Mild cerebral ventricular enlargement is associated with schizophrenia, autism, epilepsy, and attention-deficit/hyperactivity disorder. Fetal ventriculomegaly is the most common central nervous system (CNS) abnormality affecting 1% of fetuses and is associated with cognitive, language, and behavioral impairments in childhood. Neurodevelopmental outcome is partially predictable by the 2-dimensional size of the ventricles in the absence of other abnormalities. We hypothesized that isolated fetal ventriculomegaly is a marker of altered brain development characterized by relative overgrowth and aimed to quantify brain growth using volumetric magnetic resonance imaging (MRI) in fetuses with isolated ventriculomegaly. Fetal brain MRI (1.5 T) was performed in 60 normal fetuses and 65 with isolated ventriculomegaly, across a gestational age range of 22-38 weeks. Volumetric analysis of the ventricles and supratentorial brain structures was performed on 3-dimensional reconstructed datasets. Fetuses with isolated ventriculomegaly had increased brain parenchyma volumes when compared with the control cohort (9.6%, P < 0.0001) with enlargement restricted to the cortical gray matter (17.2%, P = 0.002). The extracerebral cerebrospinal fluid and third and fourth ventricles were also enlarged. White matter, basal ganglia, and thalamic volumes were not significantly different between cohorts. The presence of relative cortical overgrowth in fetuses with ventriculomegaly may represent the neurobiological substrate for cognitive, language, and behavioral deficits in these children.

Objective Myo-inositol (Myo-ins) is a marker of neuroglial cells, being present in the astrocytes of brain tissue, but also functions as an osmolyte. Numbers of astrocytes are known to increase following injury to the brain. Growth-restricted fetuses are at increased risk of later neurodevelopmental impairments even in the absence of overt lesions and despite preserved/increased cerebral blood flow. This study aims to investigate brain Myo-ins metabolism in fetuses with intrauterine growth restriction (IUGR) and evidence of cerebral redistribution using magnetic resonance spectroscopy (MRS) at a short echo time. Study design Biometry and Doppler assessment of blood flow was assessed using ultrasound in 28 fetuses with IUGR and 47 appropriately grown control subjects. MRI was used to exclude overt brain injury. Proton magnetic resonance spectroscopy of the fetal brain was then performed at an echo time of 42 ms to examine the Myo-ins:Choline (Cho), Myo-ins:Creatine (Cr) and Cho:Cr ratios. Results No alterations in brain Myo-ins:Cho, Myo-ins:Cr or Cho:Cr ratios were detected between appropriately grown and growth restricted fetuses. Conclusions IUGR is not associated with a measureable difference in brain myo-inositol ratios. This may be due to the protective effects of preserved cerebral blood flow in growth restriction and comparable astrocyte numbers when compared to controls.

SUMMARY: Fetal and neonatal MR imaging is increasingly used as a complementary diagnostic tool to sonography. MR imaging is an ideal technique for imaging fetuses and neonates because of the absence of ionizing radiation, the superior contrast of soft tissues compared with sonography, the availability of different contrast options, and the increased FOV. Motion in the normally mobile fetus and the unsettled, sleeping, or sedated neonate during a long acquisition will decrease image quality in the form of motion artifacts, hamper image interpretation, and often necessitate a repeat MR imaging to establish a diagnosis. This article reviews current techniques of motion compensation in fetal and neonatal MR imaging, including the following: 1) motion-prevention strategies (such as adequate patient preparation, patient coaching, and sedation, when required), 2) motion-artifacts minimization methods (such as fast imaging protocols, data undersampling, and motion-resistant sequences), and 3) motion-detection/correction schemes (such as navigators and self-navigated sequences, external motion-tracking devices, and postprocessing approaches) and their application in fetal and neonatal brain MR imaging. Additionally some background on the repertoire of motion of the fetal and neonatal patient and the resulting artifacts will be presented, as well as insights into future developments and emerging techniques of motion compensation.

