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.

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Risk of fetal loss after chorionic villus sampling in twin pregnancies derived from propensity score matching analysis.

Ultrasound in Obstetrics and Gynecology

To estimate the risk of fetal loss associated to chorionic villus sampling (CVS) in twin pregnancies using propensity score analysis.

This was a multicenter cohort study performed in eight fetal-medicine units in which the leadership were trained at the Harris Birthright Research Centre for fetal medicine in London and the protocols for screening, invasive testing and pregnancy management are similar. The study population of 8581 twin pregnancies undergoing ultrasound examination at 11-13 weeks' gestation, included 445 twin pregnancies that had CVS. The risk of death of at least one fetus was compared between the CVS and non-CVS groups after propensity score matching (1:1 ratio). This procedure creates two comparable groups balancing the maternal and pregnancy characteristics that lead to CVS, in a similar way in which randomization operates in a randomized clinical trial.

Death of 1 or 2 fetuses at any stage during pregnancy occurred in 11.5% (51/445) of pregnancies in the CVS group and in 6.3% (515/8136) in the non-CVS group (p<0.001). The propensity score algorithm matched 258 cases that had CVS with 258 non-CVS cases; there was at least one fetal loss in 29 (11.2%) in the CVS group and 35 (13.6%) in the matched non-CVS group (OR 0.81, 95% CI 0.48 to 1.35; p=0.415). However, there was a significant interaction between the risk of fetal loss after CVS and the background risk of feal loss; when the background risk was higher, the risk of fetal loss after CVS decreased (OR 0.46, 95% CI 0.23 to 0.90) while in pregnancies with lower background risk of fetal loss the risk of fetal loss after CVS increased (OR 2.45, 95% CI 0.95 to 7.13). The effects were statistically different (p value of the interaction = 0.005). For a pregnancy where the background risk of fetal loss was about 6% (same as in our non-CVS population) there was no change in risk after CVS, but, when the background risk was more than 6% the posterior risk was paradoxically reduced and when the background risk was less than 6% the posterior risk increased exponentially; for example, if the background risk was 2.0%, the relative risk was 2.8 and the posterior risk was 5.6%.

After accounting for the risk factors that lead to both CVS and spontaneous fetal loss and confining the analysis to pregnancies at lower prior risk, CVS seems to increase the risk of fetal loss by about 3.5% above the patient's background-risk. This article is protected by copyright. All rights reserved.

First-trimester ultrasound diagnostic features of placenta accreta spectrum in low-implantation pregnancies.

Ultrasound in Obstetrics and Gynecology

Low implantation pregnancy is an important marker for the diagnosis of placenta accreta spectrum in the first trimester. Many grayscale and color Doppler markers have been well defined in the second and third trimesters of pregnancy but not well studied in the first trimester. The aim of this study was to determine if and which placenta accreta spectrum sonographic markers can be used in the first trimester to differentiate patients with low implantation pregnancy who end up developing placenta accreta from those who do not.

This was a retrospective case-control study of pregnancies who delivered at our institution from 2009-2019. Cases represented pregnancies with placenta accreta spectrum who delivered by cesarean hysterectomy and had a first trimester ultrasound with low implantation pregnancy. Controls represented pregnancies with persistent placenta previa without placenta accreta spectrum, who delivered by cesarean section without postpartum hemorrhage and had a first trimester ultrasound with low implantation pregnancy. Sonographic images were reviewed by an investigator blinded to pregnancy outcome and sonography reports. Images were reviewed for presence of abnormal uteroplacental interface, increased lower uterine segment hypervascularity, and placental lacunae, with or without swirling on grayscale or color Doppler.

21 cases and 46 controls met the inclusion criteria. Lacunae were present in 18/21 (85.7%) cases and in 7/46 (15.2%) controls (OR 33.4; 95% CI 7.7-144.4, p<.001). The number of lacunae was significantly higher in the cases as compared to the controls with a median of 5 lacunae in the cases as compared to a median of 1 lacunae in the controls (p<.001). The median size of the lacunae was also significantly larger in the cases measuring 10.03mm (IQR 7.3-12.05) compared to 4.15mm (IQR 4.05-5.05) in the controls (p=.001). Lacunae swirling on grayscale or color Doppler was noted only in the cases with 10/12 (83.3%) having swirling on grayscale and 12/12 (100%) having swirling on color Doppler (p <.001). Presence of an abnormal uteroplacental interface was also noted only in the cases at a rate of 17/20 (85.0%, p <.001). Lower uterine segment (uterovesical, subplacental, and/or intraplacental) hypervascularity was present in 14/14 (100%) cases and only 1/12 (8.33%) controls (p <.001).

