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1.
Acad Radiol ; 2024 Oct 03.
Artículo en Inglés | MEDLINE | ID: mdl-39366802

RESUMEN

RATIONALE AND OBJECTIVES: Placenta accreta spectrum (PAS) is associated with significant morbidity and mortality. Current radiomic analysis of PAS magnetic resonance (MR) images is often performed on a single imaging plane. However, depending on the chosen imaging plane, radiomic features extracted from the same patient may vary due to the differing orientations and anatomical contexts, potentially leading to inconsistent results. In this study, we applied region of interest (ROI)-based radiomic analysis on axial and sagittal MR images in pregnant patients at high risk for PAS. Our objective was to compare MR textural features extracted from these imaging planes and to correlate these findings with surgical outcomes, aiming to enhance the accuracy of PAS diagnosis and treatment planning. MATERIALS AND METHODS: This is a retrospective review of MR images of pregnancies with prenatally suspected PAS. Volumetric placental, uterus, and internal os of the cervix regions of interest (ROI) were manually segmented on axial and sagittal MR images for each patient. Radiomic features were extracted following the image biomarker standardization initiative guideline. Agreement in features extracted from axial and sagittal images were assessed using Spearman's rank correlation coefficient. RESULTS: Of the 101 pregnant patients that met the study inclusion criteria, 65 underwent cesarean hysterectomy for PAS. 77 percent of the radiomics features had strong Spearman rank correlations (>0.8) between axial and sagittal images, indicating that these imaging planes provide similar radiomics information. The diagnostic performance of features extracted from axial and sagittal planes was quantified under the receiver operating characteristics curve (AUC). We found that axial and sagittal planes have similar performance for the prediction of hysterectomy. Shape elongation, Placental Location within the Uterus (PLU), and heterogeneity features were significant predictors for hysterectomy regardless of the imaging plane. CONCLUSION: Our study found that radiomics features extracted from axial and sagittal MR image plane in the same patient have excellent agreement and strong correlation. We identified several features present in both axial and sagittal images that were predictive in detecting PAS-suspected patient who required hysterectomy. These features may represent the underlying placental pathophysiology.

2.
Pediatr Dermatol ; 2024 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-38967953

RESUMEN

PSTPIP1-associated myeloid-related proteinemia inflammatory (PAMI) syndrome is a rare autoinflammatory disorder often arising in pediatric patients. We present a case of an 18-year-old female with a past medical history of growth failure, immunoglobulin A nephropathy, and inflammatory arthritis who presented to a pediatric dermatology clinic with findings of acne, psoriasiform dermatitis, and hidradenitis suppurativa, whose clinical, genetic, and laboratory findings were most consistent with PAMI syndrome. We conducted a literature review to better characterize this rare condition in the context of dermatologic findings. Recognition of the distinctive skin findings seen in PAMI syndrome can help distinguish it from other inflammatory disorders, enabling expedited diagnosis and treatment.

3.
Radiol Case Rep ; 19(8): 3425-3428, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38881621

RESUMEN

We present a case of an 81-year-old woman who presented to the emergency department with bleeding from a right breast wound. The patient had prior imaging suggestive of bilateral silicone implant rupture and a history of low tolerance for MRI scans. Ultrasound imaging in the emergency setting showed findings in the right breast suggestive of a fistula with free silicone and hematoma. A subsequent photon-counting CT scan with custom silicone-specific segmentation allowed differentiation of silicone from hematoma, provided anatomic assessment and location of the fistula, and revealed bilateral silicone-induced lymphadenopathy.