Monochorionic twins are at increased risk of congenital and antenatally acquired brain anomalies, particularly in the presence of twin-twin transfusion syndrome (TTTS) or single intrauterine death (sIUD). This study demonstrates the role of fetal MRI in diagnosing brain abnormalities in high risk MCDA pregnancies. Fetal MR and ultrasound findings were compared in 93 consecutive high risk MCDA pregnancies (142 fetuses) referred to our unit between 2007-2011; 26 twin pairs post fetoscopic laser ablation (FLAP) for TTTS, 13 twin pairs with structural abnormalities detected on ultrasound and 44 survivors of sIUD (13 post FLAP, 19 fetocides with radiofrequency ablation, 12 spontaneous). MR scans performed according to our local fetal protocol include T1 and T2 weighted images. Ultrasound was performed at the referring unit a median of 8 days before MRI. MR and ultrasound findings were concordant for normal findings in 69% of pregnancies and for abnormal findings in 10%. Findings were discordant in the remaining 21% (3% MR findings less severe than US, 11% abnormalities on MRI with normal ultrasound, 7% additional abnormalities seen on MRI). New MR findings occurred in all referral groups (22% TTTS twin pairs, 14% sIUD singletons and 31% twin pairs with structural abnormalities) leading to increased surveillance, earlier intervention or altered postnatal management. Fetal MRI confirms abnormality or detects new findings in 1 in 3 high risk MCDA pregnancies. Fetal MRI provides parents and clinicians with important additional information that impacts future management and should be routine in all high risk MCDA pregnancies.

Background Fetal MRI is increasingly used in clinical settings. Ongoing vigilance regarding safety is essential. Medicines and Healthcare Products Regulatory Agency (MHRA) 2007 limits whole body specific absorption rate (SAR) to 2W/Kg (normal mode) during MRI. Estimated fetal temperature must not exceed 38°C, assuming fetal-maternal temperature gradient ∼0.5°C. Temperature rise depends on the specific sequences used and length of image acquisition. Aim To audit maternal temperature during fetal MR scans in accordance with recommended safety guidance. Methods A prospective study of 100 women undergoing clinical and research fetal MR scan. Our typical protocol includes standard T2-weighted single-shot images (SAR 2 W/kg). Tympanic temperatures were measured within 5 min of the start and end of scanning and length of time in the scanner was documented. Results Mean pre and post-scan temperatures were 36.6°C (35.4–37.3°C) and 37°C (36–37.9°C) respectively. The mean temperature increase was 0.4°C (0–1.3°C). While an increase exceeding 1°C occurred in 3/100, none resulted in post-scan temperatures over 37.5°C. Six participants had a post-scan temperature above 37.5°C; of these 4 temperatures were above 37°C at the start of the scan. Mean length of time in the scanner was 59 min (25–110 min) of which approximately 75% involves image acquisition, according to our typical protocol. Conclusions Mean temperature rises during long MR examinations are acceptable. Screening maternal temperature pre-scan identifies women in whom fetal temperature is most likely to exceed 38°C. Women with pre-scan temperatures over 37°C should be imaged cautiously, with intervals between acquisitions to avoid heat absorption.

PURPOSE:To prospectively evaluate the clinical effectiveness of snapshot inversion recovery (SNAPIR), which is a dedicated optimized inversion-recovery-prepared single-shot fast spin-echo T1-weighted sequence, in the delineation of normal fetal brain anatomy compared with that of the currently used T1-weighted gradient-echo protocol, which often yields images of poor quality due to motion artifacts and inadequate contrast. MATERIALS AND METHODS:This study was approved by the hospital research ethics committee, and informed written consent was obtained from all patients. Forty-one fetuses were examined at 19-37 weeks gestation (mean, 29 weeks gestation) by using both the standard T1-weighted protocol and the optimized T1-weighted SNAPIR protocol with a 1.5-T imager. Two independent blinded observers performed qualitative analysis, evaluating overall diagnostic quality, detailed anatomic delineation, and severity of motion artifacts. Quantitative analysis comprised calculation of contrast ratios (CRs) for the cortical gray matter, subplate, white matter, and cerebrospinal fluid. The Wilcoxon signed rank test was used to compare image rating scores, the paired t test was used to compare CRs, and κ statistics were used to test interobserver agreement. RESULTS:Both overall diagnostic quality (P < .001) and detailed anatomic delineation (P < .001) were enhanced with SNAPIR compared with the standard T1-weighted acquisition. Also, motion artifacts were less severe (P = .008) and less extensive (P < .001) with SNAPIR. Corresponding CRs were increased with SNAPIR in seven of eight examined regions. CONCLUSION:SNAPIR is a promising robust alternative to the current T1-weighted acquisitions; its role in the detection of disease requires further study.

