Arzu Bayram | Kadir Has University (original) (raw)
Papers by Arzu Bayram
Biotechnology and Applied Biochemistry, 2003
Influences of the concentration and addition time of alanine-group amino acids, i.e. alanine, leu... more Influences of the concentration and addition time of alanine-group amino acids, i.e. alanine, leucine and valine, on serine alkaline protease (SAP) synthesis were investigated by Bacillus licheniformis (DSM 1969) carrying pHV1431:: sub C in a defined medium to identify the amino acids creating intracellular reaction-rate limitation in SAP production. While the precursors of alanine-group amino acids, pyruvate and alanine, did not affect SAP production considerably within the range 0-15 mM, the addition of leucine decreased both SAP production and cell formation, because of the inhibition of valine synthesis. Although valine inhibits reactions starting with pyruvate towards 2-oxo-isovalerate, due to conversion of valine into 2-oxo-isovalerate and from 2-oxo-isovalerate to leucine, valine did not inhibit leucine synthesis. Val (7.5 mM) supply at t =0 h increased SAP activity to an activity of 1070 units.cm(-3) which was 1.3-fold higher than that of the reference production medium. The highest cell growth yield on substrate (Y (X/S)) was obtained as 0.24 g.g(-1) with the supply of alanine; and the highest product formation yield on substrate was obtained as 0.134 units.g(-1) with the supply of valine. By using the results obtained, strategies for increasing SAP production and complex medium design were also discussed.
European Journal of Radiology, 2009
European Radiology, 2008
The aim of this study was to assess the feasibility of diffusion tensor imaging (DTI) of the pros... more The aim of this study was to assess the feasibility of diffusion tensor imaging (DTI) of the prostate and to determine normative fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values of healthy prostate with a 3-Tesla magnetic resonance imaging (MRI) system. Thirty volunteers with a mean age of 28 (25–35) years were scanned with a 3-Tesla MRI (Intera Achieva; Philips, The Netherlands) system using a six-channel phased array coil. Initially, T2-weighted turbo spin-echo (TSE) axial images of the prostate were obtained. In two subjects, a millimetric hypointense signal change was detected in the peripheral zones on T2-weighted TSE images. These two subjects were excluded from the study. DTI with single-shot echo-planar imaging (ssEPI) was performed in the remaining 28 subjects. ADC and FA values were measured using the manufacturer supplied software by positioning 9-pixel ROIs on each zone. Differences between parameters of the central and peripheral zones were assessed. Mean ADC value of the central (1.220 ± 0.271 × 10−3 mm2/s) was found to be significantly lower when compared with the peripheral gland (1.610 ± 0.347 × 10−3 mm2/s) (P < 0.01). Mean FA of the central gland was significantly higher (0.26), compared with the peripheral gland (0.16) (P < 0.01). This study shows the feasibility of prostate DTI with a 3-Tesla MR system and the normative FA and ADC values of peripheral and central zones of the normal prostate. The results are compatible with the microstructural organization of the gland.
American Journal of Roentgenology, 2007
The purposes of this study were to visualize the human median nerve on diffusion tensor imaging a... more The purposes of this study were to visualize the human median nerve on diffusion tensor imaging and to determine the normal fractional anisotropy (FA) value and apparent diffusion coefficient (ADC) of the normal median nerve. The wrists of 20 healthy volunteers and of two patients with carpel tunnel syndrome were examined with a 3-T MRI system with a standard eight-channel sensitivity-encoding head coil. Diffusion tensor imaging was performed with a spin-echo echo-planar sequence. A T1-weighted sequence was performed for anatomic reference. After tractography, the FA value and ADC of the whole nerve were calculated automatically. Manual focal measurements also were obtained at the levels of the flexor retinaculum, wrist, and forearm. We visualized the median nerve with MR diffusion tensor tractography and followed the nerve for approximately 77.5 mm. We found the normative diffusion values of the median nerve were an FA of 0.709 +/- 0.046 (SD) and an ADC of 1.016 +/- 0.129 x 10(-3) mm2/s. There was a statistically significant difference between the FA values obtained at the level of the flexor retinaculum and the values obtained from the other parts of the median nerve (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.0001). We found a decrease in FA value (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01) and an increase in ADC (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05) with advancing age. The normative diffusion values of the human median nerve can be used as a reference in evaluation, diagnosis, and follow-up of entrapment, trauma, and regeneration of the median nerve.