4.
JCI Insight ; 9(5)2024 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-38456511

RESUMEN

Understanding the immune responses to SARS-CoV-2 vaccination is critical to optimizing vaccination strategies for individuals with autoimmune diseases, such as systemic lupus erythematosus (SLE). Here, we comprehensively analyzed innate and adaptive immune responses in 19 patients with SLE receiving a complete 2-dose Pfizer-BioNTech mRNA vaccine (BNT162b2) regimen compared with a control cohort of 56 healthy control (HC) volunteers. Patients with SLE exhibited impaired neutralizing antibody production and antigen-specific CD4+ and CD8+ T cell responses relative to HC. Interestingly, antibody responses were only altered in patients with SLE treated with immunosuppressive therapies, whereas impairment of antigen-specific CD4+ and CD8+ T cell numbers was independent of medication. Patients with SLE also displayed reduced levels of circulating CXC motif chemokine ligands, CXCL9, CXCL10, CXCL11, and IFN-γ after secondary vaccination as well as downregulation of gene expression pathways indicative of compromised innate immune responses. Single-cell RNA-Seq analysis reveals that patients with SLE showed reduced levels of a vaccine-inducible monocyte population characterized by overexpression of IFN-response transcription factors. Thus, although 2 doses of BNT162b2 induced relatively robust immune responses in patients with SLE, our data demonstrate impairment of both innate and adaptive immune responses relative to HC, highlighting a need for population-specific vaccination studies.


Asunto(s)
COVID-19 , Lupus Eritematoso Sistémico , Humanos , Vacuna BNT162 , Vacunas contra la COVID-19 , SARS-CoV-2 , COVID-19/prevención & control , Vacunación
5.
Am J Obstet Gynecol MFM ; 6(3): 101280, 2024 03.
Artículo en Inglés | MEDLINE | ID: mdl-38216054

RESUMEN

BACKGROUND: Magnetic resonance imaging has been used increasingly as an adjunct for ultrasound imaging for placenta accreta spectrum assessment and preoperative surgical planning, but its value has not been established yet. The ultrasound-based placenta accreta index is a well-validated standardized approach for placenta accreta spectrum evaluation. Placenta accreta spectrum-magnetic resonance imaging markers have been outlined in a joint guideline from the Society of Abdominal Radiology and the European Society of Urogenital Radiology. OBJECTIVE: This study aimed to compare placenta accreta spectrum-magnetic resonance imaging parameters with the ultrasound-based placenta accreta index in pregnancies at high risk for placenta accreta spectrum and to assess the additional diagnostic value of magnetic resonance imaging for placenta accreta spectrum that requires a cesarean hysterectomy. STUDY DESIGN: This was a single-center, retrospective study of pregnant patients who underwent magnetic resonance imaging, in addition to ultrasonography, because of suspected placenta accreta spectrum. The ultrasound-based placenta accreta index and placenta accreta spectrum-magnetic resonance imaging parameters were obtained. Student's t test and Fisher's exact test were used to compare the groups in terms of the primary outcome (hysterectomy vs no hysterectomy). The diagnostic performance of magnetic resonance imaging and the ultrasound-based placenta accreta index was assessed using multivariable logistic regressions, receiver operating characteristics curves, the DeLong test, McNemar test, and the relative predictive value test. RESULTS: A total of 82 patients were included in the study, 41 of whom required a hysterectomy. All patients who underwent a hysterectomy met the International Federation of Gynecology and Obstetrics clinical evidence of placenta accreta spectrum at the time of delivery. Multiple parameters of the ultrasound-based placenta accreta index and placenta accreta spectrum-magnetic resonance imaging were able to predict hysterectomy, and the parameter of greatest dimension of invasion by magnetic resonance imaging was the best quantitative predictor. At 96% sensitivity for hysterectomy, the cutoff values were 3.5 for the ultrasound-based placenta accreta index and 2.5 cm for the greatest dimension of invasion by magnetic resonance imaging. Using this sensitivity, the parameter of greatest dimension of invasion measured by magnetic resonance imaging had higher specificity (P=.0016) and a higher positive predictive value (P=.0018) than the ultrasound-based placenta accreta index, indicating an improved diagnostic threshold. CONCLUSION: In a suspected high-risk group for placenta accreta spectrum, magnetic resonance imaging identified more patients who will not need a hysterectomy than when using the ultrasound-based placenta accrete index only. Magnetic resonance imaging has the potential to aid patient counseling, surgical planning, and delivery timing, including preterm delivery decisions for patients with placenta accreta spectrum requiring hysterectomy.


