The quantitative lung index: the left lung.

OBJECTIVE: We have previously described a gestational age-independent sonographic parameter to assess fetal lung growth in the right lung (right quantitative lung index, or QLI-R). The purpose of this study was to develop a similar sonographic parameter to assess the growth of the left lung in the fetus, independent of gestational age, or QLI-L. STUDY DESIGN: A new index, the QLI-L was derived using published formulas for the head circumference (HC) and the area of the base of the left lung (LA), with the corresponding percentiles. RESULTS: Left lung growth can be expressed using the following formula: QLI-L=LAL(HC12)2. The 50th percentile of the QLI-L remained approximately constant at 1.0 for the GA between 16-32 weeks. A small left lung (<1st percentile) was defined as a QLI-L < 0.5. CONCLUSIONS: Fetal left lung growth can be adequately described independent of gestational age using the QLI-L. Further experience is needed to assess the clinical accuracy of the QLI-L in characterizing fetal left lung growth.

The observed vs. expected lung-to-head ratio does not correct for the effect of gestational age on the lung-to-head ratio.

OBJECTIVES: To assess whether the observed vs. expected lung-to-head ratio (o/e LHR) corrects for the dependence of the LHR on gestational age. STUDY DESIGN: Published data on right lung area (LA) and LHR were used to plot the 50th percentile and different fixed values of the o/e LHR (e.g. 30%) against gestational age from 16-32 weeks. The Z-scores for various fixed o/e LHR values and similar percent value of LA were calculated. The effect of using a fixed LHR or a fixed o/e LHR was tested against gestational age. The o/e LHR-equivalent to a fixed LHR of 1.0 was assessed against gestational age. RESULTS: The LHR and the o/e LHR both increase with gestational age. The Z-score of a given fixed value of the o/e LHR (e.g. 30%) is not similar to the Z-score of the same percent (e.g., 30%) of the expected LA, and thus identifies different proportions of subjects. A fixed o/e LHR (e.g. 30%) results in different populations, depending on the gestational age. The o/e LHR equivalent to an LHR value of 1.0 decreases from 80% at 16 weeks to 30% at 32 weeks. CONCLUSIONS: The o/e LHR is not independent of gestational age. Studies using this parameter should be interpreted with caution.

The quantitative lung index (QLI): a gestational age-independent sonographic predictor of fetal lung growth.

OBJECTIVE: We sought to develop a gestational age-independent sonographic parameter to characterize lung growth. STUDY DESIGN: Reported descriptors of lung growth, including lung-to-head circumference (HC) ratio (LHR) and observed/expected LHR, were examined. A new index, the quantitative lung index (QLI) was derived using published data on HC and the area of the base of the right lung. RESULTS: Neither the LHR nor the observed/expected LHR proved to be gestational age independent. Right lung growth can be expressed using the following formula: QLI = lung area/(HC/10)^2. The 50th percentile of the QLI remained constant at approximately 1.0 for the gestational age between 16-32 weeks. A small lung (<1st percentile) was defined as a QLI <0.6. CONCLUSION: Fetal right lung growth can be adequately described using the QLI, independent of gestational age. Further studies are needed to assess the clinical accuracy of the QLI in characterizing fetal right lung growth.

Resultados visuales en 600 pacientes tratados por desprendimiento de retina / Visual results in 600 patients treated for retinal detachment

Se realizó un estudio retrospectivo en 600 pacientes con diagnóstico de desprendimiento de retina regmatógeno, con objeto de esclarecer las variables más significativas y su correlación con los resultados anatómicos, visuales y complicaciones posteriores al tratamiento quirúrgico. Los pacientes fueron tratados quirúrgicamente, con cerclaje 384 ojos (64 por ciento); cerclaje con implante 76 ojos (12.6 por ciento); vitrectomía 72 ojos (12 por ciento) e implante 68 ojos (11.3 por ciento). Se realizó un análisis estadístico (diagrama de dispersión) encontrándose que presentan una mejoría en promedio de 2 a 2.5 líneas visuales con respecto a la agudeza visual preoperatoria; que representa un 77 por ciento de probabilidades de mejoría. En cuanto al éxito anatómico (retina aplicada) se encontró que fue del 85 por ciento. Las complicaciones más frecuentes fueron: desprendimiento de retina recidivante con inclusión de área macular (15 por ciento) y vitreorretinopatía proliferativa (6.6 por ciento).