Renal ultrasound

Diagnostic accuracy of Point Of Care UltraSound (POCUS) in clinical practice: A retrospective, emergency department based study

AIMS

Point-of-care ultrasound (POCUS) is the acquisition and interpretation of ultrasound imaging at the bedside to solve specific clinical questions based on signs and symptoms of presentation. While several studies evaluated POCUS diagnostic accuracy for a variety of clinical pictures in the emergency department (ED), only a few data are available on POCUS diagnostic accuracy performed by physicians with different POCUS skills. The objective of this research was to evaluate the diagnostic accuracy of POCUS compared to standard diagnostic imaging in the ED.

MATERIALS AND METHODS

This was a retrospective study conducted in the ED of a third-level university hospital. Patients who underwent cardiac, thoracic, abdominal, or venous lower limb POCUS and a standard imaging examination between June 2021 and January 2022 were included.

RESULTS

1047 patients were screened, and 844 patients included. A total of 933 POCUS was included (102, 12.09%, cardiac; 466, 55.21%, thoracic; 336, 39.8%, abdominal; 29, 3.44%, lower limb venous POCUS), accounting for 2029 examinations. POCUS demonstrated 96.6% (95% CI 95.72-97.34) accuracy, 47.73 (95% CI 33.64-67.72) +LR, 0.09 (95% CI 0.06-0.12) -LR. +LR was greater than 10 for all investigations but for hydronephrosis (5.8), and -LR never exceeded 0.4.

CONCLUSIONS

POCUS exhibited high diagnostic accuracy for virtually all conditions when performed by emergency department physicians.

A Multicentric Audit to Reevaluate the Guidelines Adherence in Computed Tomography of Kidneys, Ureters, and Bladder (CT-KUB) X-ray Imaging in Jordan

Background With the increasing use of imaging techniques involving ionizing radiation, the area of the body scanned should be restricted to what is required to answer the clinical question. Therefore, this is a retrospective audit that intends to evaluate the presence of overscanning in renal computed tomography (CT) scan images during the process of evaluation for urinary symptoms. Objective This study aims to reduce the unnecessary scan length and exposure to radiation in patients who undergo CT scans for urinary symptoms. Materials and Methods In two months duration, patients from different clinics underwent CT imaging, and the resulting radiographic images were collected and analyzed. Overscanning was defined to be more than 10% of the total scan. Subsequently, the total length of the CT scan was measured which is used to measure the unnecessary overscan above the highest kidney margin as a percentage of the total length. Results Out of the 88 patients who were evaluated, 100% did not meet the guidelines for renal CT imaging and were exposed to a high radiation dose. However, the minimum percentage of overscanned patients was 20-40%. Conclusion A significant number of scans demonstrated surplus overscanning above the highest kidney. Therefore, recognizing the suitable anatomical landmarks for scanning and establishing a follow-up audit are suggested measures to minimize the noxious effects of radiation exposure.

Point-of-Care Abdominal Ultrasonography (POCUS) on the Way to the Right and Rapid Diagnosis

Point-of-Care ultrasound (POCUS) is based on target ultrasound that is performed wherever a patient is being treated, and by a non-radiologist directly involved in the patient’s care. It is used either for quick diagnosis or procedural guidance. Abdominal pain is one of the most common complaints in emergency departments, and POCUS can help in the differentiation of patients who need additional diagnostic tests or hospital treatment, which eventually reduces the overall costs of health care. POCUS has high sensitivity and specificity in abdominal pathology, it can be helpful in the evaluation of biliary, intestinal, and urinary tract, and it is especially used in trauma. Additionally, the gold standard for abdominal aortic aneurysm detection, follow up and screening is precisely this diagnostic procedure. Unfortunately, the quality of ultrasound examination can be affected by the experience of the physician performing it and the patient’s body weight. There is no doubt that POCUS is being increasingly recognized, but all motivated physicians should be provided with dedicated tutors and enough time for learning. This would certainly help to implement this diagnostic method as a routine in emergency and critical care departments, and significantly shorten the time until definitive diagnosis.

The influence of interstitial cells of Cajal density in the outcomes of pyeloplasty in adults: A prospective analysis

Purpose:

To evaluate if the density of interstitial cells of Cajal (ICC) in the ureteropelvic junction (UPJ) influences the outcomes of pyeloplasty in adults.

Methods:

Twenty-three patients with the diagnosis of ureteropelvic junction obstruction (UPJO) that underwent laparoscopic dismembered pyeloplasty were included. ICC density was measured using immunohistochemistry reaction for c-KIT expression in the resected UPJ segment. Pyeloplasty outcome was evaluated by patient self-report pain, urinary outflow using DTPA renogram and hydronephrosis assessment using ultrasound (US) at 12 months of follow-up. A logistic regression analysis was performed to assess the association of pyeloplasty outcomes and ICC density.

Results:

Low, moderate, and high ICC density were present in 17.4%, 30.4%, and 52.2% of the patients, respectively. Complete pain resolution was observed in 100%, 85.7%, and 75% of patients with low, moderate and high ICC density, respectively ( p = 0.791). DTPA renogram improved in 75%, 85.7%, and 91.7% of patients with low, moderate and high ICC density, respectively ( p = 0.739). Hydronephrosis improved in 25%, 85.7%, and 91.7% of patients with low, moderate and high ICC density, respectively ( p = 0.032).

Conclusions:

Patients with high ICC density have a significant amelioration of hydronephrosis after pyeloplasty. However, ICC density is not associated with functional outcomes.

Computer-aided diagnosis system for the classification of multi-class kidney abnormalities in the noisy ultrasound images

BACKGROUND AND OBJECTIVE

The primary causes of kidney failure are chronic and polycystic kidney diseases. Cyst, stone, and tumor development lead to chronic kidney diseases that commonly impair kidney functions. The kidney diseases are asymptomatic and do not show any significant symptoms at its initial stage. Therefore, diagnosing the kidney diseases at their earlier stage is required to prevent the loss of kidney function and kidney failure.

METHODS

This paper proposes a computer-aided diagnosis (CAD) system for detecting multi-class kidney abnormalities from ultrasound images. The presented CAD system uses a pre-trained ResNet-101 model for extracting the features and support vector machine (SVM) classifier for the classification purpose. Ultrasound images usually gets affected by speckle noise that degrades the image quality and performance of the CAD system. Hence, it is necessary to remove speckle noise from the ultrasound images. Therefore, a CAD based system is proposed with the despeckling module using a deep residual learning network (RLN) to reduce speckle noise. Pre-processing of ultrasound images using deep RLN helps to drastically improve the classification performance of the CAD system. The proposed CAD system achieved better prediction results when compared to the existing state-of-the-art methods.

