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Reduced Field-of-View Diffusion-Weighted Magnetic Resonance Imaging of the Pancreas: Comparison with Conventional Single-Shot Echo-Planar Imaging.

Kim H, Lee JM, Yoon JH, Jang JY, Kim SW, Ryu JK, Kannengiesser S, Han JK, Choi BI - Korean J Radiol (2015)

Bottom Line: On qualitative analysis, reduced FOV DWI showed better anatomic structure visualization (2.76 ± 0.79 at b = 0 s/mm(2) and 2.81 ± 0.64 at b = 400 s/mm(2)), lesion conspicuity (3.11 ± 0.99 at b = 0 s/mm(2) and 3.15 ± 0.79 at b = 400 s/mm(2)), IQ score (8.51 ± 2.05 at b = 0 s/mm(2) and 8.79 ± 1.60 at b = 400 s/mm(2)), and higher clinical utility (3.41 ± 0.64), as compared to full FOV DWI (anatomic structure, 2.18 ± 0.59 at b = 0 s/mm(2) and 2.56 ± 0.47 at b = 500 s/mm(2); lesion conspicuity, 2.55 ± 1.07 at b = 0 s/mm(2) and 2.89 ± 0.86 at b = 500 s/mm(2); IQ score, 7.13 ± 1.83 at b = 0 s/mm(2) and 8.17 ± 1.31 at b = 500 s/mm(2); clinical utility, 3.14 ± 0.70) (p < 0.05).Artifacts were significantly improved on reduced FOV DWI (2.65 ± 0.68) at b = 0 s/mm(2) (full FOV DWI, 2.41 ± 0.63) (p < 0.001).ADCs of adenocarcinomas (1.061 × 10(-3) mm(2)/s ± 0.133 at reduced FOV and 1.079 × 10(-3) mm(2)/s ± 0.135 at full FOV) and neuroendocrine tumors (0.983 × 10(-3) mm(2)/s ± 0.152 at reduced FOV and 1.004 × 10(-3) mm(2)/s ± 0.153 at full FOV) were significantly lower than those of parenchyma (1.191 × 10(-3) mm(2)/s ± 0.125 at reduced FOV and 1.218 × 10(-3) mm(2)/s ± 0.103 at full FOV) (p < 0.05).

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, Seoul National University Hospital, Seoul 03080, Korea. ; Aerospace Medical Group, Air Force Education and Training Command, Jinju 52634, Korea.

ABSTRACT

Objective: To investigate the image quality (IQ) and apparent diffusion coefficient (ADC) of reduced field-of-view (FOV) di-ffusion-weighted imaging (DWI) of pancreas in comparison with full FOV DWI.

Materials and methods: In this retrospective study, 2 readers independently performed qualitative analysis of full FOV DWI (FOV, 38 × 38 cm; b-value, 0 and 500 s/mm(2)) and reduced FOV DWI (FOV, 28 × 8.5 cm; b-value, 0 and 400 s/mm(2)). Both procedures were conducted with a two-dimensional spatially selective radiofrequency excitation pulse, in 102 patients with benign or malignant pancreatic diseases (mean size, 27.5 ± 14.4 mm). The study parameters included 1) anatomic structure visualization, 2) lesion conspicuity, 3) artifacts, 4) IQ score, and 5) subjective clinical utility for confirming or excluding initially considered differential diagnosis on conventional imaging. Another reader performed quantitative ADC measurements of focal pancreatic lesions and parenchyma. Wilcoxon signed-rank test was used to compare qualitative scores and ADCs between DWI sequences. Mann Whitney U-test was used to compare ADCs between the lesions and parenchyma.