Asunto(s)
Placenta Accreta , Embarazo , Recién Nacido , Femenino , Humanos , Estudios Retrospectivos , Placenta Accreta/diagnóstico por imagen , Placenta Accreta/cirugía , Ultrasonografía Prenatal/métodos , Histerectomía/métodos , Ultrasonografía , Imagen por Resonancia Magnética/métodos
6.
Eur Radiol ; 33(12): 9223-9232, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37466705

RESUMEN

OBJECTIVES: To evaluate longitudinal placental perfusion using pseudo-continuous arterial spin-labeled (pCASL) MRI in normal pregnancies and in pregnancies affected by chronic hypertension (cHTN), who are at the greatest risk for placental-mediated disease conditions. METHODS: Eighteen normal and 23 pregnant subjects with cHTN requiring antihypertensive therapy were scanned at 3 T using free-breathing pCASL-MRI at 16-20 and 24-28 weeks of gestational age. RESULTS: Mean placental perfusion was 103.1 ± 48.0 and 71.4 ± 18.3 mL/100 g/min at 16-20 and 24-28 weeks respectively in normal pregnancies and 79.4 ± 27.4 and 74.9 ± 26.6 mL/100 g/min in cHTN pregnancies. There was a significant decrease in perfusion between the first and second scans in normal pregnancies (p = 0.004), which was not observed in cHTN pregnancies (p = 0.36). The mean perfusion was not statistically different between normal and cHTN pregnancies at both scans, but the absolute change in perfusion per week was statistically different between these groups (p = 0.044). Furthermore, placental perfusion was significantly lower at both time points (p = 0.027 and 0.044 respectively) in the four pregnant subjects with cHTN who went on to have infants that were small for gestational age (52.7 ± 20.4 and 50.4 ± 20.9 mL/100 g/min) versus those who did not (85 ± 25.6 and 80.0 ± 25.1 mL/100 g/min). CONCLUSION: pCASL-MRI enables longitudinal assessment of placental perfusion in pregnant subjects. Placental perfusion in the second trimester declined in normal pregnancies whereas it remained unchanged in cHTN pregnancies, consistent with alterations due to vascular disease pathology. Perfusion was significantly lower in those with small for gestational age infants, indicating that pCASL-MRI-measured perfusion may be an effective imaging biomarker for placental insufficiency. CLINICAL RELEVANCE STATEMENT: pCASL-MRI enables longitudinal assessment of placental perfusion without administering exogenous contrast agent and can identify placental insufficiency in pregnant subjects with chronic hypertension that can lead to earlier interventions. KEY POINTS: • Arterial spin-labeled (ASL) magnetic resonance imaging (MRI) enables longitudinal assessment of placental perfusion without administering exogenous contrast agent. • ASL-MRI-measured placental perfusion decreased significantly between 16-20 week and 24-28 week gestational age in normal pregnancies, while it remained relatively constant in hypertensive pregnancies, attributed to vascular disease pathology. • ASL-MRI-measured placental perfusion was significantly lower in subjects with hypertension who had a small for gestational age infant at 16-20-week gestation, indicating perfusion as an effective biomarker of placental insufficiency.


Asunto(s)
Hipertensión , Insuficiencia Placentaria , Embarazo , Femenino , Humanos , Lactante , Placenta/diagnóstico por imagen , Marcadores de Spin , Medios de Contraste , Imagen por Resonancia Magnética/métodos , Perfusión , Biomarcadores
7.
JAMA Dermatol ; 159(3): 308-313, 2023 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-36753129

