Fig 5 - uploaded by Gervais Wansaicheong
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Bosniak category II cyst. CEUS image showing renal cyst with single mildly enhancing thin septa (arrowheads).
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Contrast-enhanced ultrasound has entered the imaging mainstream in the last few years. It is a safe technique with exquisite temporal and spatial resolution and is especially useful for evaluating focal renal mass lesions in patients with renal impairment when iodinated or gadolinium contrast agents are contraindicated. The purpose of this manuscri...
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the developed world. Magnetic resonance imaging (MRI) contrast agents are mainly gadolinium-based but...
Subharmonic signals backscattered from gas-filled lipid-shelled microbubbles have generated significant research interest because they can improve the detection and sensitivity of contrast-enhanced ultrasound imaging. However, the emission of subharmonic signals is strongly characterized by a temporal dependence, the origins of which have not been...
Contrast agents are used in radiology to increase the sensibility and specificity of radiological techniques. Some of these compounds have side effects that include organ toxicity (with kidney being the most affected organ) and hypersensitivity reactions. We performed multiple PubMed searches from January, 2008 to January, 2018 for studies regardin...
Citations
... Kidneys present a three-phased contrast enhancement consisting of an early arterial phase-in which there is rapid contrast enhancement due to the arterial blood supplyfollowed by a cortical phase marked by intense and uniform enhancement of the renal parenchyma, and a medullary phase, when the pyramids gradually uptake contrast until they are isochoic with the cortex [51,55]. ...
Simple Summary
The aim of this literature review was to present the novel imaging modalities elastography and contrast-enhanced ultrasonography. We provided an overview of the concepts and applications of each technique for the investigation of neoplastic or metastatic tumors in dogs and cats. Studies fon elastography are based on the elasticity and deformation of the evaluated tissue. The information obtained from elastography can aid in the detection and differentiation of malignant and benign structures. Descriptions of elastography studies in several organs and tissues in veterinary medicine reported that, in general, malignant tumors tend to be more rigid and, therefore, less deformable than benign lesions or in comparison to the healthy parenchyma. Contrast-enhanced ultrasonography is based on the intravenous injection of contrast media constituted by microbubbles. This imaging modality provides information on the tissue perfusion and allows the investigation of macro- and micro-circulation. Studies on different organs and tissues were performed in dogs and cats and revealed a tendency of malignant tumors to present faster transit of the contrast media (time to wash in, peak and wash out). These advanced techniques associated with other imaging modalities can be used as screening tests and can potentially represent an alternative to the invasive sampling methods required for cytological and histopathological analysis.
Abstract
The aim of this literature review was to present the novel imaging modalities elastography and contrast-enhanced ultrasonography. We provided an overview of the concepts and applications of each technique for the investigation of neoplastic and metastatic tumors in dogs and cats. Studies on elastography are based on the elasticity and deformation of the evaluated tissue. The information obtained from the different types of elastography can aid in the detection and differentiation of malignant and benign structures. Descriptions of elastography studies in several organs and tissue in veterinary medicine reported that, in general, malignant tumors tend to be more rigid and, therefore, less deformable than benign lesions or in comparison to the healthy parenchyma. Contrast-enhanced ultrasonography is based on the intravenous injection of contrast media constituted by microbubbles. This imaging modality can be performed in nonsedated animals and provides information on the tissue perfusion, allowing the investigation of macro- and micro-circulation. Studies on different organs and tissues were performed in dogs and cats and revealed a tendency of malignant tumors to present faster transit of the contrast media (time to wash-in, peak and wash-out). These advanced techniques can be associated with other imaging modalities, aiding important information to the well-established exams of B-mode and Doppler ultrasonography. They can be used as screening tests, potentially representing an alternative to the invasive sampling methods required for cytological and histopathological analysis.
... Ultrasound is the standard method for first intentional evaluation of kidney. But, it sometimes couldn't differentiate between renal cysts and mixed solid tumors, so, another medical imaging techniques were used such as computed tomography, magnetic resonance imaging, and contrast-enhanced ultrasonography (Prakash and Wansaicheong, 2011). ...
Image processing has large applications in the medical diagnosing, especially in Ultrasound Imaging (UI) that for its' safety. UI suffer from low resolution and noises, so, became a target for a lot of investigations. Three US images which represent Cyst, Benign, and Stone used in this study. Five contrast enhancement techniques and three denoising filter applied on them and best of them chose according to their PSNR and MSE values. It's found that best contrast enhancement methods were Contrast adjustment, for Benign and Cyst images, and sharpening for the Stone image. Then, the images denoised by Median filtering due to found it as better denoising filter than others studied here. Three segmenting methods (one ordinary and two hybrid techniques) were used here: thresholding, kmean with intensity selector, and bilateral filter with intensity selector. All techniques were segmented nearly same area of the cases. But thresholding needs a large of trial and error to obtain their segmenting. The kmean with intensity selector method was found better for the Benign case than other for its higher PSNR (16.68), lower MSE (1394.1), and small time of running (22.1 sec). But for Cyst and Stone images, Bilateral filter with intensity selector was found better than other according to same parameters. So, techniques of hybrid segmentation provided more efficient segmenting.
... Recently developed techniques (a combination of CEUS, contrast-specific software, and quantification tools) have been proposed to quantify the blood flow within an organ with CEUS [7,8,10,[13][14][15][16][17]. CEUS has the potential to improve the imaging of renal blood flow and renal lesional 1 3 vascularity in real time, with high temporal and spatial resolution [6,11,15,[18][19][20][21][22][23][24][25]. CEUS is a simple technique for detecting the severity of kidney microvascular perfusion deficit [6,7,13,14,17,[23][24][25][26]. ...
... Our results confirmed the research of Prakash et al. [ 13 ], according to whom heterogeneous distribution of the contrast and presence of a pseudocapsule were typical of renal cell carcinoma, while homogeneous and continuous enhancement were characteristic of AML. ...
Literature data on differential diagnosis between benign and malignant kidney tumours with CEUS is controversial. The purpose of this study was to evaluate the usefulness of Contrast-Enhanced Ultrasound (CEUS) in differentiating between renal cell carcinoma (RCC) and renal angiomyolipoma (AML). We examined 48 patients-16 with AML and 32 with RCC. We estimated the size, shape, blood flow of the formation using Conventional and Doppler Ultrasound and by CEUS-we evaluated the contrasting of the formation and we did analyses of time-intensity curves (TIC). Triplex ultrasound described formations of different sizes from 10 to 70 mm, with a heterogeneous structure in RCC. By Doppler ultrasound we found a lack of blood supply at 11/16 or peripheral blood supply at 2/16 AML and neovascularisation at 30/32 RCC. By CEUS-angiomyolipoma was contrasted from the periphery to the centre with hyper-enhancement in the late phase and homogenous distribution of contrast agent in the formation, while in RCC the entering of the contrast agent was chaotic, with heterogeneous enhancement. We found two types of TIC, which were the same for AML and RCC-slow wash-in and -out, and the second one-rapid wash-in and slow wash-out. In the first type of TIC our results showed that MTT (Mean transit time) and TTP (Time to peak) were shorter at AML with presence of hyper-enhanced formation (p < 0.05). In the second type of curve-MTT was longer in RCC (p < 0.05).
... Sehgal et al [9] first reported renal perfusion imaging with a sonographic contrast agent in 1998. Since then, many clinical investigation or experimental studies have shown that the use of microbubble agents in color and power Doppler sonography can improve the detection and characterization of various renal perfusion abnormalities [10][11][12]. However, major clinical applications of contrast ultrasound in the kidneys are related to the assessment of masses or regional perfusion differences, such as in pyelonephritis [13]. ...
The aim of this feasibility study was to prospectively explore in a dog model of chronic ischemic renal disease (CIRD) the hypothesis that real-time contrast-enhanced ultrasonography (CEUS) can quantitatively evaluate the early perfusion changes of renal cortex.
In this animal care and use committee-approved study, the model of CIRD was carried out in healthy dogs (10.0∼12.0 kg, n = 5), by placing the Ameroid ring constrictors on the distal portion of right renal artery through operation. CEUS monitoring of right kidney perfusion was performed by intravenous bolus injection of 0.6 ml Sulfur hexafluoride filled microbubbles (SonoVue; Bracco S.P.A., Milan, Italy) every week after operation. The slope rate of ascending curve (A) and descending curve (α), area under curve (AUC), derived peak intensity (DPI), and time to peak (TTP) were measured in renal cortex using commercial quantification software (Q-LAB version 6; Philips Medical Systems, Bothell,WA,USA). The sensitivity of CEUS was compared with blood serum urea nitrogen (BUN) and serum creatinine (SCr) level.
With the progression of CIRD, dogs showed delayed enhancement and perfusion in renal CEUS curve. Earliest significant changes happened 4 weeks after operation on DPI and TTP which changed from 13.04±2.71 to 15.58±4.75 dB and 9.03±2.01 to 10.62±6.04 sec, respectively (P<.05).
CEUS can display the perfusion changes of CIRD in the early period.
Objective:
The aim of the work described here was to provide an evidence-based evaluation of contrast-enhanced ultrasonography (CEUS) in acute kidney injury (AKI) and assess variations in renal microperfusion with CEUS quantitative parameters in patients at a high risk of developing AKI.
Methods:
A meta-analysis and systematic review were conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, and the Embase, MEDLINE, Web of Science and the Cochrane Library databases were used to search the relevant articles systematically (2000-2022). Studies using CEUS to assess renal cortical microcirculation in AKI were included.
Results:
Six prospective studies (374 patients) were included. The overall quality of included studies was moderate to high. CEUS measures, maximum intensity (standard mean difference [SMD]: -1.37, 95% confidence interval [CI]: -1.64 to -1.09) and wash-in rate (SMD: -0.77, 95% CI: -1.09 to -0.45) were lower in the AKI+ group than in the AKI- group, and mean transit time (SMD: 0.76, 95% CI: 0.11-1.40) and time to peak (SMD: 1.63, 95% CI: 0.99-2.27) were higher in the AKI+ group. Moreover, maximum intensity and wash-in rate values changed before creatinine changed in the AKI+ group.
Conclusion:
Patients with AKI had reduced microcirculatory perfusion, prolonged perfusion time and a reduced rising slope in the renal cortex, which occurred before serum creatinine changes. And they could be measured using CEUS, indicating that CEUS could help in the diagnosis of AKI.
Most often any kidney lesions are primary renal, but sometimes they can be secondary (metastases, lymphoma). Every year renal cell carcinoma tends to a significant increase in the incidence. Today there are many available methods of examination, however difficulties often remain in the differential diagnosis of kidney lesions. The article discusses about the modern possibilities of methods in the identification and assessment of kidney lesions, their role in determining the tactics of patient management and key approaches in imaging characterization of these masses using CT and PET, MRI and CEUS. The analysis of the modern literature has shown that the currently existing radiation diagnostic methods do not provide an absolute opportunity for differential diagnosis of rare kidney tumors. CEUS, according to various authors, demonstrates high efficiency indicators, but does not exceed these indicators in comparison with CT and MRI. Contrast-enhanced ultrasound is a potentially safe method and can be used as a method for additional examination to characterize indeterminate renal lesions.
Background
Contrast-enhanced ultrasound (CEUS) can provide more improved images of renal blood flow and much more information of both macro- and microcirculation of the kidney as comparing to Doppler US.
Objective
To investigate the usefulness of CEUS by analyzing differences in perfusion-related parameters among the three chronic kidney disease (CKD) subgroups and the control group.
Methods
Thirty-eight patients with CKD and 21 controls who were age matched (20−49 years) and included. Included CKD patients were stratified into three groups according to their eGFR: group I, eGFR ≥ 60 ml/min/1.73 m2 (GFR category I and II); group II, 30 ml/min/1.73 m2 ≤ eGFR < 60 ml/min/1.73 m2 (GFR category III); and group III, eGFR < 30 ml/min/1.73 m2 (GFR category IV and V). Comparisons with the controls (eGFR > 90 ml/min/1.73 m2 ) were performed. Real-time and dynamic renal cortex imaging was performed using CEUS. Time-intensity curves and several bolus model quantitative perfusion parameters were created using the VueBox® quantification software. We compared the parameters among the CKD subgroups and between the CKD and control groups.
Results
Eight patients were included in group I, 12 patients in group II, and 18 patients in group III. Significant differences were noted in the wash-in and wash-out rates between the CKD and control groups (p = 0.027 and p = 0.018, respectively), but not between those of the CKD subgroups. There were no significant differences of other perfusion parameters among the CKD subgroups and between the CKD and control groups.
Conclusion
A few perfusion related CEUS parameters (WiR and WoR) can be used as markers of renal microvascular perfusion relating renal function. CEUS can effectively and quantitatively exhibit the renal microvascular perfusion in patients with CKD as well as normal control participants.
Background
Contrast-enhanced ultrasound (CEUS) has the potential to improve the imaging of renal blood flow and renal lesional vascularity in real time with high temporal and spatial resolution.
Purpose
This study investigated the clinical significance of real-time CEUS in cases of chronic kidney disease (CKD).
Materials and methods
Included patients were stratified according to their estimated glomerular filtration rate (eGFR): Group I (CKD stage I and II), eGFR ≥ 60 ml/min/1.73 m²; group II (CKD stage III), eGFR of 30 ≤ eGFR < 60 ml/min/1.73 m²; and group III (CKD stage IV and V), eGFR of eGFR < 30 ml/min/1.73 m². Real-time and dynamic imaging of the renal cortex was performed using CEUS. Several bolus model perfusion and laboratory parameters were compared. The differences in perfusion or laboratory parameters among the groups and correlation between perfusion or laboratory parameters and eGFR were assessed.
Results
Of the 24 patients, 4 were classified into group I, 13 into group II, and 7 into group III. No significant differences were found among the three groups in the perfusion parameter analysis. No parameter was significantly positively correlated with eGFR. In the laboratory parameter analysis, significant differences in several parameters (RBC, BUN, SCr, glucose, TCh, phosphorus, TP, p < 0.05) were detected among the three groups. These parameters significantly correlated with eGFR (correlation coefficient, R = − 0.7625 to 0.6026).
Conclusions
Kidney perfusion parameters in CEUS do not correlate with kidney function in this pilot study.
In letteratura sono reperibili numerosi studi in merito all’utilizzo del mezzo di contrasto (mdc) ecografico di II generazione nella patologia epatica, ma negli ultimi anni é incrementato il numero di pubblicazioni inerenti le applicazioni su altri organi: rene, tenue, pancreas, testicoli e prostata [1].
