scholarly journals CT-pathologic correlation of non-calcified atherosclerotic arterial plaques: a study using carotid endarterectomy specimens

2020 ◽  
Vol 93 (1109) ◽  
pp. 20190901
Author(s):  
Masahiro Higashi ◽  
Naoaki Yamada ◽  
Satoshi Imakita ◽  
Chikao Yutani ◽  
Hatsue Ishibashi-Ueda ◽  
...  
Keyword(s):  
Carotid Endarterectomy ◽  
Fibrous Tissue ◽  
Hounsfield Unit ◽  
Atherosclerotic Plaques ◽  
Two Phase ◽  
Post Contrast ◽  
Discrimination Ability ◽  
Pathologic Features ◽  
Lower Accuracy ◽  
Contrast Ct

Objective: Pathologic features of atherosclerotic plaques on CT are not established. We compared CT values among pathologically confirmed plaque constituents and evaluated their ability to distinguish plaque constituents. Methods: 50 histopathological images of carotid endarterectomy samples from 10 males and 2 females (age 54–74 years, average 65.9 years) were examined. We compared pre-operative CT [pre-contrast (CT-P), early post-contrast phase (CT-E), delayed post-contrast phase (CT-D)] of lipid-rich necrotic core (NC) and fibrous tissue (F) plaque components with pathological images. The ability of features to differentiate plaque components using several discrimination techniques were compared. Results: CT values of NC and F were 36 ± 13, 45 ± 11 (mean ± standard deviation, Hounsfield unit, HU), 41 ± 17, 69 ± 18, and 44 ± 16, 70 ± 13 in CT-P (p < 0.01), CT-E (p < 0.0001), and CT-D (p < 0.0001), respectively. The threshold, sensitivity, and accuracy for distinguishing NC from F were 44 HU, 74%, and 68%; 55 HU, 85%, and 85%; and 63 HU, 92%, and 84% in CTP, CT-E, and CT-D, respectively. CT-P had lower accuracy than CT-E and CT-D (both p < 0.05), but CT-E and CT-D were similar. CT-E and CT-D yielded 90 and 91% sensitivity and accuracy, respectively in linear discrimination analysis. Conclusion: In both pre- and post-contrast CT, CT values were lower in NC than F. Although values overlapped, using two-phase post-contrast CTs improved discrimination ability. Advances in knowledge: Our findings may help to establish computer-aided diagnosis of vulnerable atherosclerotic plaques in future.

scholarly journals Feline injection site sarcoma: computed-tomographic density and assessment of tumor dimensions by different methods

2017 ◽  
Vol 37 (10) ◽  
pp. 1113-1118
Author(s):  
Karen Maciel Zardo ◽  
Lucas Petri Damiani ◽  
Julia Maria Matera ◽  
Ana Carolina B.C. Fonseca-Pinto
Keyword(s):  
Physical Examination ◽  
Injection Site ◽  
Malignant Neoplasm ◽  
Hounsfield Unit ◽  
Ct Images ◽  
Post Contrast ◽  
Computed Tomographic ◽  
Definition Of ◽  
Ct Density ◽  
Contrast Ct

ABSTRACT: Feline injection site sarcoma is a malignant neoplasm with digitiform projections into muscular planes that are ill recognized during physical examination and may compromise tumor margin demarcation. This study compared tumoral size of 32 cats measured by different methods, and evaluated the CT density of 10 tumoral tissues (Hounsfield unit) based on histograms. Tumor axes were measured by physical examination and CT images. Larger craniocaudal axis measurements were obtained following multiplanar reconstruction of pre- and post-contrast CT images (p=0.049 and p=0.041 respectively); dorsoventral axis measurements taken from post-contrast CT images were also larger (p=0.010). Tumor volume estimates increased following contrast-enhancement. Histograms tended to produce two peaks: one in the fat and another in the soft tissue attenuation range. Multiplanar reconstructed post-contrast CT images provided clearer definition of tumor margins and more judicious determination of tumor size. A tendency of common FISS attenuation profile could be described.

Bubble study as a medium of contrast for computerized tomography coronary angiography. (Preprint)

2020 ◽  
Author(s):  
Vijay Shah ◽  
Justyn Huang
Keyword(s):  
Pulmonary Artery ◽  
Diagnostic Yield ◽  
Negative Contrast ◽  
Hounsfield Unit ◽  
Hounsfield Units ◽  
Computed Tomographic ◽  
Invasive Test ◽  
Clinical Difference ◽  
Contrast Ct ◽  
Scan Protocol

