Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 22
Filtrar
1.
Abdom Radiol (NY) ; 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38916617

RESUMO

OBJECTIVE: To assess the value of material density (MD) images generated from a rapid kilovoltage-switching dual-energy CT (rsDECT) in early detection of peritoneal carcinomatosis (PC). MATERIALS AND METHODS: Thirty patients (60 ± 13 years; 24 women) with PC detected on multiple abdominal DECT scans were included. Four separate DECTs with varying findings of PC from each patient were used for qualitative/quantitative analysis, resulting in a total of 120 DECT scans (n = 30 × 4). Three radiologists independently reviewed DECT images (65 keV alone and 65 keV + MD) for diagnosis of PC (diagnostic confidence, lesion conspicuity, sharpness/delineation and image quality) using a 5-point Likert scale. Quantitative estimation of contrast-to-noise ratio (CNR) was done. Wilcoxon signed-rank test and Odds ratio calculation were used to compare between the two protocols. Inter-observer agreement was evaluated using Kappa coefficient analysis. P values < 0.05 were considered statistically significant. RESULTS: 65 keV + MD images showed a slightly higher sensitivity (89%[95%CI:84,92]) for PC detection compared with 65 keV images alone without statistical significance (84%[95%CI:78,88], p = 0.11) with the experienced reader showing significant improvement (98%[95%CI:93,100] vs. 90%[95%CI:83,94], p = 0.02). On a per-patient basis, use of MD images allowed earlier diagnosis for PC in an additional 13-23% of patients. On sub-group analysis, earlier diagnosis of PC was particularly beneficial in patients with BMI ≤ 29.9 kg/m2. 65 keV + MD images showed higher diagnostic confidence, lesion conspicuity, and lesion sharpness for the experienced reader (p < 0.001). CNR was higher in MD images (1.7 ± 0.5) than 65 keV images (0.1 ± 0.02, p < 0.001). All readers showed moderate interobserver agreement for determining PC by both protocols (κ = 0.58 and κ = 0.47). CONCLUSION: MD images allow earlier and improved detection of PC with the degree of benefit varying based on reader experience and patient body habitus.

2.
Abdom Radiol (NY) ; 2024 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-38832942

RESUMO

Gender-affirming surgery (GAS) is increasingly being performed. GAS is tailored to the patient leading to a diverse spectrum of radiologic post-operative findings. Radiologists who are unfamiliar with expected anatomic alterations after GAS may misdiagnose important complications leading to adverse patient outcomes. This collaborative multi-institutional review aims to: Describe relevant embryology and native anatomy. Describe relevant Gender-Affirming Surgery (GAS) techniques and expected neo-anatomy with associated complications, including common terminology. Review expected imaging appearance of neo-anatomy/postoperative findings. Review multi-modality [ultrasound, plain film, retrograde urethrogram, computed tomography] emergent imaging findings. Understand unique patient evaluation and imaging protocol considerations in the GAS population. Discuss pearls and pitfalls of imaging in the acute post-GAS setting.

3.
J Comput Assist Tomogr ; 48(4): 601-613, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38438338

RESUMO

ABSTRACT: Recent advances in molecular pathology and an improved understanding of the etiology of neuroendocrine neoplasms (NENs) have given rise to an updated World Health Organization classification. Since gastroenteropancreatic NENs (GEP-NENs) are the most common forms of NENs and their incidence has been increasing constantly, they will be the focus of our attention. Here, we review the findings at the foundation of the new classification system, discuss how it impacts imaging research and radiological practice, and illustrate typical and atypical imaging and pathological findings. Gastroenteropancreatic NENs have a highly variable clinical course, which existing classification schemes based on proliferation rate were unable to fully capture. While well- and poorly differentiated NENs both express neuroendocrine markers, they are fundamentally different diseases, which may show similar proliferation rates. Genetic alterations specific to well-differentiated neuroendocrine tumors graded 1 to 3 and poorly differentiated neuroendocrine cancers of small cell and large-cell subtype have been identified. The new tumor classification places new demands and creates opportunities for radiologists to continue providing the clinically most relevant report and on researchers to design projects, which continue to be clinically applicable.


