Evaluation of offline analysis of archived three-dimensional volume datasets in the diagnosis of fetal brain abnormalities

OBJECTIVE

To retrospectively evaluate the reliability of offline manipulation of archived three-dimensional (3D) ultrasound volumes in the assessment of the normal fetal brain and the diagnosis of fetal brain abnormalities.

METHODS

Seventy-nine 3D volume datasets, archived at the time of scanning, from women attending a tertiary center, were analyzed. They comprised 52 cases with brain abnormalities and 27 normal controls. Postnatal magnetic resonance imaging or postmortem examination confirmed the final diagnosis in all cases with brain anomalies. Offline analysis of the 79 anonymized 3D volume datasets was carried out by three fetal medicine experts, examiner one (E1), examiner two (E2) and examiner three (E3), using 4D View software. The experts were blinded to any prior diagnosis or history. Data were collected on a specially designed data sheet and entered into a specialized database for analysis. Results were compared between examiners, with the initial two-dimensional (2D) diagnosis and with the final definitive diagnosis by calculation of percentage agreement and kappa coefficients.

RESULTS

Of the 52 cases with brain anomalies, the correct diagnosis was reached in 88.5% (46/52), 98.1% (51/52) and 92.3% (48/52) of cases on analysis of the 3D volumes by E1, E2 and E3, respectively, whereas only 82.7% (43/52) of cases were correctly diagnosed on the initial 2D examination when compared with the definitive diagnosis. Fetuses without brain anomalies were identified as such by the three experts with 100% agreement. There was good agreement between the initial 2D examination and the analysis of 3D volumes by each of the experts: 86.1% for E1 (κ = 0.7), 89.9% for E2 (κ = 0.79) and 88.6% for E3 (κ = 0.76).

CONCLUSIONS

3D volume datasets are an appropriate and reliable format for storing data from examination of the fetal brain. Offline analysis of 3D datasets is a reliable method that can be used to help in the assessment of brain anomalies and could be a useful adjunct to realtime 2D ultrasonography.

The extent of ovarian damage produced by ovarian cauterisation in the human

The object of this study was to assess the extent of ovarian damage produced by ovarian cauterisation. This was a prospective comparative study between four and eight holes using monopolar diathermy comparing the extent of damage of ovarian tissue in the human. The study was carried out in the department of obstetrics and gynaecology, Cairo University. We studied 50 patients aged 40-45 years who were scheduled for abdominal hysterectomy with bilateral salpingo-oophorectomy for benign gynaecological disease. One ovary was subjected to unipolar diathermy with four holes (group I) and the contralateral ovary involved eight holes (group II). The main outcome measured was the extent of ovarian damage produced by the cautery. The percentage area of cautery showed a median of 0.4% and a mean of 0.48% +/- 0.35 in group I, compared to a median of 1% and a mean of 1% +/- 0.31 in group II. The difference between the two groups is statistically significant (P < 0.001). The study suggests that the extent of injury to the ovary produced by cautery might be small, especially when using four holes; however, it is difficult to determine long-term host tissue response.

Ethnicity and the need for correction of biochemical and ultrasound markers of chromosomal anomalies in the first trimester: a study of Oriental, Asian and Afro-Caribbean populations

OBJECTIVES

To assess whether there is a need to correct first-trimester biochemical markers (free beta-hCG and pregnancy-associated plasma protein-A (PAPP-A)) or first-trimester fetal nuchal translucency thickness (NT) in different ethnic groups, when screening for Downs syndrome at 11-14 weeks of gestation.

METHODS

Free beta-hCG, PAPP-A and fetal NT were measured at 11-14 weeks of gestation in a group of women presenting for first-trimester screening in two OSCAR centres. The group comprised 61 219 sets of data from Caucasian women (the reference group); 4835 sets of data from South Asian women; 3450 sets of data from Oriental women and 2727 sets of data from Afro-Caribbean women. The Oriental data set was supplemented with a further 480 cases collected in Hong Kong and the Afro-Caribbean data set was supplemented with 216 cases collected from Kings College. The difference in marker values between the reference group and the other ethnic groups was compared before and after weight correction for the biochemical markers using standard statistical techniques. A correction factor for ethnic origin was applied for all three markers and the screen-positive rate before and after correction was assessed for the various groups.

RESULTS

After maternal weight correction, in Afro-Caribbean women, the median PAPP-A was increased by 55% and the free beta-hCG increased by 11%. In south Asian women, the PAPP-A was increased by 8% and the free beta-hCG decreased by 7.5%. In Oriental women, the PAPP-A was increased by 9% and the free beta-hCG by 6%. For delta NT in Afro-Caribbean women, the values were 0.064 mm lower on average than in Caucasian women and for south Asian women 0.045 mm lower. The difference of -0.012 for Oriental women was not significant. Before correcting for ethnic origin, these changes resulted in the screen-positive rates being lower in the Afro-Caribbean group (3.7% vs 5.6%), the south Asian group (4.3% vs 5.6%) and Oriental group (4.9% vs 5.6%). After correction, the screen-positive rates were largely similar in the four groups.

CONCLUSION

Differences in median PAPP-A, free beta-hCG and, to a lesser extent, in NT exist in Afro-Caribbean, South Asian and Oriental women. In populations where the medians and delta NT reference ranges are established in predominantly Caucasian populations, some correction for ethnicity is appropriate and can redress differences in screen-positive rates between these different groups.

Ear length in trisomy 21 fetuses at 11-14 weeks of gestation

OBJECTIVE

To determine the value of measuring fetal ear length at 11-14 weeks of gestation in screening for chromosomal defects.

METHODS

The fetal ear length was measured in 450 fetuses immediately before chorionic villus sampling for karyotyping at 11-14 weeks of gestation.

RESULTS

The median gestational age was 12 (range, 11-14) weeks. The fetal ear was successfully examined in all cases. The fetal karyotype was normal in 409 cases and abnormal in 41, including 32 cases of trisomy 21. In the chromosomally normal group the fetal ear length increased significantly with crown-rump length from a mean of 3.7 mm at 45 mm to 6.9 mm at 84 mm. In the trisomy 21 fetuses the median ear length was significantly below the normal mean for crown-rump length by 0.45 mm (P = 0.013) but it was below the 5(th) centile of the normal range in only two (6.3%) of the cases. There was no significant association between the delta score of ear length and delta nuchal translucency in either the chromosomally normal (r = - 0.015, P = 0.753) or the trisomy 21 fetuses (r = - 0.014, P = 0.94).

CONCLUSIONS

At 11-14 weeks of gestation the ear length in trisomy 21 fetuses is significantly reduced but the degree of deviation from normal is too small for this measurement to be useful in screening for trisomy 21.

Surgical induction of ovulation in polycystic ovarian disease

The current lines of treatment of an ovulatory infertility due to polycystic ovarian disease lie between weight loss, insulin sensitising agents, clomiphene citrate, gonadotrophin therapy, or finally ovarian cauterisation. This review is looking at some of the current evidence for surgical and medical lines of treatment.