Meconium in Perinatal Imaging: Associations and Clinical Significance
SEMINARS IN ULTRASOUND CT AND MRI
2015; 36 (2): 161-177
Advances in fetal imaging.
American journal of perinatology
2014; 31 (7): 567-576
An abnormal location, distribution, volume, or appearance of meconium is associated with a spectrum of bowel abnormalities, including atresia, obstruction, perforation, fistula, aganglionosis, immaturity, and absorptive dysfunction. This review discusses the fetal and perinatal imaging of these entities, their differential diagnoses, clinical significance, and appropriate imaging workup. Understanding the spectrum of normal and abnormal, specific and nonspecific appearances of meconium and its associated abnormalities on imaging will provide a practical, useful framework for performing and interpreting imaging studies and guiding clinical management.
View details for DOI 10.1053/j.sult.2015.01.007
View details for Web of Science ID 000355575300006
Fetal MRI correlates with postnatal CT angiogram assessment of pulmonary anatomy in tetralogy of Fallot with absent pulmonary valve.
Congenital heart disease
2014; 9 (4): E105-9
While ultrasound (US) has been a part of prenatal care for almost 40 years, technical progress over the last two decades has resulted in improved image quality and detection rate of congenital anomalies. The past 15 years have also seen the expansion of three-dimensional (3D) US, providing enhancements over with 2D US, and more realistic images of babies to parents and providers. Fetal magnetic resonance imaging (MRI) was first performed over 30 years ago, and has undergone major technical improvement over the past 15 to 20 years. Fetal MRI complements US by providing better visualization in the fetus when US is limited such as in oligohydramnios or severe maternal obesity. It offers a larger field of view and better tissue contrast than US and is not limited by shadowing from osseous structures. However, MRI has a limited resolution compared with US, is less readily available, and more expensive. While indications for fetal MRI have been clearly established for some abnormalities, such as neurological anomalies, other indications especially for fetal body imaging are not as clearly defined. In this article, we discuss recent developments in fetal MRI and 3D US and their common and newest indications.
View details for DOI 10.1055/s-0034-1371712
View details for PubMedID 24792771
Advances in Fetal Imaging
AMERICAN JOURNAL OF PERINATOLOGY
2014; 31 (7): 567-576
Fetal magnetic resonance imaging: jumping from 1.5 to 3 tesla (preliminary experience)
2014; 44 (4): 376-386
In tetralogy of Fallot with absent pulmonary valve, pulmonary stenosis and regurgitation results in significant pulmonary artery dilatation. Branch pulmonary artery dilatation often compresses the tracheobronchial tree, causing fluid trapping in fetal life and air trapping and/or atelectasis after birth. Prenatal diagnosis predicts poor prognosis, which depends on the degree of respiratory insufficiency from airway compromise and lung parenchymal disease after birth. Fetal magnetic resonance imaging (MRI) has been useful in evaluating the effects of congenital lung lesions on lung development and indicating severity of pulmonary hypoplasia. This report is the first demonstrating the utility of fetal MRI in tetralogy of Fallot/absent pulmonary valve patients, which predicted postnatal pulmonary artery size and visualized airway compression and lung parenchymal lesions. The distribution of lobar fluid trapping on fetal MRI correlated with air trapping on postnatal computed tomography angiogram.
View details for DOI 10.1111/chd.12091
View details for PubMedID 23701739
Fetal bowel anomalies - US and MR assessment
2012; 42: 101-106
Fetal bowel anomalies--US and MR assessment.
2012; 42: S101-6
Several attempts have been made at imaging the fetus at 3 T as part of the continuous search for increased image signal and better anatomical delineation of the developing fetus. Until very recently, imaging of the fetus at 3 T has been disappointing, with numerous artifacts impeding image analysis. Better magnets and coils and improved technology now allow imaging of the fetus at greater magnetic strength, some hurdles in the shape of imaging artifacts notwithstanding. In this paper we present the preliminary experience of evaluating the developing fetus at 3 T and discuss several artifacts encountered and techniques to decrease them, as well as safety concerns associated with scanning the fetus at higher magnetic strength.