RESUMEN

Importance: Degos-like lesions are cutaneous manifestations of a small-vessel vasculopathy that appear as atrophic, porcelain-white papules with red, telangiectatic borders. No study has adequately examined Degos-like lesions in patients with systemic sclerosis (SSc). Objective: To characterize the serologic, cutaneous, and internal organ manifestations associated with Degos-like lesions in a large cohort of patients with SSc. Design, Settings, and Participants: This retrospective cohort study involved adult patients with SSc who were seen at Stanford Rheumatologic Dermatology Clinic between January 1, 1998, and December 31, 2018. Participants fulfilled the 2013 classification criteria for SSc. Data analysis was conducted from February 1 to June 1, 2019. Main Outcomes and Measures: Data on demographic characteristics; autoantibody status; clinical characteristics, including cutaneous and systemic manifestations of SSc; and presence of Degos-like lesions were collected. Results: The cohort comprised 506 patients with SSc (447 females [88.3%]; mean [SD] age at first non-Raynaud disease symptoms, 46.1 [15.2] years). Twenty-seven patients (5.3%) had Degos-like lesions, of whom 24 (89.0%) had lesions affecting the fingers. Patients with Degos-like lesions were more likely to have diffuse cutaneous SSc compared with patients without lesions (15 [55.6%] vs 181 [37.8%]; P = .04). Degos-like lesions were also associated with acro-osteolysis (10 [37.0%] vs 62 [12.9%]; P < .01), digital ulcers (15 [55.6%] vs 173 [36.1%]; P = .04), and calcinosis (15 [55.6%] vs 115 [24.0%]; P < .01). While Degos-like lesions were not associated with internal organ manifestations, such as scleroderma renal crisis, interstitial lung disease, or pulmonary arterial hypertension, there was P < .10 for the association with gastric antral vascular ectasia. Conclusions and Relevance: Results of this study suggest an association of Degos-like lesions with diffuse cutaneous SSc and other cutaneous manifestations of vasculopathy, including acro-osteolysis, calcinosis, and digital ulcers. A prospective longitudinal study is warranted to examine the onset of Degos-like lesions and to elucidate whether these lesions play a role in SSc.


Asunto(s)
Acroosteólisis , Calcinosis , Esclerodermia Sistémica , Enfermedades Vasculares , Adulto , Femenino , Humanos , Adolescente , Estudios Longitudinales , Estudios Prospectivos , Estudios Retrospectivos , Esclerodermia Sistémica/complicaciones , Esclerodermia Sistémica/diagnóstico , Acroosteólisis/complicaciones
8.
Artículo en Inglés | MEDLINE | ID: mdl-38486806

RESUMEN

Magnetic resonance imaging (MRI) has potential benefits in understanding fetal and placental complications in pregnancy. An accurate segmentation of the uterine cavity and placenta can help facilitate fast and automated analyses of placenta accreta spectrum and other pregnancy complications. In this study, we trained a deep neural network for fully automatic segmentation of the uterine cavity and placenta from MR images of pregnant women with and without placental abnormalities. The two datasets were axial MRI data of 241 pregnant women, among whom, 101 patients also had sagittal MRI data. Our trained model was able to perform fully automatic 3D segmentation of MR image volumes and achieved an average Dice similarity coefficient (DSC) of 92% for uterine cavity and of 82% for placenta on the sagittal dataset and an average DSC of 87% for uterine cavity and of 82% for placenta on the axial dataset. Use of our automatic segmentation method is the first step in designing an analytics tool for to assess the risk of pregnant women with placenta accreta spectrum.

9.
Artículo en Inglés | MEDLINE | ID: mdl-38501056

RESUMEN

Magnetic resonance imaging (MRI) has gained popularity in the field of prenatal imaging due to the ability to provide high quality images of soft tissue. In this paper, we presented a novel method for extracting different textural and morphological features of the placenta from MRI volumes using topographical mapping. We proposed polar and planar topographical mapping methods to produce common placental features from a unique point of observation. The features extracted from the images included the entire placenta surface, as well as the thickness, intensity, and entropy maps displayed in a convenient two-dimensional format. The topography-based images may be useful for clinical placental assessments as well as computer-assisted diagnosis, and prediction of potential pregnancy complications.

11.
Artículo en Inglés | MEDLINE | ID: mdl-36844110

RESUMEN

In women with placenta accreta spectrum (PAS), patient management may involve cesarean hysterectomy at delivery. Magnetic resonance imaging (MRI) has been used for further evaluation of PAS and surgical planning. This work tackles two prediction problems: predicting presence of PAS and predicting hysterectomy using MR images of pregnant patients. First, we extracted approximately 2,500 radiomic features from MR images with two regions of interest: the placenta and the uterus. In addition to analyzing two regions of interest, we dilated the placenta and uterus masks by 5, 10, 15, and 20 mm to gain insights from the myometrium, where the uterus and placenta overlap in the case of PAS. This study cohort includes 241 pregnant women. Of these women, 89 underwent hysterectomy while 152 did not; 141 with suspected PAS, and 100 without suspected PAS. We obtained an accuracy of 0.88 for predicting hysterectomy and an accuracy of 0.92 for classifying suspected PAS. The radiomic analysis tool is further validated, it can be useful for aiding clinicians in decision making on the care of pregnant women.