In PAS-at-risk pregnancies, ultrasound markers of PAS can and should be assessed as early as the first trimester. The use of a first-trimester prenatal ultrasound screening protocol and standardized approach to the ultrasound examination in at-risk mothers may help in increased detection of PAS and in planning for the optimal management of these pregnancies. This article is protected by copyright. All rights reserved.

Comparison of postmortem whole-body contrast-enhanced microfocus computed tomography and high field magnetic resonance imaging of human fetuses.

Ultrasound in Obstetrics and Gynecology

After stillbirth, termination of pregnancy for congenital anomalies, or intrauterine fetal demise, fetal autopsy is generally recommended to confirm or refute the antemortem diagnosis. Although fetal autopsy often results in clinically significant findings, parental acceptance of invasive autopsy has fallen over time, mainly due to the invasiveness of the procedure. Contrast-enhanced microfocus CT (micro-CT) and High Field MRI (HF-MRI, ≥3 Tesla) have both been suggested as non-invasive alternatives to conventional fetal autopsy for fetuses below 20 weeks of gestation. The aim of this study was to make a thorough comparison of these two modalities regarding postmortem whole-body fetal imaging.

In this study, the imaging process and image quality of micro-CT and HF-MRI were compared using both qualitative and quantitative assessments. For the qualitative evaluation, fetal anatomy experts scored 112 HF-MRI and micro-CT images and 21 anatomical structures of four human fetuses aged 13 to 18 gestational weeks on two components: 1) Overall image quality and 2) the ability to recognize and assess organs. For the quantitative evaluation, participants manually segmented three organs with increasing complexity to assess inter-observer variability. In addition, the signal-to-noise ratio and contrast-to-noise ratio of five major organs were determined.

Both imaging techniques were able to reach sub-millimeter voxel sizes. In this study, the highest resolution of micro-CT was 22 μm (isotropic), while the highest resolution of HF-MRI was 137 μm (isotropic). The qualitative image quality assessment form was sent to 45 fetal anatomy experts, of whom 36 (80%) responded. It was observed that micro-CT scored higher on all components of the qualitative assessment, compared to HF-MRI. In addition, the quantitative assessment showed that micro-CT had a lower inter-observer variability, a higher signal-to-noise ratio, and a higher contrast-to-noise ratio.

Our results show that micro-CT outperforms HF-MRI on both quantitative and qualitative outcomes. Combined, these findings suggest that the ability to extract diagnostic information from micro-CT images is higher than from HF-MRI images. We therefore believe micro-CT is the preferred imaging modality as alternative to conventional fetal autopsy for early gestation and is an indispensable tool in postmortem imaging services. This article is protected by copyright. All rights reserved.

Consequences of cervical pessary for subsequent pregnancies: follow-up of randomized clinical trial (ProTWIN).

Ultrasound in Obstetrics and Gynecology

To evaluate the effect of a cervical pessary, as a strategy to prevent preterm birth, on the outcome of subsequent pregnancies and maternal quality of life four years after twin pregnancy.

Between 2009 and 2012, the ProTWIN trial randomized women with a multiple pregnancy to pessary versus usual care for prevention of preterm birth. The trial showed no benefit in unselected women with a twin pregnancy, but did show a 60% reduction in poor perinatal outcomes in favour of the pessary group in the subgroup of women with a midtrimester short cervix (<38 mm). Four years after their participation in the ProTWIN trial women were invited to participate in a follow-up study. Maternal quality of life during follow-up was assessed using the EQ-5D-3L questionnaire and separate questions were asked about subsequent pregnancies. Results between pessary and controls were compared by calculating relative risk (RR) and 95% confidence intervals (95% CI). Subgroup analysis was performed for women with a midtrimester short cervix (<38mm).