RESULTS

To validate the proposed CAD system performance, the experiments have been carried out in the noisy kidney ultrasound images. The designed system framework achieved the maximum classification accuracy when compared to the existing approaches. The SVM classifier is selected for the CAD system based on performance comparison with various classifiers like K-nearest neighbour, tree, discriminant, Naive Bayes, and linear.

CONCLUSIONS

The proposed CAD system outperforms in classifying the noisy kidney ultrasound images precisely as compared to the existing state-of-the-art methods. Further, the CAD system is evaluated in terms of selectivity and sensitivity scores. The presented CAD system with the pre-processing module would serve as a real-time supporting tool for diagnosing multi-class kidney abnormalities from the ultrasound images.

Machine learning-assisted decision-support models to better predict patients with calculous pyonephrosis

Background

To develop a machine learning (ML)-assisted model capable of accurately identifying patients with calculous pyonephrosis before making treatment decisions by integrating multiple clinical characteristics.

Methods

We retrospectively collected data from patients with obstructed hydronephrosis who underwent retrograde ureteral stent insertion, percutaneous nephrostomy (PCN), or percutaneous nephrolithotomy (PCNL). The study cohort was divided into training and testing datasets in a 70:30 ratio for further analysis. We developed 5 ML-assisted models from 22 clinical features using logistic regression (LR), LR optimized by least absolute shrinkage and selection operator (Lasso) regularization (Lasso-LR), support vector machine (SVM), extreme gradient boosting (XGBoost), and random forest (RF). The area under the curve (AUC) was applied to determine the model with the highest discrimination. Decision curve analysis (DCA) was used to investigate the clinical net benefit associated with using the predictive models.

Results

A total of 322 patients were included, with 225 patients in the training dataset, and 97 patients in the testing dataset. The XGBoost model showed good discrimination with the AUC, accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 0.981, 0.991, 0.962, 1.000, 1.000, and 0.989, respectively, followed by SVM [AUC =0.985, 95% confidence interval (CI): 0.970–1.000], Lasso-LR (AUC =0.977, 95% CI: 0.958–0.996), LR (AUC =0.936, 95% CI: 0.905–0.968), and RF (AUC =0.920, 95% CI: 0.870–0.970). Validation of the model showed that SVM yielded the highest AUC (0.977, 95% CI: 0.952–1.000), followed by Lasso-LR (AUC =0.959, 95% CI: 0.921–0.997), XGBoost (AUC =0.958, 95% CI: 0.902–1.000), LR (AUC =0.932, 95% CI: 0.878–0.987), and RF (AUC =0.868, 95% CI: 0.779–0.958) in the testing dataset.

Conclusions

Our ML-based models had good discrimination in predicting patients with obstructed hydronephrosis at high risk of harboring pyonephrosis, and the use of these models may be greatly beneficial to urologists in treatment planning, patient selection, and decision-making.

The gap between ultrasonography and computed tomography in measuring the size of urinary calculi

Objective

Due to a lack of studies regarding the need for computed tomography (CT) in measuring the size of each urinary calculus before surgery, this study was conducted to elucidate the difference between ultrasonography (US) and CT in measuring the size of urinary stones.

Methods

A retrospective review of 100 stones from 83 patients. Each urinary stone was measured using both US and CT; both measurements were then compared.

Results

Of 83 patients, the mean age was 39.29 ± 23.76 years; 47 (56.62%) were male and 36 (43.37%) were female. Most of the urinary stones were <10 mm (50.0%) followed by 11-20 mm (42.0%), (P < 0.001). A cross-tabulation test revealed strong compatibility between US and CT in measuring the size of urinary stones (73.7% in stones <10 mm, 66.7% in stones 11-20 mm and 50% in stones >21 mm), (P < 0.001). Spearman's rho correlation test revealed strong compatibility between stone diameters measured by US and CT (r = 0.755), (P = 0 < 0.001). T-test for equality of means revealed no significant difference in the measured size using US and CT (mean = 11.80 ± 5.83 vs. 11.65 ± 6.59, respectively), mean difference = 0.15, and P = 0.865, 95% confidence interval: -1.584-1.884.

Conclusion

No significant difference in measuring the size of urinary stones using US and CT. However, US may slightly overestimate small stones in some cases.

Feasibility of renal resistive index measurements performed by an intermediate and novice sonographer in a volunteer population

Background

The Doppler-derived renal resistive index (RRI) is emerging as a promising bedside tool for assessing renal perfusion and risk of developing acute kidney injury in critically ill patients. It is not known what level of ultrasonography competence is needed to obtain reliable RRI values.

Objective

The aim of this study was to evaluate the feasibility of RRI measurements by an intermediate and novice sonographer in a volunteer population.

Methods

After a focused teaching session, an intermediate (resident), novice (medical student) and expert sonographer performed RRI measurements in 23 volunteers consecutively and blinded to the results of one another. Intraclass correlation coefficients and Bland–Altman plots were used to evaluate interobserver reliability, bias and precision.

Results

Both non-experts were able to obtain RRI values in all volunteers. Median RRI in the population measured by the expert was 0.58 (interquartile range 0.52–0.62). The intraclass correlation coefficient was 0.96 (95% confidence interval 0.90–0.98) for the intermediate and expert, and 0.85 (95% confidence interval 0.69–0.94) for the novice and expert. In relation to the measurements of the expert, both non-experts showed negligible bias (mean difference 0.002 [95% confidence interval − 0.005 to 0.009, p = 0.597] between intermediate and expert, mean difference 0.002 [95% confidence interval − 0.011 to 0.015, p = 0.752] between novice and expert) and clinically acceptable precision (95% limits of agreement − 0.031 to 0.035 for the intermediate, 95% limits of agreement − 0.056 to 0.060 for the novice).

Conclusions

RRI measurements by both an intermediate and novice sonographer in a volunteer population were reliable, accurate and precise after a brief course. RRI is easy to learn and feasible within the scope of point-of-care ultrasound.

Point-of-care ultrasound in internal medicine: A position paper by the ultrasound working group of the European federation of internal medicine

Point-of-care ultrasound (POCUS) is increasingly used to assess medical patients. It has many uses in daily clinical practice, including improved diagnostic timeliness and accuracy, and providing information about a patient's prognosis and follow-up. It has been integrated into numerous specialities, but remains relatively undefined in internal medicine training programs. Ultrasonography is a useful tool in the standard clinical practice of internists in numerous clinical scenarios (Emergency Department, hospital ward, general and specific consultations, and home care). Although POCUS has been recently included in the European curriculum of internal medicine, there are differences between European internists in its use, ranging from not at all to well structured educational programs. The use of POCUS needs to be widespread in internal medicine departments, and to accomplish this we must encourage structured training. This document details the consensus-based recommendations by the European Federation of Internal Medicine (EFIM) Ultrasound working group. We establish POCUS core competencies and clinical settings for internists in a symptom-based approach. We also propose training requirements, providing a framework for training programs at a national level.