12.
Artículo en Inglés | MEDLINE | ID: mdl-36798450

RESUMEN

Magnetic resonance imaging (MRI) is useful for the detection of abnormalities affecting maternal and fetal health. In this study, we used a fully convolutional neural network for simultaneous segmentation of the uterine cavity and placenta on MR images. We trained the network with MR images of 181 patients, with 157 for training and 24 for validation. The segmentation performance of the algorithm was evaluated using MR images of 60 additional patients that were not involved in training. The average Dice similarity coefficients achieved for the uterine cavity and placenta were 92% and 80%, respectively. The algorithm could estimate the volume of the uterine cavity and placenta with average errors of less than 1.1% compared to manual estimations. Automated segmentation, when incorporated into clinical use, has the potential to quantify, standardize, and improve placental assessment, resulting in improved outcomes for mothers and fetuses.

13.
Artículo en Inglés | MEDLINE | ID: mdl-36798853

RESUMEN

In severe cases, placenta accreta spectrum (PAS) requires emergency hysterectomy, endangering the life of both mother and fetus. Early prediction may reduce complications and aid in management decisions in these high-risk pregnancies. In this work, we developed a novel convolutional network architecture to combine MRI volumes, radiomic features, and custom feature maps to predict PAS severe enough to result in hysterectomy after fetal delivery in pregnant women. We trained, optimized, and evaluated the networks using data from 241 patients, in groups of 157, 24, and 60 for training, validation, and testing, respectively. We found the network using all three paths produced the best performance, with an AUC of 87.8, accuracy 83.3%, sensitivity of 85.0, and specificity of 82.5. This deep learning algorithm, deployed in clinical settings, may identify women at risk before birth, resulting in improved patient outcomes.

15.
Res Diagn Interv Imaging ; 2: 100011, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-39076838

RESUMEN

Rationale and objectives: A method for visualizing and analyzing the complete information contained in spectral CT scans using two-dimensional histograms (i.e. Material Attenuation Decomposition plots - MADplots) of the water-photoelectric attenuation versus water-scatter attenuation at the cohort (combination of multiple studies across patients), examination, series, slice, and organ/ROI levels is described. Materials and methods: The appearance of a MADplot with several standard biological materials was predicted using ideal material properties available from NIST and the ICRU to generate a map for this non-spatial data space. Software tools were developed to generate MADplots as new DICOM series that facilitate spectral analysis. Illustrative examples were selected from an IRB-approved, retrospective cohort of Spectral Basis Images (SBIs) scanned using a pre-release, dual-layer detector spectral CT. Results: By combining all of the voxels for contrast and non-contrast studies, the predicted appearance of the MADplot was confirmed. Locations of several kinds of tissue, the shape of the tissue distributions in normal lung, and the variations in the manner in which organ-specific MADplots change with pathology are demonstrated for the presence of fat in both the liver and pancreas highlighting the potential use for identifying pathologies on spectral CT images. Conclusions: The examples of MADplots shown at cohort (combined studies), examination, series, slice, organ, and ROI levels illustrate their potential utility in analyzing and displaying spectral CT data. Future studies are directed at developing MADplot based organ segmentation and the automated detection and display of organ based pathologies.

16.
Radiol Case Rep ; 16(12): 3662-3665, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34630796

RESUMEN

We present the case of a 24-year-old woman who presented to the emergency department with mid-epigastric pain and nausea. Contrast enhanced dual-energy CT showed high iodine signal in the small bowel lumen concerning for gastrointestinal bleeding since oral contrast was not given. However, overt bleeding symptoms were absent. Further in-house analysis of the dual-energy CT data revealed the hyperattenuating intraluminal material to be oral indigestion medicine containing magnesium, aluminum, or bismuth, and not extravasated iodine.