Assuntos
Tumores Neuroendócrinos , Organização Mundial da Saúde , Humanos , Tumores Neuroendócrinos/diagnóstico por imagem , Tumores Neuroendócrinos/patologia , Tumores Neuroendócrinos/classificação , Neoplasias Pancreáticas/diagnóstico por imagem , Neoplasias Pancreáticas/classificação , Neoplasias Pancreáticas/patologia
4.
AJR Am J Roentgenol ; 222(5): e2330720, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38353447

RESUMO

BACKGROUND. The 2022 Society of Radiologists in Ultrasound (SRU) consensus conference recommendations for small gallbladder polyps support management that is less aggressive than earlier approaches and may help standardize evaluation of polyps by radiologists. OBJECTIVE. The purpose of the present study was to assess the interreader agreement of radiologists in applying SRU recommendations for management of incidental gallbladder polyps on ultrasound. METHODS. This retrospective study included 105 patients (75 women and 30 men; median age, 51 years) with a gallbladder polyp on ultrasound (without features highly suspicious for invasive or malignant tumor) who underwent cholecystectomy between January 1, 2003, and January 1, 2021. Ten abdominal radiologists independently reviewed ultrasound examinations and, using the SRU recommendations, assessed one polyp per patient to assign risk category (extremely low risk, low risk, or indeterminate risk) and make a possible recommendation for surgical consultation. Five radiologists were considered less experienced (< 5 years of experience), and five were considered more experienced (≥ 5 years of experience). Interreader agreement was evaluated. Polyps were classified pathologically as nonneoplastic or neoplastic. RESULTS. For risk category assignments, interreader agreement was substantial among all readers (k = 0.710), less-experienced readers (k = 0.705), and more-experienced readers (k = 0.692). For surgical consultation recommendations, inter-reader agreement was substantial among all readers (k = 0.795) and more-experienced readers (k = 0.740) and was almost perfect among less-experienced readers (k = 0.811). Of 10 readers, a median of 5.0 (IQR, 2.0-8.0), 4.0 (IQR, 2.0-7.0), and 0.0 (IQR, 0.0-0.0) readers classified polyps as extremely low risk, low risk, and indeterminate risk, respectively. Across readers, the percentage of polyps classified as extremely low risk ranged from 32% to 72%; as low risk, from 24% to 65%; and as indeterminate risk, from 0% to 8%. Of 10 readers, a median of zero change to 0 (IQR, 0.0-1.0) readers recommended surgical consultation; the percentage of polyps receiving a recommendation for surgical consultation ranged from 4% to 22%. Of a total of 105 polyps, 102 were nonneo-plastic and three were neoplastic (all benign). Based on readers' most common assessments for nonneoplastic polyps, the risk category was extremely low risk for 53 polyps, low risk for 48 polyps, and indeterminate risk for one polyp; surgical consultation was recommended for 16 polyps. CONCLUSION. Ten abdominal radiologists showed substantial agreement for polyp risk categorizations and surgical consultation recommendations, although areas of reader variability were identified. CLINICAL IMPACT. The findings support the overall reproducibility of the SRU recommendations, while indicating opportunity for improvement.


Assuntos
Achados Incidentais , Pólipos , Ultrassonografia , Humanos , Feminino , Masculino , Pessoa de Meia-Idade , Pólipos/diagnóstico por imagem , Pólipos/cirurgia , Estudos Retrospectivos , Ultrassonografia/métodos , Adulto , Doenças da Vesícula Biliar/diagnóstico por imagem , Doenças da Vesícula Biliar/cirurgia , Idoso , Variações Dependentes do Observador , Radiologistas , Sociedades Médicas , Consenso , Guias de Prática Clínica como Assunto
5.
Can Urol Assoc J ; 18(4): 121-128, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38381941