Clinical Guidance for Point-of-Care Ultrasound in the Emergency and Critical Care Areas after Implementing Insurance Coverage in Korea

Point-of-care ultrasound (POCUS) is a useful tool that is widely used in the emergency and intensive care areas. In Korea, insurance coverage of ultrasound examination has been gradually expanding in accordance with measures to enhance Korean National Insurance Coverage since 2017 to 2021, and which will continue until 2021. Full coverage of health insurance for POCUS in the emergency and critical care areas was implemented in July 2019. The National Health Insurance Act classified POCUS as a single or multiple-targeted ultrasound examination (STU vs. MTU). STU scans are conducted of one organ at a time, while MTU includes scanning of multiple organs simultaneously to determine each clinical situation. POCUS can be performed even if a diagnostic ultrasound examination is conducted, based on the physician's decision. However, the Health Insurance Review and Assessment Service plans to monitor the prescription status of whether the POCUS and diagnostic ultrasound examinations are prescribed simultaneously and repeatedly. Additionally, MTU is allowed only in cases of trauma, cardiac arrest, shock, chest pain, and dyspnea and should be performed by a qualified physician. Although physicians should scan all parts of the chest, heart, and abdomen when they prescribe MTU, they are not required to record all findings in the medical record. Therefore, appropriate prescription, application, and recording of POCUS are needed to enhance the quality of patient care and avoid unnecessary cut of medical budget spending. The present article provides background and clinical guidance for POCUS based on the implementation of full health insurance coverage for POCUS that began in July 2019 in Korea.

Point-of-care ultrasound for the acute abdomen in the primary health care

Point-of-care ultrasound (POCUS) is a focused examination, which is performed and interpreted at the bedside by the treating physician answering a specific clinical question. It is currently utilized as an essential adjunct to physical examination in many medical specialties. Recent advances in technology have made POCUS machines portable, affordable, and could be used with minimal training even by nonradiologists. This review aims to cover the fundamental physics of POCUS and its applications for diagnosing the acute abdomen in the primary health care including the most common causes encountered by family physicians. These are acute appendicitis, acute cholecystitis, renal colic, ectopic pregnancy, acute diverticulitis, bowel obstruction, and abdominal aortic aneurysm. We hope to encourage primary care physicians to incorporate POCUS in their routine clinical practice. We also highlight challenges encountered when using POCUS in the primary health care including limited availability and the need for proper training. Furthermore, we review the POCUS results when performed by primary health-care physicians. Integrating POCUS in primary health care empowers primary health-care physicians to provide high-quality, safe, and cost-effective care to the patients.

Cystatin C in Evaluating Renal Function in Ureteral Calculi Hydronephrosis in Adults

BACKGROUND

Serum cystatin C (CysC) is still becoming used as a marker of renal function but is far from being commonly used worldwide. The purpose of this study was to characterize the ureteral calculi patients with hydronephrosis-caused CysC changes in renal function.

METHODS

To better reflect the changes of renal function, we constructed models of ureteral obstruction in rats to mimic the hydronephrosis caused by human ureteral calculi. Moreover, our study included 200 patients diagnosed with ureteral calculi in our hospital between June 2017 and 2018. We compared the estimated glomerular filtration rate using different equations based on CysC and/or serum creatinine (SCr).

RESULTS

We found that the expression of CysC and SCr increased with the prolonged obstruction time by enzyme linked immunosorbent assay. Moreover, quantitative real-time polymerase chain reaction, Western blot and immunohistochemistry further demonstrated that the expression of CysC increases with the degree of hydronephrosis. Among 200 patients with ureteral calculi, 40 (20.0%) had no hydronephrosis, 110 (55.0%) had mild hydronephrosis, 32 (16.0%) had moderate hydronephrosis and 18 (9.0%) had severe hydronephrosis. As the degree of hydronephrosis increased, the expression of neutrophil percentage, CysC, blood urea nitrogen, SCr and serum uric acid also increased. Multivariate analyses demonstrated that only CysC was an independent risk factor for hydronephrosis (p = 0.003). In addition, CysC and the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) CysC equation showed the highest veracity in renal function estimation of patients with hydronephrosis caused by ureteral calculus.

CONCLUSION

For patients with hydronephrosis caused by ureteral calculi, CysC better reflects the changes in renal function, and the CKD-EPI CysC equation has the highest accuracy.

Usefulness of Protocolized Point-of-Care Ultrasonography for Patients with Acute Renal Colic Who Visited Emergency Department: A Randomized Controlled Study

Background and Objectives: Ultrasonography is useful in evaluating patients with renal colic and it has high sensitivity and specificity for diagnosing ureter stones by revealing hydronephrosis. We evaluated the efficacy of point-of-care ultrasonography protocol in managing patients with acute renal colic who visited the emergency department (ED). Materials and Methods: Between March 2019 and July 2019, patients who visited the ED because of renal colic were randomly assigned by date of visit either to the conventional group (CG), who underwent routine diagnostic work-up without ultrasonography, or to the ultrasonography group (UG), who underwent bedside ultrasonography as an initial diagnostic testing. When hydronephrosis was detected in the UG group, a confirmatory non-contrast abdomen computed tomography scan was promptly performed. The ED length of stay, complications, and missed or delayed high-risk diagnosis were evaluated. Results: In total, 128 of 147 analyzed patients were confirmed to have ureter stones. The ED length of stay was significantly lower in the UG group than in the CG group (mean 172 min; 95% confidence interval (CI): 151–194 min vs. mean 234 min; 95% CI: 216–252 min). The medical cost was also remarkably lower in the UG group than in the CG group (259 USD vs. 319 USD; p < 0.001). The incidence of complications within 30 days after visiting ED and missed or delayed high-risk diagnosis were not significantly different between the two groups. Conclusions: We found that protocolized point-of-care ultrasonography in patients with acute renal colic who visited the ED can more effectively reduce the length of stay and medical cost without 30-day complication than usual clinical practice.

Point-of-Care Ultrasound for the Pediatric Hospitalist's Practice

Point-of-care ultrasound (POCUS) has the potential to provide real-time valuable information that could alter diagnosis, treatment, and management practices in pediatric hospital medicine. We review the existing pediatric POCUS literature to identify potential clinical applications within the scope of pediatric hospital medicine. Diagnostic point-of-care applications most relevant to the pediatric hospitalist include lung ultrasound for pneumothorax, pleural effusion, pneumonia, and bronchiolitis; cardiac ultrasound for global cardiac function and hydration status; renal or bladder ultrasound for nephrolithiasis, hydronephrosis, and bladder volumes; soft tissue ultrasound for differentiating cellulitis from abscess; and procedural-guidance applications, including line placement, lumbar puncture, and abscess incision and drainage. We discuss POCUS applications with reviews of major pathologic findings, research gaps, the integration of POCUS into practice, and barriers to implementation.