View details for DOI 10.1007/s00247-013-2857-0
View details for Web of Science ID 000333529100002
View details for PubMedID 24671739
Effectiveness of a Staged US and CT Protocol for the Diagnosis of Pediatric Appendicitis: Reducing Radiation Exposure in the Age of ALARA
2011; 259 (1): 231-239
The technical quality of prenatal US and fetal MRI has significantly improved during the last decade and allows an accurate diagnosis of bowel pathology prenatally. Accurate diagnosis of bowel pathology in utero is important for parental counseling and postnatal management. It is essential to recognize the US presentation of bowel pathology in the fetus in order to refer the patient for further evaluation or follow-up. Fetal MRI has been shown to offer some advantages over US for specific bowel abnormalities. In this paper, we review the normal appearance of the fetal bowel on US and MRI as well as the typical presentations of bowel pathologies. We discuss more specifically the importance of recognizing on fetal MRI the abnormalities of size and T1-weighted signal of the meconium-filled distal bowel.
View details for DOI 10.1007/s00247-011-2174-4
View details for PubMedID 22395722
Management of fetal mediastinal shift: A practical approach
JOURNAL DE RADIOLOGIE
2011; 92 (2): 118-124
To evaluate the effectiveness of a staged ultrasonography (US) and computed tomography (CT) imaging protocol for the accurate diagnosis of suspected appendicitis in children and the opportunity for reducing the number of CT examinations and associated radiation exposure.This retrospective study was compliant with HIPAA, and a waiver of informed consent was approved by the institutional review board. This study is a review of all imaging studies obtained in children suspected of having appendicitis between 2003 and 2008 at a suburban pediatric emergency department. A multidisciplinary staged US and CT imaging protocol for the diagnosis of appendicitis was implemented in 2003. In the staged protocol, US was performed first in patients suspected of having appendicitis; follow-up CT was recommended when US findings were equivocal. Of 1228 pediatric patients who presented to the emergency department for suspected appendicitis, 631 (287 boys, 344 girls; age range, 2 months to 18 years; median age, 10 years) were compliant with the imaging pathway. The sensitivity, specificity, negative appendectomy rate (number of appendectomies with normal pathologic findings divided by the number of surgeries performed for suspected appendicitis), missed appendicitis rate, and number of CT examinations avoided by using the staged protocol were analyzed.The sensitivity and specificity of the staged protocol were 98.6% and 90.6%, respectively. The negative appendectomy rate was 8.1% (19 of 235 patients), and the missed appendicitis rate was less than 0.5% (one of 631 patients). CT was avoided in 333 of the 631 patients (53%) in whom the protocol was followed and in whom the US findings were definitive.A staged US and CT imaging protocol in which US is performed first in children suspected of having acute appendicitis is highly accurate and offers the opportunity to substantially reduce radiation.
View details for DOI 10.1148/radiol.10100984
View details for Web of Science ID 000288848800028
View details for PubMedID 21324843
A continuous heparin infusion does not prevent catheter-related thrombosis in infants after cardiac surgery
PEDIATRIC CRITICAL CARE MEDICINE
2010; 11 (4): 489-495
The purpose of this article is to review the technique of fetal chest ultrasound screening evaluation, the diagnostic work-up in the presence of fetal mediastinal shift and which ultrasound imaging features to look for. The first step in evaluating the fetal thorax is to confirm situs. Then, a median sagittal line is drawn from a four-chamber view to assist in spatial orientation followed by echotexture analysis of the structures of the thorax in the presence of mediastinal shift. We propose a systematic approach based on the direction of the mediastinal shift and echogenicity of the compressing hemithorax. When the hemithorax contralateral to the mediastinal shift is enlarged, which is the most frequent situation, diaphragmatic hernia and macrocystic congenital cystic adenomatoid malformation are the most likely etiologies when the mass is heterogeneous. Microcystic congenital cystic adenomatoid malformation, sometimes associated with sequestration, is the most frequent etiology when the mass is homogeneous. When the hemithorax ipsilateral to the mediastinal shift is small, which is less frequent, and the contralateral hemithorax is homogeneously isoechoic, then a diagnosis of lung hypoplasia-agenesis-aplasia should be considered.