Results: On qualitative analysis, reduced FOV DWI showed better anatomic structure visualization (2.76 ± 0.79 at b = 0 s/mm(2) and 2.81 ± 0.64 at b = 400 s/mm(2)), lesion conspicuity (3.11 ± 0.99 at b = 0 s/mm(2) and 3.15 ± 0.79 at b = 400 s/mm(2)), IQ score (8.51 ± 2.05 at b = 0 s/mm(2) and 8.79 ± 1.60 at b = 400 s/mm(2)), and higher clinical utility (3.41 ± 0.64), as compared to full FOV DWI (anatomic structure, 2.18 ± 0.59 at b = 0 s/mm(2) and 2.56 ± 0.47 at b = 500 s/mm(2); lesion conspicuity, 2.55 ± 1.07 at b = 0 s/mm(2) and 2.89 ± 0.86 at b = 500 s/mm(2); IQ score, 7.13 ± 1.83 at b = 0 s/mm(2) and 8.17 ± 1.31 at b = 500 s/mm(2); clinical utility, 3.14 ± 0.70) (p < 0.05). Artifacts were significantly improved on reduced FOV DWI (2.65 ± 0.68) at b = 0 s/mm(2) (full FOV DWI, 2.41 ± 0.63) (p < 0.001). On quantitative analysis, there were no significant differences between the 2 DWI sequences in ADCs of various pancreatic lesions and parenchyma (p > 0.05). ADCs of adenocarcinomas (1.061 × 10(-3) mm(2)/s ± 0.133 at reduced FOV and 1.079 × 10(-3) mm(2)/s ± 0.135 at full FOV) and neuroendocrine tumors (0.983 × 10(-3) mm(2)/s ± 0.152 at reduced FOV and 1.004 × 10(-3) mm(2)/s ± 0.153 at full FOV) were significantly lower than those of parenchyma (1.191 × 10(-3) mm(2)/s ± 0.125 at reduced FOV and 1.218 × 10(-3) mm(2)/s ± 0.103 at full FOV) (p < 0.05).

Conclusion: Reduced FOV DWI of the pancreas provides better overall IQ including better anatomic detail, lesion conspicuity and subjective clinical utility.

No MeSH data available.


Related in: MedlinePlus

38-year-old man with neuroendocrine tumor (not shown) in pancreas tail.Images are cropped to focus on pancreas. A. Full field-of-view (FOV) diffusion-weighted imaging (DWI) sequence at b = 0 s/mm2. Margin of pancreas is blurred and duct is not visible. Normal lobulated appearance of pancreas is hardly recognizable. B. Full FOV DWI at b = 500 s/mm2. C. Corresponding apparent diffusion coefficient (ADC) map of full FOV DWI. D. Reduced FOV DWI at b = 0 s/mm2. Note that lobulated appearance of pancreas border and pancreatic duct are more clearly visualized on reduced FOV image. E. Reduced FOV DWI at b = 400 s/mm2. F. Corresponding ADC map of reduced FOV DWI.
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Figure 2: 38-year-old man with neuroendocrine tumor (not shown) in pancreas tail.Images are cropped to focus on pancreas. A. Full field-of-view (FOV) diffusion-weighted imaging (DWI) sequence at b = 0 s/mm2. Margin of pancreas is blurred and duct is not visible. Normal lobulated appearance of pancreas is hardly recognizable. B. Full FOV DWI at b = 500 s/mm2. C. Corresponding apparent diffusion coefficient (ADC) map of full FOV DWI. D. Reduced FOV DWI at b = 0 s/mm2. Note that lobulated appearance of pancreas border and pancreatic duct are more clearly visualized on reduced FOV image. E. Reduced FOV DWI at b = 400 s/mm2. F. Corresponding ADC map of reduced FOV DWI.

Mentions: Reduced FOV DWI showed significantly better scores in anatomic structural visualization (2.76 ± 0.79 at b = 0 s/mm2 and 2.81 ± 0.64 at b = 400 s/mm2) (Fig. 2), lesion conspicuity (3.11 ± 0.99 at b = 0 s/mm2 and 3.15 ± 0.79 at b = 400 s/mm2) and total IQ score (8.51 ± 2.05 at b = 0 s/mm2 and 8.79 ± 1.60 at b = 400 s/mm2), as compared to full FOV DWI (anatomic structure, 2.18 ± 0.59 at b = 0 s/mm2 and 2.56 ± 0.47 at b = 500 s/mm2; lesion conspicuity, 2.55 ± 1.07 at b = 0 s/mm2 and 2.89 ± 0.86 at b = 500 s/mm2; IQ score, 7.13 ± 1.83 at b = 0 s/mm2 and 8.17 ± 1.31 at b = 500 s/mm2) (all p < 0.05). In addition, the subjective clinical utility of reduced FOV DWI (3.41 ± 0.64) was also higher than that of full FOV DWI (3.14 ± 0.70) (p < 0.001). MR artifacts were significantly improved on reduced FOV DWI (2.65 ± 0.68) at b = 0 s/mm2 (full FOV DWI, 2.41 ± 0.63) (p < 0.001), however, no significant difference was noted between reduced FOV (2.83 ± 0.57) and full FOV DWI (2.72 ± 0.45) at b = 400 or 500 s/mm2 (p = 0.061). Detailed data were shown in Table 3.


