scholarly journals Optimized Flat-Detector CT in Stroke Imaging: Ready for First-Line Use?

2016 ◽  
Vol 43 (1-2) ◽  
pp. 9-16 ◽  
Author(s):  
Matthias Eckert ◽  
Philipp Gölitz ◽  
Hannes Lücking ◽  
Tobias Struffert ◽  
Frauke Knossalla ◽  
...  
Keyword(s):  
Imaging Modality ◽  
High Sensitivity ◽  
Reconstruction Algorithm ◽  
Clinical Findings ◽  
Rater Agreement ◽  
Flat Detector ◽  
Stroke Imaging ◽  
Imaging Approach ◽  
Ischemic Attack ◽  
Subarachnoid Hemorrhages

Background: Using flat-detector CT (FD-CT) for stroke imaging has the advantage that both diagnostic imaging and endovascular therapy can be performed directly within the Angio Suite without any patient transfer and time delay. Thus, stroke management could be speeded up significantly, and patient outcome might be improved. But as precondition for using FD-CT as primary imaging modality, a reliable exclusion of intracranial hemorrhage (ICH) has to be possible. This study aimed to investigate whether optimized native FD-CT, using a newly implemented reconstruction algorithm, may reliably detect ICH in stroke patients. Additionally, the potential to identify ischemic changes was evaluated. Methods: Cranial FD-CT scans were obtained in 102 patients presenting with acute ischemic stroke (n = 32), ICH (n = 45) or transient ischemic attack (n = 25). All scans were reconstructed with a newly implemented half-scan cone-beam algorithm. Two experienced neuroradiologists, unaware of clinical findings, evaluated independently the FD-CTs screening for hemorrhage or ischemic signs. The findings were correlated to CT, and rater and inter-rater agreement was assessed. Results: FD-CT demonstrated high sensitivity (95-100%) and specificity (100%) in detecting intracerebral and intraventricular hemorrhage (IVH). Overall, interobserver agreement (κ = 0.92) was almost perfect and rater agreement to CT highly significant (r = 0.81). One infratentorial ICH and 10 or 11 of 22 subarachnoid hemorrhages (SAHs) were missed of whom 7 were perimesencephalic. The sensitivity for detecting acute ischemic signs was poor in blinded readings (0 or 25%, respectively). Conclusions: Optimized FD-CT, using a newly implemented reconstruction algorithm, turned out as a reliable tool for detecting supratentorial ICH and IVH. However, detection of infratentorial ICH and perimesencephalic SAH is limited. The potential of FD-CT in detecting ischemic changes is poor in blinded readings. Thus, plain FD-CT seems insufficient as a standalone modality in acute stroke, but within a multimodal imaging approach primarily using the FD technology, native FD-CT seems capable to exclude reliably supratentorial hemorrhage. Currently, FD-CT imaging seems not yet ready for wide adoption, replacing regular CT, and should be reserved for selected patients. Furthermore, prospective evaluations are necessary to validate this approach in the clinical setting.

scholarly journals Radiochemistry, Production Processes, Labeling Methods, and ImmunoPET Imaging Pharmaceuticals of Iodine-124

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 414
Author(s):  
Krishan Kumar ◽  
Arijit Ghosh
Keyword(s):  
Physical Properties ◽  
Imaging Modality ◽  
Target Selection ◽  
Positron Emission Tomography Imaging ◽  
High Sensitivity ◽  
High Specificity ◽  
Production Processes ◽  
Positron Emission ◽  
Significant Research ◽  
Clinical Environments

Target-specific biomolecules, monoclonal antibodies (mAb), proteins, and protein fragments are known to have high specificity and affinity for receptors associated with tumors and other pathological conditions. However, the large biomolecules have relatively intermediate to long circulation half-lives (>day) and tumor localization times. Combining superior target specificity of mAbs and high sensitivity and resolution of the PET (Positron Emission Tomography) imaging technique has created a paradigm-shifting imaging modality, ImmunoPET. In addition to metallic PET radionuclides, 124I is an attractive radionuclide for radiolabeling of mAbs as potential immunoPET imaging pharmaceuticals due to its physical properties (decay characteristics and half-life), easy and routine production by cyclotrons, and well-established methodologies for radioiodination. The objective of this report is to provide a comprehensive review of the physical properties of iodine and iodine radionuclides, production processes of 124I, various 124I-labeling methodologies for large biomolecules, mAbs, and the development of 124I-labeled immunoPET imaging pharmaceuticals for various cancer targets in preclinical and clinical environments. A summary of several production processes, including 123Te(d,n)124I, 124Te(d,2n)124I, 121Sb(α,n)124I, 123Sb(α,3n)124I, 123Sb(3He,2n)124I, natSb(α, xn)124I, natSb(3He,n)124I reactions, a detailed overview of the 124Te(p,n)124I reaction (including target selection, preparation, processing, and recovery of 124I), and a fully automated process that can be scaled up for GMP (Good Manufacturing Practices) production of large quantities of 124I is provided. Direct, using inorganic and organic oxidizing agents and enzyme catalysis, and indirect, using prosthetic groups, 124I-labeling techniques have been discussed. Significant research has been conducted, in more than the last two decades, in the development of 124I-labeled immunoPET imaging pharmaceuticals for target-specific cancer detection. Details of preclinical and clinical evaluations of the potential 124I-labeled immunoPET imaging pharmaceuticals are described here.