BACKGROUND Computed tomographic coronary angiogram (CTCA) is a non-invasive test with a negative predictive value of nearly 100% for the detection of coronary artery study. While diagnostic yield of a dedicated CTCA with bubble contrast is not yet evaluated OBJECTIVE To assess the diagnostic performance of injected bubble contrast and ability to measure difference in hounsfield units and use it as a "negative contrast" in computed tomographic METHODS This is a single center, single patient study. Baseline acquisition of a non-contrast CT scan was acquired to get hounsfield unit count in the aorta and pulmonary artery- (Calcium scan protocol) 1.4 mGy (19.5 mGy/cm). Secondly, Echo contrasts (Definity) - 5mls was injected and an echocardiogram confirmed filling in the aortic region. Finally, bubble contrast (1ml air, 8mls water and 1mls blood was drawn up and agitated through a 3 way tap) - was injected, a timing run was initiated to calculate for the bubbles to opacity the pulmonary artery. The same scan protocol was used– 1.4 mGy (19.5 mGy/cm). RESULTS Hounsfield units’ difference in the aorta and pulmonary artery from baseline compared to echo contrast and bubble contrast were not significant. CONCLUSIONS We believe this is the first ever recorded case to use bubbles as CT contrast. While results were not significant, secondary to small volume of bubbles injected. Further research needs to be implemented to assess clinical difference with amount of bubbles and volume required. CLINICALTRIAL Single centre study

scholarly journals 123 Gemcitabine-related radiation recall as a cause of focal myositis and muscle necrosis

2019 ◽  
Vol 90 (e7) ◽  
pp. A40.1-A40
Author(s):  
Sean Byrnes
Keyword(s):  
Palliative Radiotherapy ◽  
Radiation Recall ◽  
Post Contrast ◽  
Immune Mediated ◽  
Cutaneous Tissue ◽  
Muscle Necrosis ◽  
History Of ◽  
Contrast Ct ◽  
Ct And Mri

IntroductionRadiation recall is a phenomenon in which chemotherapy triggers an inflammatory response in tissue previously subjected to radiation therapy. A wide variety of agents have been implicated. Cutaneous tissue is most frequently affected but other tissue can be involved; myositis has been associated with administration of gemcitabine in particular. Incidence has been estimated at less than 6% and the pathophysiology is not understood. We present a case report from Gosford Hospital, with the additional feature of positive SRP antibodies.CaseA 74 year old female presented with a one day history of left hip pain and inability to weight bear. She had been diagnosed with metastatic squamous cell carcinoma of the lung five months earlier and underwent palliative radiotherapy to a left acetabular metastasis. 12 days prior to presentation she completed her second cycle of chemotherapy with carboplatin and gemcitabine. Pre- and post-contrast CT and MRI demonstrated necrosis in left sartorius, with foci of myositis in other muscles of the thigh, and surrounding soft tissue oedema. Symptoms improved after chemotherapy was ceased. Myositis antibody studies subsequently revealed low level positive Ku and SRP antibodies.ConclusionRadiation recall should be considered in the differential diagnosis of myositis in oncology patients. The serum of our patient contained SRP antibodies, which are associated with immune mediated necrotising myopathy. A previous case study reported gemcitabine-induced radiation recall muscle necrosis associated with dermatomyositis. These findings hint that radiation recall myositis may occur in the setting of a predisposition to immune mediated myopathy.

scholarly journals Plant Sterols in Serum and in Atherosclerotic Plaques of Patients Undergoing Carotid Endarterectomy

2005 ◽  
Vol 45 (11) ◽  
pp. 1794-1801 ◽  
Author(s):  
Tatu A. Miettinen ◽  
Mikael Railo ◽  
Mauri Lepäntalo ◽  
Helena Gylling
Keyword(s):  
Carotid Endarterectomy ◽  
Plant Sterols ◽  
Atherosclerotic Plaques

Friction Factor Equations Accuracy for Single and Two-Phase Flows

2020 ◽  
Author(s):  
Germano Scarabeli Custódio Assunção ◽  
Dykenlove Marcelin ◽  
João Carlos Von Hohendorff Filho ◽  
Denis José Schiozer ◽  
Marcelo Souza De Castro
Keyword(s):  
Pressure Drop ◽  
Friction Factor ◽  
Single Phase ◽  
Computational Cost ◽  
Two Phase Flows ◽  
Two Phase ◽  
Explicit Equation ◽  
Implicit Equation ◽  
Lower Accuracy ◽  
Statistical Metrics

Abstract Estimate pressure drop throughout petroleum production and transport system has an important role to properly sizing the various parameters involved in those complex facilities. One of the most challenging variables used to calculate the pressure drop is the friction factor, also known as Darcy–Weisbach’s friction factor. In this context, Colebrook’ s equation is recognized by many engineers and scientists as the most accurate equation to estimate it. However, due to its computational cost, since it is an implicit equation, several explicit equations have been developed over the decades to accurately estimate friction factor in a straightforward way. This paper aims to investigate accuracy of 46 of those explicit equations and Colebrook implicit equation against 2397 experimental points from single-phase and two-phase flows, with Reynolds number between 3000 and 735000 and relative roughness between 0 and 1.40 × 10−3. Applying three different statistical metrics, we concluded that the best explicit equation, proposed by Achour et al. (2002), presented better accuracy to estimate friction factor than Colebrook’s equation. On the other hand, we also showed that equations developed by Wood (1966), Rao and Kumar (2007) and Brkić (2016) must be used in specifics conditions which were developed, otherwise can produce highly inaccurate results. The remaining equations presented good accuracy and can be applied, however, presented similar or lower accuracy than Colebrook’s equation.

Novel Strategy of the Determination of Mechanical Properties of Human Carotid Atherosclerotic Plaques

2012 ◽  
Author(s):  
Renate W. Boekhoven ◽  
Richard G. P. Lopata ◽  
Marcel C. M. Rutten ◽  
Marc R. H. M. van Sambeek ◽  
Frans N. van de Vosse
Keyword(s):  
Mechanical Properties ◽  
Carotid Endarterectomy ◽  
Early Stage ◽  
Three Dimensions ◽  
Atherosclerotic Plaques ◽  
Ct Data ◽  
Novel Strategy ◽  
Unstable Plaques ◽  
Set Up

Carotid endarterectomy is the procedure of choice in patients with a recent symptomatic stenosis of 70–99%. Currently, the selection of candidates eligible for carotid endarterectomy is based on stenosis size only. However, the treatment is only beneficial for patients with unstable plaques, which comprises only 16% of the patient population [1]. Hence, identifying plaque stability at an early stage would permit timely intervention, while substantially reducing overtreatment of stable plaques. The objective of this study is to distinguish between stable and unstable carotid atherosclerotic plaques by determining the plaque geometry, the plaque composition and the mechanical properties of plaque components in three dimensions (3D). Mechanical properties from healthy vessels were assessed earlier by van den Broek et al. [2] using ultrasound (US) imaging. They obtained a dynamic dataset in 2D + t. When blood pressure and vessel wall movement are known, mechanical properties can be extracted from these data using a constitutive model. However, atherosclerotic plaques are mostly asymmetric, and present calcifications will cause unfavorable acoustic shadowing when using US. In this study, the focus is on the assessment of plaque geometry, from in vitro echo-CT data, overcoming the aforementioned problems. In an experimental set-up (Fig. 1) both healthy and endarterectomy specimens were mounted, and exposed to physiological intraluminal pressures. Echo-CT was used to image the arterial segments in 3D+t. Automated geometry assessment of the arterial segments will be demonstrated and validated using microCT (μCT).

In Vitro Three Dimensional Imaging of Human Carotid Atherosclerotic Plaques Using Ultrasonography

2011 ◽  
Author(s):  
Renate W. Boekhoven ◽  
Marcel C. M. Rutten ◽  
Marc R. H. M. van Sambeek ◽  
Frans N. van de Vosse
Keyword(s):  
Mechanical Properties ◽  
Carotid Artery ◽  
Carotid Endarterectomy ◽  
Early Stage ◽  
Three Dimensional ◽  
Atherosclerotic Plaques ◽  
Unstable Plaques ◽  
Human Carotid ◽  
Selection Of

Ruptured atherosclerotic plaques in the carotid artery are the main cause of stroke (70–80%). To prevent it, carotid endarterectomy is the procedure of choice in patients with a recent symptomatic 70–99% stenosis. Today, the selection of candidates is based on stenosis size only. However, endarterectomy is beneficial for only 1 out of 6 patients [1], the patients with unstable plaques (Fig. 1). Knowledge of mechanical properties of different components in the atherosclerotic arteries is important, because it will allow the identification of plaque stability at an early stage.

Giant vertebro-basilar aneurysm: an unusual cerebello-pontine angle lesion

2006 ◽  
Vol 120 (2) ◽  
pp. 1-3 ◽  
Author(s):  
Sudhakiran Kalavagunta ◽  
Apostolos Karkanevatos ◽  
Andrew C Swift
Keyword(s):  
Mr Angiography ◽  
Rare Case ◽  
Three Dimensional ◽  
Digital Subtraction ◽  
Post Contrast ◽  
Acoustic Neuromas ◽  
Dimensional Reconstruction ◽  
Diagnostic Difficulties ◽  
Contrast Ct ◽  
Mr Sequences

Acoustic neuromas (vestibular schwannomas) comprise more than 90 per cent of all cerebello-pontine angle (CPA) lesions. We present a rare case of a giant vertebro-basilar aneurysm presenting as a CPA lesion. The general condition of the patient precluded the completion of the magnetic resonance (MR) sequences. The clinical and limited radiological results (T2 images alone, the features of which were not specific) initially did not lead to a specific diagnosis. To obtain further radiological information a computed tomography (CT) scan with contrast was performed and this revealed the lesion to be an aneurysm. The diagnostic difficulties and the treatment dilemmas of such a lesion are discussed. The importance of fine, axial, post-contrast CT arteriography with three-dimensional reconstruction, MR angiography and digital subtraction angiography are highlighted. The limitations of MR imaging in patients with CPA lesions are discussed.

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