RESUMO

INTRODUCTION: We investigated the incidence of secondary bladder (BCa) and rectal cancers (RCa) after external beam radiotherapy (EBRT) for prostate cancer (PCa) compared to radical prostatectomy (RP) alone, and compared cancer-specific survival (CSS) of these secondary neoplasms to their primary counterparts. METHODS: This retrospective cohort study included men in the SEER cancer registry with a diagnosis of non-metastatic, clinically node-negative PCa treated with either RP or EBRT from 1995-2011 and allowed a minimum five-year lag period for the development of secondary BCa or RCa. Patients were divided into two eras, 1995-2002 and 2003-2011, to examine differences in incidence of secondary malignancies over time. Univariable and multivariable competing risk analyses with Fine-Gray subdistribution hazard and cause-specific hazard models were used to examine the risk of developing a secondary BCa or RCa. Competing risks analyses were used to compare CSS of primary vs. secondary BCa and RCa. RESULTS: A total of 198 184 men underwent RP and 190 536 underwent EBRT for PCa. The cumulative incidence of secondary BCa at 10 years was 1.71% for RP, and 3.7% for EBRT (p<0.001), while that of RCa was 0.52% for RP and 0.99% for EBRT (p<0.001). EBRT was associated with almost twice the risk of developing a secondary BCa and RCa compared to RP. The hazard of secondary BCa following EBRT delivered during 2003-2011 was 20% less than from 1995-2002 (p<0.09, Fine-Gray model), while that of secondary RCa was 31% less (p<0.001) (hazard ratio 0.78, p<0.001) for Fine-Gray and cause-specific hazard models. In the Fine-Gray model, the risk of death from BCa was 27% lower for secondary BCa after RP compared to primary BCa, while the risk of death was 9% lower for secondary BCa after EBRT compared to primary BCa. There was no difference in RCa-specific survival between primary or secondary RCa after RP or EBRT. CONCLUSIONS: The risk of BCa and RCa is almost twice as high for men undergoing EBRT for localized PCa vs. RP, but that risk is declining, likely reflecting advances in radiation delivery. The development of secondary RCa or BCa does not confer elevated risk of death compared to their primary counterparts.

6.
Radiology ; 309(2): e223146, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37934095

RESUMO

Nonalcoholic fatty liver disease (NAFLD) is a common cause of morbidity and mortality. Nonfocal liver biopsy is the historical reference standard for evaluating NAFLD, but it is limited by invasiveness, high cost, and sampling error. Imaging methods are ideally situated to provide quantifiable results and rule out other anatomic diseases of the liver. MRI and US have shown great promise for the noninvasive evaluation of NAFLD. US is particularly well suited to address the population-level problem of NAFLD because it is lower-cost, more available, and more tolerable to a broader range of patients than MRI. Noninvasive US methods to evaluate liver fibrosis are widely available, and US-based tools to evaluate steatosis and inflammation are gaining traction. US techniques including shear-wave elastography, Doppler spectral imaging, attenuation coefficient, hepatorenal index, speed of sound, and backscatter-based estimation have regulatory clearance and are in clinical use. New methods based on channel and radiofrequency data analysis approaches have shown promise but are mostly experimental. This review discusses the advantages and limitations of clinically available and experimental approaches to sonographic liver tissue characterization for NAFLD diagnosis as well as future applications and strategies to overcome current limitations.


Assuntos
Técnicas de Imagem por Elasticidade , Hepatopatia Gordurosa não Alcoólica , Humanos , Biópsia , Inflamação
7.
Sci Rep ; 13(1): 16450, 2023 09 30.
Artigo em Inglês | MEDLINE | ID: mdl-37777523