European Journal of Radiology, 2009
European Journal of Radiology, 2009
European Journal of Radiology, 2009
The purposes of this study were to visualize the human median nerve on diffusion tensor imaging a... more The purposes of this study were to visualize the human median nerve on diffusion tensor imaging and to determine the normal fractional anisotropy (FA) value and apparent diffusion coefficient (ADC) of the normal median nerve. The wrists of 20 healthy volunteers and of two patients with carpel tunnel syndrome were examined with a 3-T MRI system with a standard eight-channel sensitivity-encoding head coil. Diffusion tensor imaging was performed with a spin-echo echo-planar sequence. A T1-weighted sequence was performed for anatomic reference. After tractography, the FA value and ADC of the whole nerve were calculated automatically. Manual focal measurements also were obtained at the levels of the flexor retinaculum, wrist, and forearm. We visualized the median nerve with MR diffusion tensor tractography and followed the nerve for approximately 77.5 mm. We found the normative diffusion values of the median nerve were an FA of 0.709 +/- 0.046 (SD) and an ADC of 1.016 +/- 0.129 x 10(-3) mm2/s. There was a statistically significant difference between the FA values obtained at the level of the flexor retinaculum and the values obtained from the other parts of the median nerve (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.0001). We found a decrease in FA value (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01) and an increase in ADC (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05) with advancing age. The normative diffusion values of the human median nerve can be used as a reference in evaluation, diagnosis, and follow-up of entrapment, trauma, and regeneration of the median nerve.
European Journal of Radiology, 2009
The purposes of this study were to visualize the human median nerve on diffusion tensor imaging a... more The purposes of this study were to visualize the human median nerve on diffusion tensor imaging and to determine the normal fractional anisotropy (FA) value and apparent diffusion coefficient (ADC) of the normal median nerve. The wrists of 20 healthy volunteers and of two patients with carpel tunnel syndrome were examined with a 3-T MRI system with a standard eight-channel sensitivity-encoding head coil. Diffusion tensor imaging was performed with a spin-echo echo-planar sequence. A T1-weighted sequence was performed for anatomic reference. After tractography, the FA value and ADC of the whole nerve were calculated automatically. Manual focal measurements also were obtained at the levels of the flexor retinaculum, wrist, and forearm. We visualized the median nerve with MR diffusion tensor tractography and followed the nerve for approximately 77.5 mm. We found the normative diffusion values of the median nerve were an FA of 0.709 +/- 0.046 (SD) and an ADC of 1.016 +/- 0.129 x 10(-3) mm2/s. There was a statistically significant difference between the FA values obtained at the level of the flexor retinaculum and the values obtained from the other parts of the median nerve (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.0001). We found a decrease in FA value (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01) and an increase in ADC (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05) with advancing age. The normative diffusion values of the human median nerve can be used as a reference in evaluation, diagnosis, and follow-up of entrapment, trauma, and regeneration of the median nerve.
European Radiology, 2008
The aim of this study was to assess the feasibility of diffusion tensor imaging (DTI) of the pros... more The aim of this study was to assess the feasibility of diffusion tensor imaging (DTI) of the prostate and to determine normative fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values of healthy prostate with a 3-Tesla magnetic resonance imaging (MRI) system. Thirty volunteers with a mean age of 28 (25–35) years were scanned with a 3-Tesla MRI (Intera Achieva; Philips, The Netherlands) system using a six-channel phased array coil. Initially, T2-weighted turbo spin-echo (TSE) axial images of the prostate were obtained. In two subjects, a millimetric hypointense signal change was detected in the peripheral zones on T2-weighted TSE images. These two subjects were excluded from the study. DTI with single-shot echo-planar imaging (ssEPI) was performed in the remaining 28 subjects. ADC and FA values were measured using the manufacturer supplied software by positioning 9-pixel ROIs on each zone. Differences between parameters of the central and peripheral zones were assessed. Mean ADC value of the central (1.220 ± 0.271 × 10−3 mm2/s) was found to be significantly lower when compared with the peripheral gland (1.610 ± 0.347 × 10−3 mm2/s) (P < 0.01). Mean FA of the central gland was significantly higher (0.26), compared with the peripheral gland (0.16) (P < 0.01). This study shows the feasibility of prostate DTI with a 3-Tesla MR system and the normative FA and ADC values of peripheral and central zones of the normal prostate. The results are compatible with the microstructural organization of the gland.