View details for DOI 10.1016/j.jradio.2010.12.002
View details for Web of Science ID 000288768400003
View details for PubMedID 21352743
Magnetic resonance imaging in the prenatal diagnosis of congenital diarrhea
ULTRASOUND IN OBSTETRICS & GYNECOLOGY
2010; 35 (5): 560-565
To determine whether a continuous infusion of heparin reduces the rate of catheter-related thrombosis in neonates and infants post cardiac surgery. Central venous and intracardiac catheters are used routinely in postoperative pediatric cardiac patients. Catheter-related thrombosis occurs in 8% to 45% of pediatric patients with central venous catheters.Single-center, randomized, placebo-controlled, double-blinded trial.Cardiovascular intensive care unit, university-affiliated children's hospital.Children <1 yr of age recovering from cardiac surgery.Patients were randomized to receive either continuous heparin at 10 units/kg/hr or placebo. The primary end point was catheter-related thrombosis as assessed by serial ultrasonography.Study enrollment was discontinued early based on results from an interim futility analysis. Ninety subjects were enrolled and received the study drug (heparin, 53; placebo, 37). The catheter-related thrombosis rate in the heparin group, compared with the placebo group, was 15% vs. 16% (p = .89). Subjects in the heparin group had a higher mean partial thromboplastin time (52 secs vs. 42 secs, p = .001), and this difference was greater for those aged <30 days (64 secs vs. 43 secs, p = .008). Catheters in place > or = 7 days had both a greater risk of thrombus formation (odds ratio, 4.3; p = .02) and catheter malfunction (odds ratio, 11.2; p = .008). We observed no significant differences in other outcome measures or in the frequency of adverse events.A continuous infusion of heparin at 10 units/kg/hr was safe but did not reduce catheter-related thrombus formation. Heparin at this dose caused an increase in partial thromboplastin time values, which, unexpectedly, was more pronounced in neonates.
View details for DOI 10.1097/PCC.0b013e3181ce6e29
View details for Web of Science ID 000279641500008
View details for PubMedID 20101197
MR Assessment of Normal Fetal Lung Volumes: A Literature Review
AMERICAN JOURNAL OF ROENTGENOLOGY
2010; 194 (2): W212-W217
Congenital diarrhea is very rare, and postnatal diagnosis is often made once the condition has caused potentially lethal fluid loss and electrolyte disorders. Prenatal detection is important to improve the immediate neonatal prognosis. We aimed to describe the prenatal ultrasound and magnetic resonance (MRI) imaging findings in fetuses with congenital diarrhea.The study reports the pre- and postnatal findings in four fetuses that presented with generalized bowel dilatation and polyhydramnios. We analyzed the fetal ultrasound and MRI examinations jointly, then compared our provisional diagnosis with the amniotic fluid biochemistry and subsequently with the neonatal stool characteristics.In each of the four cases an ultrasound examination between 22 and 30 weeks' gestation showed moderate generalized bowel dilatation and polyhydramnios suggesting intestinal obstruction. MRI examinations performed between 24 and 32 weeks' gestation confirmed that the dilatation was of gastrointestinal (GI) origin, with a signal indicating intraluminal water visible throughout the small bowel and colon. The expected hypersignal on T1-weighted sequences characteristic of physiological meconium was absent in the colon and rectum. This suggested that the meconium had been completely diluted and flushed out by the water content of the bowel. The constellation of MRI findings enabled a prenatal diagnosis of congenital diarrhea. The perinatal lab test findings revealed two cases of chloride diarrhea and two of sodium diarrhea.Congenital diarrhea may be misdiagnosed as intestinal obstruction on prenatal ultrasound but has characteristic findings on prenatal MRI enabling accurate diagnosis; this is important for optimal neonatal management.