17.
J Med Imaging (Bellingham) ; 8(5): 054001, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34589556

RESUMEN

Purpose: Magnetic resonance imaging has been recently used to examine the abnormalities of the placenta during pregnancy. Segmentation of the placenta and uterine cavity allows quantitative measures and further analyses of the organs. The objective of this study is to develop a segmentation method with minimal user interaction. Approach: We developed a fully convolutional neural network (CNN) for simultaneous segmentation of the uterine cavity and placenta in three dimensions (3D) while a minimal operator interaction was incorporated for training and testing of the network. The user interaction guided the network to localize the placenta more accurately. In the experiments, we trained two CNNs, one using 70 normal training cases and the other using 129 training cases including normal cases as well as cases with suspected placenta accreta spectrum (PAS). We evaluated the performance of the segmentation algorithms on two test sets: one with 20 normal cases and the other with 50 images from both normal women and women with suspected PAS. Results: For the normal test data, the average Dice similarity coefficient (DSC) was 92% and 82% for the uterine cavity and placenta, respectively. For the combination of normal and abnormal cases, the DSC was 88% and 83% for the uterine cavity and placenta, respectively. The 3D segmentation algorithm estimated the volume of the normal and abnormal uterine cavity and placenta with average volume estimation errors of 4% and 9%, respectively. Conclusions: The deep learning-based segmentation method provides a useful tool for volume estimation and analysis of the placenta and uterus cavity in human placental imaging.

18.
Clin Cancer Res ; 27(17): 4794-4806, 2021 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-34210685

RESUMEN

PURPOSE: Intratumoral heterogeneity (ITH) challenges the molecular characterization of clear cell renal cell carcinoma (ccRCC) and is a confounding factor for therapy selection. Most approaches to evaluate ITH are limited by two-dimensional ex vivo tissue analyses. Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) can noninvasively assess the spatial landscape of entire tumors in their natural milieu. To assess the potential of DCE-MRI, we developed a vertically integrated radiogenomics colocalization approach for multi-region tissue acquisition and analyses. We investigated the potential of spatial imaging features to predict molecular subtypes using histopathologic and transcriptome correlatives. EXPERIMENTAL DESIGN: We report the results of a prospective study of 49 patients with ccRCC who underwent DCE-MRI prior to nephrectomy. Surgical specimens were sectioned to match the MRI acquisition plane. RNA sequencing data from multi-region tumor sampling (80 samples) were correlated with percent enhancement on DCE-MRI in spatially colocalized regions of the tumor. Independently, we evaluated clinical applicability of our findings in 19 patients with metastatic RCC (39 metastases) treated with first-line antiangiogenic drugs or checkpoint inhibitors. RESULTS: DCE-MRI identified tumor features associated with angiogenesis and inflammation, which differed within and across tumors, and likely contribute to the efficacy of antiangiogenic drugs and immunotherapies. Our vertically integrated analyses show that angiogenesis and inflammation frequently coexist and spatially anti-correlate in the same tumor. Furthermore, MRI contrast enhancement identifies phenotypes with better response to antiangiogenic therapy among patients with metastatic RCC. CONCLUSIONS: These findings have important implications for decision models based on biopsy samples and highlight the potential of more comprehensive imaging-based approaches.


Asunto(s)
Carcinoma de Células Renales/diagnóstico por imagen , Carcinoma de Células Renales/genética , Carcinoma de Células Renales/patología , Neoplasias Renales/diagnóstico por imagen , Neoplasias Renales/genética , Neoplasias Renales/patología , Imagen por Resonancia Magnética/métodos , Genómica de la Radiación , Microambiente Tumoral , Adulto , Anciano , Anciano de 80 o más Años , Inhibidores de la Angiogénesis/uso terapéutico , Carcinoma de Células Renales/tratamiento farmacológico , Femenino , Humanos , Neoplasias Renales/tratamiento farmacológico , Masculino , Persona de Mediana Edad , Estudios Prospectivos
19.
Eur Radiol ; 31(10): 8060-8067, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-33856524