Use of Point-of-Care Ultrasound to Assess and Guide Renal Stent Repositioning in the Pediatric Emergency Department

Point-of-care ultrasound can be used as an assessment tool during the evaluation of children with renal colic. We discuss the case of a 7-year-old girl presenting to the pediatric emergency department with left flank pain, vomiting, and urinary incontinence status post-left renal stent placement. Renal ultrasound revealed ureteral obstruction caused by renal stent displacement. Point-of-care ultrasound performed by pediatric emergency department physicians was used to assess renal stent location, repositioning, and confirmation of the new location by the urology team. We discuss the role of transabdominal point-of-care ultrasound for the evaluation and treatment of the symptomatic child with recent ureter stent placement.

Atypical Causes of Urinary Tract Obstruction

Acute kidney injury due to urinary tract obstruction invariably suggests lower urinary tract obstruction or bilateral ureteric obstruction since obstruction of a single kidney while the contralateral kidney is normal and not obstructed would not cause a perceptible rise in creatinine. Assuming a total body volume of 42 L, 70 kg male that generates approximately 1400 mg of creatinine daily (20 mg/kg/day) who has complete urinary tract obstruction would experience a 3.33 mg/dL per day increase in serum creatinine. Thus, for an individual who had prior normal renal function and who presents with a creatinine of 30 mg/dL, one could surmise that the obstructive pathology had lasted at least 10 days. However, the rise in serum creatinine is a poor marker of renal injury and subsequent prognosis. Urinary tract obstruction leading to AKI can be due to a variety of causes, and its management is tailored to the underlying etiology. This case series describes the varied clinical course of four patients at our center who experienced AKI from atypical causes of obstructive uropathy. Current and future diagnostic modalities and caveats in the treatment of this disease entity are also discussed.

Assessment of the renal collecting system using a pocket-sized ultrasound device

PURPOSE

To assess the performance of a pocket-sized ultrasound device (PUD) for evaluating dilatation of the renal collecting system with high-end ultrasound devices (HUDs) as a reference standard.

METHODS

One sonographer examined both kidneys using a PUD to evaluate dilatation of the collecting system. The grading of the dilatation ranged from 0 to 4. Immediately after the examination, another sonographer blinded to the previous results performed a formal examination with a HUD.

RESULTS

Two hundred kidneys in 100 patients were included in the analysis. The agreement of grades between the PUD and HUDs was excellent (weighted kappa = 0.83; P < 0.001). When hydronephrosis was defined as grade 1 or higher, the test characteristics of the PUD were as follows: sensitivity 91% (95% confidence interval (CI) 79-97%), positive predictive value 73% (95% CI 60-83%), and negative predictive value 96% (95% CI 92-99%). When hydronephrosis was defined as grade 2 or higher, the test characteristics were as follows: sensitivity 88% (95% CI 73-97%), positive predictive value 75% (95% CI 59-87%), and negative predictive value 98% (95% CI 94-99%).

CONCLUSION

Ultrasound using a PUD is useful for evaluating dilatation of the collecting system, especially for ruling out its presence.

Bilateral ureterolithiasis: A true positive and false negative PoCUS exam in a patient with renal colic

Acute flank pain from suspected urolithiasis is a common presenting complaint in the Emergency Department. Multiple computed tomography (CT) has traditionally been the standard imaging modality used to diagnose obstructive kidney stones, however point of care ultrasound (PoCUS) can play an important role in the diagnostic algorithm and risk stratification of acute flank pain. Here, we present the case of a 29-year-old female with suspected urolithiasis, who underwent PoCUS that revealed right-sided hydronephrosis and normal left kidney, bladder, and aorta. A subsequent KUB was negative. As the clinical course failed to improve with therapy, an abdominal and pelvic CT was ordered revealing a 5 mm distal obstructing ureteric calculus at the right vesico-ureteric junction and another 5 mm left mid ureteric calculus. To the best of our knowledge, this is the first case in which a patient presenting with acute right-sided flank pain demonstrated unilateral hydronephrosis on PoCUS, but had clinically significant bilateral ureteric stones on CT. Emergency physicians who employ PoCUS for evaluation of flank pain must be aware of its benefits and drawbacks and how they apply to each patient. As such, we have developed a script emergency physicians can use for shared decision-making with renal colic patients when deciding on the appropriate imaging modality.

Kidney segmentation in ultrasound, magnetic resonance and computed tomography images: A systematic review

BACKGROUND AND OBJECTIVE

Segmentation is an essential step in computer-aided diagnosis and treatment planning of kidney diseases. In recent years, several researchers proposed multiple techniques to segment the kidney in medical images from distinct imaging acquisition systems, namely ultrasound, magnetic resonance, and computed tomography. This article aims to present a systematic review of the different methodologies developed for kidney segmentation.

METHODS

With this work, it is intended to analyze and categorize the different kidney segmentation algorithms, establishing a comparison between them and discussing the most appropriate methods for each modality. For that, articles published between 2010 and 2016 were analyzed. The search was performed in Scopus and Web of Science using the expressions "kidney segmentation" and "renal segmentation".

RESULTS

A total of 1528 articles were retrieved from the databases, and 95 articles were selected for this review. After analysis of the selected articles, the reviewed segmentation techniques were categorized according to their theoretical approach.

CONCLUSIONS

Based on the performed analysis, it was possible to identify segmentation approaches based on distinct image processing classes that can be used to accurately segment the kidney in images of different imaging modalities. Nevertheless, further research on kidney segmentation must be conducted to overcome the current drawbacks of the state-of-the-art methods. Moreover, a standardization of the evaluation database and metrics is needed to allow a direct comparison between methods.

Ultrasonography for Acute Blunt Renal Trauma: Does it Help?

The role of ultrasonography in diagnosing blunt renal trauma is uncertain because it is much less sensitive in detecting parenchymal organ injuries. Indirect evidence such as perinephric haematoma may be easier to identify by ultrasonography and it is highly suggestive of underlying renal parenchymal injury. A patient with significant renal injuries diagnosed by bedside ultrasonography is reported and the role of ultrasonography in renal trauma is discussed.

Hospital Medicine Point of Care Ultrasound Credentialing: An Example Protocol

Though the use of point-of-care ultrasound (POCUS) has increased over the last decade, formal hospital credentialing for POCUS may still be a challenge for hospitalists. This document details the Hospital Medicine Department Ultrasound Credentialing Policy from Regions Hospital, which is part of the HealthPartners organization in Saint Paul, Minnesota. National organizations from internal medicine and hospital medicine (HM) have not published recommended guidelines for POCUS credentialing. Revised guidelines for POCUS have been published by the American College of Emergency Physicians, though these are not likely intended to guide hospitalists when working with credentialing committees and medical boards. This document describes the scope of ultrasound in HM and our training, credentialing, and quality assurance program. This report is intended to be used as a guide for hospitalists as they work with their own credentialing committees and will require modification for each institution. However, the overall process described here should assist in the establishment of POCUS at various institutions.