Background Antenatal ultrasound studies report similar transcerebellar diameter (TCD) measurements within monochorionic twin pairs regardless of growth concordance. Biparietal diameter (BPD) studies demonstrate less consistent results. The cerebellum is recognised as having an important role in later behaviour and cognition. Recent research shows reduced cerebellar growth in IUGR singletons. We hypothesise that monochorionic twins treated for twin-twin transfusion syndrome (TTTS) will show differences in cerebellar measurements as well as BPD. Methods The study population comprised twenty three MCDA twin pregnancies with TTTS treated by fetoscopic laser photocoagulation between 16 and 24 weeks gestational age (mean 20 weeks). Fetal MRI scan was performed approximately 5 weeks post treatment (range 2–10 weeks). BPD and TCD were measured for each twin and analysed using paired samples t-test. Twins with signs of congenital or acquired brain injury were excluded. Results BPDs as well as TCDs and cerebellar vermis height were significantly different (p<0.01) within twin pairs affected by TTTS. However the ratio of TCD to BPD was significantly greater in the smaller twin (p<0.01). Conclusion We report the novel finding of significant intrapair differences in both BPD and cerebellar parameters measured by fetal MRI in twins treated for TTTS. There appears to be some sparing of the cerebellum relative to cerebral hemisphere growth, possibly due to its anastamotic blood supply and reflecting its importance as an evolutionary structure. Cerebellar underdevelopment may underlie later impairments seen in smaller twins.

Background: Episodes of intestinal ischaemia are likely to be central to the pathogenesis of necrotising enterocolitis. Echocardiographic techniques can estimate volume of superior mesenteric artery(SMA) flow1, however these measures have not yet been validated. Phase Contrast Magnetic resonance(PCMR) techniques have been shown to provide repeatable quantifications of cardiac output and systemic perfusion in newborn infants2. The aim of this study was to assess the feasibility of performing PCMR assessments of abdominal visceral blood flow in newborn preterm infants. Methods: Scans were performed on 7 infants with median(range) gestation 34(30.3-37.7) weeks, weight at scan 1833(790-2800)grams using a Philips 3.0T scanner. PCMR slices(resolution-0.6/0.6/4mm,TR/TE-5.9/3.1ms) were placed at the proximal SMA and on the descending aorta(DAo) proximal to the celiac plexus and distal to the renal arteries(Figure). Flow was quantified using in-built software(ViewForum) incorporating automated vessel-edge detection Results: Intestinal flow was taken as SMA flow; visceral non-SMA(VnonSMA) flow was taken as proximal DAo - SMA - distal DAo (=celiac plexus plus inferior mesenteric and renal artery flow). Images were successfully obtained in all 7 infants. Median intestinal flow was 31.8(12.1-67.1)ml/kg/min, VnonSMA was 55.7(34.3-99)ml/kg/min. Conclusions: PCMR assessment of volume of SMA and visceral non-SMA blood flow is feasible in newborn infants. Further study is required to assess repeatability and correlation with echocardiography.

Magnetic Resonance Imaging (MRI) has become an established technique in fetal medicine, providing complementary information to ultrasound in studies of the brain. MRI can provide detailed structural information irrespective of the position of the fetal head or maternal habitus. Proton Magnetic Resonance Spectroscopy ((1)HMRS) is based on the same physical principles as MRI but data are collected as a spectrum, allowing the biochemical and metabolic status of in vivo tissue to be studied in a non-invasive manner. (1)HMRS has been used to assess metabolic function in the neonatal brain but fetal studies have been limited, primarily due to fetal motion. This review will assess the technique and findings from fetal studies to date.

