Fetal pyelectasis: relationship to maturation of the pelviureteric pacemaker, ureteric peristalsis and to bladder fullness

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Abstracts

examination of the region of interest for the confirmation of the ultrasonic interpretation. Results: The most frequent L1-, and L2-value in healthy individuals (A) was 1 (0 = black, 60 =bright white). However the level L4 – L5 and L5/S1 showed slightly higher L-values. In addition, when considering the factor ‘age’ there was also an inconstant increase in the L1- and L2-values sometimes to 18. The group B showed inconstantly higher L1- and L2-values than the healthy group A. However there was no explanation for people without low back pain showing L1- and L2-values of 10 or more. At this point we introduced the above mentioned L-ratio (L2:L1) which is a method to get an idea about the homogeneosity of the muscle. This L-ratio was crosschecked and confirmed with corresponding MRI sections of the lumbar spine. Group A showed at each cross section L-ratios above 0.6. In the group B we found a significant decrease in L-ratios at the affected but also at the adjacent levels. The L-ratio-value remained below 0.5. Finally in the group C all patients with ‘unknown’ low back pain history were detected by L-ratio. It was possible to discriminate upper middle and lower lumbar spine major complaints. The pathohistology confirmed the L-ratio although this technique is not commonly accepted. Discussion: The L-ratio provides information about the adjacent soft tissue column of the lumbar spine which represents an indicator of vertebral discal or ligamental disorders of the spine. It is an investigation in the very early diagnostic of low back pain. A L-ratio above 0.6 seems to indicate no structural spinal problems. A L-ratio below 0.5 has a significant (95%) tissue density change which is relied to a spinal disorder. The physician is able to realize more likely a somatic or a psychological disorder affecting the lumbar spine area.

Clinical implications of prenatally diagnosed lung lesions. A short term follow up Martinez D.a; Cameron H.a; Clarendon W.b aNorthern Fetal Society, General Infirmary, Leeds, UK b X-ray Department, General Infirmary, Leeds, UK Data was collected on 111 lung lesions diagnosed on prenatal ultrasound; 50 retrospectively and 61 prospectively. One-third of cases ended in termination of pregnancy or perinatal death, and two-thirds were liveborn and had no significant respiratory problems. Of the liveborn, one-third had a normal chest radiograph and two-thirds an abnormal radiograph. In neonates with an abnormal chest radiograph, further radiological investigation and/or surgical intervention was performed in a quarter of cases. Comparison between the retrospective and prospective series shows a significant fall in the rate of termination of pregnancy and postnatal surgical intervention, surgery being performed in only 10% of cases in the prospective series. Examples of prenatal ultrasound appearances correlated with postnatal radiographs and clinical outcome will be presented. There is a growing realisation that these lesions are clinically benign in the majority of cases. However, we emphasise, that

further follow up is required to determine whether they will become clinically significant in the long term. Fetal pyelectasis: relationship to maturation of the pelviureteric pacemaker, ureteric peristalsis and to bladder fullness Leung V.Y.F.; Metreweli C. Department of Diagnostic Radiology and Organ Imaging, Prince of Wales Hospital, Shatin, N.T., Hong Kong Objecti6e: To establish a nomogram of fetal hydronephrosis index (HI) [anteroposterior (AP) diameter of the renal pelvis divided by urinary bladder volume (UBV)] at different gestational age. Method: Five hundred and four uncomplicated singleton pregnancies from 20 to 38 weeks gestation were included. In each fetus, the maximum AP diameters of both renal pelves were measured on transverse view. The UBV was calculated using the ovoid volume formula.Results: The HI was not constant throughout the pregnancy, higher (mean =0.1543) from 20 to 27 weeks’ gestation and lower (mean =0.0253) from 28 to 38 weeks’ gestation (PB 0.0001). As the gestational age increased, the HI decreased (r 2 =0.5921). The correlation between fetal AP renal pelvis and the UBV was weak (r 2 = 0.1194). Conclusions: The behaviour of the HI suggests that the transmission and amplitude of the peristaltic wave, initiated in the renal pelvis pacemaker matures about 28 weeks’ gestation. Furthermore a full bladder is not a cause for dilatation of the renal pelvis in the fetus compared with the situations in adults and children. Comparative serial assessment of fetal parameters by ultrasound and MRI Walton J.M.a; Exton S.a; Roberts N.a; Whitehouse G.H.a; Pilling D.b aDepartment of Medical Imaging, The Uni6ersity of Li6erpool, Li6erpool, UK b Ultrasound Department, Li6erpool Womens Hospital, Li6erpool, UK MRI is a safe, non-invasive scanning technique which is finding increased research applications to assess fetal growth, particularly in the third trimester. The aims of this study were to estimate total fetal volume, fetal brain and liver volumes using MRI and the Cavalieri method, to measure fetal head and abdominal circumferences using ultrasound and to compare these measures with the relevant individual organ volumes and to predict and compare fetal weights determined by MRI and ultrasound. The subject was a healthy 32 year old, Gradiva 2: Para 1, with no obstetric problems. The fetus was imaged at 30 + , 32 +, 34 + and 38 +weeks gestation. MR images were obtained using a GRASS fast scan sequence in axial, sagittal and coronal sections. Fetal head and abdominal circumferences were measured using ultrasound. The total fetal volumes (MRI) were used to predict the fetal weight in grams using regression analysis. The fetus demonstrated a normal ultrasound growth profile. The total fetal volume, brain and liver volumes increased linearly with age between 30 and 38 weeks (actual increases