Introduction of a new imaging guideline for suspected renal colic in the ED reduces CT urography utilisation

BACKGROUND

Patients presenting to the ED with suspected renal colic are frequently imaged with CT urography (CTU), which rarely alters diagnosis or management. To reduce use of CTU in this population, we instigated a new imaging and management guideline in our ED.

METHODS

This was a quasi-experimental prospective study, whereby a new guideline was commenced at the intervention site (Monash Medical Centre) and the existing guideline continued at the control site (Dandenong Hospital). The new guideline promotes focused ultrasound for diagnosing renal colic and restricts CT to those with poor response to analgesia or 'red flags'. A consecutive series of patients with suspected renal colic were prospectively enrolled and outcomes compared between the sites. The primary outcome was CTU utilisation and secondary outcomes were radiation exposure, stone rate on CTU, admission, ED length of stay and rates of urological intervention and returns to ED at 4-week follow-up.

RESULTS

Preintervention CTU rates were 76.7% at Monash and 72.1% at Dandenong. 324 patients were enrolled; 148 at Monash and 176 at Dandenong. Median age 47 years vs 49 years, males 76.4% vs 66.5% and medianSex, Timing, Origin, Nausea, Erythrocytes (STONE) score 10 vs 10 for Monash and Dandenong, respectively. CTU was performed in 54.1% vs 75.0% (p<0.001), median radiation exposure 2.8 vs 4.0 mSv (p<0.001) and urological intervention occurred in 16.4% vs 15.7% for Monash and Dandenong, respectively.

CONCLUSIONS

We found that use of CTU for renal colic was significantly reduced by introduction of a guideline promoting ultrasound and encouraging selective CTU. Although intervention rates were similar between the two sites, further prospective study is needed to ensure other patient-centred outcomes do not differ.

Does the use of bedside ultrasonography reduce emergency department length of stay for patients with renal colic?: a pilot study

Objective

The aim of this study was to evaluate the effect of adding bedside ultrasonography to the diagnostic algorithm for nephrolithiasis on emergency department (ED) length of stay.

Methods

A prospective, randomized, controlled pilot study was conducted from October 2014 to December 2014 with patients with acute flank pain. In the non-ultrasonography group (NUSG), non-contrast computed tomography was selected based on clinical features and hematuria in the urinalysis. In the ultrasonography group (USG), non-contrast computed tomography was selected based on clinical features and hydronephrosis on bedside ultrasonography. The primary outcome was ED length of stay. The secondary outcomes were radiation exposure, amount of analgesics, proportion of patients with diseases other than ureteral calculus, and proportion of patients with unexpected ED revisits within 7 days from the index visit.

Results

A total of 103 patients were enrolled (NUSG, 51; USG, 52). The ED length of stay for the USG (89.0 minutes) was significantly shorter than that for the NUSG (163.0 minutes, P<0.001). There were no significant differences between the two groups in the radiation exposure dose (5.29 and 5.08 mSv, respectively; P=0.392), amount of analgesics (P=0.341), proportion of patients with diseases other than ureteral calculus (13.0% and 6.8%, respectively; P=0.486), and proportion of patients with unexpected ED revisits within 7 days from the index visit (7.8% and 9.6%, respectively; P=1.000).

Conclusion

The use of early bedside ultrasonography for patients with acute flank pain could reduce the ED length of stay without increasing unexpected ED revisits.

Point-of-Care Ultrasonography for Primary Care Physicians and General Internists

Point-of-care ultrasonography (POCUS) is a safe and rapidly evolving diagnostic modality that is now utilized by health care professionals from nearly all specialties. Technological advances have improved the portability of equipment, enabling ultrasound imaging to be executed at the bedside and thereby allowing internists to make timely diagnoses and perform ultrasound-guided procedures. We reviewed the literature on the POCUS applications most relevant to the practice of internal medicine. The use of POCUS can immediately narrow differential diagnoses by building on the clinical information revealed by the traditional physical examination and refining clinical decision making for further management. We describe 2 common patient scenarios (heart failure and sepsis) to highlight the impact of POCUS performed by internists on efficiency, diagnostic accuracy, resource utilization, and radiation exposure. Using POCUS to guide procedures has been found to reduce procedure-related complications, along with costs and lengths of stay associated with these complications. Despite several undisputed advantages of POCUS, barriers to implementation must be considered. Most importantly, the utility of POCUS depends on the experience and skills of the operator, which are affected by the availability of training and the cost of ultrasound devices. Additional system barriers include availability of templates for documentation, electronic storage for image archiving, and policies and procedures for quality assurance and billing. Integration of POCUS into the practice of internal medicine is an inevitable change that will empower internists to improve the care of their patients at the bedside.

Ultrasound for patients in a high HIV/tuberculosis prevalence setting: a needs assessment and review of focused applications for Sub-Saharan Africa

Ultrasound is increasingly used in point-of-care applications and has great potential to support the diagnosis of infectious diseases, especially in resource-limited settings. A cross-sectional study was performed involving 100 Malawian patients with a clinical indication for ultrasound. Furthermore, the literature on point-of-care ultrasound (POCUS) in Sub-Saharan Africa was reviewed to establish its applicability, most frequent indications, findings, and implications for treatment, and therefore relevance in POCUS curricula, with a main focus on infectious diseases. In Malawi, the main indications for ultrasound were weight loss, abdominal pain, and shortness of breath. Abnormal findings were observed in 77% of patients, the most common being enlarged abdominal lymph nodes (n=17), pericardial effusion (n=15), splenic microabscesses (n=15), and pleural effusion (n=14). POCUS led to a change in treatment in 72% of patients. The literature on the various POCUS applications used in Malawi was reviewed, including focused assessment with sonography for HIV-associated TB (FASH), heart, liver, kidney, deep venous thrombosis (DVT), and gynaecology. Based on disease prevalence, impact of POCUS on treatment, and technical difficulty, it is proposed that FASH, heart, and DVT are the most relevant POCUS applications in comparable Sub-Saharan African settings and should be incorporated in POCUS curricula.

Ultrasonography in the emergency department

Point-of-care ultrasonography (POCUS) is a useful imaging technique for the emergency medicine (EM) physician. Because of its growing use in EM, this article will summarize the historical development, the scope of practice, and some evidence supporting the current applications of POCUS in the adult emergency department. Bedside ultrasonography in the emergency department shares clinical applications with critical care ultrasonography, including goal-directed echocardiography, echocardiography during cardiac arrest, thoracic ultrasonography, evaluation for deep vein thrombosis and pulmonary embolism, screening abdominal ultrasonography, ultrasonography in trauma, and guidance of procedures with ultrasonography. Some applications of POCUS unique to the emergency department include abdominal ultrasonography of the right upper quadrant and appendix, obstetric, testicular, soft tissue/musculoskeletal, and ocular ultrasonography. Ultrasonography has become an integral part of EM over the past two decades, and it is an important skill which positively influences patient outcomes.