The purposes of this study were to visualize the human median nerve on diffusion tensor imaging a... more The purposes of this study were to visualize the human median nerve on diffusion tensor imaging and to determine the normal fractional anisotropy (FA) value and apparent diffusion coefficient (ADC) of the normal median nerve. The wrists of 20 healthy volunteers and of two patients with carpel tunnel syndrome were examined with a 3-T MRI system with a standard eight-channel sensitivity-encoding head coil. Diffusion tensor imaging was performed with a spin-echo echo-planar sequence. A T1-weighted sequence was performed for anatomic reference. After tractography, the FA value and ADC of the whole nerve were calculated automatically. Manual focal measurements also were obtained at the levels of the flexor retinaculum, wrist, and forearm. We visualized the median nerve with MR diffusion tensor tractography and followed the nerve for approximately 77.5 mm. We found the normative diffusion values of the median nerve were an FA of 0.709 +/- 0.046 (SD) and an ADC of 1.016 +/- 0.129 x 10(-3) mm2/s. There was a statistically significant difference between the FA values obtained at the level of the flexor retinaculum and the values obtained from the other parts of the median nerve (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.0001). We found a decrease in FA value (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01) and an increase in ADC (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05) with advancing age. The normative diffusion values of the human median nerve can be used as a reference in evaluation, diagnosis, and follow-up of entrapment, trauma, and regeneration of the median nerve.
The purposes of this study were to visualize the human median nerve on diffusion tensor imaging a... more The purposes of this study were to visualize the human median nerve on diffusion tensor imaging and to determine the normal fractional anisotropy (FA) value and apparent diffusion coefficient (ADC) of the normal median nerve. The wrists of 20 healthy volunteers and of two patients with carpel tunnel syndrome were examined with a 3-T MRI system with a standard eight-channel sensitivity-encoding head coil. Diffusion tensor imaging was performed with a spin-echo echo-planar sequence. A T1-weighted sequence was performed for anatomic reference. After tractography, the FA value and ADC of the whole nerve were calculated automatically. Manual focal measurements also were obtained at the levels of the flexor retinaculum, wrist, and forearm. We visualized the median nerve with MR diffusion tensor tractography and followed the nerve for approximately 77.5 mm. We found the normative diffusion values of the median nerve were an FA of 0.709 +/- 0.046 (SD) and an ADC of 1.016 +/- 0.129 x 10(-3) mm2/s. There was a statistically significant difference between the FA values obtained at the level of the flexor retinaculum and the values obtained from the other parts of the median nerve (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.0001). We found a decrease in FA value (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01) and an increase in ADC (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05) with advancing age. The normative diffusion values of the human median nerve can be used as a reference in evaluation, diagnosis, and follow-up of entrapment, trauma, and regeneration of the median nerve.
Biotechnology and Applied Biochemistry, 2003
Influences of the concentration and addition time of alanine-group amino acids, i.e. alanine, leu... more Influences of the concentration and addition time of alanine-group amino acids, i.e. alanine, leucine and valine, on serine alkaline protease (SAP) synthesis were investigated by Bacillus licheniformis (DSM 1969) carrying pHV1431:: sub C in a defined medium to identify the amino acids creating intracellular reaction-rate limitation in SAP production. While the precursors of alanine-group amino acids, pyruvate and alanine, did not affect SAP production considerably within the range 0-15 mM, the addition of leucine decreased both SAP production and cell formation, because of the inhibition of valine synthesis. Although valine inhibits reactions starting with pyruvate towards 2-oxo-isovalerate, due to conversion of valine into 2-oxo-isovalerate and from 2-oxo-isovalerate to leucine, valine did not inhibit leucine synthesis. Val (7.5 mM) supply at t =0 h increased SAP activity to an activity of 1070 units.cm(-3) which was 1.3-fold higher than that of the reference production medium. The highest cell growth yield on substrate (Y (X/S)) was obtained as 0.24 g.g(-1) with the supply of alanine; and the highest product formation yield on substrate was obtained as 0.134 units.g(-1) with the supply of valine. By using the results obtained, strategies for increasing SAP production and complex medium design were also discussed.
European Journal of Radiology, 2009
European Radiology, 2008
The aim of this study was to assess the feasibility of diffusion tensor imaging (DTI) of the pros... more The aim of this study was to assess the feasibility of diffusion tensor imaging (DTI) of the prostate and to determine normative fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values of healthy prostate with a 3-Tesla magnetic resonance imaging (MRI) system. Thirty volunteers with a mean age of 28 (25–35) years were scanned with a 3-Tesla MRI (Intera Achieva; Philips, The Netherlands) system using a six-channel phased array coil. Initially, T2-weighted turbo spin-echo (TSE) axial images of the prostate were obtained. In two subjects, a millimetric hypointense signal change was detected in the peripheral zones on T2-weighted TSE images. These two subjects were excluded from the study. DTI with single-shot echo-planar imaging (ssEPI) was performed in the remaining 28 subjects. ADC and FA values were measured using the manufacturer supplied software by positioning 9-pixel ROIs on each zone. Differences between parameters of the central and peripheral zones were assessed. Mean ADC value of the central (1.220 ± 0.271 × 10−3 mm2/s) was found to be significantly lower when compared with the peripheral gland (1.610 ± 0.347 × 10−3 mm2/s) (P < 0.01). Mean FA of the central gland was significantly higher (0.26), compared with the peripheral gland (0.16) (P < 0.01). This study shows the feasibility of prostate DTI with a 3-Tesla MR system and the normative FA and ADC values of peripheral and central zones of the normal prostate. The results are compatible with the microstructural organization of the gland.