RESUMO

Post-operative urinary retention is a medical condition where patients cannot urinate despite having a full bladder. Ultrasound imaging of the bladder is used to estimate urine volume for early diagnosis and management of urine retention. Moreover, the use of bladder ultrasound can reduce the need for an indwelling urinary catheter and the risk of catheter-associated urinary tract infection. Wearable ultrasound devices combined with machine-learning based bladder volume estimation algorithms reduce the burdens of nurses in hospital settings and improve outpatient care. However, existing algorithms are memory and computation intensive, thereby demanding the use of expensive GPUs. In this paper, we develop and validate a low-compute memory-efficient deep learning model for accurate bladder region segmentation and urine volume calculation. B-mode ultrasound bladder images of 360 patients were divided into training and validation sets; another 74 patients were used as the test dataset. Our 1-bit quantized models with 4-bits and 6-bits skip connections achieved an accuracy within [Formula: see text] and [Formula: see text], respectively, of a full precision state-of-the-art neural network (NN) without any floating-point operations and with an [Formula: see text] and [Formula: see text] reduction in memory requirements to fit under 150 kB. The means and standard deviations of the volume estimation errors, relative to estimates from ground-truth clinician annotations, were [Formula: see text] ml and [Formula: see text] ml, respectively. This lightweight NN can be easily integrated on the wearable ultrasound device for automated and continuous monitoring of urine volume. Our approach can potentially be extended to other clinical applications, such as monitoring blood pressure and fetal heart rate.


Assuntos
Bexiga Urinária , Retenção Urinária , Humanos , Bexiga Urinária/diagnóstico por imagem , Algoritmos , Redes Neurais de Computação , Ultrassonografia/métodos , Retenção Urinária/diagnóstico por imagem
8.
J Surg Oncol ; 128(7): 1190-1194, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37525571

RESUMO

BACKGROUND AND OBJECTIVES: To assess the impact of Gadolinium-enhanced magnetic resonance imaging (MRI) sequences on Preoperative imaging evaluation and surgical planning parameters for osteosarcoma (OS) of the knee in pediatric and young adult patients. METHODS: Thirty MRI scans of patients with OS about the knee were reviewed by five orthopedic oncologists. Key preoperative parameters (neurovascular bundle involvement, intra-articular tumor extension, extent of intramedullary extension) and surgical plans were evaluated based on non-contrast versus Gd contrast enhanced sequences. Assessment agreement, inter-rater agreement, and intrarater agreement between pre and postcontrast images were evaluated via Kappa statistics. RESULTS: Moderate agreement was seen between non and contrast-enhanced assessment of neurovascular involvement and intra-articular tumor extension. Intrarater reproducibility was substantial for neurovascular bundle involvement (precontrast Kappa: 0.63, postcontrast Kappa: 0.69). Intrarater reproducibility was also substantial for precontrast (Kappa: 0.70) and moderate for postcontrast (Kappa: 0.50) assessment of intra-articular tumor extension. Planned resection length and choice of surgical approach were similar between sequences. The addition of Gd-enhanced sequences improved the inter-rater agreement across collected parameters. CONCLUSIONS: While some findings suggest that contrast enhanced sequences may not significantly alter the assessment of key preoperative planning parameters by orthopedic oncologists, they may help reduce variability among providers with differing experience levels.

9.
Ultrasound Med Biol ; 49(11): 2327-2335, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37550173

RESUMO

Non-alcoholic fatty liver disease (NAFLD) is a significant cause of diffuse liver disease, morbidity and mortality worldwide. Early and accurate diagnosis of NALFD is critical to identify patients at risk of disease progression. Liver biopsy is the current gold standard for diagnosis and prognosis. However, a non-invasive diagnostic tool is desired because of the high cost and risk of complications of tissue sampling. Medical ultrasound is a safe, inexpensive and widely available imaging tool for diagnosing NAFLD. Emerging sonographic tools to quantitatively estimate hepatic fat fraction, such as tissue sound speed estimation, are likely to improve diagnostic accuracy, precision and reproducibility compared with existing qualitative and semi-quantitative techniques. Various pulse-echo ultrasound speed of sound estimation methodologies have been investigated, and some have been recently commercialized. We review state-of-the-art in vivo speed of sound estimation techniques, including their advantages, limitations, technical sources of variability, biological confounders and existing commercial implementations. We report the expected range of hepatic speed of sound as a function of liver steatosis and fibrosis that may be encountered in clinical practice. Ongoing efforts seek to quantify sound speed measurement accuracy and precision to inform threshold development around meaningful differences in fat fraction and between sequential measurements.


