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In vivo assessment of hypertensive nephrosclerosis using ultrasound localization microscopy
Lanyan Qiu1, Jingke Zhang2, Yi Yang2
1Department of Ultrasound, Beijing Friendship Hospital, Capital Medical University, Beijing, China.
Insights
Ultrasound localization microscopy (ULM) effectively detects early hypertensive nephrosclerosis (HN) by measuring kidney microvascular blood flow speed. This method surpasses conventional tests in diagnosing this chronic kidney disease.
Area of Science:
- Nephrology
- Medical Imaging
- Cardiovascular Science
Background:
- Hypertensive nephrosclerosis (HN) is a common chronic kidney disease (CKD) characterized by microvascular damage.
- Early diagnosis of HN is challenged by conventional ultrasound's limited sensitivity and specificity.
- Ultrasound localization microscopy (ULM) offers potential for improved microvascular assessment in the kidney.
Purpose of the Study:
- To evaluate the efficacy of ULM in the early diagnosis of hypertensive nephrosclerosis (HN).
- To compare the diagnostic performance of ULM-derived quantitative indexes against conventional clinical and imaging methods for HN.
- To investigate mean arterial blood flow speeds in interlobular arteries using ULM.
Main Methods:
- Quantitative indexes from ULM were compared with conventional serum/urine tests and ultrasound Doppler/CEUS imaging.
- Examinations were conducted on spontaneously hypertensive rats (SHR) and normal Wistar-Kyoto (WKY) rats at 10 weeks of age.
- Mean arterial blood flow speeds in interlobular arteries were measured using ULM.
Main Results:
- Conventional clinical and ultrasound imaging methods showed no significant differences between hypertensive and healthy rats.
- Contrast-enhanced ultrasound imaging (CEUS) showed a significantly higher time to peak (TTP) in SHR compared to WKY rats (p < 0.05).
- ULM revealed significantly higher mean blood flow speed in the interlobular artery of SHR (12.47 ± 1.06 mm/s) compared to WKY rats (10.13 ± 1.17 mm/s; p < 0.01).
Conclusions:
- ULM demonstrated advantages over conventional methods for the early diagnosis of HN.
- ULM effectively diagnoses early-stage HN by detecting changes in interlobular artery blood flow speed.
- ULM shows promise as a reliable technique for future early HN diagnosis.
Purpose:
As a typical chronic kidney disease (CKD), hypertensive nephrosclerosis (HN) is a common syndrome of hypertension, characterized by chronic kidney microvascular damage. Early diagnosis of microvascular damage using conventional ultrasound imaging encounters challenges in sensitivity and specificity owing to the inherent diffraction limit. Ultrasound localization microscopy (ULM) has been developed to obtain microvasculature and microvascular hemodynamics within the kidney, and would be a promising tool for the early diagnosis of CKD.
Methods:
In this study, the advantage of quantitative indexes obtained by using ULM (mean arterial blood flow speeds of different segments of interlobular arteries) over indexes obtained using conventional clinical serum (β2-microglobulin, serum urea nitrogen, and creatinine) and urine (24-h urine volume and urine protein) tests and ultrasound Doppler imaging (peak systolic velocity [PSV], end-diastolic velocity [EDV], and resistance index [RI]) and contrast-enhanced ultrasound imaging (CEUS; rise time [RT], peak intensity [IMAX], mean transit time [mTT], and area under the time-intensity curve [AUC]) for early diagnosis of HN were investigated. Examinations were carried out on six spontaneously hypertensive rats (SHR) and five normal Wistar-Kyoto (WKY) rats at the age of 10 weeks.
Results:
The experimental results show that the indicators derived from conventional clinical inspections (serum and urine tests) and ultrasound imaging (PSV, EDV, RI, RT, IMAX, mTT, and AUC) do not show significant difference between hypertensive and healthy rats (p > 0.05), while the TTP of the SHR group (28.52 ± 5.52 s) derived from CEUS is significantly higher than that of the WKY group (18.68 ± 7.32 s; p < 0.05). The mean blood flow speed in interlobular artery of SHR (12.47 ± 1.06 mm/s) derived from ULM is significantly higher than that of WKY rats (10.13 ± 1.17 mm/s; p < 0.01).
Conclusion:
The advantages of ULM over conventional clinical inspections and ultrasound imaging methods for early diagnosis of HN were validated. The quantitative results show that ULM can effectively diagnose HN at the early stage by detecting the blood flow speed changes of interlobular arteries. ULM may promise a reliable technique for early diagnosis of HN in the future.