American Journal of Roentgenology, 2007
The purposes of this study were to visualize the human median nerve on diffusion tensor imaging a... more The purposes of this study were to visualize the human median nerve on diffusion tensor imaging and to determine the normal fractional anisotropy (FA) value and apparent diffusion coefficient (ADC) of the normal median nerve. The wrists of 20 healthy volunteers and of two patients with carpel tunnel syndrome were examined with a 3-T MRI system with a standard eight-channel sensitivity-encoding head coil. Diffusion tensor imaging was performed with a spin-echo echo-planar sequence. A T1-weighted sequence was performed for anatomic reference. After tractography, the FA value and ADC of the whole nerve were calculated automatically. Manual focal measurements also were obtained at the levels of the flexor retinaculum, wrist, and forearm. We visualized the median nerve with MR diffusion tensor tractography and followed the nerve for approximately 77.5 mm. We found the normative diffusion values of the median nerve were an FA of 0.709 +/- 0.046 (SD) and an ADC of 1.016 +/- 0.129 x 10(-3) mm2/s. There was a statistically significant difference between the FA values obtained at the level of the flexor retinaculum and the values obtained from the other parts of the median nerve (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.0001). We found a decrease in FA value (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01) and an increase in ADC (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05) with advancing age. The normative diffusion values of the human median nerve can be used as a reference in evaluation, diagnosis, and follow-up of entrapment, trauma, and regeneration of the median nerve.
European Journal of Radiology, 2009
European Journal of Radiology, 2009
European Journal of Radiology, 2009
The purposes of this study were to visualize the human median nerve on diffusion tensor imaging a... more The purposes of this study were to visualize the human median nerve on diffusion tensor imaging and to determine the normal fractional anisotropy (FA) value and apparent diffusion coefficient (ADC) of the normal median nerve. The wrists of 20 healthy volunteers and of two patients with carpel tunnel syndrome were examined with a 3-T MRI system with a standard eight-channel sensitivity-encoding head coil. Diffusion tensor imaging was performed with a spin-echo echo-planar sequence. A T1-weighted sequence was performed for anatomic reference. After tractography, the FA value and ADC of the whole nerve were calculated automatically. Manual focal measurements also were obtained at the levels of the flexor retinaculum, wrist, and forearm. We visualized the median nerve with MR diffusion tensor tractography and followed the nerve for approximately 77.5 mm. We found the normative diffusion values of the median nerve were an FA of 0.709 +/- 0.046 (SD) and an ADC of 1.016 +/- 0.129 x 10(-3) mm2/s. There was a statistically significant difference between the FA values obtained at the level of the flexor retinaculum and the values obtained from the other parts of the median nerve (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.0001). We found a decrease in FA value (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01) and an increase in ADC (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05) with advancing age. The normative diffusion values of the human median nerve can be used as a reference in evaluation, diagnosis, and follow-up of entrapment, trauma, and regeneration of the median nerve.
European Journal of Radiology, 2009
The purposes of this study were to visualize the human median nerve on diffusion tensor imaging a... more The purposes of this study were to visualize the human median nerve on diffusion tensor imaging and to determine the normal fractional anisotropy (FA) value and apparent diffusion coefficient (ADC) of the normal median nerve. The wrists of 20 healthy volunteers and of two patients with carpel tunnel syndrome were examined with a 3-T MRI system with a standard eight-channel sensitivity-encoding head coil. Diffusion tensor imaging was performed with a spin-echo echo-planar sequence. A T1-weighted sequence was performed for anatomic reference. After tractography, the FA value and ADC of the whole nerve were calculated automatically. Manual focal measurements also were obtained at the levels of the flexor retinaculum, wrist, and forearm. We visualized the median nerve with MR diffusion tensor tractography and followed the nerve for approximately 77.5 mm. We found the normative diffusion values of the median nerve were an FA of 0.709 +/- 0.046 (SD) and an ADC of 1.016 +/- 0.129 x 10(-3) mm2/s. There was a statistically significant difference between the FA values obtained at the level of the flexor retinaculum and the values obtained from the other parts of the median nerve (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.0001). We found a decrease in FA value (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01) and an increase in ADC (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05) with advancing age. The normative diffusion values of the human median nerve can be used as a reference in evaluation, diagnosis, and follow-up of entrapment, trauma, and regeneration of the median nerve.
