A retrospective segmentation analysis of placental volume by magnetic resonance imaging from first trimester to term gestation.

BACKGROUND: Abnormalities of the placenta affect 5-7% of pregnancies. Because disturbances in fetal growth are often preceded by dysfunction of the placenta or attenuation of its normal expansion, placental health warrants careful surveillance. There are limited normative data available for placental volume by MRI. OBJECTIVE: To determine normative ranges of placental volume by MRI throughout gestation. MATERIALS AND METHODS: In this cross-sectional retrospective analysis, we reviewed MRI examinations of pregnant females obtained between 2002 and 2017 at a single institution. We performed semi-automated segmentation of the placenta in images obtained in patients with no radiologic evidence of maternal or fetal pathology, using the Philips Intellispace Tumor Tracking Tool. RESULTS: Placental segmentation was performed in 112 women and had a high degree of interrater reliability (single-measure intraclass correlation coefficient =0.978 with 95% confidence interval [CI] 0.956, 0.989; P<0.001). Normative data on placental volume by MRI increased nonlinearly from 6 weeks to 39 weeks of gestation, with wider variability of placental volume at higher gestational age (GA). We fit placental volumetric data to a polynomial curve of third order described as placental volume = -0.02*GA3 + 1.6*GA2 - 13.3*GA + 8.3. Placental volume showed positive correlation with estimated fetal weight (P=0.03) and birth weight (P=0.05). CONCLUSION: This study provides normative placental volume by MRI from early first trimester to term gestation. Deviations in placental volume from normal might prove to be an imaging biomarker of adverse fetal health and neonatal outcome, and further studies are needed to more fully understand this metric. Assessment of placental volume should be considered in all routine fetal MRI examinations.

Physiotherapist-designed aquatic exercise programme for community-dwelling elders with osteoarthritis of the knee: a Hong Kong pilot study.

OBJECTIVES. To examine the effectiveness and feasibility of a community-based aquatic exercise programme for elders with osteoarthritis of the knee. DESIGN. Prospective intervention study, with a before-and-after design. SETTING. Community elders. PARTICIPANTS. Twenty elders aged 65 years or above (mean, 72 years) attending four Elderly Health Centres of the Department of Health who had suffered from osteoarthritis of the knee for at least 3 years and with mild-to-severe knee pain. INTERVENTION. A 10-week aquatic exercise programme designed and led by physiotherapists. MAIN OUTCOME MEASURES. Range of motion and power of extension of the knees, functional reach test, repeated sit-to-stand test, and the Chinese Arthritis Impact Measurement Scales 2. RESULTS. There was an improvement in the median range of knee flexion from 115° to 125° (P<0.01) and the median strength of the quadriceps from 9 kg to 21 kg (P<0.001). The median score of the functional reach test increased from 20 cm to 28 cm (P<0.001) and the repeated sit-to-stand test from 10 to 14 repetitions (P<0.001). Also, there was an improvement in the mobility level (P<0.01), walking and bending ability of the trunk (P<0.05), levels of pain (P<0.01) and mood (P<0.01), and the total score (P<0.01) in the Chinese Arthritis Impact Measurement Scales 2. CONCLUSIONS. Physiotherapist-designed aquatic exercise has definite benefits in terms of physical and psychosocial functioning, and should be promoted as one of the strategies to enhance long-term self-management of community elders with knee osteoarthritis.