In total 408 women (50% of the original trial) participated in this follow-up study (n=228 pessary versus n=180 control). Median time between participation in the ProTWIN trial and participation in this follow-up study was 4.1 years (IQR 3.9-7.1). Ninety-eight participants (24%) tried to conceive after their participation in the ProTWIN trial. Of those, 22 women (22%) did not have a subsequent pregnancy (no difference between pessary and controls), seven women (7%) had miscarriage(s) but no live birth, and 67 women (68%) had live births (35 pessary versus 32 control group; RR 0.93, 95% CI 0.81-1.07). In two women the pregnancy outcome was unknown. Preterm delivery of the first live birth occurred in three (8.6%) women in pessary versus one woman (3.3%) in control group (none of them twins); RR 2.57 (95% CI 0.28-23.44). No differences were found in the subgroup of midtrimester short cervix, but numbers analyzed were small. The median health state index score was 0.95 (IQR 0.82-0.95) with no difference between pessary and control group.

Our data suggests no long term effects of pessary use on the outcome of subsequent pregnancies and maternal quality of life. Data on obstetrical outcomes were limited due to small numbers. This article is protected by copyright. All rights reserved.

Resolution of low-lying placenta and placenta previa is associated with increased risk of postpartum hemorrhage.

Ultrasound in Obstetrics and Gynecology

To determine if women who experience resolution of low-lying placenta and placenta previa are at increased risk of postpartum hemorrhage compared to those with normal placentation throughout pregnancy.

Retrospective cohort study including women who delivered at Mount Sinai Hospital between 2015 and 2019, diagnosed with low-lying placenta or placenta previa using transvaginal ultrasound at the time of second trimester anatomical survey with resolution of low placentation on subsequent ultrasound. Women undergoing second trimester anatomical survey diagnosed with normal placentation using transvaginal ultrasound were randomly identified for comparison. The primary outcome was rate of postpartum hemorrhage. Secondary outcomes included need for blood transfusion, use of additional uterotonic medication, need for additional procedures to control bleeding and maternal ICU admission. Outcomes were assessed using a multivariable logistic regression model.

1,256 women were identified for analysis, 628 in the resolved low placentation cohort and 628 in the normal placentation cohort. Resolved low placentation was associated with commercial health insurance (p=0.04), older maternal age (mean age 33 ± 5.4 vs. 31.5 ± 5.8), lower BMI (mean BMI 27.9 ± 5.5 vs. 30.3 ± 6.0), use of in vitro fertilization, Non-Hispanic White race, and posterior placental location (all p<0.01). Patients with resolved low versus normal placentation had greater odds of postpartum hemorrhage (adjusted OR 3.5, 95% CI 2.0-6.0; p<0.01), additional uterotonic use (adjusted OR 2.2, 95% CI 1.5-3.1; p<0.01) and increased rates of additional procedures to control bleeding (adjusted OR 4.0, 95% CI 1.2-11.9; p=0.01).

Despite high rates of resolution of low-lying placentas and placenta previas at term, women with resolved low placentation remain at increased risk of postpartum hemorrhage compared to those with normal placentation throughout pregnancy. This article is protected by copyright. All rights reserved.

A multicenter evaluation of the accuracy of prehospital eFAST by a physician-staffed helicopter emergency medical service.

Emergency Radiology

The purpose of this study is to report the relative accuracy of prehospital extended focused assessment with sonography in trauma (eFAST) examinations performed by HEMS physicians.

Trauma patients who received prehospital eFAST by HEMS clinicians between January 2013 and December 2017 were reviewed. The clinician's interpretations of these ultrasounds were compared to gold standard references of CT imaging or operating room findings. The outcomes measured include the calculated accuracy of eFAST for detecting intraperitoneal free fluid (IPFF), pneumothorax, hemothorax, and pericardial fluid compared to available gold standard results.

Of the 411 patients with adequate data for comparison, the median age was 39.5 years with 73% male and 98% sustaining blunt force trauma. For the detection of IPFF, eFAST had a sensitivity of 25% (95% CI 16-36%) and specificity of 96% (95% CI 93-98%). Sensitivities and specificities were calculated for pneumothorax (38% and 96% respectively), hemothorax (17% and 97% respectively), and pericardial effusion (17% and 100% respectively). These results did not change significantly when reassessed with several sensitivity analyses.

Prehospital eFAST is reliable for detecting the presence of intraperitoneal free fluid. This finding should inform receiving trauma teams to prepare for early definitive care in these patients. The low sensitivities across all components of the eFAST highlight the importance of cautiously interpreting negative studies while prompting the need for further studies.

ACTRN12618001973202 (Registered on 06/12/2018).

Doppler evaluation of normal and abnormal placenta.

Ultrasound in Obstetrics and Gynecology

Doppler techniques are needed for the evaluation of the intraplacental circulation and greatly contribute in the diagnosis of placental anomalies. ...