RESUMEN

OBJECTIVES: To develop a dual-energy CT method for differentiating and quantifying high-Z contrast elements and to evaluate the limitations based on element concentration and atomic number by using an anthropomorphic phantom study. METHODS: Mass spectrometry standards for iodine, barium, gadolinium, ytterbium, tantalum, gold, and bismuth were diluted from 10.0 to 0.3 mg/mL, placed inside 7-mL vials, and scanned with dual-energy CT using an abdominal phantom and cylindrical water-filled insert. This procedure was repeated with all seven high-Z elements at six isoattenuating values from 250 to 8 HU. Quantification accuracy was measured using a linear regression model and residual error analysis with 90% limits of agreement. The limit of detection for each element was evaluated using the limit of blank of water. Pairwise differentiation of isoattenuating vials was evaluated using AUC values and the difference in fit angles between the two elements. RESULTS: Each high-Z element had a unique concentration vector in a two-dimensional plot of Compton scattering versus photoelectric effect attenuations. Mean quantification values were within ± 0.1 mg/mL of the true values for each element with no proportional bias. Limits of detection ranged from 0.35 to 0.56 mg/mL. Pairwise differentiations were proportional to the isoattenuating HU and the angle between the linear fits with mean AUC values increasing from 0.61 to 0.98 at 8 to 250 HU, respectively. CONCLUSION: Dual-energy CT can differentiate and quantify isoattenuating high-Z elements. The high-attenuation characteristics and unique concentration vectors of ytterbium, tantalum, gold, and bismuth are well suited for new dual-energy CT contrast agents especially when simultaneously imaged with iodine, barium, or gadolinium. KEY POINTS: • Dual-energy CT can accurately quantify high-Z contrast elements and readily differentiate iodine, barium, and gadolinium from ytterbium, tantalum, gold, and bismuth. • The differentiation and quantification capabilities for high-Z contrast elements are largely unaffected by phantom size and transaxial location within the phantom. • Potential benefits of new CT contrast agents based on these high-Z elements include alternatives for patients with iodine sensitivity, high conspicuity at both 120 and 140 kVp, simultaneous imaging of two contrast agents, and reduced injection volume.


Asunto(s)
Medios de Contraste , Yodo , Gadolinio , Humanos , Fantasmas de Imagen , Tomografía Computarizada por Rayos X
20.
J Ultrasound Med ; 40(12): 2735-2743, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-33724510

RESUMEN

OBJECTIVES: Ultrasound (US) prediction of placenta accreta spectrum (PAS) in the first trimester may be aided by postprocessing mechanisms employing color pixel quantification near the bladder-uterine serosal interface. Our objective was to create a postprocessing algorithm of color images to identify findings associated with PAS and compare quantification to sonologist impression in prospectively obtained cine US images. METHODS: Transverse transvaginal (TV) US color cines obtained in the first trimester as part of a prospective study were reviewed. Investigators blinded to clinical outcomes reviewed anonymized cines that were archived and labeled the bladder-uterine serosal interface. Color pixels within 2 cm of the defined bladder-uterine serosal interface were ascertained using a Python-based plugin in the Horos open-source DICOM viewer. A sonologist classified the findings as suspicious for invasion, indeterminate, or normal. Statistical analysis was performed using Wilcoxon rank-sum test, Cochran-Armitage trend test, and calculation of receiver-operating characteristic (ROC) curves. RESULTS: Fifty-four studies met inclusion criteria. Of those, six (11%) required hysterectomy with pathologic confirmation of PAS. Women requiring hysterectomy had a significantly higher color Doppler pixel area than those not requiring hysterectomy (P = .0205). A significant trend was identified in the sonologist impression of invasion (P = .0003). ROC's comparing sonologist impression to Doppler color imaging areas were comparable (P = .054). CONCLUSIONS: Color Doppler mapping in the first trimester showed an increase in color pixel area near the bladder-uterine serosal interface in women requiring cesarean hysterectomy with histologically confirmed PAS at time of delivery, compared to women without hysterectomy or pathologic evidence of PAS.


Asunto(s)
Placenta Accreta , Femenino , Humanos , Placenta Accreta/diagnóstico por imagen , Embarazo , Primer Trimestre del Embarazo , Estudios Prospectivos , Estudios Retrospectivos , Ultrasonografía Prenatal
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