Objective: To elucidate the magnetic resonance imaging (MRI) characteristics for distinguishing solitary fibrous tumors (SFTs) from desmoid tumors (DTs). Materials and Methods: A retrospective study of 66 consecutive patients with histopathologically proven SFT (n = 34; 13 males and 21 females; mean age, 52.0 ± 17.1 years) or DT (n = 32; 11 males and 21 females; mean age, 39.0 ± 21.3 years) was conducted. The two groups were quantitatively compared in terms of the size, signal intensity ratio (SIR), and apparent diffusion coefficient value. For qualitative analysis, the tumor location, boundary, shape, internal uniformity, predominant signal intensity, T1-weighted images (T1WI) characteristics (hyperintense area), T2-weighted images (T2WI) characteristics (hypointense area, marked hyperintense area, flow void, band sign, and yin-yang sign), and contrast-enhanced T1WI characteristics (unenhanced area and degree of enhancement) were compared between the two groups. Multiple stepwise logistic regression analyses were conducted to distinguish between the SFT and DT. Results: T1 (P = 0.010) and T2 (P = 0.026) SIRs were higher in SFTs than in DTs. Hyperintense areas on T1WI (P < 0.001), marked hyperintense areas on T2WI (P = 0.025), and flow void (P = 0.025) were more frequently noted in SFTs. On T1WI, the solid component predominantly revealed hyperintensity in SFTs and isointensity in DTs (P < 0.001). Indistinct tumor boundary (P < 0.001), hypointense area on T2WI (P < 0.001), and band sign (P < 0.001) were more frequently observed in DTs. Multiple stepwise logistic regression analysis revealed that the hyperintense area on T1WI (odds ratio favoring SFT, 12.80, P = 0.002) and band sign (odds ratio favoring DT, 0.03; P < 0.001) were independent predictors. Conclusion MRI characteristics can help distinguish SFT from DT. The presence of a hyperintense area relative to the skeletal muscle on T1WI in SFTs and the band sign on T2WI in DTs are important MRI features.

Objective: To elucidate the magnetic resonance imaging (MRI) characteristics for distinguishing solitary fibrous tumors (SFTs) from desmoid tumors (DTs). Materials and Methods: A retrospective study of 66 consecutive patients with histopathologically proven SFT (n = 34; 13 males and 21 females; mean age, 52.0 ± 17.1 years) or DT (n = 32; 11 males and 21 females; mean age, 39.0 ± 21.3 years) was conducted. The two groups were quantitatively compared in terms of the size, signal intensity ratio (SIR), and apparent diffusion coefficient value. For qualitative analysis, the tumor location, boundary, shape, internal uniformity, predominant signal intensity, T1-weighted images (T1WI) characteristics (hyperintense area), T2-weighted images (T2WI) characteristics (hypointense area, marked hyperintense area, flow void, band sign, and yin-yang sign), and contrast-enhanced T1WI characteristics (unenhanced area and degree of enhancement) were compared between the two groups. Multiple stepwise logistic regression analyses were conducted to distinguish between the SFT and DT. Results: T1 (P = 0.010) and T2 (P = 0.026) SIRs were higher in SFTs than in DTs. Hyperintense areas on T1WI (P < 0.001), marked hyperintense areas on T2WI (P = 0.025), and flow void (P = 0.025) were more frequently noted in SFTs. On T1WI, the solid component predominantly revealed hyperintensity in SFTs and isointensity in DTs (P < 0.001). Indistinct tumor boundary (P < 0.001), hypointense area on T2WI (P < 0.001), and band sign (P < 0.001) were more frequently observed in DTs. Multiple stepwise logistic regression analysis revealed that the hyperintense area on T1WI (odds ratio favoring SFT, 12.80, P = 0.002) and band sign (odds ratio favoring DT, 0.03; P < 0.001) were independent predictors. Conclusion MRI characteristics can help distinguish SFT from DT. The presence of a hyperintense area relative to the skeletal muscle on T1WI in SFTs and the band sign on T2WI in DTs are important MRI features.

Objective: To elucidate the magnetic resonance imaging (MRI) characteristics for distinguishing solitary fibrous tumors (SFTs) from desmoid tumors (DTs). Materials and Methods: A retrospective study of 66 consecutive patients with histopathologically proven SFT (n = 34; 13 males and 21 females; mean age, 52.0 ± 17.1 years) or DT (n = 32; 11 males and 21 females; mean age, 39.0 ± 21.3 years) was conducted. The two groups were quantitatively compared in terms of the size, signal intensity ratio (SIR), and apparent diffusion coefficient value. For qualitative analysis, the tumor location, boundary, shape, internal uniformity, predominant signal intensity, T1-weighted images (T1WI) characteristics (hyperintense area), T2-weighted images (T2WI) characteristics (hypointense area, marked hyperintense area, flow void, band sign, and yin-yang sign), and contrast-enhanced T1WI characteristics (unenhanced area and degree of enhancement) were compared between the two groups. Multiple stepwise logistic regression analyses were conducted to distinguish between the SFT and DT. Results: T1 (P = 0.010) and T2 (P = 0.026) SIRs were higher in SFTs than in DTs. Hyperintense areas on T1WI (P < 0.001), marked hyperintense areas on T2WI (P = 0.025), and flow void (P = 0.025) were more frequently noted in SFTs. On T1WI, the solid component predominantly revealed hyperintensity in SFTs and isointensity in DTs (P < 0.001). Indistinct tumor boundary (P < 0.001), hypointense area on T2WI (P < 0.001), and band sign (P < 0.001) were more frequently observed in DTs. Multiple stepwise logistic regression analysis revealed that the hyperintense area on T1WI (odds ratio favoring SFT, 12.80, P = 0.002) and band sign (odds ratio favoring DT, 0.03; P < 0.001) were independent predictors. Conclusion MRI characteristics can help distinguish SFT from DT. The presence of a hyperintense area relative to the skeletal muscle on T1WI in SFTs and the band sign on T2WI in DTs are important MRI features.

