Ultrasound evaluation of polymer gel dosimeters

A new method for the evaluation of radiotherapy 3D polymer gel dosimeters has been developed using ultrasound to assess the significant structural changes that occur following irradiation of the dosimeters. The ultrasonic parameters of acoustic speed of propagation, attenuation and transmitted signal intensity were measured as a function of absorbed radiation dose. The dose sensitivities for each parameter were determined as 1.8 x 10(-4) s m(-1) Gy(-1), 3.9 dB m(-1) Gy(-1) and 3.2 V-1 Gy(-1) respectively. All parameters displayed a strong variation with absorbed dose that continued beyond absorbed doses of 15 Gy. The ultrasonic measurements demonstrated a significantly larger dynamic range in dose response curves than that achieved with previously published magnetic resonance imaging (MRI) dose response data. It is concluded that ultrasound shows great potential as a technique for the evaluation of polymer gel dosimeters.

Assessment of image quality of a standard and two dose-reducing protocols in paediatric pelvic CT

Background: Concerns exist regarding the effect of radiation dose from paediatric pelvic CT scans and the potential later risk of radiation-induced neoplasm and teratogenic outcomes in these patients. Objective: To assess the diagnostic quality of CT images of the paediatric pelvis using either reduced mAs or increased pitch compared with standard settings. Materials and methods: A prospective study of pelvic CT scans of 105 paediatric patients was performed using one of three protocols: (1) 31 at a standard protocol of 200 mA with rotation time of 0.75 s at 120 kVp and a pitch factor approximating 1.4; (2) 31 at increased pitch factor approaching 2 and 200 mA; and (3) 43 at a reduced setting of 100 mA and a pitch factor of 1.4. All other settings remained the same in all three groups. Image quality was assessed by radiologists blinded to the protocol used in each scan. Results: No significant difference was found between the quality of images acquired at standard settings and those acquired at half the standard mAs. The use of increased pitch factor resulted in a higher proportion of poor images. Conclusions: Images acquired at 120 kVp using 75 mAs are equivalent in diagnostic quality to those acquired at 150 mAs. Reduced settings can provide useful imaging of the paediatric pelvis and should be considered as a standard protocol in these situations.

The systematic use of intraoperative vascular Doppler ultrasound during microsurgical subinguinal varicocelectomy improves precise identification and preservation of testicular blood supply

Objective: To evaluate the impact of systematic use of intraoperative Doppler ultrasound during microsurgical subinguinal varicocele repair. Design: Prospective clinical study. Setting: Andrology laboratory and male infertility section of the urology department of a tertiary care hospital. Patient(s): Two hundred and thirteen men with clinical varicocele. Intervention(s): Subinguinal microsurgical varicocele ligation using an intraoperative vascular Doppler flow detector. Main Outcome Measure(s): Number of veins ligated, lymphatic spared, arteries identified or accidentally ligated. Result(s): A statistically significant greater number of arteries were identified and preserved when intraoperative vascular Doppler was used. In addition, the average number of internal spermatic veins ligated was statistically significantly greater in the same group. Accidental artery ligation occurred in two cases (1.1%) in which the Doppler was not applied. There was no statistically significant difference in number of lymphatics spared between groups. Conclusion(s): Our findings showed that concomitant use of intraoperative vascular Doppler during microsurgical varicocelectomy allows more arterial branches to be preserved, and more internal spermatic veins are likely to be ligated. This device should be considered an attractive tool to improve surgical outcomes and safety. (Fertil Steril (R) 2010; 93: 2396-9. (C)2010 by American Society for Reproductive Medicine.)

Transvaginal ultrasonography with bowel preparation is able to predict the number of lesions and rectosigmoid layers affected in cases of deep endometriosis, defining surgical strategy

Successful surgical treatment of deep bowel endometriosis depends on obtaining detailed information about the lesions, prior to the procedure. The objective of this study was to determine the capability of transvaginal ultrasonography with bowel preparation (TVUS-BP) to predict the presence of one or more rectosigmoid nodules and the deepest bowel layer affected by the disease. A prospective study of 194 patients with clinical and TVUS-BP suspected deep endometriosis submitted to videolaparoscopy. Image data were compared with surgical and histological results. With respect to bowel nodule detection and presence of at least two rectosigmoid lesions, TVUS-BP had a sensitivity of 97 and 81%, specificity 100 and 99%, positive predictive value (PPV) 100 and 93% and negative predictive value (NPV) 98 and 96%, respectively. Regarding diagnosis of infiltration of the submucosal/mucosal layer, TVUS-BP had a sensitivity of 83%, specificity 94%, PPV 77%, NPV 96%. These findings show that TVUS-BP is an adequate exam for evaluating the presence of one or more rectosigmoid nodules and the deepest layer affected in deep infiltrating bowel endometriosis, confirming the importance of this technique for defining the most appropriate surgical strategy to be implemented.

