Tissue-mimicking materials for teaching sonographers and evaluation of their specifications after three years

In this paper, an algorithm is introduced for making breast phantoms and abnormal masses (cyst, fibroadenoma and cancer). The evaluation of ultrasonic properties (sound velocity and amplitude attenuation coefficient) of these normal breast phantoms and abnormal masses and their ultrasonic images shows that they are stable over 3 years. The measurement and evaluation results of ultrasonic images of our phantoms show that they behave like human breast tissues. Practicing with these phantoms for developing fine-needle aspiration (FNA) skills in sonographers shows that these phantoms reduce the time required for successful FNA. The ultrasonic phantoms have different ultrasonic applications, including ultrasonic medical imaging, the quality control of ultrasound (US) instruments, processing technique evaluation and US training; moreover, they are stable in room temperature and can keep their specifications for more than 3 years. (E-mail: Mokhtarm@modares.ac.ir)     

Estimating the absorbed dose to critical organs during dual X-ray absorptiometry.

OBJECTIVE: The purpose of this study is to estimate a patient's organ dose (effective dose) during performance of dual X-ray absorptiometry by using the correlations derived from the surface dose and the depth doses in an anthropomorphic phantom. MATERIALS AND METHODS: An anthropomorphic phantom was designed and TLDs (Thermoluminescent Dosimeters) were placed at the surface and these were also inserted at different depths of the thyroid and uterus of the anthropomorphic phantom. The absorbed doses were measured on the phantom for the spine and femur scan modes. The correlation coefficients and regression functions between the absorbed surface dose and the depth dose were determined. The derived correlation was then applied for 40 women patients to estimate the depth doses to the thyroid and uterus. RESULTS: There was a correlation between the surface dose and depth dose of the thyroid and uterus in both scan modes. For the women's dosimetry, the average surface doses of the thyroid and uterus were 1.88 microGy and 1.81 microGy, respectively. Also, the scan center dose in the women was 5.70 microGy. There was correlation between the thyroid and uterus surface doses, and the scan center dose. CONCLUSION: We concluded that the effective dose to the patient's critical organs during dual X-ray absorptiometry can be estimated by the correlation derived from phantom dosimetry.     

Effect of fractionation on treatment outcome in local dual-frequency sonication and Dox-encapsulated nanomicelles

Purpose

The goal of this study was to localize drug release from nanomicelles using dual-frequency sonication at low levels of acoustic intensity.

Methods

In this study, the antitumor effect of simultaneous dual-frequency sonication (28 kHz and 3 MHz) at low levels of acoustic intensity in combination with doxorubicin and micellar doxorubicin injection was assessed in a spontaneous model of breast adenocarcinoma in female Balb/c mice. Sixty-three tumor-bearing mice were randomly grouped into control, sham, dual-frequency sonication, doxorubicin injection with and without dual-frequency sonication, and micellar doxorubicin injection with and without dual-frequency sonication groups.

Results

The results of volume change relative to initial volume showed that in the micellar doxorubicin injection with sonication group, this parameter was significantly different from that of the control, sham, sonication, and doxorubicin injection groups (P < 0.05). In addition, the volume began to increase on the 15th day after the start of treatment, which is a good indication to repeat treatment; therefore, another group received an extra treatment on day 15. The animal life span in the micellar doxorubicin with sonication and repeated treatment groups was significantly higher than that in all the other experimental groups except for the micellar doxorubicin injection group (P < 0.05).

Conclusion

It was concluded that dual-frequency sonication with micellar doxorubicin injection extends the life span relative to doxorubicin injection or dual-frequency sonication alone, and that repeating this treatment on day 15 decreases the rate of tumor growth significantly.     

