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Advantage of Adding Diffusion Weighted Imaging to Routine MRI Examinations in the Diagnostics of Scrotal Lesions.

Algebally AM, Tantawy HI, Yousef RR, Szmigielski W, Darweesh A - Pol J Radiol (2015)

Bottom Line: The results of MRI and DWI of the group of patients treated surgically were correlated with histopathological findings.There was a significant difference between ADC values of malignant testicular lesions and normal testicular tissues as well as benign testicular lesions (P=0.000).At a cut-off ADC value of ≤0.99, it had a sensitivity of 93.3%, specificity of 90%, positive predictive value of 87.5%, and negative predictive value of 94.7% in the characterization of intratesticular masses.

View Article: PubMed Central - PubMed

Affiliation: Department of Diagnostic Imaging, Zagazig University, Zagazig, Egypt.

ABSTRACT

Background: The purpose of the study is to identify the diagnostic value of adding diffusion weighted images (DWI) to routine MRI examinations of the scrotum.

Material/methods: The study included 100 testes of 50 patients with a unilateral testicular disease. Fifty normal contralateral testes were used as a control group. All patients underwent conventional MRI and DWI examinations of the scrotum. The results of MRI and DWI of the group of patients treated surgically were correlated with histopathological findings. The MRI and DWI results of non-surgical cases were correlated with the results of clinical, laboratory and other imaging studies. Comparison of the ADC value of normal and pathological tissues was carried out followed by a statistical analysis.

Results: There was a significant difference between ADC values of malignant testicular lesions and normal testicular tissues as well as benign testicular lesions (P=0.000). At a cut-off ADC value of ≤0.99, it had a sensitivity of 93.3%, specificity of 90%, positive predictive value of 87.5%, and negative predictive value of 94.7% in the characterization of intratesticular masses.

Conclusions: Inclusion of DWI to routine MRI has a substantial value in improving diagnosis in patients with scrotal lesions and consequently can reduce unnecessary radical surgical procedures in these patients.

No MeSH data available.


Related in: MedlinePlus

Male, 31 years old, with right testicular swelling due to seminoma. (A) T2WI with fat saturation: Hypointense signal (arrow), (B) DWI b800: Restriction, (C) ADC map: Low signal.
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Related In: Results  -  Collection


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f3-poljradiol-80-442: Male, 31 years old, with right testicular swelling due to seminoma. (A) T2WI with fat saturation: Hypointense signal (arrow), (B) DWI b800: Restriction, (C) ADC map: Low signal.