OBJECTIVE:The purpose of this study was to investigate alterations in brain metabolism in fetuses with intrauterine growth restriction (IUGR) and evidence of cerebral redistribution of blood flow. STUDY DESIGN:Biometry and Doppler assessment of blood flow was assessed with ultrasound in 28 fetuses with IUGR and cerebral redistribution and in 41 appropriately grown control subjects. Proton magnetic resonance spectroscopy of the fetal brain was then performed to determine the presence of choline (Cho), creatine (Cr), N-acetylaspartate (NAA), and lactate and to generate ratios for NAA:Cho, NAA:Cr, and Cho:Cr. RESULTS:Sixty-five percent of spectra were interpretable: N-acetylaspartate, choline, and creatine peaks were identified in all these spectra; lactate was present in 5 IUGR fetuses and in 3 appropriately grown fetuses. NAA:Cr and NAA:Cho ratios were significantly lower in IUGR fetuses with cerebral redistribution. CONCLUSION:Cerebral redistribution is associated with altered brain metabolism that is evidenced by a reduction in NAA:Cho and NAA:Cr ratios.

Objective: Our objectives were to determine if MR imaging of the placenta could demonstrate a specific placental phenotype in small for gestational age fetuses with increasing severity of fetal growth restriction, and if MRI findings at the time of scan could be used to predict fetal or neonatal mortality.Method: We included singleton growth restricted fetuses with increasing severity of fetal growth restriction secondary to placental insufficiency. 20 growth restricted fetuses and 28 normal fetuses were scanned once during pregnancy at varying gestations. MRI scans were performed on a 1.5T system using ssFSE sequences through the uterus. Data was collected on the severity of fetal growth restriction and pregnancy outcome, including clinical neonatal details, perinatal mortality, and birthweight and centile. Placental volume, maximal placental thickness, the placental thickness to volume ratio, the placenta to amniotic fluid signal intensity ratio, and the presence of abnormal signal intensity consistent with placental pathology were noted. In a subset of patients, histopathological diagnosis was compared with the MRI appearance of the placenta.Results: There was a significant increase in the placental volume affected by pathology in growth restricted fetuses (p < 0.001). The placental appearance was also thickened and globular, with an increase in the placental thickness to volume ratio (p < 0.001). Although placental volume increased with increasing gestation, it remained reduced in the growth restricted fetuses (p = 0.003). There was a significant correlation between the severity of fetal growth restriction and the placental volume affected by pathology, the placental thickness to volume ratio, and the placental volume. ROC analysis showed that fetal or neonatal death was predicted by the percentage of abnormal signal intensity consistent with placental pathology (p = 0.002). The presence of a thickened, globular placenta and a maximal placental thickness to volume ratio above the 95% confidence limit for gestation was significantly associated with an increased incidence of fetal or neonatal mortality (relative risk = 1.615, p = 0.001 and relative risk = 7, p < 0.001).Conclusions: The MRI appearance of the placenta provides an indication of the severity and underlying disease process in fetal growth restriction. In units where MRI imaging of the growth restricted fetus occurs, we suggest that the assessment of the placenta should also occur as it may contribute to management decisions in cases at the threshold of viability. It may have a role to play in monitoring disease severity, and the effect of future interventions designed to improve placental function. Crown Copyright (C) 2010 Published by Elsevier Ltd. All rights reserved.

BACKGROUND AND PURPOSE: The assessment of motor function is an essential component of neurologic examinations, which imaging studies have extended to the fetus. US assessment is hampered by a limited FOV, whereas MR imaging has the potential to be an alternative. Our objectives were to optimize a cine MR imaging sequence for capturing fetal movements and to perform a pilot analysis of the relationship between the frequency of movements and uterine spatial constrictions in healthy fetuses.MATERIALS AND METHODS: Initially, a bSSFP cine sequence was selected for optimizatior, and various compromises were explored in all acquisition parameters to achieve an effective balance between anatomic coverage of the fetus and the temporal resolution of cine data, with the aim of maximizing both. Subsequently, cross-sectional qualitative and quantitative analyses of fetal movements were performed prospectively by using a cohort of 37 healthy fetuses (median GA, 29 weeks; range, 20-37 weeks) with the optimized cine protocol. Two smaller subgroups were selected for representative sampling of overall behavior patterns by using cine data of longer duration and for volumetric quantification of free intrauterine space.RESULTS: The optimized cine sequence, with TR/TE of 3.21/1.59 ms, coupled with parallel imaging and partial-Fourier imaging, resulted in a section-acquisition time of 0.303 seconds. Anatomic coverage was enhanced by using a combination of thick sagittal sections (30-40 mm) and multisection acquisitions to display movements in all fetal limbs, head, and trunk simultaneously. All expected motor patterns were observed throughout this gestational period, and a significant decreasing trend in overall movement frequency with age was demonstrated (r = -0.514, P = .0011). Also a significant negative correlation was found between overall movement frequency and the total intrauterine free space (r = -0.703, P = .0001). Furthermore, a significant decrease in the frequency of leg movements was shown in fetuses older then 30 weeks' GA compared with those younger than that (P = .015).CONCLUSIONS: Cine MR imaging is effective for observing fetal movements from midgestation with near full-body coverage. Also, reductions in free space with increasing GA appear to be a factor in the gradual reductions in overall levels of fetal activity as well as in restrictions in movement within specific regions of the fetal anatomy.

