Renal sonographic changes in heterogeneity index and echogenicity in children with hypertension: a novel assessment.

The kidneys are thought to contribute to the pathogenesis of primary hypertension, but hypertension is also known to cause target organ damage in the kidney. Noninvasive methods to capture possible changes in the kidney related to hypertension are limited. A new program that has been used to quantify the heterogeneity and percent echogenicity in renal ultrasound images was implemented to assess patients with hypertension. Children and adolescents <21 years with primary hypertension diagnosed by ambulatory blood pressure monitoring were compared with normotensive age- and sex-matched controls. Renal ultrasound images were evaluated by a technique that measured pixels of gray-scale images and transformed them into a binary map, which was converted to a heterogeneity index (HI) and percent echogenicity score. This study included 99 children with hypertension and 99 control subjects. Body mass index (BMI) was greater in the hypertension group. Average HI for hypertension was significantly higher than in controls (1.37 ± 0.19 vs. 1.2 ± 0.23, P = .001), while echogenicity scores were not different (26.6 ± 8.9 vs. 25.9 ± 10, P = .8). In regression analysis adjusting for BMI z-score and race, hypertension was associated with greater HI compared with controls (ß = 0.11, 95% confidence interval 0.03-0.18, P = .005). In a model adjusted for age, sex, and BMI z-score in the hypertension group only, no ambulatory blood pressure monitoring measures were associated with HI or echogenicity scores (P > .05).HI was significantly greater in the hypertension group compared with normotensive controls. HI may be a novel method to detect changes in the kidney related to hypertension.

Ultrasonic Assessment of Cervical Heterogeneity for Prediction of Spontaneous Preterm Birth: A Feasibility Study.

BACKGROUND: In a normal pregnancy, cervical collagen fibers remain organized in predictable patterns throughout most of the gestation. Cervical remodeling reflects a rearrangement of collagen fibers in which they become increasingly disordered and contribute to the pathogenesis of spontaneous preterm birth. Quantitative ultrasound analysis of cervical tissue echotexture may have the capacity to identify microstructural changes before the onset of cervical shortening. OBJECTIVE: The primary objective of this study was to examine the utility of a novel quantitative sonographic marker, the cervical heterogeneity index (HI), which reflects the relative organization of cervical collagen fibers. Also, we aimed to determine an optimal HI cut-point to predict spontaneous preterm birth. STUDY DESIGN: This retrospective cohort study employed a novel image-processing technique on transvaginal ultrasound images of the cervix in gestations between 14 and 28 completed weeks. The transvaginal sonography images were analyzed in MATLAB (MathWorks, Natick, MA) using a custom image-processing technique that assessed the relative heterogeneity of the cervical tissue. RESULTS: A total of 151 subjects were included in the study. The mean HI in subjects who delivered preterm and at term was 8.28 ± 3.73 and 12.35 ± 5.80, respectively (p < 0.0001). Thus, decreased tissue heterogeneity was associated with preterm birth, and increased tissue heterogeneity was associated with delivery at term. In our study population, preterm birth was associated with a short cervix (<2.5 cm), history of preterm birth and lower HI, and our findings indicate that HI may improve prediction of preterm birth. CONCLUSION: Quantitative ultrasound measurement of the cervical HI is a promising, noninvasive tool for early prediction of spontaneous preterm birth.

Ultrasonographic Assessment of Testicular Viability Using Heterogeneity Levels in Torsed Testicles.

PURPOSE: Gross testicular heterogeneity on ultrasound has been associated with testis loss following testicular torsion in children. We aimed to quantify the extent of temporal heterogeneity associated with testis loss in testicular torsion cases using a noninvasive technique to determine a HI (heterogeneity index) on ultrasound images. MATERIALS AND METHODS: We retrospectively studied the records of patients who presented with acute scrotal pain to the Pediatric Emergency Department over a 6-year period. Ultrasound images of the affected testis and the unaffected contralateral testis were examined using a proprietary program to determine the extent of heterogeneity of each image. The difference between the HI of the torsed testis and that of the contralateral normal testis was termed ΔHI. Receiver operating characteristics curve analysis was performed to determine the ΔHI threshold for nonviability. RESULTS: Among 529 patients who presented with acute scrotal pain 147 had testicular torsion based on surgical findings. Of these 147 patients 110 (74.8%) were found to have a viable testis while 37 (25.2%) had a nonviable testis. Using the ΔHI cutoff of 0.394 or greater for nonviability, sensitivity and specificity were 100% and 94.5%, respectively. Positive and negative predictive values were 86% and 100%, respectively. CONCLUSIONS: Our results demonstrate that a quantifiable temporal gradation of heterogeneity exists and the heterogeneity index can be used as an objective parameter to determine the viability of a torsed testicle. By developing the technology to measure the heterogeneity index in real time, we could potentially identify which patients with testicular torsion have a nonviable testicle and, thus, would not require immediate surgical exploration.

Ultrasonic assessment of extracellular matrix content in healing Achilles tendon.

Although several imaging modalities have been utilized to observe tendons, assessing injured tendons by tracking the healing response over time with ultrasound is a desirable method which is yet to be realized. This study examines the use of ultrasound for non-invasive monitoring of the healing process of Achilles tendons after surgical transection. The overall extracellular matrix content of the transection site is monitored and quantified as a function of time. B-mode images (built from successive A-scan signatures) of the injury site were obtained and compared to biomechanical properties. A quantitative measure of tendon healing using the extracellular matrix (ECM) content of the injury site was analyzed using linear regression with all biomechanical measures. Contralateral tendons were used as controls. The trend in the degree of ECM regrowth in the 4 weeks following complete transection of excised tendons was found to be most closely paralleled with that of linear stiffness (R(2) = 0.987, p < .05) obtained with post-ultrasound biomechanical tests. Results suggest that ultrasound can be an effective imaging technique in assessing the degree of tendon healing, and can be used to correlate structural properties of Achilles tendons.