View details for DOI 10.1002/uog.7509
View details for Web of Science ID 000278210600010
View details for PubMedID 20069658
Performance of PROPELLER relative to standard FSE T2-weighted imaging in pediatric brain MRI
2009; 39 (10): 1038-1047
Fetal lung volume can be assessed from MR images by planimetric measurement and comparison with normal values. We review 10 MRI articles that report normal fetal lung volumes based on gestational age to assess reproducibility and application of data.The articles were analyzed for differences in methodology and disparities in reported normal lung volumes by gestational age. Overall, there is substantial variability among studies regarding reported normal fetal lung volumes as measured on MRI.
View details for DOI 10.2214/AJR.09.2469
View details for Web of Science ID 000273951900053
View details for PubMedID 20093576
Three-Dimensional MRI Volumetric Measurements of the Normal Fetal Colon
AMERICAN JOURNAL OF ROENTGENOLOGY
2009; 192 (3): 761-765
T2-weighted fast spin-echo imaging (T2-W FSE) is frequently degraded by motion in pediatric patients. MR imaging with periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) employs alternate sampling of k-space to achieve motion reduction.To compare T2-W PROPELLER FSE (T2-W PROP) with conventional T2-W FSE for: (1) image quality; (2) presence of artefacts; and (3) ability to detect lesions.Ninety-five pediatric patients undergoing brain MRI (1.5 T) were evaluated with T2-W FSE and T2-W PROP. Three independent radiologists rated T2-W FSE and T2-W PROP, assessing image quality, presence of artefacts, and diagnostic confidence. Chi-square analysis and Wilcoxon signed rank test were used to assess the radiologists' responses.Compared with T2-W FSE, T2-W PROP demonstrated better image quality and reduced motion artefacts, with the greatest benefit in children younger than 6 months. Although detection rates were comparable for the two sequences, blood products were more conspicuous on T2-W FSE. Diagnostic confidence was higher using T2-W PROP in children younger than 6 months. Average inter-rater agreement was 87%.T2-W PROP showed reduced motion artefacts and improved diagnostic confidence in children younger than 6 months. Thus, use of T2-W PROP rather than T2-W FSE should be considered in routine imaging of this age group, with caution required in identifying blood products.
View details for DOI 10.1007/s00247-009-1292-8
View details for Web of Science ID 000269861000003
View details for PubMedID 19669747
Accuracy of MDCT in predicting site of gastrointestinal tract perforation
AMERICAN JOURNAL OF ROENTGENOLOGY
2006; 187 (5): 1179-1183
The use of fetal MRI markedly improves characterization of abdominal congenital anomalies. Accurate prenatal diagnosis of the level and cause of congenital intestinal obstruction is desired for optimal parental counseling and perinatal care. Because accurate diagnosis would be aided by nomograms of colonic volume, this study was conducted to determine normal colonic volumes at different gestational ages.This retrospective study consisted of a review of 83 fetal MRI examinations performed on fetuses with no gastrointestinal abnormalities. MRI was performed with a 1.5-T system. Axial, sagittal, and coronal T1-weighted fast gradient-refocused echo images were acquired at TR/TE, 165/2.6; flip angle, 90 degrees; matrix size, 384 x 192; slice thickness, 5 mm; field of view, 38 cm(2). Two investigators determined the region of interest in the colon by outlining areas of high signal intensity of meconium slice by slice. They then calculated colonic luminal volume in the regions of interest. Colonic luminal volumes were reported relative to gestational age and abdominal circumference. Normative curves were generated, and interobserver and intraobserver analyses were performed.Seventeen of the 83 fetuses (20%) were excluded because of movement artifacts on the images. Normal colonic luminal volume increased exponentially with gestational age and abdominal circumference. The range of colonic luminal volumes at 20-37 weeks' gestational age was 1.1-65 mL. Variation of volume was greater at advanced gestational age. Interobserver and intraobserver correlation was good.This study yielded preliminary volumetric measurements of the normal fetal colon at 20-37 weeks of gestational age that suggest the fetal colon grows exponentially.