Ultrasound detection rate of single umbilical artery in the first trimester of pregnancy

Objective To determine accuracy of first trimester detection of single umbilical artery (SUA). Methods The number of vessels in the umbilical cord was examined in a prospective cohort of 779 singleton, low-risk, unselected pregnancies, in the first (11-13 weeks) and second (17-24 weeks) trimesters, using both power and color Doppler and after delivery, by placental histopathologic exam. Concordance between first and second trimester findings to postnatal diagnoses was compared by calculating kappa coefficients. Results There was medium concordance between the findings in the first trimester and the postnatal diagnoses (kappa = 0.52) and high concordance (kappa = 0.89) for the second trimester scan. Sensitivity, specificity, positive and negative predictive values for the findings in the first trimester were 57.1, 98.9, 50.0 and 99.2% and for the second trimester were 86.6, 99.9, 92.9 and 99.7%. Conclusion Sensitivity and positive predictive value of first trimester scan to identify an isolated SUA in a prospective unselected population was poor. Diagnosis of isolated SUA as well as a definitive judgment about the presence of associated anomalies would still require a scan in the second trimester. Copyright (C) 2011 John Wiley & Sons, Ltd.

Metabolic differences between male and female adolescents with non-alcoholic fatty liver disease, as detected by ultrasound

Background: Age, developmental stage and gender are risk factors for paediatric non-alcoholic fatty liver disease (NAFLD). Aims: The aim of this study was to identify differences in clinical or laboratory variables between sexes in adolescents with NAFLD. Methodology: Ninety obese adolescents including 36 males and 54 females were evaluated. Inclusion criteria for this study were a Body Mass Index above the 95th percentile, as set forth by the National Center for Health Statistics, and an age of 10-19 years. A clinical and laboratory evaluation was conducted for all adolescents. Results: The variables that were found to be predictive of NAFLD in adolescence were visceral fat, Aminotransferase, Gamma-Glutamyl Transferase, triglyderides, cholesterol and LDL-cholesterol. We also observed that cholesterol and LDL-cholesterol variables were influenced by gender, i.e. there was a significant statistical difference in the values of these variables between male and female adolescents. With regard to cholesterol serum concentrations, the risk was 6.99 times greater for females, compared with 1.2 times for males; and for LDL-cholesterol serum concentrations the risk was 8.15 times greater for females, compared with and 1.26 times for males. Conclusion: Female adolescents with NAFLD showed a significantly different metabolic behaviour than males.

Effect of ultrasound therapy on the repair of Gastrocnemius muscle injury in rats

The aim of this study was to evaluate the effect of the pulsed ultrasound therapy (PUT) in stimulating myoregeneration and collagen deposition in an experimental model of lacerative gastrocnemius muscle lesion in 30 Wistar rats. Fifteen rats were treated (TG) daily with 1 MHz pulsed ultrasound (50%) at 0.57 W/cm(2) for 5 min, and 15 were control animals (CG). Muscle samples were analyzed on postoperative days 4, 7 and 14 through H&E, Picrosirius-polarization and immunohistochemistry for desmin. The lesions presented similar inflammatory responses in both treated and control groups. The areal fraction of fibrillar collagen was larger in the TG at 4 days post-operatively (17.53 +/- 6.2% vs 6.79 +/- 1.3%, p = 0.0491), 7 days (31.07 +/- 7.45% vs 12.57 +/- 3.6%, p = 0.0021) and 14 days (30.39 +/- 7.3% vs 19.13 +/- 3.51%, p = 0.0118); the areal fraction of myoblasts and myotubes was larger in the TG at 14 days after surgery (41.66 +/- 2.97% vs 34.83 +/- 3.08%, p = 0.025). Our data suggest that the PUT increases the differentiation of muscular lineage cells, what would favor tissue regeneration. On the other hand, it is also suggested that there is a larger deposition of collagenous fibers, what could mean worse functional performance. However, the percentage of fibers seems to have stabilized at day 7 in TG and kept increasing in CG. Furthermore, the collagen supramolecular organization achieved by the TG is also significant according to the Sirius red staining results. (C) 2008 Elsevier B.V. All rights reserved.