scholarly journals Impact of the COVID-19 pandemic on the selection of chest imaging modalities and reporting systems: a survey of Italian radiologists

2021 ◽  
Author(s):  
Andrea Borghesi ◽  
Nicola Sverzellati ◽  
Roberta Polverosi ◽  
Maurizio Balbi ◽  
Elisa Baratella ◽  
...  
Keyword(s):  
Continuing Education ◽  
Reporting System ◽  
Imaging Modality ◽  
Diagnostic Technique ◽  
Imaging Modalities ◽  
Chest Imaging ◽  
Reporting Systems ◽  
Imaging Approach ◽  
Narrative Report ◽  
Selection Of

Abstract Purpose Chest imaging modalities play a key role for the management of patient with coronavirus disease (COVID-19). Unfortunately, there is no consensus on the optimal chest imaging approach in the evaluation of patients with COVID-19 pneumonia, and radiology departments tend to use different approaches. Thus, the main objective of this survey was to assess how chest imaging modalities have been used during the different phases of the first COVID-19 wave in Italy, and which diagnostic technique and reporting system would have been preferred based on the experience gained during the pandemic. Material and Methods The questionnaire of the survey consisted of 26 questions. The link to participate in the survey was sent to all members of the Italian Society of Medical and Interventional Radiology (SIRM). Results The survey gathered responses from 716 SIRM members. The most notable result was that the most used and preferred chest imaging modality to assess/exclude/monitor COVID-19 pneumonia during the different phases of the first COVID-19 wave was computed tomography (51.8% to 77.1% of participants). Additionally, while the narrative report was the most used reporting system (55.6% of respondents), one-third of participants would have preferred to utilize structured reporting systems. Conclusion This survey shows that the participants’ responses did not properly align with the imaging guidelines for managing COVID-19 that have been made by several scientific, including SIRM. Therefore, there is a need for continuing education to keep radiologists up to date and aware of the advantages and limitations of the chest imaging modalities and reporting systems.

scholarly journals Elasto-mammography: Theory, Algorithm, and Phantom Study

2006 ◽  
Vol 2006 ◽  
pp. 1-11 ◽  
Author(s):  
Z. G. Wang ◽  
Y. Liu ◽  
L. Z. Sun ◽  
G. Wang ◽  
L. L. Fajardo
Keyword(s):  
Elastic Moduli ◽  
Imaging Modality ◽  
Contrast Ratio ◽  
Reconstruction Algorithm ◽  
Displacement Measurement ◽  
Breast Compression ◽  
Before And After ◽  
Breast Tissues ◽  
Displacement Information

A new imaging modality framework, called elasto-mammography, is proposed to generate the elastograms of breast tissues based on conventional X-ray mammography. The displacement information is extracted from mammography projections before and after breast compression. Incorporating the displacement measurement, an elastography reconstruction algorithm is specifically developed to estimate the elastic moduli of heterogeneous breast tissues. Case studies with numerical breast phantoms are conducted to demonstrate the capability of the proposed elasto-mammography. Effects of noise with measurement, geometric mismatch, and elastic contrast ratio are evaluated in the numerical simulations. It is shown that the proposed methodology is stable and robust for characterization of the elastic moduli of breast tissues from the projective displacement measurement.

scholarly journals Source reconstruction for bioluminescence tomography via L1∕2 regularization

2018 ◽  
Vol 11 (02) ◽  
pp. 1750014 ◽  
Author(s):  
Jingjing Yu ◽  
Qiyue Li ◽  
Haiyu Wang
Keyword(s):  
Image Quality ◽  
Matching Pursuit ◽  
Imaging Modality ◽  
Reconstruction Algorithm ◽  
Reconstruction Method ◽  
Reconstruction Algorithms ◽  
Preclinical Research ◽  
Bioluminescence Tomography ◽  
Comparison Results ◽  
Stable Reconstruction