View details for DOI 10.2214/AJR.08.1504
View details for Web of Science ID 000264005700032
View details for PubMedID 19234275
Quantitative diffusion imaging in breast cancer: A clinical prospective study
JOURNAL OF MAGNETIC RESONANCE IMAGING
2006; 24 (2): 319-324
The purpose of this study was to prospectively evaluate the accuracy of MDCT for preoperative determination of the site of surgically proven gastrointestinal tract perforations and to determine the most predictive findings in this diagnosis.We prospectively studied 85 consecutive patients with extraluminal air on MDCT who had surgically proven gastrointestinal tract perforations. All patients underwent surgery within 12 hours after MDCT was performed. Two experienced radiologists, blinded to the surgical diagnosis, reached a consensus prediction of the site of the perforation using the following eight MDCT findings: concentration of extraluminal air bubbles adjacent to the bowel wall, free air in supramesocolic or inframesocolic compartments, extraluminal air in both abdomen and pelvis, focal defect in the bowel wall, segmental bowel-wall thickening, perivisceral fat stranding, abscess, and extraluminal fluid. MDCT imaging results were compared with surgical and pathologic findings. Logistic regression analyses were performed to assess the significance of the different radiologic criteria.Analysis of MDCT images was predictive of the site of gastrointestinal tract perforation in 73 (86%) of 85 patients. Logistic regression showed that concentration of extraluminal air bubbles (p < 0.001), segmental bowel wall thickening (p < 0.001), and focal defect of the bowel wall (p = 0.007) were strong predictors of the site of bowel perforation.MDCT is highly accurate for predicting the site of gastrointestinal tract perforations. Three of eight CT findings significantly correlate with surgical diagnosis.
View details for DOI 10.2214/AJR.05.1179
View details for Web of Science ID 000241510800010
View details for PubMedID 17056902
Intragastric band erosion after laparoscopic adjustable gastric banding for morbid obesity: Imaging characteristics of an underreported complication
AMERICAN JOURNAL OF ROENTGENOLOGY
2005; 184 (1): 109-112
To study the correlation between apparent diffusion coefficient (ADC) and pathology in patients with undefined breast lesion, to validate how accurately ADC is related to histology, and to define a threshold value of ADC to distinguish malignant from benign lesions.Seventy-eight patients (110 lesions) were referred for positive or dubious findings. Three-dimensional fast low-angle shot (3D-FLASH) with contrast injection was applied. EPI diffusion-weighted imaging (DWI) with fat saturation was performed, and ROIs were selected on subtraction 3D-FLASH images before and after contrast injection, and copied on an ADC map. Inter- and intraobserver analyses were performed.At pathology 22 lesions were benign, 65 were malignant, and 23 were excluded. The ADCs of malignant and benign lesions were statistically different. In malignant tumors the ADC was (mean +/- SEM) 0.95 +/- 0.027 x 10(-3)mm(2)/second, and in benign tumors it was 1.51 +/- 0.068 x 10(-3)mm(2)/second. According to receiver operating characteristic (ROC) curves, we found a threshold between malignant and benign lesions for highest sensitivity and specificity (both 86%) around 1.13 +/- 0.10 x 10(-3)mm(2)/second. For a threshold of 0.95 +/- 0.10 x 10(-3)mm(2)/second, specificity was 100% but sensitivity was very low. Inter- and intraobserver studies showed good reproducibility.The ADC may help to differentiate benign and malignant lesions with good specificity, and may increase the overall specificity of breast MRI.