Daily ambient temperature and renal colic incidence in Guangzhou, China: a time-series analysis

Few previous studies have examined the association between temperature and renal colic in developing regions, especially in China, the largest developing country in the world. We collected daily emergency ambulance dispatches (EADs) for renal colic from Guangzhou Emergency Center from 1 January 2008 to 31 December 2012. We used a distributed-lag nonlinear model in addition to the over-dispersed generalized additive model to investigate the association between daily ambient temperature and renal colic incidence after controlling for seasonality, humidity, public holidays, and day of the week. We identified 3158 EADs for renal colic during the study period. This exposure-response curve was almost flat when the temperature was low and moderate and elevated when the temperature increased over 21 °C. For heat-related effects, the significant risk occurred on the concurrent day and diminished until lag day 7. The cumulative relative risk of hot temperatures (90th percentile) and extremely hot temperatures (99th percentile) over lag days 0-7 was 1.92 (95 % confidence interval, 1.21, 3.05) and 2.45 (95 % confidence interval, 1.50, 3.99) compared with the reference temperature of 21 °C. This time-series analysis in Guangzhou, China, suggested a nonlinear and lagged association between high outdoor temperatures and daily EADs for renal colic. Our findings might have important public health significance to prevent renal colic.

Factors predicting infectious complications following percutaneous nephrolithotomy

Objective:

To determine the predictors of infectious complications following percutaneous nephrolithotomy (PCNL) in a prospective study.

Materials and Methods:

A total of 332 patients with renal or upper ureteric calculi who underwent PCNL between January 2013 and June 2014 were included in the study. Infectious complications included febrile urinary tract infection and septicemia. The patients were divided into Group A and B depending on whether they developed or did not develop infectious complications. Patient, stone, renal, and procedure-related factors were compared between the two groups.

Results:

There was no significant (P > 0.05) correlation among age (37.03 ± 16.24 vs. 36.72 ± 14.88), sex, and body mass index (21.00 ± 1.77 vs. 21.03 ± 2.25) between Group A and B. The patients in Group A were found to have significantly higher incidence of renal failure (39.5% vs. 9.2%,P= 0.0001), diabetes mellitus (12 [31.5%] vs. 33 [11.2%],P= 0.0001), previous percutaneous nephrostomy (PCN) tube placement (11 [28%] vs. 21 [7.1%]P= 0.0001), moderate to severe hydronephrosis (HDN), larger stone surface area (812.68 ± 402.07 vs. 564.92 ± 361.32,P= 0.0001), mean number of punctures (1.57 ± 0.50 vs. 1.20 ± 0.47,P= 0.002), and mean duration of surgery (94.28 ± 18.23 vs. 69.12 ± 21.23,P= 0.0001) than Group B.

Conclusion:

Post-PCNL infectious complications were found to be more common in patients with renal failure, diabetes mellitus, preoperative PCN placement, staghorn calculi, severe HDN, multiple punctures, and prolonged duration of surgery.

STONE PLUS: Evaluation of Emergency Department Patients With Suspected Renal Colic, Using a Clinical Prediction Tool Combined With Point-of-Care Limited Ultrasonography

STUDY OBJECTIVE

We determine whether renal point-of-care limited ultrasonography (PLUS) used in conjunction with the Sex, Timing, Origin, Nausea, Erythrocytes (STONE) clinical prediction score can aid identification of emergency department (ED) patients with uncomplicated ureteral stone or need for urologic intervention.

METHODS

This was a prospective observational study of adult ED patients undergoing computed tomography (CT) scan for suspected ureteral stone. The previously validated STONE score classifies patients into risk categories of low (≈10%), moderate (≈50%), or high (≈90%) for symptomatic stone. Renal PLUS assessed for presence of hydronephrosis before CT scanning. The primary outcomes of symptomatic ureteral stone or acutely important alternative finding were abstracted from CT reports. The secondary outcome, urologic intervention, was assessed by 90-day follow-up interview and record review.

RESULTS

Of 835 enrolled patients, ureteral stone was identified in 53%, whereas 6.5% had an acutely important alternative finding on CT. Renal PLUS modestly increased sensitivity for symptomatic stone among low and moderate STONE score categories. Moderate or greater hydronephrosis improved specificity from 67% (62% to 72%) to 98% (93% to 99%) and 42% (37% to 47%) to 92% (86% to 95%) in low- and moderate-risk patients, with likelihood ratios of 22 (95% CI, 4.2-111) and 4.9 (95% CI, 2.9-8.3), respectively. Test characteristics among high-risk patients were unchanged by renal PLUS. For urologic intervention, any hydronephrosis was 66% sensitive (57% to 74%), whereas moderate or greater hydronephrosis was 86% specific overall (83% to 89%) and 81% (69% to 90%) sensitive and 79% 95% CI, (73-84) specific among patients with the highest likelihood of symptomatic stone.

CONCLUSION

Hydronephrosis on renal PLUS modestly improved risk stratification in low- and moderate-risk STONE score patients. The presence or absence of hydronephrosis among high-risk patients did not significantly alter likelihood of symptomatic stone but may aid in identifying patients more likely to require urologic intervention.

Ultrasonography of the Kidney: A Pictorial Review

Ultrasonography of the kidneys is essential in the diagnosis and management of kidney-related diseases. The kidneys are easily examined, and most pathological changes in the kidneys are distinguishable with ultrasound. In this pictorial review, the most common findings in renal ultrasound are highlighted.

Is Hydronephrosis a Complication after Anterior Lumbar Surgery?

Study Design Prospective follow-up design. Objective Ureteral injury is a recognized complication following gynecologic surgery and can result in hydronephrosis. Anterior lumbar surgery includes procedures like anterior lumbar interbody fusion (ALIF) and total disk replacement (TDR). Anterior approaches to the spine require mobilization of the great vessels and visceral organs. The vascular supply to the ureter arising from the iliac arteries may be compromised during midline retraction of the ureter, which could theoretically lead to ureter ischemia and stricture with subsequent hydronephrosis formation. Methods Potential candidates with previous ALIF or TDR via anterior retroperitoneal access between January 2008 and March 2012 were chosen from those operated on by a single surgeon in a university hospital setting (n = 85). Renal ultrasound evaluation of hydronephrosis was performed on all participants. Simple descriptive and inferential statistics were used to generate results. Results A total of 37 voluntary participants were recruited (23 male, 14 female subjects; average age 51.8 years). The prevalence of hydronephrosis in our population was 0.0% (95% confidence interval 0 to 8.1%). Conclusions Retraction of the ureter across the midline in ALIF and TDR does not result in an increase in hydronephrosis and appears to be a safe surgical technique.