Assuntos
Hepatopatia Gordurosa não Alcoólica , Humanos , Hepatopatia Gordurosa não Alcoólica/patologia , Reprodutibilidade dos Testes , Ultrassom , Fígado/diagnóstico por imagem , Fígado/patologia , Ultrassonografia/métodos , Imageamento por Ressonância Magnética
10.
Ultrasound Med Biol ; 48(8): 1547-1554, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35660106

RESUMO

To develop an ultrasound-based machine learning classifier to diagnose benignity within indeterminate thyroid nodules (ITNs) by fine-needle aspiration, 180 patients with 194 ITNs (Bethesda classes III, IV and V) undergoing surgery over a 5-y study period were analyzed. The data set was randomly divided into training and testing data sets with 155 and 39 ITNs, respectively. All nodules were evaluated by ultrasound using the American College of Radiology Thyroid Imaging Reporting and Data System by manually scoring composition, echogenicity, shape, margin and echogenic foci. Nodule size, participant age and patient sex were recorded. A support vector machine (SVM) model with a cost-sensitive approach was developed using the aforementioned eight parameters with surgical histopathology as the reference standard. Surgical pathology determined 90 (46.4%) ITNs were malignant and 104 (53.6%) were benign. The SVM model classified 14 nodules as benign in the testing data set, of which 13 were correct (sensitivity = 93.8%, specificity = 56.5%). Considering malignancy prevalence by Bethesda group, the negative predictive values of this model for Bethesda III and IV categories were 93.9% and 93. 8%, respectively. The high negative predictive value of the SVM ultrasound-based model suggests a pathway by which surgical excision of Bethesda III and IV ITNs classified as benign may be avoided.


Assuntos
Neoplasias da Glândula Tireoide , Nódulo da Glândula Tireoide , Biópsia por Agulha Fina , Humanos , Aprendizado de Máquina , Estudos Retrospectivos , Neoplasias da Glândula Tireoide/patologia , Nódulo da Glândula Tireoide/patologia
11.
Biosensors (Basel) ; 11(12)2021 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-34940279

RESUMO

Hemorrhage is a leading cause of trauma death, particularly in prehospital environments when evacuation is delayed. Obtaining central vascular access to a deep artery or vein is important for administration of emergency drugs and analgesics, and rapid replacement of blood volume, as well as invasive sensing and emerging life-saving interventions. However, central access is normally performed by highly experienced critical care physicians in a hospital setting. We developed a handheld AI-enabled interventional device, AI-GUIDE (Artificial Intelligence Guided Ultrasound Interventional Device), capable of directing users with no ultrasound or interventional expertise to catheterize a deep blood vessel, with an initial focus on the femoral vein. AI-GUIDE integrates with widely available commercial portable ultrasound systems and guides a user in ultrasound probe localization, venous puncture-point localization, and needle insertion. The system performs vascular puncture robotically and incorporates a preloaded guidewire to facilitate the Seldinger technique of catheter insertion. Results from tissue-mimicking phantom and porcine studies under normotensive and hypotensive conditions provide evidence of the technique's robustness, with key performance metrics in a live porcine model including: a mean time to acquire femoral vein insertion point of 53 ± 36 s (5 users with varying experience, in 20 trials), a total time to insert catheter of 80 ± 30 s (1 user, in 6 trials), and a mean number of 1.1 (normotensive, 39 trials) and 1.3 (hypotensive, 55 trials) needle insertion attempts (1 user). These performance metrics in a porcine model are consistent with those for experienced medical providers performing central vascular access on humans in a hospital.