Evaluation of large niche in women after Cesarean section based on postmenstrual spotting: Chinese cohort study in non-pregnant women.

Ultrasound in Obstetrics and Gynecology

A large niche after cesarean section (CS) is associated with severe long-term complications, of which postmenstrual spotting is positively associated with the size of niche. However, the diagnosis of a large niche is inconsistent in the literature and definition is subjective.

To generate the definition of a large niche in women underwent CS.

A total of 727 women received their last CS in our hospital between January 2012 to June 2017 were recruited in this study. All the participants had an examination of CS incision scar by transvaginal sonography (2D color Doppler) during their mid-follicular phase. 263 women diagnosed with niche were classified into two groups according to whether they suffered from postmenstrual spotting. Logistic regression analysis was used to analyze the cut-off values for the niche parameters (depth, length, width, RMT, AMT, depth/AMT). The area under the receiver operating curve (AUC) was for the relationship to postmenstrual spotting.

In this study, the large niche was defined as more than 0.50 cm in depth, or less than 0.21 cm in residual myometrial thickness (RMT), or more than 0.56 in depth/ adjacent myometrial thickness (AMT). The prevalence of large niche was 22.4% (163/727). The specificity and sensitivity for the current definition of a large niche was 61.17% (95% CI: 52.34%-70.41%) and 76.87% (95% CI: 70.28%-84.16%).

This study has provided an objective evaluation for a large niche after cesarean delivery. This article is protected by copyright. All rights reserved.

Automatic identification and segmentation of the slice of minimal hiatal dimensions in transperineal ultrasound volumes.

Ultrasound in Obstetrics and Gynecology

Automatic selection and segmentation of the slice of minimal hiatal dimensions (SMHD) in transperineal ultrasound (TPUS) volumes.

The SMHD was manually selected and the urogenital hiatus (UH) segmented in TPUS volumes of 116 women with symptomatic pelvic organ prolapse (POP). These data were used to train two deep learning algorithms: the first one provides an estimation of the position of the SMHD. Based on this estimation a slice is selected and fed into the second algorithm, which automatically segments the UH. From this segmentation measurements of hiatal area (HA), anteroposterior (APD) and coronal (CD) diameter are computed. The mean absolute distance between manually and automatically selected SMHD, the overlap (dice similarity index (DSI)) between manual and automatic UH segmentation and the intraclass correlation coefficient (ICC) between manual and automatic UH measurements were assessed on a testset of 30 TPUS volumes.

The mean absolute distance between manually and automatically selected SMHD was 0.20 cm. DSI values between manual and automatic segmentation were all above 0.85. The ICC values and 95% confidence interval between manual and automatic levator hiatus measurements were 0.94 (0.87-0.97) for levator HA, 0.92 (0.78-0.97) for APD and 0.82 (0.66-0.91) for CD.

Our deep learning algorithms allow for reliable automatic selection and segmentation of the SMHD in TPUS volumes of women with symptomatic POP. These algorithms can be implemented in the software of TPUS machines, thus reducing clinical analysis time and easing the examination of TPUS data for research or clinical purposes. This article is protected by copyright. All rights reserved.

Definition and sonographic reporting system for Cesarean scar pregnancy in early pregnancy: modified Delphi method.

Ultrasound in Obstetrics and Gynecology

To develop a standardized sonographic evaluation and reporting system for a cesarean scar pregnancy (CSP) in the first trimester for both general gynecology and expert clinic.

A modified Delphi procedure. Twenty-eight experts in obstetrics and gynecology ultrasonography were invited to participate. Extensive experience in the use of ultrasound to evaluate cesarean section scars in early pregnancy and/or publications concerning CSP or niche evaluation was required to participate. Relevant items for detection and evaluation of CSP were determined based on the results of a literature search. Consensus was predefined as a level of agreement on at least 70% per item, and minimum of three Delphi rounds were planned (two online questionnaires and one group meeting).

