-
[show abstract]
[hide abstract]
ABSTRACT: To evaluate the usefulness of diffusion-weighted imaging (DWI) for differentiating between desmoid tumors and malignant soft tissue tumors.
Conventional MRI and DWI were performed for 8 desmoid tumors and 74 malignant soft tissue tumors. DWI was obtained with a single-shot echo-planar imaging sequence using a 1.5 Tesla (T) MR imager. DW images were acquired with motion-probing gradient pulses applied along three directions (x, y, and z axes) with three b-factors (0, 500, and 1000 s/mm²). Two observers blinded to clinical information measured three regions of interest within the solid tumor and selected a minimum apparent diffusion coefficient () in each lesion. The mean ADC of desmoid tumors was calculated and compared with that of malignant soft tissue tumors using the Mann-Whitney U test.
The mean ADC of desmoid tumors and malignant soft tissue tumors was 1.36 ± 0.48 × 10⁻³ mm² /s and 0.88 ± 0.20 × 10⁻³ mm² /s (mean ± SD), respectively. The mean ADC of the desmoid tumors was significantly higher than that of malignant soft tissue tumors (P < 0.01).
DWI is considered to be useful for differentiating between desmoid tumors and malignant soft tissue tumors. In the future, further investigation in a large series is necessary.
Journal of Magnetic Resonance Imaging 01/2011; 33(1):189-93. · 2.70 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The objective of this study was to evaluate whether the average apparent diffusion coefficient (ADC) or the minimum ADC is more useful for evaluating the chemotherapeutic response of osteosarcoma.
Twenty-two patients with osteosarcoma were examined in this study. Diffusion-weighted (DW) and magnetic resonance (MR) images were performed for all patients before and after chemotherapy. The pre- and post-chemotherapy values were obtained both in the average and minimum ADC. The pre-chemotherapy values of the average ADC and minimum ADC respectively were compared with the post-chemotherapy values. In addition, the ADC ratios ([ADC(post) - ADC(pre)] / ADC(pre)) were calculated using the average ADC and the minimum ADC. Twenty-two patients with osteosarcomas were divided into two groups, those with a good response to chemotherapy (> or = 90% tumor necrosis, n = 7) and those with a poor response (< 90% tumor necrosis, n = 15). The average ADC ratio and the minimum ADC ratio of the two groups were compared.
With both the average ADC and the minimum ADC, post-chemotherapy values were significantly higher than pre-chemotherapy values (P < 0.05). The patients with a good response had a significantly higher minimum ADC ratio than those with a poor response (1.01 + or - 0.22 and 0.55 + or - 0.29 respectively, P < 0.05). However, with regard to the average ADC ratio, no significant difference was observed between the two groups (0.66 + or - 0.18 and 0.46 + or - 0.31 respectively, P = 0.19).
The minimum ADC is useful for evaluating the chemotherapeutic response of osteosarcoma.
Skeletal Radiology 11/2009; 39(2):141-6. · 1.54 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To detect differences in magnetic resonance imaging (MRI) between chondroblastic osteosarcoma and the other types of osteosarcomas or chondrosarcomas using gadolinium-enhanced versus diffusion-weighted sequences.
Contrast-enhanced MRI and diffusion-weighted imaging (DWI) were performed in five chondroblastic osteosarcoma (CO) cases, 17 other types of osteosarcomas (OS), and 18 chondrosarcomas (CS). DWI was obtained with a single-shot echo-planar imaging (EPI) sequence using a 1.5 T MR imager. The apparent diffusion coefficients (ADCs) of the minimum and maximum values were also obtained. The contrast-enhancement pattern was evaluated and minimum-maximum ADC value of CO was compared with other types of OS and CS.
Both CO and CS showed a similar enhancement pattern; both showed septonodular and peripheral rim enhancement. The minimum ADC value of CO (1.24 +/- 0.10 x 10(-3)mm(2)/sec) was significantly higher than that of other types of OS (0.84 +/- 0.15 x 10(-3)mm(2)/sec) and was significantly lower than that of CS (1.64 +/- 0.20 x 10(-3)mm(2)/sec). In addition, the maximum ADC value of CO (2.28 +/- 0.20 x 10(-3)mm(2)/sec) was significantly higher than that of other types of OS (1.33 +/- 0.26 x 10(-3)mm(2)/sec).
DWI appears to be more useful for differentiating between chondroblastic osteosarcoma and chondrosarcoma or other types of osteosarcoma than Gd-enhanced MRI.
Journal of Magnetic Resonance Imaging 05/2009; 29(4):895-900. · 2.70 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To evaluate the potential of diffusion-weighted imaging (DWI) in distinguishing chronic expanding hematomas (CEHs) from malignant soft tissue tumors.
We performed conventional MRI and DWI of six CEHs and 31 malignant soft tissue tumors from 37 patients seen between May 2000 and November 2006. DWI was obtained with a single-shot echo-planar imaging (EPI) sequence using a 1.5T MR imager. The mean apparent diffusion coefficient (ADC) value was also calculated. We evaluated MRI findings of CEHs and compared ADC value of CEHs with malignant soft tissue tumors.
On conventional MRI, two of six CEHs were difficult to differentiate from malignant soft tissue tumors based on imaging findings. The mean ADC value of CEHs and malignant soft tissue tumors was 1.55+/-0.121x10(-3) mm2/sec and 0.92+/-0.139x10(-3) mm2/sec (mean+/-SD), respectively. The mean ADC value of CEHs was significantly higher than that of malignant soft tissue tumors (P<0.01). There was no overlap in the minimum ADC values among CEHs and malignant soft tissue tumors.
DWI is useful for differentiating between CEHs and malignant soft tissue tumors.
Journal of Magnetic Resonance Imaging 11/2008; 28(5):1195-200. · 2.70 Impact Factor