Reduced Field-of-View Diffusion-Weighted Magnetic Resonance Imaging of the Pancreas: Comparison with Conventional Single-Shot Echo-Planar Imaging.

Kim H, Lee JM, Yoon JH, Jang JY, Kim SW, Ryu JK, Kannengiesser S, Han JK, Choi BI - Korean J Radiol (2015)

38-year-old man with neuroendocrine tumor (not shown) in pancreas tail.Images are cropped to focus on pancreas. A. Full field-of-view (FOV) diffusion-weighted imaging (DWI) sequence at b = 0 s/mm2. Margin of pancreas is blurred and duct is not visible. Normal lobulated appearance of pancreas is hardly recognizable. B. Full FOV DWI at b = 500 s/mm2. C. Corresponding apparent diffusion coefficient (ADC) map of full FOV DWI. D. Reduced FOV DWI at b = 0 s/mm2. Note that lobulated appearance of pancreas border and pancreatic duct are more clearly visualized on reduced FOV image. E. Reduced FOV DWI at b = 400 s/mm2. F. Corresponding ADC map of reduced FOV DWI.
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Figure 2: 38-year-old man with neuroendocrine tumor (not shown) in pancreas tail.Images are cropped to focus on pancreas. A. Full field-of-view (FOV) diffusion-weighted imaging (DWI) sequence at b = 0 s/mm2. Margin of pancreas is blurred and duct is not visible. Normal lobulated appearance of pancreas is hardly recognizable. B. Full FOV DWI at b = 500 s/mm2. C. Corresponding apparent diffusion coefficient (ADC) map of full FOV DWI. D. Reduced FOV DWI at b = 0 s/mm2. Note that lobulated appearance of pancreas border and pancreatic duct are more clearly visualized on reduced FOV image. E. Reduced FOV DWI at b = 400 s/mm2. F. Corresponding ADC map of reduced FOV DWI.
Mentions: Reduced FOV DWI showed significantly better scores in anatomic structural visualization (2.76 ± 0.79 at b = 0 s/mm2 and 2.81 ± 0.64 at b = 400 s/mm2) (Fig. 2), lesion conspicuity (3.11 ± 0.99 at b = 0 s/mm2 and 3.15 ± 0.79 at b = 400 s/mm2) and total IQ score (8.51 ± 2.05 at b = 0 s/mm2 and 8.79 ± 1.60 at b = 400 s/mm2), as compared to full FOV DWI (anatomic structure, 2.18 ± 0.59 at b = 0 s/mm2 and 2.56 ± 0.47 at b = 500 s/mm2; lesion conspicuity, 2.55 ± 1.07 at b = 0 s/mm2 and 2.89 ± 0.86 at b = 500 s/mm2; IQ score, 7.13 ± 1.83 at b = 0 s/mm2 and 8.17 ± 1.31 at b = 500 s/mm2) (all p < 0.05). In addition, the subjective clinical utility of reduced FOV DWI (3.41 ± 0.64) was also higher than that of full FOV DWI (3.14 ± 0.70) (p < 0.001). MR artifacts were significantly improved on reduced FOV DWI (2.65 ± 0.68) at b = 0 s/mm2 (full FOV DWI, 2.41 ± 0.63) (p < 0.001), however, no significant difference was noted between reduced FOV (2.83 ± 0.57) and full FOV DWI (2.72 ± 0.45) at b = 400 or 500 s/mm2 (p = 0.061). Detailed data were shown in Table 3.

Bottom Line: On qualitative analysis, reduced FOV DWI showed better anatomic structure visualization (2.76 ± 0.79 at b = 0 s/mm(2) and 2.81 ± 0.64 at b = 400 s/mm(2)), lesion conspicuity (3.11 ± 0.99 at b = 0 s/mm(2) and 3.15 ± 0.79 at b = 400 s/mm(2)), IQ score (8.51 ± 2.05 at b = 0 s/mm(2) and 8.79 ± 1.60 at b = 400 s/mm(2)), and higher clinical utility (3.41 ± 0.64), as compared to full FOV DWI (anatomic structure, 2.18 ± 0.59 at b = 0 s/mm(2) and 2.56 ± 0.47 at b = 500 s/mm(2); lesion conspicuity, 2.55 ± 1.07 at b = 0 s/mm(2) and 2.89 ± 0.86 at b = 500 s/mm(2); IQ score, 7.13 ± 1.83 at b = 0 s/mm(2) and 8.17 ± 1.31 at b = 500 s/mm(2); clinical utility, 3.14 ± 0.70) (p < 0.05).Artifacts were significantly improved on reduced FOV DWI (2.65 ± 0.68) at b = 0 s/mm(2) (full FOV DWI, 2.41 ± 0.63) (p < 0.001).ADCs of adenocarcinomas (1.061 × 10(-3) mm(2)/s ± 0.133 at reduced FOV and 1.079 × 10(-3) mm(2)/s ± 0.135 at full FOV) and neuroendocrine tumors (0.983 × 10(-3) mm(2)/s ± 0.152 at reduced FOV and 1.004 × 10(-3) mm(2)/s ± 0.153 at full FOV) were significantly lower than those of parenchyma (1.191 × 10(-3) mm(2)/s ± 0.125 at reduced FOV and 1.218 × 10(-3) mm(2)/s ± 0.103 at full FOV) (p < 0.05).