My patient has abdominal and flank pain: Identifying renal causes

Acute flank and abdominal pain are common presenting complaints in the emergency department. With increasing access to point-of-care ultrasound (PoCUS), emergency physicians have an added tool to help identify renal problems as a cause of a patient's pain. PoCUS for hydronephrosis has a sensitivity of 72-83.3% and a varying specificity, similar to radiology-performed ultrasonography. In addition to assessment for hydronephrosis, PoCUS can help emergency physicians to exclude other serious causes of flank and abdominal pain such as the presence of an abdominal aortic aneurysm, or free fluid in the intraperitoneal space, which could represent hemorrhage. Use of PoCUS for the assessment of flank pain has resulted in more rapid diagnosis, decreased use of computed tomography, and shorter emergency department length of stay.

The utility of renal ultrasonography in the diagnosis of renal colic in emergency department patients

Objective:

Computed tomography (CT) is an imaging modality used to detect renal stones. However, there is concern about the lifetime cumulative radiation exposure attributed to CT. Ultrasonography (US) has been used to diagnose urolithiasis, thereby avoiding radiation exposure. The objective of this study was to determine the ability of US to identify renal colic patients with a low risk of requiring urologic intervention within 90 days of their initial emergency department (ED) visit.

Methods:

We completed a retrospective medical record review for all adult patients who underwent ED-ordered renal US for suspected urolithiasis over a 1-year period. Independent, double data extraction was performed for all imaging reports and US results were categorized as “normal,” “suggestive of ureterolithiasis,” “ureteric stone seen” or “disease unrelated to urolithiasis.” Charts were reviewed to determine how many patients underwent subsequent CT and urologic intervention.

Results:

Of the 817 renal US procedures ordered for suspected urolithiasis during the study period, the results of 352 (43.2%) were classified as normal, and only 2 (0.6%) of these patients required urologic intervention. The results of 177 (21.7%) renal US procedures were suggestive of ureterolithiasis. Of these, 12 (6.8%) patients required urologic intervention. Of the 241 (29.5%) patients who had a ureteric stone seen on US, 15 (6.2%) required urologic intervention. The rate of urologic intervention was significantly lower in those with normal results on US (p &lt; 0.001) than in those with abnormal results on US.

Conclusion:

A normal result on renal US predicts a low likelihood for urologic intervention within 90 days for adult ED patients with suspected urolithiasis.

Accuracy of bedside emergency physician performed ultrasound in diagnosing different causes of acute abdominal pain: a prospective study

OBJECTIVE

Abdominal pain is a common complaint in the emergency department and accurate diagnosis of its etiology may affect the patient's outcome.

METHOD

Patients with abdominal pain underwent ultrasound study first by trained emergency physicians and then by radiologists blinded to emergency physician's results.

RESULT

Emergency physician who performed bedside ultrasound had 78% diagnostic accuracy. Emergency physicians showed better results in diagnosing some entities (abdominal aortic aneurysm and renal stones) than the others (acute appendicitis, cholelithiasis, and cholecystitis).

CONCLUSION

Bedside ultrasound can accurately identify the etiology of acute nontraumatic abdominal pain in the hands of emergency physicians.

Sonographic assessment of renal size in healthy adults

OBJECTIVE

To assess the normal sonographic values of renal length and cortical thickness in healthy adults and establish reference ranges in our population for comparison when examining renal disease.

SUBJECTS AND METHODS

Sonographic assessment of renal length and cortical thickness were performed from January 2006 to December 2011 in 252 healthy individuals who were self-referred to the El-Reshaid Renal Clinic in Kuwait. They were screened for the absence of renal abnormalities. Weight and height were measured, and body mass index (BMI) and body surface area calculated. Patients were divided into 5 age groups: 18-30, 31-40, 41-50, 51-60 and 61-80 years, in order to generate reference graphs for renal length and cortical thickness.

RESULTS

The mean renal lengths for the right and left kidney were 10.68 ± 1.4 and 10.71 ± 1.0 cm, respectively (p = 0.56) without a significant change with age. The minimum cortical thickness was 0.6 cm. The renal length correlated with the weight of the patients (p < 0.01) and their BMI (p < 0.01) but not with their height. There was no difference in renal size or cortical thickness in patients older than 60 years despite an age-related decline in the glomerular filtration rate (p < 0.001).

CONCLUSIONS

Renal length and cortical thickness did not vary significantly with age. Renal length correlated well with weight and BMI but not with height. Hence, establishing normal ranges of renal parameters is essential for comparison in situations where possible renal disease is being investigated.

Predicting female ureteral length: a mathematical model

Aim:

Ureteral double J stent placement is a common urological procedure. A stent placement is performed for multiple conditions but some of them are contraindicated, mainly in pregnant female patients, because of X-rays. This work aims to suggest a mathematical model to predict female ureteral length by finding a link among different physical data.

Materials and methods:

Between June 2007 and July 2009, 100 female patients who had undergone ureteral stent placement were enrolled in the present study with the exception of those with septic conditions, history or evidence of TCC, congenital and acquired kidney or ureteral malformations, and previous ureteral surgery. The physical data of each patient were collected (mean age 55.8 years, range 18–89 SD 15.27, mean height 173 cm, range 160–182 SD 6.31, mean weight 75.33 kg, range 62–94 SD 8.81). A previous ureteral retrograde pyelography was performed during the procedure to individualise the pyeloureteral junction. Ureteral length was estimated through a graduated ureteral catheter with a final result between 24 and 27 cm. The length was read in cystoscopy examining the ureteral orifice while the catheter tip reached the pyeloureteral junction. The collected data were then analysed.

Results:

A link between the female patients’ ureteral length and height was observed. The following mathematical model can predict female ureteral length starting from the patient’s height: Result: y = 0.151712487 (height expressed in cm) ± 0.12; correlation coefficient: r = 0,973, residual sum of squares: rss = 5.285. No link was found between ureteral length and patients’ age and weight.

Conclusions:

A good estimation of the length of the ureter to be cannulated enables us to choose in advance the proper one to use. Female patient height correlates with ureteral length. A cost reduction can also be obtained, avoiding an intra-operative X-ray control. An X-ray-free ureteral stenting procedure can be described simply through an ultrasound control mainly in pregnant women. Further studies are needed to obtain a similar mathematical model for male patients.

Emergency point-of-care ultrasound diagnosis of hematocolpometra and imperforate hymen in the pediatric emergency department

A 12-year-old girl presented to the pediatric emergency department with a history of difficulty voiding and was found to have a firm, tender suprapubic mass on examination. Transabdominal emergency point-of-care ultrasound was used at the bedside to diagnose hematocolpometra due to an imperforate hymen. The diagnosis was confirmed by a comprehensive abdominal ultrasound and magnetic resonance imaging in the radiology suite. The patient was discharged on oral contraceptive medication and scheduled for an outpatient surgical hymenectomy following consultation with the gynecology service.