Assuntos
Cateterismo Venoso Central , Procedimentos Cirúrgicos Robóticos , Ultrassonografia de Intervenção , Animais , Inteligência Artificial , Veia Femoral/diagnóstico por imagem , Humanos , Suínos
12.
Radiology ; 299(2): 264-271, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33754829

RESUMO

A 72-year-old woman with an elevated body mass index and moderate alcohol intake was seen in the gastroenterology clinic. The patient had a past history of abnormal liver function tests and previous biopsy-proven steatosis with early fibrosis. She was reevaluated, following an initial loss to follow-up, by using US elastography to assess for fibrosis progression. The utility of US elastography in the noninvasive diagnosis and longitudinal monitoring of hepatic fibrosis is discussed. An overview of available technologies, including transient elastography and shear-wave elastography, is provided. ©RSNA, 2021 Online supplemental material is available for this article.


Assuntos
Técnicas de Imagem por Elasticidade/métodos , Cirrose Hepática/diagnóstico por imagem , Ultrassonografia/métodos , Progressão da Doença , Fígado Gorduroso/diagnóstico por imagem , Humanos
14.
AJR Am J Roentgenol ; 217(1): 141-151, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-32903060

RESUMO

BACKGROUND. PI-RADS version 2.1 (v2.1) modifications primarily address transition zone (TZ) interpretation. The revisions also impact peripheral zone (PZ) interpretation, which has received less attention. OBJECTIVE. The purpose of this study was to compare interobserver agreement of PI-RADS version 2 (v2) and v2.1 in the prostate PZ and TZ and perform a pilot comparison of their diagnostic performance in the two zones. METHODS. Six radiologists with varying experience retrospectively assessed 80 prostate lesions (40 PZ, 40 TZ) on MRI in separate sessions for PI-RADS v2 and v2.1. Interobserver agreement was assessed using Conger kappa (κ). For 50 lesions with pathology data, average AUC for detecting clinically significant cancer was compared between versions using multireader multicase statistical methods. Error variance and covariance results informed post hoc power analysis. RESULTS. Interobserver agreement for PI-RADS category 4 or greater was higher for version 2.1 (κ = 0.64) than version 2 (κ = 0.51) in the PZ, but similar for version 2 (κ = 0.64) and version 2.1 (κ = 0.60) in the TZ. The PI-RADS v2.1 DWI descriptor "linear/wedge-shaped" had higher agreement than its predecessor version 2 descriptor "indistinct hypointense" (κ = 0.52 vs κ = 0.18) and yielded 14 more true-negative versus five more false-negative interpretations. The ADC signal descriptor "markedly hypointense," for which only version 2.1 provides a specific definition, had lower agreement in version 2.1 (κ = 0.26) than version 2 (κ = 0.52). Modified TZ T2-weighted category 2 descriptors in version 2.1 had fair agreement (κ = 0.21), and agreement for PI-RADS category 2 in the TZ was lower in version 2.1 (κ = 0.31) than version 2 (κ = 0.57). DWI upgraded a TZ lesion category from 2 to 3 in four patients, detecting two additional cancers. Average AUC was not different between versions 2 and 2.1 for the PZ (AUC, 0.81 vs 0.85; p = .24) or the TZ (AUC, 0.69 vs 0.69; p = .94), though among experienced readers AUC was higher for version 2.1 than version 2 for the PZ (0.91 vs 0.82; p = .001). Overall performance comparison had sufficient power (0.8) to detect a 0.085 difference in AUC. CONCLUSION. Interobserver agreement improved using PI-RADS v2.1 in the PZ but not the TZ. Diagnostic performance improved using version 2.1 only in the PZ for experienced readers. Specific version 2.1 modifications yielded mixed results. CLINICAL IMPACT. The impact of PI-RADS v2.1 in the PZ is notable given the emphasis on version 2.1 TZ modifications. The findings suggest areas in which additional modification could further improve interobserver agreement and performance.