Magnetic resonance imaging of the brain is invaluable in assessing the neonate who presents with encephalopathy. Successful imaging requires adaptations to both the hardware and sequences used for adults. Knowledge of the perinatal and postnatal details are essential for the correct interpretation of the imaging findings. Perinatal lesions are at their most obvious on conventional imaging between 1 and 2 weeks from delivery. Very early imaging is useful to guide management in ventilated neonates but abnormalities may be subtle on conventional sequences. Diffusion-weighted imaging (DWI) is clinically useful for the early identification of ischaemic tissue in the neonatal brain, the pattern of which can predict outcome. DWI may underestimate the final extent of injury, particularly basal ganglia and thalamic lesions. Serial imaging with quantification of both tissue damage and structure size provides invaluable insights into the effects of perinatal injury on the developing brain.

INTRODUCTION Intrauterine fetal growth restriction secondary to placental insufficiency often results in iatrogenic preterm delivery, and a complicated neonatal period. Although in the intrauterine period these fetuses demonstrate the brain sparing effect where head growth tends to be maintained at the expense of other organs; in the longer term, these children may have neurodevelopmental delay and behavioural disorders indicating compromised brain development that cannot be explained by the complications of premature delivery alone. The cerebellum is increasingly recognised to play an important role in cognitive and behavioural functions and one fetal 3D ultrasound study found a reduction total brain and regional brain growth in intrauterine growth restriction from as early as 24 weeks gestation, however intrauterine assessment of fetal brain and cerebellar volume using MRI has been limited by difficulties assessing this in the presence of fetal motion.

International Journal of Gynecology & ObstetricsVolume 107, Issue S2 p. S350-S350 Free communication (oral) presentations O901 Lactate and the normally developing fetal brain L. Story, L. StorySearch for more papers by this authorM. Damodaram, M. DamodaramSearch for more papers by this authorJ. Allsop, J. AllsopSearch for more papers by this authorA. McGuinness, A. McGuinnessSearch for more papers by this authorM. Wylezinksa-Arridge, M. Wylezinksa-ArridgeSearch for more papers by this authorS. Kumar, S. KumarSearch for more papers by this authorM. Rutherford, M. RutherfordSearch for more papers by this author L. Story, L. StorySearch for more papers by this authorM. Damodaram, M. DamodaramSearch for more papers by this authorJ. Allsop, J. AllsopSearch for more papers by this authorA. McGuinness, A. McGuinnessSearch for more papers by this authorM. Wylezinksa-Arridge, M. Wylezinksa-ArridgeSearch for more papers by this authorS. Kumar, S. KumarSearch for more papers by this authorM. Rutherford, M. RutherfordSearch for more papers by this author First published: 20 November 2009 https://doi.org/10.1016/S0020-7292(09)61274-1AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume107, IssueS2Abstracts of XIX FIGO World Congress of Gynecology and ObstetricsOctober 2009Pages S350-S350 RelatedInformation