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, Seoul National University Hospital, Seoul 03080, Korea. ; Aerospace Medical Group, Air Force Education and Training Command, Jinju 52634, Korea.

ABSTRACT

Objective: To investigate the image quality (IQ) and apparent diffusion coefficient (ADC) of reduced field-of-view (FOV) di-ffusion-weighted imaging (DWI) of pancreas in comparison with full FOV DWI.

Materials and methods: In this retrospective study, 2 readers independently performed qualitative analysis of full FOV DWI (FOV, 38 × 38 cm; b-value, 0 and 500 s/mm(2)) and reduced FOV DWI (FOV, 28 × 8.5 cm; b-value, 0 and 400 s/mm(2)). Both procedures were conducted with a two-dimensional spatially selective radiofrequency excitation pulse, in 102 patients with benign or malignant pancreatic diseases (mean size, 27.5 ± 14.4 mm). The study parameters included 1) anatomic structure visualization, 2) lesion conspicuity, 3) artifacts, 4) IQ score, and 5) subjective clinical utility for confirming or excluding initially considered differential diagnosis on conventional imaging. Another reader performed quantitative ADC measurements of focal pancreatic lesions and parenchyma. Wilcoxon signed-rank test was used to compare qualitative scores and ADCs between DWI sequences. Mann Whitney U-test was used to compare ADCs between the lesions and parenchyma.

Results: On qualitative analysis, reduced FOV DWI showed better anatomic structure visualization (2.76 ± 0.79 at b = 0 s/mm(2) and 2.81 ± 0.64 at b = 400 s/mm(2)), lesion conspicuity (3.11 ± 0.99 at b = 0 s/mm(2) and 3.15 ± 0.79 at b = 400 s/mm(2)), IQ score (8.51 ± 2.05 at b = 0 s/mm(2) and 8.79 ± 1.60 at b = 400 s/mm(2)), and higher clinical utility (3.41 ± 0.64), as compared to full FOV DWI (anatomic structure, 2.18 ± 0.59 at b = 0 s/mm(2) and 2.56 ± 0.47 at b = 500 s/mm(2); lesion conspicuity, 2.55 ± 1.07 at b = 0 s/mm(2) and 2.89 ± 0.86 at b = 500 s/mm(2); IQ score, 7.13 ± 1.83 at b = 0 s/mm(2) and 8.17 ± 1.31 at b = 500 s/mm(2); clinical utility, 3.14 ± 0.70) (p < 0.05). Artifacts were significantly improved on reduced FOV DWI (2.65 ± 0.68) at b = 0 s/mm(2) (full FOV DWI, 2.41 ± 0.63) (p < 0.001). On quantitative analysis, there were no significant differences between the 2 DWI sequences in ADCs of various pancreatic lesions and parenchyma (p > 0.05). ADCs of adenocarcinomas (1.061 × 10(-3) mm(2)/s ± 0.133 at reduced FOV and 1.079 × 10(-3) mm(2)/s ± 0.135 at full FOV) and neuroendocrine tumors (0.983 × 10(-3) mm(2)/s ± 0.152 at reduced FOV and 1.004 × 10(-3) mm(2)/s ± 0.153 at full FOV) were significantly lower than those of parenchyma (1.191 × 10(-3) mm(2)/s ± 0.125 at reduced FOV and 1.218 × 10(-3) mm(2)/s ± 0.103 at full FOV) (p < 0.05).

Conclusion: Reduced FOV DWI of the pancreas provides better overall IQ including better anatomic detail, lesion conspicuity and subjective clinical utility.

No MeSH data available.


Related in: MedlinePlus