Assuntos
Imageamento por Ressonância Magnética/métodos , Neoplasias da Próstata/diagnóstico por imagem , Radiologistas/estatística & dados numéricos , Sistemas de Informação em Radiologia , Idoso , Humanos , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Próstata/diagnóstico por imagem , Reprodutibilidade dos Testes , Estudos Retrospectivos , Sensibilidade e Especificidade
15.
Eur J Radiol ; 129: 109126, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32544805

RESUMO

PURPOSE: To investigate whether the 2-seed placement per Magnetic Resonance Imaging (MRI) suspicious lesion yields a higher seed placement accuracy than a 1-seed strategy on a phantom. METHODS: Eight olives embedded in gelatin, each simulating a prostate, underwent MRI. Three virtual spherical lesions (3, 5, and 8 mm diameters) were marked in each olive on the MRI images and co-registered to the MRI/Transrectal Ultrasonography (TRUS) fusion biopsy system. Two radiologists placed 0.5 mm fiducials, targeting the center of each virtual lesion under fusion image guidance. Half of the 8 olives in each phantom were assigned either to the 1-seed or 2-seeds per lesion strategy. Post-procedure Computed Tomography (CT) images identified each seed and were fused with MR to localize each virtual lesion and collected the seed placement error - distance between the virtual target and the corresponding seed (using the closer seed for the 2-seed strategy). Seed placement success is defined as fiducial placement within a lesion boundary. RESULTS: Each operator repeated the procedure on three different phantoms, and data from 209 seeds placed for 137 lesions were analyzed, with an overall error of 3.03 ±â€¯1.52 mm. The operator skill, operator phantom procedural experience, lesion size, and number of seeds, were independently associated with the seed placement error. Seed placement success rate was higher for the 2-seed group compared to 1-seed, although the difference was not statistically significant. CONCLUSIONS: Placing 2 seeds per MRI lesion yielded a significantly lower error compared to 1-seed strategy, although seed placement success rate was not significantly different.


Assuntos
Imageamento por Ressonância Magnética/métodos , Imagem Multimodal/métodos , Imagens de Fantasmas , Neoplasias da Próstata/diagnóstico , Ultrassonografia/métodos , Humanos , Biópsia Guiada por Imagem/métodos , Masculino , Reto , Reprodutibilidade dos Testes
16.
Ultrasound Med Biol ; 46(4): 972-980, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32005510

RESUMO

In this study, we evaluated the diagnostic accuracy of shear wave elastography (SWE) for differentiating high-risk non-alcoholic steatohepatitis (hrNASH) from non-alcoholic fatty liver and low-risk non-alcoholic steatohepatitis (NASH). Patients with non-alcoholic fatty liver disease scheduled for liver biopsy underwent pre-biopsy SWE. Ten SWE measurements were obtained. Biopsy samples were reviewed using the NASH Clinical Research Network Scoring System and patients with hrNASH were identified. Receiver operating characteristic curves for SWE-based hrNASH diagnosis were charted. One hundred sixteen adult patients underwent liver biopsy at our institution for the evaluation of non-alcoholic fatty liver disease. The area under the receiver operating characteristic curve of SWE for hrNASH diagnosis was 0.73 (95% confidence interval: 0.61-0.84, p < 0.001). The Youden index-based optimal stiffness cutoff value for hrNASH diagnosis was calculated as 8.4 kPa (1.67 m/s), with a sensitivity of 77% and specificity of 66%. SWE may be useful for the detection of NASH patients at risk of long-term liver-specific morbidity and mortality.


Assuntos
Técnicas de Imagem por Elasticidade/métodos , Fígado/diagnóstico por imagem , Hepatopatia Gordurosa não Alcoólica/diagnóstico por imagem , Biomarcadores , Biópsia com Agulha de Grande Calibre , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Hepatopatia Gordurosa não Alcoólica/diagnóstico , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
17.
Female Pelvic Med Reconstr Surg ; 26(2): 111-115, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31990798

