Publications by authors named "Alexey Petraikin"

2 Publications

  • Page 1 of 1

Diffusion processes modeling in magnetic resonance imaging.

Insights Imaging 2020 Apr 28;11(1):60. Epub 2020 Apr 28.

Central Institute of Traumatology and Orthopaedics named after N. N. Priorov, 10, ul. Priorova, Moscow, 127299, Russia.

Background: The paper covers modern approaches to the evaluation of neoplastic processes with diffusion-weighted imaging (DWI) and proposes a physical model for monitoring the primary quantitative parameters of DWI and quality assurance. Models of hindered and restricted diffusion are studied.

Material And Method: To simulate hindered diffusion, we used aqueous solutions of polyvinylpyrrolidone with concentrations of 0 to 70%. We created siloxane-based water-in-oil emulsions that simulate restricted diffusion in the intracellular space. To obtain a high signal on DWI in the broadest range of b values, we used silicon oil with high T: cyclomethicone and caprylyl methicone. For quantitative assessment of our phantom, we performed DWI on 1.5T magnetic resonance scanner with various fat suppression techniques. We assessed water-in-oil emulsion as an extracorporeal source signal by simultaneously scanning a patient in whole-body DWI sequence.

Results: We developed phantom with control substances for apparent diffusion coefficient (ADC) measurements ranging from normal tissue to benign and malignant lesions: from 2.29 to 0.28 mm/s. The ADC values of polymer solutions are well relevant to the mono-exponential equation with the mean relative difference of 0.91%.

Conclusion: The phantom can be used to assess the accuracy of the ADC measurements, as well as the effectiveness of fat suppression. The control substances (emulsions) can be used as a body marker for quality assurance in whole-body DWI with a wide range of b values.
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April 2020

Age and Gender Differences of the Frontal Bone: A Computed Tomographic (CT)-Based Study.

Aesthet Surg J 2019 06;39(7):699-710

Department of Medical Education, Albany Medical College, Albany, NY.

Background: Age-related changes of the frontal bone in both males and females have received limited attention, although understanding these changes is crucial to developing the best surgical and nonsurgical treatment plans for this area.

Objectives: To investigate age-related and gender-related changes of the forehead.

Methods: Cranial computed tomographic images from 157 Caucasian individuals were investigated (10 males and 10 females from each of the following decades: 20-29 years, 30-39 years, 40-49 years, 50-59 years, 60-69 years, 70-79 years, 80-89 years, and of 8 males and 9 females aged 90-98 years). Frontal bone thickness and forehead distance measurements were carried out to analyze age and gender differences.

Results: With increasing age, the size of a male forehead reduces until no significant differences to a female forehead is present at old age (P = 0.307). The thickness of the frontal bone of the lower forehead (≤4 cm cranial to the nasal root) increased slightly in both genders with increasing age. In the upper forehead (≥4 cm cranial to the nasal root), frontal bone thickness decreased significantly (P = 0.002) in males but showed no statistically significant change in thickness in females (P = 0.165).

Conclusions: The shape of the frontal bone varies in young individuals of different genders and undergoes complex changes with age because of bone remodeling. Understanding these bony changes, in addition to those in the soft tissues, helps physicians choose the best surgical and nonsurgical treatment options for the forehead.

Level Of Evidence: 4:
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June 2019