European Radiology, 2008
The aim of this study was to assess the feasibility of diffusion tensor imaging (DTI) of the pros... more The aim of this study was to assess the feasibility of diffusion tensor imaging (DTI) of the prostate and to determine normative fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values of healthy prostate with a 3-Tesla magnetic resonance imaging (MRI) system. Thirty volunteers with a mean age of 28 (25–35) years were scanned with a 3-Tesla MRI (Intera Achieva; Philips, The Netherlands) system using a six-channel phased array coil. Initially, T2-weighted turbo spin-echo (TSE) axial images of the prostate were obtained. In two subjects, a millimetric hypointense signal change was detected in the peripheral zones on T2-weighted TSE images. These two subjects were excluded from the study. DTI with single-shot echo-planar imaging (ssEPI) was performed in the remaining 28 subjects. ADC and FA values were measured using the manufacturer supplied software by positioning 9-pixel ROIs on each zone. Differences between parameters of the central and peripheral zones were assessed. Mean ADC value of the central (1.220 ± 0.271 × 10−3 mm2/s) was found to be significantly lower when compared with the peripheral gland (1.610 ± 0.347 × 10−3 mm2/s) (P < 0.01). Mean FA of the central gland was significantly higher (0.26), compared with the peripheral gland (0.16) (P < 0.01). This study shows the feasibility of prostate DTI with a 3-Tesla MR system and the normative FA and ADC values of peripheral and central zones of the normal prostate. The results are compatible with the microstructural organization of the gland.
The purposes of this study were to visualize the human median nerve on diffusion tensor imaging a... more The purposes of this study were to visualize the human median nerve on diffusion tensor imaging and to determine the normal fractional anisotropy (FA) value and apparent diffusion coefficient (ADC) of the normal median nerve. The wrists of 20 healthy volunteers and of two patients with carpel tunnel syndrome were examined with a 3-T MRI system with a standard eight-channel sensitivity-encoding head coil. Diffusion tensor imaging was performed with a spin-echo echo-planar sequence. A T1-weighted sequence was performed for anatomic reference. After tractography, the FA value and ADC of the whole nerve were calculated automatically. Manual focal measurements also were obtained at the levels of the flexor retinaculum, wrist, and forearm. We visualized the median nerve with MR diffusion tensor tractography and followed the nerve for approximately 77.5 mm. We found the normative diffusion values of the median nerve were an FA of 0.709 +/- 0.046 (SD) and an ADC of 1.016 +/- 0.129 x 10(-3) mm2/s. There was a statistically significant difference between the FA values obtained at the level of the flexor retinaculum and the values obtained from the other parts of the median nerve (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.0001). We found a decrease in FA value (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01) and an increase in ADC (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05) with advancing age. The normative diffusion values of the human median nerve can be used as a reference in evaluation, diagnosis, and follow-up of entrapment, trauma, and regeneration of the median nerve.
The purposes of this study were to visualize the human median nerve on diffusion tensor imaging a... more The purposes of this study were to visualize the human median nerve on diffusion tensor imaging and to determine the normal fractional anisotropy (FA) value and apparent diffusion coefficient (ADC) of the normal median nerve. The wrists of 20 healthy volunteers and of two patients with carpel tunnel syndrome were examined with a 3-T MRI system with a standard eight-channel sensitivity-encoding head coil. Diffusion tensor imaging was performed with a spin-echo echo-planar sequence. A T1-weighted sequence was performed for anatomic reference. After tractography, the FA value and ADC of the whole nerve were calculated automatically. Manual focal measurements also were obtained at the levels of the flexor retinaculum, wrist, and forearm. We visualized the median nerve with MR diffusion tensor tractography and followed the nerve for approximately 77.5 mm. We found the normative diffusion values of the median nerve were an FA of 0.709 +/- 0.046 (SD) and an ADC of 1.016 +/- 0.129 x 10(-3) mm2/s. There was a statistically significant difference between the FA values obtained at the level of the flexor retinaculum and the values obtained from the other parts of the median nerve (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.0001). We found a decrease in FA value (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01) and an increase in ADC (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05) with advancing age. The normative diffusion values of the human median nerve can be used as a reference in evaluation, diagnosis, and follow-up of entrapment, trauma, and regeneration of the median nerve.