Bioluminescence tomography (BLT) is an important noninvasive optical molecular imaging modality in preclinical research. To improve the image quality, reconstruction algorithms have to deal with the inherent ill-posedness of BLT inverse problem. The sparse characteristic of bioluminescent sources in spatial distribution has been widely explored in BLT and many L1-regularized methods have been investigated due to the sparsity-inducing properties of L1 norm. In this paper, we present a reconstruction method based on L[Formula: see text] regularization to enhance sparsity of BLT solution and solve the nonconvex L[Formula: see text] norm problem by converting it to a series of weighted L1 homotopy minimization problems with iteratively updated weights. To assess the performance of the proposed reconstruction algorithm, simulations on a heterogeneous mouse model are designed to compare it with three representative sparse reconstruction algorithms, including the weighted interior-point, L1 homotopy, and the Stagewise Orthogonal Matching Pursuit algorithm. Simulation results show that the proposed method yield stable reconstruction results under different noise levels. Quantitative comparison results demonstrate that the proposed algorithm outperforms the competitor algorithms in location accuracy, multiple-source resolving and image quality.

scholarly journals The Accuracy of Point-of-Care Ultrasound in Detecting Small Bowel Obstruction in Emergency Department

2018 ◽  
Vol 2018 ◽  
pp. 1-5 ◽  
Author(s):  
A. Pourmand ◽  
U. Dimbil ◽  
A. Drake ◽  
H. Shokoohi
Keyword(s):  
Small Bowel ◽  
Small Bowel Obstruction ◽  
Bowel Obstruction ◽  
Imaging Modality ◽  
Point Of Care ◽  
High Sensitivity ◽  
Point Of Care Ultrasound ◽  
Emergency Physicians ◽  
Short Term ◽  
Intestinal Peristalsis

Radiological imaging plays an essential role in the evaluation of a patient with suspected small bowel obstruction (SBO). In a few studies, point-of-care ultrasound (POCUS) has been utilized as a primary imaging modality in patients with suspected SBO. POCUS has been shown to be an accurate tool in the diagnosis of SBO with multiple research studies noting a consistent high sensitivity with a range of 94–100% and specificity of 81–100%. Specific sonographic findings that increase the likelihood of SBO include dilatation of small bowel loops > 25 mm, altered intestinal peristalsis, increased thickness of the bowel wall, and intraperitoneal fluid accumulation. Studies also reported that emergency physicians could apply this technique with limited and short-term ultrasound training. In this article, we aim to review the sensitivity and specificity of ultrasound examinations performed by emergency physicians in patients with suspected SBO.

Attenuation imaging as a new ultrasonographic application for identifying placental haematoma

2021 ◽  
Vol 14 (3) ◽  
pp. e239287
Author(s):  
Masahiro Yamaguchi ◽  
Takeshi Umazume ◽  
Kiwamu Noshiro ◽  
Hidemichi Watari
Keyword(s):  
Diagnostic Accuracy ◽  
Placental Abruption ◽  
Imaging Modality ◽  
Clinical Findings ◽  
Attenuation Imaging

We present a case in which attenuation imaging (ATI), a recently developed ultrasonographic application, facilitated the diagnosis of preplacental and postplacental haematoma. Placental abruption is a serious condition that affects the prognosis of infants and is difficult to diagnose. Ultrasonography is the primary imaging modality that complements the clinical findings in the diagnosis; however, its sensitivity is low, and improved diagnostic accuracy is desired. Here, we found that placental haematomas on the placental fetal surface observed at 19 weeks of gestation were indistinct from placental parenchyma in B-mode ultrasonographic imaging. In ATI, the placental parenchyma was colour-mapped, but the haematoma portion was not, which helped identify the haematoma. ATI, which also colour-maps uniform tissues, did not colour-map vessels within the placenta. ATI has a breakthrough potential for improving the diagnosis of placental abruption.

