The latest medical research on Radiology

The research magnet gathers the latest research from around the web, based on your specialty area. Below you will find a sample of some of the most recent articles from reputable medical journals about radiology gathered by our medical AI research bot.

The selection below is filtered by medical specialty. Registered users get access to the Plexa Intelligent Filtering System that personalises your dashboard to display only content that is relevant to you.

Want more personalised results?

Sign up for free

Hysterotomy level at cesarean section and occurrence of large scar defects: a randomized single-blind trial.

Ultrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology

To study the effect of cesarean hysterotomy level on the occurrence of large uterine scar defects 6-9 months after delivery.

This was a two-center, randomized, single-blind trial of a surgical procedure with masked assessment of the principal outcome under study. Women in active labor (cervix dilatation ≥5 cm) were randomized into a high incision (HIGH) or a low incision (LOW) group. Hysterotomy was performed 2 cm above (HIGH) or 2 cm below (LOW) the plica vesicouterina. Women were examined with saline contrast sonohysterography to assess the appearance of the hysterotomy scar 6-9 months after delivery. The main outcome was occurrence of a large scar defect. A scar defect was defined as large if the remaining myometrial thickness over the defect was ≤2.5 mm. Secondary outcomes were operative complications, perinatal- and long-term outcomes.

122 patients were included in the trial and 114 were assessed with ultrasound. Large scar defects were seen in 4 (7%) of 55 women in the high incision group and in 24 (41%) of 59 women in the low incision group (P< 0.001) odds ratio 8.7 (95% CI 2.8-27.4).

The cesarean hysterotomy level in women in advanced labor is associated with the occurrence of large scar defects detected by transvaginal ultrasound 6-9 months after delivery. This article is protected by copyright. All rights reserved.

Local validation and calibration of preeclampsia screening algorithms.

Ultrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology

A recent Practice Guideline issued by the International Society of Ultrasound in Obstetrics and Gynecology recommends a combination of a priori fac...

Evaluation of automated tool for 2D fetal biometry.

Ultrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology

To determine whether an automated tool can automatically measure the fetal head circumference (HC), abdominal circumference (AC) and femur length (FL) on frozen 2D ultrasound images.

Ultrasound images from 100 pregnancies between 20 to 40 weeks of gestation were assessed, ensuring equal distribution of data throughout gestational age. For each pregnancy, three standard biometric variables (HC, AC, FL) were measured three times (nine independent image acquisitions). An algorithm (Philips Research) was then used to detect the structure and automatically place measurement calipers. This caliper placement was assessed in two ways. Firstly, clinical assessment was undertaken to determine whether the caliper placement was correct, defined as "acceptable for clinical management"; or whether minor or major adjustment was required. Secondly, the resulting automatic measurements were compared to manual measurements, taken in real time. Differences were calculated and expressed as percentages to correct for fetal growth with advancing gestation.

After exclusion of one pregnancy (due to technical failure), a total of 891 images, 297 for each biometric variable, were analyzed. The algorithm failed to place calipers for the AC in 9 images, whereas there were no failures on HC and FL. In the subjective quality assessment of automatic caliper placement, 475 images (53.3%) were judged to be clinically acceptable and did not require any adjustment, while 317 (35.6%) and 90 images (10.1%) required minor and major adjustments respectively. The mean error (ME) between manual and automatic HC was -0.21cm (-0.81%) with 95% limits of agreement (LOA) between -3.73% and 2.12%. For AC and FL the ME was 0.72cm (2.40%) with LOA between -9.48% and 14.27%; and 0.21cm (3.76%, LOA between -8.38% and 15.91%), respectively.

The automated tool correctly identified the biometric variable in 99% of frozen images. The resulting measurements have a high degree of accuracy and compare well with previously published manual to manual agreement. The measurements exhibited bias, with the automated tool underestimating biometry; this could be overcome by further improvements in the algorithm. Nevertheless, adjustable calipers for manual correction remains a requirement. This article is protected by copyright. All rights reserved.

How to assess the ureters during pelvic ultrasound.

Ultrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology

In this paper, we describe a '6 step' detailed approach to ultrasound assessment of the ureters during pelvic ultrasound examination. We discuss tips and common examination findings.

The pelvic segments of normal ureters can be identified in almost all women on transvaginal ultrasound examination and the method described is useful in detecting urinary tract abnormalities. This article is protected by copyright. All rights reserved.

Deep learning enables automatic quantitative assessment of the puborectalis muscle and the urogenital hiatus in the plane of minimal hiatal dimensions.

Ultrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology

Measuring the length, width and area of the urogenital hiatus (UH), and the length and mean echo intensity (MEP) of the Puborectalis muscle (PRM) automatically and observer independently in the plane of minimal hiatal dimensions from transperineal ultrasound (TPUS) images by automatic segmentation of the UH and the PRM using deep learning.

In 1318 3D/4D TPUS volume datasets, images of the plane of minimal hiatal dimensions were manually obtained and the UH and the PRM were manually segmented. Those images were obtained from 253 nulliparae at 12 and 36 weeks pregnancy with the PRM at rest, contraction and Valsalva. A total of 713 images were used to train a convolutional neural network (CNN) to automatically segment the UH and the PRM in the plane of minimal hiatal dimensions. In the remaining dataset (test set 1, TS1, 601 images, 4 images were excluded), the performance of the CNN was evaluated and compared to the manual segmentations. The performance of the CNN was also tested on 119 images of an independent dataset of 40 nulliparae at 12 weeks pregnancy. This dataset was acquired and manually segmented by another different observer (TS2, 2 images were excluded). For these segmentations, the segmentation success was manually scored. Based on the CNN segmentations the following clinically relevant parameters were measured; the length, width and area of the UH, and the length and mean echo intensity of the PRM. The overlap (Dice similarity index (DSI)), surface distance (mean absolute distance (MAD) and Hausdorff distance(HDD)) between manual and CNN segmentations were measured to investigate the similarity of both segmentations. For the measured clinically relevant parameters, the intraclass correlation coefficients (ICC) between manual and CNN results were determined.

Fully automatic CNN segmentation was successful in 99.0% and 93.2% for TS1 and TS2, respectively. DSI, MAD and HDD showed good overlap and distance between manual and CNN segmentations in both test sets. This was reflected in the ICC values of the length (0.96 resp. 0.95), width (0.77 resp. 0.87) and area (0.96 resp. 0.91) of the UH and the length of the PRM (0.87 resp. 0.73) and the MEP (0.95 resp. 0.97), which showed a good to very good agreement.

Deep learning can be used to automatically and reliably segment the PRM and UH in 2D, in the plane of minimal hiatal dimensions, of the nulliparous female pelvic floor. These segmentations can be used to reliably measure the parameters; hiatal dimensions, PRM length and MEP. This article is protected by copyright. All rights reserved.

Echogenicity of the puborectalis muscle, the cervix and the vastus lateralis muscle in pregnancy in relation to mode of delivery.

Ultrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology

The primary objective of this study was to confirm our previous observation that hiatal dimensions and mean echogenicity of the puborectalis muscle (MEP) were statistically significant different at 12 weeks gestation in women who delivered by a caesarean section (CS) due to failure to progress (FTP), compared to women who delivered vaginally. The secondary objective was to assess the association between the echogenicity of the cervix and the vastus lateralis muscle and mode of delivery.

In this multicenter study 306 nulliparous women with a singleton pregnancy received ultrasound assessments of the pelvic floor at rest, contraction and on Valsalva maneuver, of the cervix and of the vastus lateralis muscle at 12 weeks' gestation. Dimensions of the levator hiatus and mean echogenicity of the puborectalis muscle, cervix and vastus lateralis muscle were measured.

Two hundred forty-seven women were eligible for analyses. We were unable to confirm our previous finding that the MEP and hiatal transverse diameter and area at 12 weeks gestation are significantly associated with the mode of delivery. In addition, we could not demonstrate a significant association between the echogenicity of the cervix and vastus lateralis muscle and mode of delivery. Furthermore, no significant differences between the levator hiatal dimensions and the modes of delivery are found. Overall, we noticed a mean 20 points lower MEP in all women in the new database as compared to the previous study, despite the use of the same ultrasound equipment.