Clinical value of acute pyelonephritis grade based on computed tomography in predicting severity and course of acute pyelonephritis

PURPOSE

This study aimed to evaluate the efficacy of computed tomography (CT)-based acute pyelonephritis (APN) grades for predicting clinical severity and disease course.

MATERIALS AND METHODS

This study involved the analysis of the data of 204 consecutive patients with APN who underwent a CT examination at admission. Patients who had undergone prior treatment and those with ureteral calculi or an abscess by CT were excluded. Computed tomographic findings were divided into 4 grades according to renal parenchymal involvement, as follows: no renal parenchyma involvement (grade 1), less than 25% involvement (grade 2), 25% to 50% involvement (grade 3), and greater than 50% (grade 4). Patients with these grades were compared with respect to APN severity index (highest body temperature, initial C-reactive protein, and leukocytosis) and recovery index (hospital stay, fever duration, and leukocytosis duration).

RESULTS

A total of 204 patients of mean age 39.3 years were included. Acute pyelonephritis severity indices and recovery indices increased with APN grade. Mean highest body temperature values were 38.3°C and 38.9°C in grades 1 and 4, respectively (P = 0.002). Mean hospital stay increased from 5.7 days for grade 1 to 7.6 days for grade 4 (P < 0.001). Initial C-reactive protein, initial leukocytosis, fever duration, and leukocytosis duration also increased with APN grade.

CONCLUSIONS

This study suggests that APN grades, as determined by CT examination, valuably predict the clinical course of APN.

Comparison of conventional radiography combined with ultrasonography versus nonenhanced helical computed tomography in evaluation of patients with renal colic

The aim of this study is to determine whether kidneys ureters bladder X-ray (KUB) film combined with ultrasound (US) can be effectively used in evaluation of renal colic and miss stones with clinically significant size identified on nonenhanced computed tomography (NECT) in patients with urolithiasis. This retrospective study evaluated the clinical and radiological records of 300 patients at our institution undergoing KUB and/or US and/or NECT for the evaluation of renal colic from June 2007 to December 2010. Of patients with negative findings on KUB and/or US, 22 had renal stones on NECT (mean size 4.4 mm, range 3-8), 3 had lower ureteral stone (mean size 3.3 mm, range 2-5). In patients with isolated suspicious renal ectasia without stone image, two had renal stone on NECT (mean size 4 mm, range 2-6), 5 had upper ureteral stone (mean size 4.4 mm, range 4-6), 7 had middle ureteral stone (mean size 3.7 mm, range 3-4) and 14 had lower ureteral stone (mean size 4 mm, range 2-6). The cost-effective and almost radiation-free combination of KUB and US should be preferred for diagnosis of urolithiasis, as it detects most of the ureteral and renal calculi which are clinically significant.

Urologist-operated ultrasound and its use in urological outpatient clinics

INTRODUCTION

Ultrasonograghy plays an important role in the evaluation of urinary tract disorders in cases of medical or surgical renal disorders, because of its lower cost, availability, and lack of ionizing radiation and because with it there is no need for contrast material injection or ingestion. It needs no intervention or preparation and specifically can differentiate between the multiple causes of flank pain. Urologist-operated sonography is a quick, cost-effective, and time-saving modality for both the physician and patient for obtaining first or final diagnosis. Based on its results, patients can be selected for appropriate management and further assessment.

MATERIALS AND METHODS

The efficacy of ultrasound examination by a trained urologist in the differentiation of urological emergencies admitted in a district private clinic was studied. Between April 2008 and April 2010, a total of 724 patients (1448 renal units) had renal ultrasound performed by a trained urologist on acute admission. The sonographic findings were compared with subsequent definitive radiological investigations performed as needed, such as KUB (kidney, ureter, bladder) or IVP (intravenous pyelogram). Patient satisfaction and permission for ultrasonography were evaluated by oral consent. Loin pain was the presenting symptom in 45% of the patients (n = 326 cases).

RESULTS

Diagnosis was achieved in 96% of patients. Further evaluations were requested as needed in suspicious cases. If any hydronephrosis was detected and patients' history and/or complaints were suggestive of renal or ureteral stones, an outpatient KUB was requested. For more complex situations, IVP was the next option. Abnormal findings were recorded in 184 cases (25.5%). Mild to moderate unilateral hydronephrosis with or without hydronephrosis was the most common finding observed sonographically. The sensitivity of our ultrasonography evaluation was 99.7%.

CONCLUSION

Office urologist-operated sonograghy may supplement the information available through routine history, physical examination, and laboratory studies. Our study shows that urological trainees can use ultrasound with high levels of accuracy, thereby improving patient management with a high level of patient satisfaction.

Twinkle twinkle little stone: utilizing color Doppler in emergency ultrasound diagnosis of a ureterovesicular stone

Case report

A case of a 43-year-old woman presenting with acute left flank pain is reported.

Method and result

Point-of-care ultrasound utilizing color Doppler revealed a twinkling artifact at the left ureterovesicular junction, consistent with a ureterovesicular stone. The sonographic findings and significance of the twinkling artifact are described.

Diagnosis of acute pyelonephritis by contrast-enhanced ultrasonography in kidney transplant patients

BACKGROUND

Diagnostic imaging of acute pyelonephritis (APN) in renal transplanted patients is an important clinical issue. While conventional ultrasonography (US) has a limited diagnostic role, contrast-enhanced computer tomography and magnetic resonance imaging (MRI) represent the gold standard diagnostic tests. However, nephrotoxicity of either iodinated or paramagnetic contrast medium limits their use, especially in patients with kidney disease. Contrast-enhanced US (CEUS) may detect poorly perfused parenchymal renal areas, a useful feature in the diagnosis of APN. The aim of this study was to evaluate the diagnostic value of CEUS in APN compared with MRI as the reference test.

METHODS

From a pool of 389 kidney transplant patients, we prospectively recruited 56 patients with clinical suspicion of APN of the transplanted kidney. They underwent both CEUS and MRI, performed in a blinded manner by two different operators. Sensitivity, specificity, accuracy, positive and negative predictive values, and K statistics were calculated.

RESULTS

Thirty-seven out of 56 patients (66.1%) resulted positive for APN with the reference test, gadolinium-enhanced MRI. Thirty-five out of these 37 patients showed positive results for APN with CEUS, and 19 patients showed negative results for APN with both MRI and CEUS: sensitivity 95% (CI 82-99), specificity 100% (CI 83-100), accuracy 96% (CI 88-99), positive predictive value 100% (CI 90-100), negative predictive value 90% (CI 71-97) and K statistics 0.92 (P<0.01).

CONCLUSIONS

Our results suggest, for the first time, the feasibility of CEUS, a low-cost and low-risk diagnostic procedure, in the diagnosis of APN in kidney transplant patients.