Developmental Hip Dysplasia

2019 ◽  
pp. 297-300
Author(s):  
Dorothy L. Gilbertson-Dahdal
Keyword(s):  
Risk Factors ◽  
Problem Solving ◽  
Imaging Modality ◽  
Treatment Options ◽  
Hip Dislocation ◽  
Clinical Findings ◽  
Developmental Dysplasia ◽  
Developmental Hip Dysplasia ◽  
Hormonal Factors ◽  
Dysplasia Of The Hip

Chapter 112 focuses on developmental dysplasia of the hip, which includes a spectrum of abnormalities ranging from a stable hip with a mildly dysplastic acetabulum to complete hip dislocation. Pathophysiology, clinical findings, and screening studies are explored. The pathophysiology is multifactorial including mechanical, genetic and hormonal factors. Imaging strategies, findings, and treatment options are also discussed. Screening US, which is the imaging modality of choice, is performed on infants with predisposing risk factors. Outcome is quite variable with many cases resolving spontaneously without treatment whereas others stabilize with acetabular dysplasia. Treatment options include immobilization and surgery. MRI is used for problem solving in postoperative patients.

scholarly journals P1302 B-cell lymphoma presenting as an ejection systolic murmur

2020 ◽  
Vol 21 (Supplement_1) ◽  
Author(s):  
T Constantinides ◽  
M Ioannides ◽  
K Yiagou ◽  
P Avraamides
Keyword(s):  
B Cell ◽  
Transthoracic Echocardiography ◽  
Cell Lymphoma ◽  
Imaging Modality ◽  
Pulmonary Stenosis ◽  
B Cell Lymphoma ◽  
Large Mass ◽  
Clinical Findings ◽  
Ct Guided ◽  
Mediastinal Masses

Abstract OnBehalf Nicosia General Hospital We present the case of a young patient with large B-cell lymphoma causing severe extrinsic pulmonary stenosis. This patient presented to the emergency department with chest discomfort ,fatigue and dyspnea on minimal exertion. A loud ejection mid-systolic crescendo-decrescendo murmur with widely split S2 located in 2nd left parasternal border, raised the suspicion of pulmonary stenosis and patient underwent immediate transthoracic echocardiography as the first imaging modality of choice.On transthoracic echocardiography a large mass was seen, causing severe extrinsic pulmonary stenosis, and was further diagnosed as B-cell lymphoma after CT-guided biopsy. We discuss the high index of lymphoma suspicion in cases of pulmonary stenosis findings such as loud ejection murmur in pulmonic valve auscultation area, in otherwise healthy patients, with no history of congenital heart disease. Lymphoma and other mediastinal masses represent the most common aetiology of acquired pulmonary stenosis and should be suspected in otherwise healthy patients who present with clinical findings of pulmonary stenosis and vice-versa, pulmonary stenosis should be suspected in the presence of symptomatic mediastinal masses. Abstract P1302 Figure. Lymphoma PSAX

scholarly journals Clinical and ultrasound features associated with congenital cytomegalovirus infection as potential predictors for targeted newborn screening in high-risk pregnancies

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Hitomi Imafuku ◽  
Hideto Yamada ◽  
Akiko Uchida ◽  
Masashi Deguchi ◽  
Tokuro Shirakawa ◽  
...  
Keyword(s):  
Preterm Delivery ◽  
Medical Center ◽  
Clinical Manifestations ◽  
High Sensitivity ◽  
Clinical Findings ◽  
Youden Index ◽  
Cmv Infection ◽  
Fetal Abnormality ◽  
Congenital Cytomegalovirus ◽  
Fetal Abnormalities

AbstractThis prospective cohort study aimed to determine clinical factors associated with congenital cytomegalovirus (CMV) infection in pregnancy. Newborns born at a perinatal medical center received PCR analyses for CMV-DNA in their urine with informed consent. Clinical data, including age, maternal fever or flu-like symptoms, complications, ultrasound fetal abnormality, gestational weeks at delivery, and birth weight, were collected. Logistic regression analyses determined clinical findings associated with congenital CMV infection (cCMV). cCMV was diagnosed in 32 of 4380 pregnancies. Univariate and multivariable analyses revealed that age < 25 years old (OR 2.7, 95% CI 1.1–6.6; p < 0.05), the presence of maternal fever or flu-like symptoms (5.4, 2.6–11.2; p < 0.01), ultrasound fetal abnormalities (12.7, 5.8–27.7; p < 0.01), and preterm delivery at less than 34 gestational weeks (2.6, 1.1–6.0; p < 0.05) were independent clinical findings associated with cCMV. A combination of maternal fever/flu-like symptoms, ultrasound fetal abnormalities, or preterm delivery at less than 34 gestational weeks as optimal predictive factors showed 90.6% sensitivity, 66.4% specificity, and a maximum Youden index of 0.57. CMV-DNA tests in the urine of newborns born to mothers with these clinical manifestations may be an effective method in detecting cCMV as a targeted screening with a high sensitivity.

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