In a second, independent multicenter dataset we were unable to confirm our previous finding that the hiatal dimensions and MEP on contraction were statistically significant associated with the mode of delivery. The overall lower MEP in all women was caused by to a higher depth in all ultrasound images of the current study. This article is protected by copyright. All rights reserved.

Physiological effects of cold-dry versus heated-humidified partial amniotic carbon dioxide insufflation in sheep.

Ultrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology

Partial amniotic carbon dioxide (CO2 ) insufflation (PACI) is used to improve visualisation and enable complex fetoscopic surgery. However, concerns exist about fetal hypercapnic acidosis and post-operative fetal membrane inflammation. We assessed whether heated-humidified CO2 would reduce the impact of PACI on the fetus and fetal membranes in sheep.

Fetal lambs 105 days gestation (term=145 days) were partially delivered through a caesarean section and instrumented with arterial catheters and flow probes. Fetuses were returned to the uterus which was then closed and insufflated with cold-dry (22o C at 0-5% humidity, n=7) or heated-humidified CO2 (40o C at 100% humidity, n=5) at 15mmHg for 180 minutes. Fetal membranes were collected immediately after insufflation for histological analysis. Physiological data and membrane cell counts are presented as mean±SEM and median [IQR] as appropriate.

After 180 minutes, fetal survival was 0% with cold-dry PACI, and 60% with heated-humidified. Compared to cold-dry, heated-humidified PACI reduced fetal hypercapnia (170.5 ±28.5 vs. 82.7 ±9.1mmHg, p<0.01), lactate accumulation (8.5 ±0.9 vs. 1.4 ±0.4mmol/L, p<0.01) and subsequent acidosis (pH 6.75 ±0.04 vs. 7.10 ±0.04, p<0.01). Heated-humidified PACI also maintained arterial pressures (46.8±1.2 vs. 12.3 ±8.5mmHg, p=0.22) and significantly reduced the number of leukocytes in the chorion (0.7x10-5 [0.5x10-5 ] vs. 3.2x10-5 [1.8x10-5 ] cells per square micron, p=0.02).

Cold-dry PACI caused fetal hypercapnia, acidosis, hypotension and fetal membrane inflammation in sheep raising potential concerns for use in humans. Heated-humidified PACI partially mitigated these effects and may be a suitable alternative that reduces the risk of fetal acid base disturbances and fetal membrane inflammation following complex fetoscopic surgery. This article is protected by copyright. All rights reserved.

Doppler changes in the umbilical artery and ductus venosus during fetoscopic prenatal surgical repair of myelomeningocele.

Ultrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology

Cardiac dysfunction has been described in 60% of fetuses undergoing open myelomeningocele (MMC) repair. Routine Doppler evaluation of the umbilical artery (UA) and ductus venosus (DV) is challenging during fetal surgery. This study describes Doppler changes in the UA and DV in a cohort of fetuses during MMC repair.

Fetuses who underwent fetoscopic repair of MMC at a single institution between 2014 and 2017 were included in this study (n=35). Ultrasound images taken intraoperatively were analyzed to describe the changes in Doppler parameters of the UA and DV during fetal MMC repair. The timing of Doppler changes was matched with the phase of the surgery to determine whether a pattern to their appearance could be ascertained.

Fetoscopic (n=35) fetal MMC repairs were included. Of the 35 fetoscopic MMC repairs, Doppler data of the UA was obtained in 12 cases, and Doppler data of the DV was obtained in 13 cases. In the 12 fetoscopic repairs for which there was UA data, 9 (75%) showed transient absence of end-diastolic flow (EDF), with 5 (41.7%) of them progressing to reversal of EDF. In the 13 fetoscopic cases for which there was DV data, 9 had elevated pulsatility index; however, none of them had absent or reversed blood flow during the atrial contractions. In the 9 fetoscopic cases with absent EDF in the UA, this abnormality first appeared during the fetoscopic repair in 5 cases (55.6%), after uterus exteriorization but before CO2 insufflation in 2 cases (22.2%), after uterus replacement but before skin closure in 1 case (11.1%), and after CO2 insufflation but before the start of the MMC repair in 1 case (11.1%). The Doppler abnormalities in four fetuses with reversed EDF and in three with absent EDF resolved during surgery. Follow-up scan one day after surgery demonstrated resolution of UA and DV Doppler abnormalities in all fetuses.