Objective: To elucidate the magnetic resonance imaging (MRI) characteristics for distinguishing solitary fibrous tumors (SFTs) from desmoid tumors (DTs). Materials and Methods: A retrospective study of 66 consecutive patients with histopathologically proven SFT (n = 34; 13 males and 21 females; mean age, 52.0 ± 17.1 years) or DT (n = 32; 11 males and 21 females; mean age, 39.0 ± 21.3 years) was conducted. The two groups were quantitatively compared in terms of the size, signal intensity ratio (SIR), and apparent diffusion coefficient value. For qualitative analysis, the tumor location, boundary, shape, internal uniformity, predominant signal intensity, T1-weighted images (T1WI) characteristics (hyperintense area), T2-weighted images (T2WI) characteristics (hypointense area, marked hyperintense area, flow void, band sign, and yin-yang sign), and contrast-enhanced T1WI characteristics (unenhanced area and degree of enhancement) were compared between the two groups. Multiple stepwise logistic regression analyses were conducted to distinguish between the SFT and DT. Results: T1 (P = 0.010) and T2 (P = 0.026) SIRs were higher in SFTs than in DTs. Hyperintense areas on T1WI (P < 0.001), marked hyperintense areas on T2WI (P = 0.025), and flow void (P = 0.025) were more frequently noted in SFTs. On T1WI, the solid component predominantly revealed hyperintensity in SFTs and isointensity in DTs (P < 0.001). Indistinct tumor boundary (P < 0.001), hypointense area on T2WI (P < 0.001), and band sign (P < 0.001) were more frequently observed in DTs. Multiple stepwise logistic regression analysis revealed that the hyperintense area on T1WI (odds ratio favoring SFT, 12.80, P = 0.002) and band sign (odds ratio favoring DT, 0.03; P < 0.001) were independent predictors. Conclusion MRI characteristics can help distinguish SFT from DT. The presence of a hyperintense area relative to the skeletal muscle on T1WI in SFTs and the band sign on T2WI in DTs are important MRI features.

Objective: To elucidate the magnetic resonance imaging (MRI) characteristics for distinguishing solitary fibrous tumors (SFTs) from desmoid tumors (DTs). Materials and Methods: A retrospective study of 66 consecutive patients with histopathologically proven SFT (n = 34; 13 males and 21 females; mean age, 52.0 ± 17.1 years) or DT (n = 32; 11 males and 21 females; mean age, 39.0 ± 21.3 years) was conducted. The two groups were quantitatively compared in terms of the size, signal intensity ratio (SIR), and apparent diffusion coefficient value. For qualitative analysis, the tumor location, boundary, shape, internal uniformity, predominant signal intensity, T1-weighted images (T1WI) characteristics (hyperintense area), T2-weighted images (T2WI) characteristics (hypointense area, marked hyperintense area, flow void, band sign, and yin-yang sign), and contrast-enhanced T1WI characteristics (unenhanced area and degree of enhancement) were compared between the two groups. Multiple stepwise logistic regression analyses were conducted to distinguish between the SFT and DT. Results: T1 (P = 0.010) and T2 (P = 0.026) SIRs were higher in SFTs than in DTs. Hyperintense areas on T1WI (P < 0.001), marked hyperintense areas on T2WI (P = 0.025), and flow void (P = 0.025) were more frequently noted in SFTs. On T1WI, the solid component predominantly revealed hyperintensity in SFTs and isointensity in DTs (P < 0.001). Indistinct tumor boundary (P < 0.001), hypointense area on T2WI (P < 0.001), and band sign (P < 0.001) were more frequently observed in DTs. Multiple stepwise logistic regression analysis revealed that the hyperintense area on T1WI (odds ratio favoring SFT, 12.80, P = 0.002) and band sign (odds ratio favoring DT, 0.03; P < 0.001) were independent predictors. Conclusion MRI characteristics can help distinguish SFT from DT. The presence of a hyperintense area relative to the skeletal muscle on T1WI in SFTs and the band sign on T2WI in DTs are important MRI features.