A noninvasive method for early detection of MNNG-induced gastric cancer of male Wistar rat: ultrasonic study

Gastric cancer is often diagnosed at advanced stages and there is no accurate method for its screening and diagnosis, especially in small animals. Here, we explain the application of B-mode ultrasound imaging (BMUI) for screening of gastric changes in the rat. Thus, male Albino Wistar rats, weighing 100-120 grams were randomly divided into two groups. The control group rats (n = 10) were given water as routine; the remaining (n = 90), were given N-methyl-N-nitro-N-nitrosoguanidine (MNNG, 100 μg/mL) in drinking water ad libitum for 40 weeks. Fifteen rats were killed at different time intervals and the others were sacrificed after 55 weeks. The BMUI of the stomach of animals after MNNG administration show some changes compared with the normal groups. Pathologic investigations of the stomach indicate cancer induction at different levels. The sensitivity and specificity of BMUI is 96.6% and 78.78%, respectively. Thus, it is a useful method of diagnosis of gastric cancer in rats. (E-mail: bathai_z@modares.ac.ir or zbatha2000@yahoo.com)     

Optimal fluid intake in daily diet: Avicenna’s view

Adequate daily water consumption is an important factor of keeping regular homeostasis. However, the best quantity of daily water consumption for a healthy individual is not virtually stated in the literature. Despite the dearth of evidence-based recommendations, it is commonly thought that ingesting eight glasses of water a day is good for a healthy person. Avicenna had a unique viewpoint. He believed that daily water intake depended on numerous elements together with age, intercourse, body temperament, season, occupation and various internal and external elements. He also cited a few essential and useful measures regarding proper water consumption, which have additionally been emphasized in Islamic hadiths.     

Ultrasound Dose Fractionation in Sonodynamic Therapy

Sonodynamic therapy (SDT) is a new modality in cancer therapy and it is based on preferential uptake and/or retention of a sonosensitizing drug in tumor tissues and subsequent activation of the drug by ultrasound. The dose fractionation effect in radiation therapy has been known for more than a century, but it is not reported in SDT so far. In this study, the in vivo antitumor effect of the simultaneous dual-frequency ultrasound (1 MHz and 150 kHz) at low-level intensity (cumulative I_SATA = 2.2W/cm²; total energy density 3960J/cm²; for 30 min sonication) in combination with the sonosensitizer of photofrin (PF) (sodium porfimer) was investigated in dose fractionation regime in a spontaneous murine model of breast adenocarcinoma in Balb/c mice. The tumor-bearing mice were divided into six groups (n = 8 to 10): Untreated groups included control and sham; experimental groups were treated with 5 mg/kg intravenous injection of PF alone, with combined PF and ultrasound for 30-min sonication in one fraction at 24 h after PF administration; with combined PF and ultrasound for 30 min sonicatin in three fraction at 18, 24 and 30 h after PF administration; and finally with combined PF and ultrasound for 30 min sonication in five fraction at 12, 18, 24, 30 and 36 h after PF administration. The tumor growth delay (TGD) parameters and the percent of apoptotic index AI (%) were measured in treated and untreated groups. The results show that the TGD parameters in treatment groups with combined drug and ultrasound fractionation mode were significantly different compared with other groups (p < 0.05). Also the sonodynamic ultrasound dose fractionation in five fractions is more effective than of the three-fraction regime. The AI of the tumor tissues treated by ultrasound dose fractionation was also significantly higher in the other groups (p < 0.05), in which the AI (%) in the group treated with five fractions was higher with respect to group treated with 3 fractions (11.56 ± 1.2; 8.7 ± 0.87), respectively. In conclusion, the ultrasound dose fractionation can be useful in therapeutic effect in SDT and may have future clinical applications. (E-mail: ah_barati@yahoo.com)     

Radial strain assessment of the interventricular septum wall by a new technique in healthy subjects

The aim of this study was to design a new approach for the acquisition of regional radial strain from the middle portion of the interventricular septum. We designed and wrote a program in Matlab (computer-assisted method) for use on a personal computer so that the septum thickness throughout the cardiac cycle could be measured instantaneously. Computer-assisted and conventional manual methods were used on the same 2D echocardiography image frames. Then, real-time 2D color Doppler myocardial imaging and conventional 2D imaging of the septum walls of 12 healthy participants at rest using apical four-chamber view were acquired. Wall thickness was measured using both the computerized program and velocity data used for tracking the segment and intensity line profile modification automatically. Then, the radial strain was estimated. Bland-Altman statistical analysis shows good agreement between the computer-assisted method and conventional manual method. The average of the peak and mean radial strains from the mid-septum of 12 healthy participants were 63.5 ± 10.7 and 31.7 ± 7.5%, respectively. We introduced a simple approach that is capable of radial strain estimation of the septum wall, which cannot be measured by current Doppler based methods in echocardiography systems.