Prenatal sonographic findings of cloacal anomaly

  J. Ryu, M. J. Song, Y. H. Lee, J. Y. Cho, B. H. Yi, M. H. Moon
  Ultrasound in Obstetrics and Gynecology 08/2003; 22(S1):112 - 112. · 3.01 Impact Factor
• Article: Normal pericardial fluid in the fetus: color and spectral Doppler analysis.

  S J Yoo, J Y Min, Y H Lee
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  ABSTRACT: To estimate the incidence of sonographic identification of pericardial fluid in normal fetuses and to evaluate the flow pattern of pericardial fluid by using color and spectral Doppler techniques. We evaluated 27 normal fetuses for the presence of pericardial fluid by using gray-scale two-dimensional and M-mode ultrasound, and color and spectral Doppler techniques. Pericardial fluid was detected in 52% of cases by two-dimensional and M-mode ultrasound and in 81% of cases by color Doppler. The pericardial fluid moved towards the ventricles during systole and towards the atria during diastole. In 9 of 22 fetuses with pericardial fluid identified by color Doppler, spectral waveforms were obtained. The waveforms confirmed the bidirectional flow pattern identified at color Doppler. In six cases there was monophasic systolic and biphasic diastolic flow. In the remaining three cases, the flow was monophasic during both systole and diastole. Pericardial fluid can be identified with color Doppler in the majority of normal fetuses. It characteristically shows bidirectional flow as it moves with ventricular systole and diastole. Spectral waveforms can be obtained from the pericardial fluid. The presence of pericardial fluid per se should not be considered as abnormal. Color-coded pericardial fluid should not be mistaken for coronary artery blood flow.
  Ultrasound in Obstetrics and Gynecology 10/2001; 18(3):248-52. · 3.01 Impact Factor
• Article: Diagnosis of left juxtaposition of the atrial appendages in the fetus.

  M Abdullah, S J Yoo, Y H Lee, J Smallhorn, L K Hornberger
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  ABSTRACT: We describe two cases of left juxtaposition of the atrial appendages in which fetal echocardiograms provided a clue to the diagnosis. Both cases were associated with complex cyanotic congenital heart disease. The clue to the diagnosis was found at the three-vessel view. Abnormal vascular spaces were seen on the left side of the cross-sections of the great arterial trunks.
  Cardiology in the Young 06/2000; 10(3):220-4. · 0.76 Impact Factor