Transient Doppler abnormalities of the umbilical artery without significant changes in the ductus venosus can be seen during fetal MMC repair. The clinical significance of these Doppler findings remains unclear due to their transient and intermittent nature. This article is protected by copyright. All rights reserved.

How repeatable is the assessment of external anal sphincter trauma by exo-anal 4D ultrasound?

Ultrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology

Three/Four dimensional translabial ultrasound (TLUS) is gaining popularity for assessment of anal sphincter trauma, although repeatability data is lacking. This study aimed to determine TLUS repeatability for external anal sphincter trauma and compare the performance of a novice with that of an experienced investigator.

This is a retrospective study analysing archived ultrasound datasets of 103 patients. Each was assessed twice between 2012 and 2016 at an average interval of 260 (1-1100) days. All volumes were obtained using Voluson 730 expert or E8 systems. Post-processing of volumes was performed independently by two authors, one with over one year's experience and another with no prior experience, blinded against all other data including results obtained at the other time point. Intra- and interobserver agreement were determined using Cohen's kappa and Intra-class correlation coefficients.

During the study period, 105 women had two TLUS assessments of the anal sphincter. Two had missing volumes, leaving 103 datasets. The novice investigator produced average repeatability for significant trauma and single slice defect (κ 0.3 and 0.22) despite relatively high agreement (84.5% and 79.3%), whereas the experienced investigator demonstrated good to very good repeatability (κ 0.91 and 0.78) between the two assessments which equates to 98.9% and 94.7% agreement.

The repeatability of TLUS measurements for external anal sphincter trauma seem to be very good when imaging is undertaken with state of the art equipment and the analysis is performed by an experienced observer in comparison to analysis being performed by a novice investigator. This article is protected by copyright. All rights reserved.

Left ventricular mechanics in the late second trimester of healthy pregnancy.

Ultrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology

Healthy pregnancy causes significant changes in maternal hemodynamics that lead to structural and functional adaptation of a woman's heart. Reductions in ejection fraction have been reported in healthy pregnancy; however, this measure of cardiac contractile function is over simplistic and insensitive to the underpinning hemodynamic load. Indices of systolic myocardial deformation, such as left ventricular strain and twist ('LV mechanics') may therefore provide a more accurate assessment of cardiac function during gestation. As such, the aim of this study was to evaluate LV mechanics in the second trimester of healthy pregnancy and secondly, to determine the influence of underpinning hemodynamics (heart rate (HR), preload and afterload) on LV mechanics during gestation.

We conducted a cross-sectional study of non-pregnant (n=18), primiparous pregnant (22-26 weeks gestation; n=14) and postpartum (12-16 weeks after delivery; n=13) women. All pregnant and postpartum women had uncomplicated, singleton gestations. Cardiac structure and function were assessed using echocardiography. LV mechanics, specifically longitudinal strain, circumferential strain and twist/untwist, were measured using speckle-tracking echocardiography. Differences between groups were identified using ANCOVA, with age, HR, end-diastolic volume (EDV) and systolic blood pressure (SBP) as covariates. Relationships between LV mechanics and hemodynamics were examined using Pearson's correlation.

Pregnant women had significantly greater resting longitudinal and basal circumferential strain compared to non-pregnant women (-22±2 vs. -17±3%, P=0.002 and -23±4 vs. -16±2%, P=0.001, respectively) but not apical circumferential strain or LV twist. No statistically significant relationships between LV mechanics and HR, EDV or SBP were observed within groups.

Compared to the non-pregnant state, pregnant women in the second trimester of healthy pregnancy have significantly greater resting systolic function, as assessed by LV longitudinal and circumferential strain. Contrary to previous work, these data show that healthy pregnant women should not exhibit reductions in resting systolic function between 22-26 weeks. The enhanced myocardial contractile function does not appear to be related to hemodynamic load and could be the result of other physiological adaptations during gestation. This article is protected by copyright. All rights reserved.