Findings of Pelvic Endometriosis at Transvaginal US, MR Imaging, and Laparoscopy

Endometriosis is a common multifocal gynecologic disease that manifests during the reproductive years, often causing chronic pelvic pain and infertility. It may occur as invasive peritoneal fibrotic nodules and adhesions or as ovarian cysts with hemorrhagic content. Although findings at physical examination may be suggestive, imaging is necessary for definitive diagnosis, patient counseling, and treatment planning. The imaging techniques that are most useful for preoperative disease mapping are transvaginal ultrasonography (US) after bowel preparation, and magnetic resonance (MR) imaging. Initial transvaginal US is a reliable technique for detecting rectosigmoid endometriotic lesions. MR imaging is indicated as a complementary examination in complex cases of endometriosis with extensive adhesions and ureteral involvement. Peritoneal endometriotic implants are typically hypoechoic on transvaginal US images and demonstrate low signal intensity on T2-weighted MR images. Endometriotic implants most commonly are found in retrocervical and rectosigmoid sites, followed by the vagina, bladder, and ureters. Cysts with low-level internal echoes and echogenic peripheral foci at transvaginal US are suggestive of endometriomas. MR imaging has high specificity for identifying endometriomas, which are characterized by high signal intensity on T1-weighted images and low signal intensity on T2-weighted images. Correlation of the radiologic imaging features of endometriotic lesions with their laparoscopic appearances may help improve individual proficiency in the radiologic diagnosis of endometriosis. Supplemental material available at http:// radiographics.rsna.org/lookup/suppl/doi: 10.1148/rg.314105193/-/DC1. (C) RSNA, 2011 radiographics.rsna.org

Factors associated with pelvic asymmetry in transverse plane during gait in patients with cerebral palsy

The purpose of this study was to describe the patterns of pelvic rotational asymmetry in the transverse plane and identify the possible factors related to this problem. One thousand and forty-five patients with cerebral palsy (CP) and complete documentation in the gait laboratory were reviewed in a retrospective study. Pelvic asymmetry in the transverse plane was observed in 52.7% of the patients; and to identify the possible causes of pelvic retraction, clinical (Thomas test, popliteal angle, and gastrocnemius tightness) and dynamic parameters (mean rotation of the hip in stance, minimum hip flexion, minimum knee flexion, and peak ankle dorsiflexion) were evaluated. The association between these parameters and pelvic retraction was assessed statistically. The results showed that 75.7% of patients with asymmetric pattern of the pelvis had clinical diagnosis of diplegic spastic CP. Among the patients with asymmetrical CP, the most common pattern was pelvic retraction on the affected side. The relationship between pelvic retraction and internal hip rotation was stronger in patients with asymmetrical diplegic CP than in those with hemiplegic (P<0.001) or symmetrical diplegic CP (P=0.014). All of the patients exhibited a significant association among clinical parameters (Thomas test, popliteal angle, and gastrocnemius tightness) and pelvic retraction. In conclusion, pelvic retraction seems to be a multifactorial problem, and the etiology can change according to topographic classification, which must be taken into account during the decision-making process in patients with CP. J Pediatr Orthop B 18:320-324 (C) 2009 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.

Ultrasound evaluation of prognosis in fetuses with posterior urethral valves

Purpose: The aim of this study was to evaluate the ability of prenatal ultrasound markers to predict postnatal renal prognosis in fetuses with posterior urethral valves. Methods: Medical files on fetuses with prenatal diagnosis of posterior urethral valves from 2000 to 2006 were reviewed retrospectively. Data from prenatal follow-up included gestational age at diagnosis, ultrasound renal parenchyma evaluation, and presence and time of oligohydramnios onset. Prenatal parameters studied were correlated to postnatal renal function. Results: Thirty-one male fetuses were included. Six pregnancies were terminated. Of the remaining 25 pregnancies that were continued, 4 children had abnormal creatine and 21 normal creatinine levels at follow-up. Presence and time of oligohydramnios onset did not differ between groups (P = .43). Ultrasound detected bilateral renal abnormalities in 3 fetuses (75%) with altered renal function, and 10 fetuses (55%) with normal creatinine, at follow-up. Conclusions: None of the ultrasound parameters evaluated were able to reliably predict postnatal renal function. (C) 2011 Elsevier Inc. All rights reserved.