OBJECTIVE: To evaluate the multiphase contrast-enhanced magnetic resonance (MR) imaging features of Bacillus Calmette-Guerin (BCG)-induced granulomatous prostatitis (GP). MATERIALS AND METHODS: Magnetic resonance images obtained from five patients with histopathologically proven BCG-induced GP were retrospectively analyzed for tumor location, size, signal intensity on T2-weighted images (T2WI) and diffusion-weighted images (DWI), apparent diffusion coefficient (ADC) value, and appearance on gadolinium-enhanced multiphase images. MR imaging findings were compared with histopathological findings. RESULTS: Bacillus Calmette-Guerin-induced GP (size range, 9-40 mm; mean, 21.2 mm) were identified in the peripheral zone in all patients. The T2WI showed lower signal intensity compared with the normal peripheral zone. The DWIs demonstrated high signal intensity and low ADC values (range, 0.44-0.68 x 10(-3) mm2/sec; mean, 0.56 x 10(-3) mm2/sec), which corresponded to GP. Gadolinium-enhanced multiphase MR imaging performed in five patients showed early and prolonged ring enhancement in all cases of GP. Granulomatous tissues with central caseation necrosis were identified histologically, which corresponded to ring enhancement and a central low intensity area on gadolinium-enhanced MR imaging. The findings on T2WI, DWI, and gadolinium-enhanced images became gradually obscured with time. CONCLUSION: Bacillus Calmette-Guerin-induced GP demonstrates early and prolonged ring enhancement on gadolinium-enhanced MR imaging which might be a key finding to differentiate it from prostate cancer.
Aged ; Gadolinium/*diagnostic use ; Humans ; Image Enhancement ; Immunotherapy/*adverse effects ; Magnetic Resonance Imaging/*methods ; Magnetic Resonance Spectroscopy ; Male ; Middle Aged ; Mycobacterium bovis/*pathogenicity ; Prostate-Specific Antigen/blood ; Prostatic Neoplasms/diagnosis ; Prostatitis/*diagnosis ; Retrospective Studies ; Urinary Bladder Neoplasms/drug therapy

Objective: To assess the noncontrast two-dimensional single-shot balanced turbo-field-echo magnetic resonance angiography (b-TFE MRA) features of the abdominal aortic aneurysm (AAA) status following endovascular aneurysm repair (EVAR) and evaluate to detect endoleaks (ELs). Materials and Methods: We examined four aortic stent-grafts in a phantom study to assess the degree of metallic artifacts. We enrolled 46 EVAR-treated patients with AAA and/or common iliac artery aneurysm who underwent both computed tomography angiography (CTA) and b-TFE MRA after EVAR. Vascular measurements on CTA and b-TFE MRA were compared, and signal intensity ratios (SIRs) of the aneurysmal sac were correlated with the size changes in the AAA after EVAR (AAA prognoses). Furthermore, we examined six feasible b-TFE MRA features for the assessment of ELs. Results: There were robust intermodality (r = 0.92–0.99) correlations and interobserver (intraclass correlation coefficient = 0.97–0.99) agreement. No significant differences were noted between SIRs and aneurysm prognoses. Moreover, “mottled high-intensity” and “creeping high-intensity with the low-band rim” were recognized as significant imaging findings suspicious for the presence of ELs (p < 0.001), whereas “no signal black spot” and “layered high-intensity area” were determined as significant for the absence of ELs (p < 0.03). Based on the two positive features, sensitivity, specificity, and accuracy for the detection of ELs were 77.3%, 91.7%, and 84.8%, respectively. Furthermore, the k values (0.40–0.88) displayed moderate-toalmost perfect agreement. Conclusion Noncontrast MRA could be a promising imaging modality for ascertaining patient follow-up after EVAR.

Objective: To assess the noncontrast two-dimensional single-shot balanced turbo-field-echo magnetic resonance angiography (b-TFE MRA) features of the abdominal aortic aneurysm (AAA) status following endovascular aneurysm repair (EVAR) and evaluate to detect endoleaks (ELs). Materials and Methods: We examined four aortic stent-grafts in a phantom study to assess the degree of metallic artifacts. We enrolled 46 EVAR-treated patients with AAA and/or common iliac artery aneurysm who underwent both computed tomography angiography (CTA) and b-TFE MRA after EVAR. Vascular measurements on CTA and b-TFE MRA were compared, and signal intensity ratios (SIRs) of the aneurysmal sac were correlated with the size changes in the AAA after EVAR (AAA prognoses). Furthermore, we examined six feasible b-TFE MRA features for the assessment of ELs. Results: There were robust intermodality (r = 0.92–0.99) correlations and interobserver (intraclass correlation coefficient = 0.97–0.99) agreement. No significant differences were noted between SIRs and aneurysm prognoses. Moreover, “mottled high-intensity” and “creeping high-intensity with the low-band rim” were recognized as significant imaging findings suspicious for the presence of ELs (p < 0.001), whereas “no signal black spot” and “layered high-intensity area” were determined as significant for the absence of ELs (p < 0.03). Based on the two positive features, sensitivity, specificity, and accuracy for the detection of ELs were 77.3%, 91.7%, and 84.8%, respectively. Furthermore, the k values (0.40–0.88) displayed moderate-toalmost perfect agreement. Conclusion Noncontrast MRA could be a promising imaging modality for ascertaining patient follow-up after EVAR.