Prediction of adverse perinatal outcomes by the cerebroplacental ratio in women undergoing induction of labour.

Ultrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology

To investigate the performance of screening for adverse perinatal outcome by the cerebroplacental ratio (CPR) measured within 24 hours of induction of labor.

This was a prospective observational study in 1,902 singleton pregnancies undergoing induction of labor at ≥ 37 weeks' gestation. Doppler ultrasound was used to measure the pulsatility index (PI) in the umbilical artery (UA) and fetal middle cerebral artery (MCA) before induction of labor. The measured UA PI and MCA PI and their ratio were converted to multiples of the median (MoM) after adjustment for gestational age. Univariate and multivariate logistic regression analysis was used to determine whether CPR improved the prediction of adverse perinatal outcome that was provided by maternal characteristics, medical history and obstetric factors. The detection rate (DR) and false-positive rate (FPR) of screening by CPR were estimated for cesarean section for presumed fetal distress and neonatal adverse outcome, which included umbilical arterial or venous cord blood pH ≤7 and ≤7.1, respectively, 5-minute Apgar score <7, admission to the neonatal intensive care unit (NICU) for >24 hours, or hypoxic ischemic encephalopathy.

A combination of maternal and pregnancy characteristics, including age, weight, racial origin, previous obstetric history, preeclampsia, gestational age at delivery and amniotic fluid volume, identified 39% of pregnancies requiring cesarean section for fetal distress at FPR of 10%; addition of CPR did not improve the performance of screening. In screening for adverse neonatal outcome by a combination of parity and CPR the DR was 17% at FPR of 10%.

Low CPR, measured within 24 hours of induction of labor, is associated with increased risk of cesarean section for fetal distress and adverse neonatal outcome, but the performance of CPR for such surrogates of adverse perinatal outcome is poor. This article is protected by copyright. All rights reserved.

Learning curve for the ultrasonographic diagnosis of deep endometriosis using a structured off-line training program.

Ultrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology

The aim of the present study was to assess the learning curves of trainees during a structured off-line/hands-on training program on the diagnosis of deep infiltrating endometriosis (DIE).

A two-week training program was conducted. One day was devoted to theoretical issues and guided off-line analysis of 10 volumes of three-dimensional (3D) ultrasound. During the following days, five sessions of real-time sonographic examinations were performed in a DIE referral center Ultrasound unit. In between sessions, the trainees analyzed four off-line sets, containing twenty-five 3D volumes each. At the end of each set, misinterpreted volumes were assessed with the trainer. One trainer and 4 trainees (all post-graduated Ob/Gyn with at least 5 years of experience in ultrasonography in Obstetrics and Gynecology but with no experience in DIE sonographic examinations) participated in the study. Presence or absence of DIE at surgery was considered as gold standard for the trainees. Trainee's results were evaluated by learning curve cumulative summation (LC-CUSUM) and the deviations of the level of trainees' performance at the control stage by CUSUM (standard CUSUM) for different locations of DIE.

The trainees reached competence on average after 17 evaluations (range 21-14) for bladder locations, after 39 evaluations (range 60-30) for rectosigmoid locations, after 25 evaluations (range 34-14) for forniceal locations, after 44 evaluations (range 66-25) for utero-sacral locations (USL), after 21 evaluations (range 43-14) for rectovaginal septum (RVS) locations respectively, and kept the process under control with error levels of less than 4.5% until the end of the test. The overall accuracy for each trainee at the different locations ranged from 0.91 to 0.96 for bladder DIE, from 0.80 to 0.94 for recto-sigmoid DIE, from 0.90 to 0.94% for forniceal DIE, from 0.79 to 0.82 for utero-sacral ligaments DIE and from 0.89 to 0.97 for recto-vaginal septum DIE.

The suggested two-weeks learning program based on a mix of off-line and live sessions is feasible and suggests a good performance in training for the diagnosis of DIE. This article is protected by copyright. All rights reserved.