Sixteen experts participated in the Delphi study and four Delphi rounds were performed. In total 58 items were identified to be relevant. We differentiated between basic measurements to be performed in general practice and advanced measurement for expert centers or for research purposes. The panel also formulated advice on indications for referral to an expert clinic. Consensus was reached for all 58 items on the definition, terminology, relevant items for evaluation and reporting of CSP. First cesarean scar evaluation to determine the location of the pregnancy is recommended to be performed at 6-7 weeks of pregnancy using transvaginal ultrasound. MRI is not needed. It was agreed that a CSP is defined as pregnancies with implantation in or in close contact with the niche. Relevant items to register include gestational size, vascularity, localization in relation to uterine vascularity, thickness of the residual myometrium and its localization in relation to the uterine cavity and serosa. According to its localization a CSP can be reported as: (1) CSP in which the largest part of the GS protrudes towards the uterine cavity; (2) CSP in which the largest part of the GS is embedded in the myometrium; and (3) CSP in which the GS is partially located outside the outer contour of the cervix or uterus. Type of CSP may change with advancing gestation. Future studies are needed to validate this reporting system and the value of the different CSP types.

Satisfactory consensus amongst experts was achieved regarding the sonographic evaluation of the uterine scar and CSP. This article is protected by copyright. All rights reserved.

Emergency pediatric radiology imaging trends for non-COVID-19-related illnesses through different stages of the pandemic.

Emergency Radiology

To evaluate how the COVID-19 pandemic affected the imaging utilization patterns for non-COVID-19-related illness in a pediatric emergency department (ED).

We retrospectively reviewed radiology reports for ultrasound, CT, MRI, and fluoroscopy studies performed at a pediatric ED in April from 2017 to 2021, excluding studies for respiratory symptoms and trauma. Radiology reports and medical records were reviewed to determine if patients had a positive radiology diagnosis, the type of diagnosis, and whether it required hospital admission. Results from during the pandemic were compared to predicted rates based on pre-pandemic years.

A total of 2198 imaging studies were included. During the COVID-19 pandemic, fewer ED imaging studies were performed compared to predicted. The decrease was greater in April 2020 (RR = 0.56, p < 0.001) than in April 2021 (RR = 0.80, p = 0.038). The odds of positive diagnosis was higher during the pandemic than before, and higher in 2020 (OR 2.53, p < 0.001) than in 2021 (OR 1.38, p = 0.008). The expected numbers of positive diagnoses and hospital admittances remained within the predicted range during the pandemic (p = 0.505-0.873).

Although imaging volumes decreased during the studied months of the pandemic, the number of positive findings was unchanged compared to prior years. No differences were demonstrated in the percentage of patients admitted to the hospital with positive imaging findings. This suggests that, at our institution, the pandemic did not lead to a substantial number of missed diagnoses or severely delay the diagnosis of non-COVID-related conditions. While still lower than expected, imaging volumes increased in April 2021 suggesting a return towards baseline patient behavior as the pandemic conditions improved.

Evaluation of classic and novel ultrasound signs of placenta accreta spectrum.

Ultrasound in Obstetrics and Gynecology

Improvements in the antenatal diagnosis of placenta accreta spectrum (PAS) would allow preparations for delivery in centers of excellence, leading to decreased maternal mortality and severe morbidity. Our objectives were to assess the performance of classic ultrasound signs and to determine the value of novel signs in the detection of PAS.

Cases of second trimester placenta previa who also had third trimester vaginal ultrasound, and all cases of PAS, at seven medical centers had outcome-blinded retrospective image review for signs of PAS by three MFM physicians. Classic signs of PAS were defined as placental lacunae, bladder wall interruption, myometrial thinning, and subplacental hypervascularity. Novel signs were defined as small placental lacunae, irregular placental myometrial interface (PMI), vascular PMI, non-tapered placental edge, and placental bladder bulge. PAS was diagnosed by difficulty in removing the placenta or placental pathologic confirmation. Multivariate regression analyses were performed, and ROC curves generated.

A total of 55 cases of PAS were included (28 accreta, 11 increta, 16 percreta) The area under the curve and 95% CI for classic markers, novel markers and a model combining both were 0.82 (95% CI 0.75-0.88), 0.84 (95% CI 0.77-0.90) and 0.88 (95% CI 0.82-0.94) respectively. A model combining classic and novel signs was better than either model alone (p=0.03). An increasing number of signs was associated with greater likelihood of PAS. With the presence of 0, 1, 2, and >3 classic ultrasound signs, PAS was present in 5%, 24%, 57%, and 94% of cases respectively.

We confirmed the value of classic ultrasound signs of PAS. The addition of novel ultrasound signs improves detection of PAS. These findings have clinical implications for the detection of PAS, and may help guide the obstetrical management of patients diagnosed with these placental disorders. This article is protected by copyright. All rights reserved.