RESUMO

OBJECTIVE: Horseshoe kidney (HSK) is the most common renal fusion defect that can alter vascular and upper urinary tract anatomy. Anatomic variations in the presacral space can make surgical dissection very challenging. The aim of this study was to characterize presacral anatomy in women with HSK. METHODS: Large academic centers' database was queried to identify imaging studies in adult women with HSK. Available multiplanar computed tomography and magnetic resonance imaging images were reviewed, and relevant vascular and upper urinary tract anatomy was measured and compared with published normal values. Study population was compared with the normal controls using Student t test, χ test, or Fisher exact test as appropriate. RESULTS: One hundred seventy-eight women were identified initially, and 20 confirmed to have HSK on imaging. The mean ± SD age was 54.5 ± 16.9 years, and body mass index was 27.3 ± 7.5 kg/m. Women with HSK had a narrower angle of aortic bifurcation (39.1 ± 18.7 degrees vs 55.6 ± 4.5 degrees, P = 0.014); the right ureter was closer to midline (22.9 ± 8.8 mm vs 32.3 ± 1.2 mm, P < 0.001) when compared with normal controls anatomy. In 40% of women with HSK, the bifurcation of the vena cava was below the level of L5 in contrast to the 8% in the normal population (P < 0.001). In 60% of women with HSK, the inferior pole of the kidney was at or below L5. CONCLUSIONS: Ureteral, renal, and vascular anatomic alterations in women with HSK may make presacral surgical anatomy challenging by obscuring the anterior longitudinal ligament anchoring point. Preoperative imaging is warranted to determine the feasibility of female pelvic reconstructive surgery in HSK patients.


Assuntos
Aorta Abdominal/diagnóstico por imagem , Rim Fundido/diagnóstico por imagem , Rim , Pelve , Ureter/diagnóstico por imagem , Pontos de Referência Anatômicos , Variação Anatômica , Procedimentos Clínicos , Feminino , Humanos , Rim/anatomia & histologia , Rim/irrigação sanguínea , Rim/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Pessoa de Meia-Idade , Pelve/diagnóstico por imagem , Pelve/cirurgia , Cuidados Pré-Operatórios/métodos , Procedimentos de Cirurgia Plástica/métodos , Tomografia Computadorizada por Raios X/métodos
18.
AJR Am J Roentgenol ; 214(4): 786-791, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31939698

RESUMO

OBJECTIVE. The purpose of this study was to assess the accuracy of portal vein pulsatility for noninvasive diagnosis of high-risk nonalcoholic fatty liver disease (NAFLD). MATERIALS AND METHODS. This retrospective study included patients with biopsy-proven diagnosis of NAFLD who underwent duplex Doppler ultrasound assessment of the main portal vein within 1 year of liver biopsy (January 2014 to February 2018). Doppler ultrasound images were reviewed. The spectral waveform was used to measure the maximum (Vmax) and minimum (Vmin) velocity of blood in the portal veins. Venous pulsatility index (VPI) defined as (Vmax - Vmin) / Vmax was calculated. ROC curve analysis was used to calculate AUC as a measure of accuracy to determine the value of this index for diagnosis of high-risk NAFLD and compared with that of the following four clinical decision aids: NAFLD fibrosis score (FS), fibrosis-4 index (FIB-4), BARD score (body mass index, aspartate aminotransferase [AST]-to-alanine aminotransferase ratio, diabetes mellitus), and AST-to-platelet ratio index (APRI). The value of adding VPI to these indexes was also investigated. RESULTS. Of 123 study subjects, 33 (26.8%) had high-risk NAFLD and were found to have a lower VPI than the other 90 subjects (0.19 vs 0.32; p < 0.001). VPI, NAFLD FS, FIB-4, and APRI had statistically significant diagnostic values for high-risk NAFLD. VPI had the highest optimism-corrected AUC (VPI, 0.84 [95% CI, 0.77-0.91]; NAFLD FS, 0.74 [95% CI, 0.63-0.83]; FIB-4, 0.81 [95% CI, 0.72-0.89]; APRI, 0.73 [95% CI, 0.61-0.82]). Addition of VPI to any of the four scoring systems significantly improved the diagnostic value of the score for high-risk NAFLD. CONCLUSION. VPI may be an accurate noninvasive biomarker for diagnosis of high-risk NAFLD.


Assuntos
Hepatopatia Gordurosa não Alcoólica/diagnóstico por imagem , Veia Porta/fisiopatologia , Fluxo Pulsátil , Ultrassonografia Doppler Dupla , Adulto , Idoso , Biomarcadores/análise , Biópsia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA