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A Most common form of renal transplant vascular reconstruction with end-to-side anastomosis of the donor renal artery and vein with the recipient external iliac artery and vein. B Renal transplant vascular reconstruction with end-to-end anastomosis of the donor renal artery with the recipient internal iliac artery. C Pediatric ‘en bloc’ transplant with pediatric donor aorta and IVC anastomosed to recipient external iliac vessels
Source publication
Doppler ultrasound is routinely used for the post-operative evaluation of renal transplant patients. Knowledge of the surgical anatomy and application of a robust technique are important for appropriate evaluation of a transplanted kidney. In this review article, we discuss the surgical anatomy of renal transplantation, techniques to optimize image...
Citations
... However, there are several limitations to US including its inability to assess renal function or differentiate between the different causes of renal dysfunction. For appropriate evaluation of a graft dysfunction, renal biopsy remains the gold standard for diagnosis [10]. Our results showed that: Group I: Recipients with rejection representing 16 out of 31 patients (51.6%). ...
... This includes contact with the organ and a time-consuming measurement that provides only selective spatial and temporal information. 27,28 A continuous and contactless monitoring of such parameter would make a significant contribution to organ assessment prior and during the transplantation. ...
Significance: Hyperspectral and multispectral imaging (HMSI) in medical applications provides information about the physiology, morphology, and composition of tissues and organs. The use of these technologies enables the evaluation of biological objects and can potentially be applied as an objective assessment tool for medical professionals.
Aim: Our study investigates HMSI systems for their usability in medical applications.
Approach: Four HMSI systems (one hyperspectral pushbroom camera and three multispectral snapshot cameras) were examined and a spectrometer was used as a reference system, which was initially validated with a standardized color chart. The spectral accuracy of the cameras reproducing chemical properties of different biological objects (porcine blood, physiological porcine tissue, and pathological porcine tissue) was analyzed using the Pearson correlation coefficient.
Results: All the HMSI cameras examined were able to provide the characteristic spectral properties of blood and tissues. A pushbroom camera and two snapshot systems achieve Pearson coefficients of at least 0.97 compared to the ground truth, indicating a very high positive correlation. Only one snapshot camera performs moderately to high positive correlation (0.59 to 0.85).
Conclusion: The knowledge of the suitability of HMSI cameras for accurate measurement of chemical properties of biological objects offers a good opportunity for the selection of the optimal imaging tool for specific medical applications, such as organ transplantation.
... Central vascularity was preserved (Fig. 2) and were grossly patent. Failure to detect color Doppler blood flow in general should prompt further evaluation with power Doppler, which is more sensitive [22]. This is commonly used in evaluation for areas of infarction in renal transplants, but given the potential for thrombotic complications associated with COVID-19, should have been considered in our case. ...
SARS-CoV-2 (COVID-19) is well known to have extrapulmonary manifestations, including acute renal failure. While radiologic findings of COVID-19 pulmonary-involvement have been described, renal findings associated with COVID-19 have not. We present a case of a 38-year-old Afro-Caribbean female diagnosed with COVID-19 whose renal ultrasound showed increased parenchymal echogenicity, decreased global color Doppler signal with elevated resistive indices, but no large vessel thrombi. Non-targeted renal biopsy demonstrated collapsing focal segmental glomerulosclerosis (FSGS), likely secondary to COVID-19 infection, which may be a specific manifestation of this disease that has been predominantly reported in Black patients. We report several findings on renal ultrasound with duplex Doppler not previously associated with COVID, specifically with FSGS, which in conjunction can be useful to both the radiologist and the clinician, potentially pointing them in the direction of this diagnosis and early treatment.
... Ряд авторів проводили ретроспективний одноцентровий аналіз вимірювань RІ та його здатність прогнозувати виживання нирки, особливо з огляду на часовий момент виміру RІ. Вони висунули гіпотезу, що прогностична сила RІ варіює від інтервалу часу після трансплантації нирок [7]. ...
... Fortunately, it is possible to evaluate transplant arteries without GBCA by using ferumoxytolenhanced or noncontrast-enhanced renal MR angiography (182). MR angiography with standard or lower than standard dose group II GBCAs, contrast-enhanced CT, and Doppler US are additional options (183,184). ...
Background Although nephrogenic systemic fibrosis (NSF) affects the use of gadolinium-based contrast agents (GBCAs) in MRI, there continues to be limited knowledge because of the small number of patients with NSF. Purpose To perform a systematic review of NSF. Materials and Methods PubMed database was searched by using the term "Nephrogenic systemic fibrosis" from January 2000 to February 2019. Articles reporting details on individual patients with NSF diagnosis on the basis of both clinical presentations and biopsy confirmation were included. Data were pooled and authors were contacted for clarifications. Rates of NSF were compared through 2008 versus after 2008 and for group I versus group II GBCAs, assuming equal market share. Results Included were 639 patients from 173 articles. Data regarding sex were found for 295 men and 254 women. Age at NSF symptom onset was reported for 177 patients (mean, 49 years ± 16 [standard deviation]; age range, 6-87 years). There were 529 patients with documented exposure to GBCAs including gadodiamide (n = 307), gadopentetate dimeglumine (n = 49), gadoversetamide (n = 6), gadobutrol (n = 1), gadobenate dimeglumine (n = 1), multiple (n = 41), and unknown (n = 120). Among patients with previous exposure, only seven patients were administered GBCA after 2008, yielding a lower rate of NSF after 2008 (P < .001). There were motion limitations in 70.8% (296 of 418) of patients, indicating a more serious debilitation. Associated factors reported for NSF included exposure to GBCA group I (P < .001), dialysis, proinflammatory conditions, hyperphosphatemia, β-blockers, and epoetin. For 341 patients with follow-up, 12 patients were cured and 72 patients partially improved including one during pregnancy. Among those 84 patients reported as cured or improved, in 34 patients cure or improvement occurred after renal function restoration. Four deaths were attributed to NSF. Conclusion Although 639 patients with biopsy-confirmed nephrogenic systemic fibrosis were reported, only seven were after gadolinium-based contrast agent exposure after 2008, indicating that regulatory actions and practice changes have been effective preventive measures. Improvement and sometimes cure with renal function restoration are now possible. © RSNA, 2019 See also the editorial by Davenport in this issue.
... Ultrasound gray-scale and color Doppler are useful in the detection of pre-transplanted donor characteristics, the detection of renal graft measurements (length and width) and anatomical characteristics (cortico-medullary differentiation, the existence of hydronephrosis affecting the graft, perinephric fluid collections or masses), and the detection of vascular flow [40]. Periodic RI measurement is useful in patients affected by these complications to help monitor graft function [41]. ...
After the age of 30 years, GFR progressively declines at an average rate of 8 mL/min/1.73 m/decade. A problem of advanced age is that the evaluation of renal function on the basis of indicators valid in young adults, such as creatininemia, is unreliable. In fact, many patients with chronic renal failure may have serum creatinine levels within the normal range even if they have a significant reduction in renal function. Ultrasound has become a routine method of investigation in renal disease: kidney size and parenchymal echogenicity are considered markers of renal function, so US is useful in assessing the presence and degree of renal failure. CEUS is useful in the evaluation of kidney disease in the elderly: the increased hemodynamic resistance of renal microvessels reduces perfusion in the renal cortex, so fewer microbubbles enter the renal cortex. EcoColor and EcoDoppler are also useful in the evaluation of senile alterations: here, the distribution of color-signals, as compared to that in the young adult population, appears more attenuated, limited to intersegmental and interlobar districts. Among the ecoDoppler parameters, the resistance index can be considered a marker of renal damage progression, with attention needing to paid to possible concomitant confounding factors. Ultrasonography, color-Doppler and CEUS are a non-invasive and convenient modality for managing kidney disease; their integration with anamnestic, objective and laboratory data permits fast and reliable clinical, diagnostic, and therapeutic classification. It also allows early therapeutic intervention and, ultimately, improvements in patient management.
Point-of-care ultrasonography (POCUS) is emerging as a valuable tool in nephrology, providing real-time insights into the etiology of acute kidney injury (AKI). This narrative review explores POCUS applications in AKI, emphasizing its role in diagnostic kidney ultrasound and comprehensive hemodynamic assessments. AKI, prevalent in hospitalized patients, poses significant morbidity and mortality risks. POCUS aids in unraveling AKI’s multifaceted origins, categorizing it into hemodynamic, obstructive, and intrinsic renal causes. We discuss the utility of POCUS in urinary obstruction by identifying hydronephrosis and detecting stones and providing prompt diagnostic assistance. In intrinsic AKI, POCUS has limited utility but can potentially differentiate between acute and chronic kidney disease and identify infectious complications. POCUS-assisted hemodynamic AKI assessment involves thorough evaluation of the cardiac, lung, and end organ venous congestion. As technology advances, the role of POCUS in the diagnosis and management of AKI is likely to increase, offering a portable, cost-effective, and radiation-free bedside diagnostic modality. This also has the potential to improve patient outcomes. However, proper training in techniques of POCUS and an understanding of the limitations of POCUS are essential elements in ensuring its optimal and appropriate use in the right clinical context.
Aim
To assess the Doppler ultrasonographic tissue perfusion at dental implant sites augmented with connective tissue graft (CTG) using coronally advanced flap (CAF) or tunnel technique (TUN).
Materials and Methods
Twenty‐eight patients presenting with isolated healthy peri‐implant soft‐tissue dehiscence (PSTD) were included in this randomized clinical trial. PSTDs were treated with either CAF + CTG or TUN + CTG. Ultrasound scans were taken at baseline, 1 week, 1 month, 6 months and 12 months. Tissue perfusion at the mid‐facial, mesial and distal aspects of the implant sites was assessed by colour Doppler velocity (CDV) and power Doppler imaging (PDI). Early vascularization of the graft and the flap at 1 week and at 1 month were evaluated via dynamic tissue perfusion measurements (DTPMs), including flow intensity (FI), mean perfusion relief intensity (pRI) and mean perfused area (pA).
Results
Regression analysis did not reveal significant differences in terms of mid‐facial CDV and PDI changes between CAF and TUN over 12 months ( p > .05), while significant differences between the two groups were observed at the interproximal areas ( p < .001 for both CDV and PDI changes). Higher early DTPMs were observed at the TUN‐treated sites in terms of mean FI of the graft ( p = .027) and mean FI ( p = .024) and pRI of the flap ( p = .031) compared with CAF‐treated sites at 1 week. Assessment of the FI direction showed that CTG perfusion at 1 week and at 1 month mainly occurred from the flap towards the implant/bone. Early tissue perfusion outcomes were found to be associated with the 12‐month mean PSTD coverage and mucosal thickness gain.
Conclusions
Doppler ultrasonography shows tissue perfusion changes occurring at implant sites augmented with CTG. The main differences in tissue perfusion between CAF and TUN were observed at the interproximal sites, with early perfusion associated with clinical and volumetric outcomes at 12 months.
Kidney transplantation has become the standard treatment for end-stage renal disease. Even though the success rates are high, early and late post-transplant complications remain a major clinical problem due to the risk of graft failure. Therefore, it is of highest interest to early diagnose post-transplant complications. Ultrasound with color coded Duplex analysis plays a crucial role in imaging mechanical and vascular complications. In this article, we give an update of the visualizable complications in kidney transplant recipients and discuss the value of resistive index (RI) measurement with its limitations in allograft rejection.