View details for DOI 10.1002/jmri.20643
View details for Web of Science ID 000239410300009
View details for PubMedID 16786565
Imaging of the articular cartilage in osteoarthritis of the knee joint: 3D spatial-spectral spoiled gradient-echo vs. fat-suppressed 3D spoiled gradient-echo MR imaging
JOURNAL OF MAGNETIC RESONANCE IMAGING
2003; 18 (1): 66-71
Our purpose was to describe the imaging findings of intragastric band erosion, an underreported complication after laparoscopic adjustable gastric banding for the treatment of morbid obesity. In this long-term complication, the gastric band fastened around the upper stomach to create a small proximal gastric pouch gradually erodes into the stomach wall and can extend into the gastric lumen. We present three cases of patients with band erosion in whom findings on an upper gastrointestinal series and CT established the diagnosis.Diagnosis of intragastric band erosion after gastric banding is usually made with endoscopy. However, the radiologic appearance of band erosion when visualized on an upper gastrointestinal series is pathognomonic and allows initial imaging diagnosis. In patients with extraluminal air or prosthesis infection, CT findings also are suggestive of this postoperative complication.
View details for Web of Science ID 000226507900021
View details for PubMedID 15615959
Gd-labeled liposomes for monitoring liposome-encapsulated chemotherapy: Quantification of regional uptake in tumor and effect on drug delivery
2002; 9: S525-S527
Phase II and III studies with new drugs for non-small cell lung cancer: A systematic review of the literature with a methodology quality assessment
1999; 19 (5C): 4379-4390
To compare three-dimensional (3D) spatial-spectral (SS) spoiled gradient-recalled acquisition in the steady state (SPGR) imaging with fat-suppressed 3D SPGR sequences in MR imaging of articular cartilage of the knee joint in patients with osteoarthritis.MR images of six patients with osteoarthritis of the knee were prospectively examined with a 1.5T MR scanner. For quantitative analyses, the signal-to-noise ratios, contrast-to-noise ratios, and contrast of cartilage and adjacent structures including meniscus, synovial fluid, muscle, fat tissue, and bone marrow were measured.In patients with osteoarthritis, 3DSS-SPGR images demonstrated higher spatial resolution and higher mean signal-to-noise (S/N) ratios (cartilage, 24.9; synovial fluid, 12.3; muscle, 20.7; meniscus, 21.6), with shorter acquisition times (7 minutes 20 seconds), when compared to fat-suppressed 3D SPGR images (cartilage, 22.3; synovial fluid, 10.8; muscle, 16.7; meniscus, 13.4).3DSS-SPGR imaging is a promising method for evaluating cartilage pathology in patients with osteoarthritis of the knee and has the potential to replace fat-suppressed 3D SPGR imaging.
View details for DOI 10.1002/jmri.10320
View details for Web of Science ID 000183899500008
View details for PubMedID 12815641
We carried out a systematic review of new drugs active in non-small cell lung carcinoma (NSCLC). Fifty five phase II and III trials were reviewed (vinorelbine (19 trials), paclitaxel (15), gemcitabine (11), docetaxel (6), topotecan (2) or irinotecan (2)). The first four ones could be considered as active drugs when given as single agent. More information is required for the camptothecin derivatives. Four phase III randomised studies were available, all concerning vinorelbine. They showed that in combination with cisplatin, vinorelbine improved the response rate and perhaps survival, in comparison to vinorelbine alone and that vinorelbine was better than 5 fluorouracil and vindesine. A quantitative overview was impracticable, because of too few randomised trials. A qualitative overview was carried out using the European Lung Cancer Working Party score. The overall median quality score was 65.3%. There was no statistically significant difference between the drugs, but there was a positive correlation between the score and the number of patients. There was also an improvement of the quality score in favour of the randomised trials. Some important methodological aspects were often missing in the articles. In conclusion, gemcitabine, vinorelbine, paclitaxel and docetaxel are active against NSCLC but more good-quality data are required to define their exact role in the routine.
View details for Web of Science ID 000084768200004
View details for PubMedID 10650780