DOPPLER ULTRASONOGRAPHY OF THE KIDNEYS IN UROLITHIASIS

Аннотация

Urolithiasis is one of the most pressing clinical problems in urology, as the incidence of the disease increases annually, this disease is diagnosed in 12% of the world's population, being the most common disease of the urinary tract. This increase can be explained by many factors, including missed cases of small stones, sedentary lifestyle, high BMI, lack of physical activity and poor nutrition. In addition, a significant contribution to the formation of urolithiasis can be made by an increase in the incidence of comorbidities such as diabetes, dyslipidemia, infections and multiple surgeries on the urinary tract. Kidney stones have been shown to exhibit a “twinkle artifact” (TA) on color Doppler ultrasound. Although this technique has better specificity than conventional B-mode imaging, it has lower sensitivity. To improve the overall performance of TA as a diagnostic tool, the Doppler output parameters were optimized in vitro . The data collected support the previous hypothesis that TA is caused by random vibrations of micron-sized bubbles trapped in the cracks and crevices of kidney stones. A set of optimized parameters was implemented such that MI and TI remained within FDA-approved limits. Several clinical renal scans were performed with the optimized settings and stones were detected with improved SNR compared tothe default settings. Key words: ultrasound, diplography, kidney stones, flicker artifact detection, optimization, urolithiasis. The aim of this study was to conduct a comprehensive meta-analysis to evaluate the overall diagnostic valueof Dopplerflickering forthe diagnosis of urolithiasis. Introduction. Urolithiasis is a common problem in general practice. Prevalence rates range from 7 to 13% in North America, 5 to 9% in Europe, and 1 to 5% in Asia. Nephrolithiasis is influenced by many factors including genetic predisposition, age, gender, diet, occupation, and lifestyle. Nephrolithiasis is more common in men than in women. Kidney stone formation is a common urological problem with a lifetime prevalence of approximately 10% in men and 6% in women, and its prevalence is increasing in many developed countries, witha recurrencerate of almost60% within10years ofinitial treatment. Many diagnostic modalities are considered helpful in identifying urolithiasis, including plain radiography, intravenous pyelourethrography, ultrasonography (US), and computed tomography (CT). Non-contrast CT is widely considered the current gold standard for diagnosing urolithiasis. Non-contrast CT is the most sensitive (up to 98%) and specific (96– 100%) method for detecting urinary stones. A history of nephrolithiasis with onset of flank pain should prompt non-contrast CT of the abdomen and pelvis to evaluate for urinary stones. Moreover, because of its ability to detect non-urologic causes of abdominal pain, CT has become the primary imaging modality for confirming urinary stones. However, one of the limitations of CT is that the associated radiation exposure is increasingly recognized as a public health issue, as radiation exposure can damage the genetic material in cells and lead 98,7:ROTCAFTCAPMI.SECNEICSLACIDEM ,5202 ,lirpA,5emuloV gro.srehsilbupcimedaca.www to radiation-induced cancers years later or to hereditary diseases in the offspring of exposed individuals, and this can lead to various developmental outcomes under certain conditions. In contrast, abdominal ultrasound does not involve radiation and has been shown to detect urinary stones using the common criterion of seeing a hyperechoic lesion with posterior acoustic shadowing. Hydroureteronephrosis also significantly improves the detection of urinary stones using B -mode ultrasound imaging. However, this phenomenon used alone has limited sensitivity, particularly for small stones (53% of stones are less than 5 mm in size). Ultrasound examination using Doppler flicker ( TA ) artifacts is considered an effective tool for detecting urinary tract stones. The flicker artifact was first described by the French radiologist Rahmouni and can be seen with color Doppler ultrasound, which appears as a rapidly changing mixture of red and blue colors behind a rough interface object such as a calcification [ 19 ]. Moreover, the chemical composition of the stone is related to the creation of the artifact. It is found that calcium oxalate dihydrate and calcium phosphate stones always give the TA sign , while stones composed of calcium oxalate monohydrate and urate do not have the TA sign . The validity of TA as a diagnostic tool for the presence of urolithiasis using a systematic review and meta-analysis. The TA sign may be useful as anadditional toolin thediagnostic work-up of patientswith suspected urolithiasis. Materials and methods. Ultrasound is a widely used imaging method in the primary diagnostics ofthe urinary tract in urolithiasis.This method has several advantages over other diagnostic methods, such as noninvasiveness and absence of radiation exposure. Ultrasoun