International Journal of Gynecology & ObstetricsVolume 107, Issue S2 p. S149-S149 Free communication (oral) presentations O198 Three-dimensional MR reconstruction and evaluation of the cerebellum to whole brain ratio in IUGR fetuses M. Damodaram, M. DamodaramSearch for more papers by this authorL. Story, L. StorySearch for more papers by this authorJ. Allsop, J. AllsopSearch for more papers by this authorA. McGuinness, A. McGuinnessSearch for more papers by this authorA. Patel, A. PatelSearch for more papers by this authorS. Kumar, S. KumarSearch for more papers by this authorM. Rutherford, M. RutherfordSearch for more papers by this author M. Damodaram, M. DamodaramSearch for more papers by this authorL. Story, L. StorySearch for more papers by this authorJ. Allsop, J. AllsopSearch for more papers by this authorA. McGuinness, A. McGuinnessSearch for more papers by this authorA. Patel, A. PatelSearch for more papers by this authorS. Kumar, S. KumarSearch for more papers by this authorM. Rutherford, M. RutherfordSearch for more papers by this author First published: 20 November 2009 https://doi.org/10.1016/S0020-7292(09)60570-1Citations: 1AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article.Citing Literature Volume107, IssueS2Abstracts of XIX FIGO World Congress of Gynecology and ObstetricsOctober 2009Pages S149-S149 RelatedInformation

International Journal of Gynecology & ObstetricsVolume 107, Issue S2 p. S463-S464 Poster presentations P186 3-dimensional MR reconstruction and brain volumetry in IUGR fetuses M. Damodaram, M. DamodaramSearch for more papers by this authorL. Story, L. StorySearch for more papers by this authorJ. Allsop, J. AllsopSearch for more papers by this authorA. McGuinness, A. McGuinnessSearch for more papers by this authorA. Patel, A. PatelSearch for more papers by this authorS. Kumar, S. KumarSearch for more papers by this authorM. Rutherford, M. RutherfordSearch for more papers by this author M. Damodaram, M. DamodaramSearch for more papers by this authorL. Story, L. StorySearch for more papers by this authorJ. Allsop, J. AllsopSearch for more papers by this authorA. McGuinness, A. McGuinnessSearch for more papers by this authorA. Patel, A. PatelSearch for more papers by this authorS. Kumar, S. KumarSearch for more papers by this authorM. Rutherford, M. RutherfordSearch for more papers by this author First published: 20 November 2009 https://doi.org/10.1016/S0020-7292(09)61677-5Citations: 1AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article.Citing Literature Volume107, IssueS2Abstracts of XIX FIGO World Congress of Gynecology and ObstetricsOctober 2009Pages S463-S464 RelatedInformation

T. Hayat, J. Allsop, A. McGuinness, F. Ferrari, M. Rutherford, and J. V. Hajnal Robert Steiner MRI Unit, Imaging Sciences Department, MRC Clinical Sciences Centre, Hammersmith Hospital, Imperial College London, London, United Kingdom, Perinatal Imaging Group, MRC Clinical Sciences Centre, Hammersmith Hospital, Imperial College London, London, United Kingdom, Department of Pediatrics and Neonatology, Modena University Hospital, Italy

Introduction Diffusion tensor imaging (DTI) of the fetal brain is attracting increasing interest [1-3] with recent papers starting to present tractography results [4]. To overcome maternal motion, many studies have been performed using breath-hold methods, although this severely reduces the amount of available data. However, even in breath-held acquisitions, the fetus can move substantially, so that individual diffusion weighted (DW) images acquired at the same geometrical slice position can be anatomically inconsistent. This problem was addressed by Jiang et al. [5], who extended the Snapshot to Volume Reconstruction (SVR) technique [6, 7] for application to DTI. The SVR approach works on single shot image slices with image registration to determine their correct location in an anatomical space, and then uses scattered data interpolation to reconstruct self consistent high resolution volume images. For snap-shot images of consistent contrast the registration process can employ cost functions like cross correlation (CC) and this has been shown to position slices in anatomical space with sub-voxel accuracy. In the case of DW images, the contrast changes with sensitization direction, so a more general cost function has to be used. Using this approach, high quality apparent diffusion maps of the fetal brain were made, but fractional anisotrophy (FA) maps proved less robust, and tractography was not demonstrated. In this work, we improved the DTI-SVR algorithm using more robust model-driven registrations, which improved the final reconstructed images and allowed white matter tracts to be obtained using a standard tracking approach.