Mentions: The study included 100 testes of 50 patients with a unilateral testicular disease. Fifty normal contralateral testes (50%) were used as a control group. The normal testicular parenchyma appeared hyperintense on both T2-weighted and DW images, and slightly hypointense on the ADC maps. The mean ±s.d. of (ADC value 10−3mm2·s−1) of the normal testis was (1.12±0.67). The other 50 testes (50%) were abnormal with scrotal disorders. The study included 35 intratesticular lesions (70%), of which 15 (43%) were malignant and 20 (57%) benign. Extratesticular lesions were 15 cases, which all (100%) proved to be benign (Table 1). A total of 35 cases had benign-nature lesions of both intra- and extratesticular locations (70%) and 15 cases were histopathologically proved as malignant lesions (30%) all of intratesticular location. The conventional MRI features of 3 cases of tubular ectasia of rete testis and 3 cases of testicular cysts were typical in this series, in the form of the presence of testicular cyst or multicystic lesions involving the mediastinum of the testis, with fluid signal intensity, not enhancing after intravenous contrast material administration [31,32]. Seven cases of epididymo-orchitis were also correctly characterized by conventional MR images. Enlargement and contrast enhancement of the epididymis and the testis, combined with signal hyperintensity on T2-weighted images, were findings proved to correspond with acute inflammation on clinical and sonographic follow-up in this study. This study also included four cases of post-traumatic/post-infective heterogeneity which was seen by ultrasound and MRI, and the latter was aimed to rule out malignancy. The cases showed heterogeneous T2 signal with no mass effect or signs of pathological contrast enhancement. Three cases of pathologically proved testicular granulomas were included in this study, one case showed low signal in T2 and other two cases showed mixed hyperintense signals in T2 images; all three cases showed peripheral delayed enhancement. All benign 20 testicular lesions in this study (100%), were detected without causing significant restricted diffusion, therefore of low signal intensity on DW sequences. The mean ±s.d. of ADC values of benign intratesticular lesions was 1.58±0.63. This study included 15 cases of paratesticular lesions. MR imaging identified normal epididymis at T2-weighted and DW sequences as relatively hypointense, when compared to the normal testicular parenchyma. Three cases of acute epididymitis showed enlargement and post-contrast enhancement of the epididymis combined with heterogeneous low signal intensity. Two cases of chronic granulomatous epididymitis with enlarged heterogeneous epididymis, showed a T2 heterogeneous low signal pattern with delayed heterogeneous enhancement. The study included four cases of adenomatoid tumors of the tunica and epididymis (Figure 1), which presented as an isointense-signal lesion in a T2-weighted image with early post-contrast enhancement. Also two cases of epididymal fibrous tumors showed a hypointense signal in both T1- and T2-weighted images and post- contrast enhancement. Two cases of spermatocele with a typical fluid signal and no post-contrast enhancement were detected (Figure 2). Both extratesticular benign neoplastic and inflammatory lesions showed signal hypointensity and hyperintensity on DW sequences and ADC maps, respectively. The mean ±s.d. of ADC values of normal epididymis was 1.08±0.033. The mean ±s.d. of ADC values of benign paratesticular lesions including both neoplastic and inflammatory ones was 1.17±0.48. The statistical difference between the ADC values of the normal epididymis and those of benign paratesticular lesions was noted (P=0.49), which was insignificant (Table 2). The mean ±s.d. of the ADC value of a benign paratesticular neoplasm was 0.99±1.53 and the mean ±s.d. of the ADC value of paratesticular inflammatory lesions was 1.29±0.59. Statistical difference between the ADC values of the benign neoplastic and inflammatory paratesticular lesions was noted (P=0.25), which was insignificant (Table 3). Two false positive cases for malignancy, based on the DW data alone, with acute post-traumatic epididymal hematoma were detected with restricted diffusion on DW images and very low ADC values. However, conventional MR sequences enabled the correct characterization in those patients. Both conventional and DW images proved accurate in characterizing the benign nature of all (100%) paratesticular lesions in this series. We had 15 malignant cases, all were intratesticular. There were 8 cases of seminoma (53%), (Figure 3) and 7 (47%) non-seminoma cases (Figure 4), (47%). Testicular malignancies were detected on T2-weighted images as either low signal in 9 cases or heterogeneous signal intensity in 6 cases, with areas of hemorrhage in 2 cases and necrosis in 4 cases, all heterogeneously enhancing after intravenous contrast material administration, except for three cases with mainly cystic components that showed peripheral enhancement. Invasion of the testicular tunica by a neoplasm in 5 cases, invasion of the epididymis in 2 cases and extension of the tumor to the spermatic cord in two cases were detected. When assessed by DW imaging, 12 cases (80%) of all testicular malignancies including seminoma (Figure 3) and non-seminoma (Figure 4), were depicted as areas of restricted diffusion, appearing hyperintense when compared to the normal testicular parenchyma and hypointense on the ADC maps, respectively. Three cases (20%) of malignancy with mainly cystic/necrotic components and a thin peripheral soft tissue rim showed no restriction in the cystic parts in DW images, appearing as a hyperintense signal in ADC maps. The mean ±s.d. of ADC values of intratesticular malignancies was 0.79±0.16. Conventional MR had a sensitivity of 100%, specificity of 80%, positive predictive value of 86.5%, negative predictive value of 100% and overall accuracy of 90% in differentiating malignant from benign testicular lesions. The ANOVA analysis between normal testis, benign and malignant intratesticular lesions showed that the mean ADC values were different (F23.0, P 0.00) (Table 4). The least significance difference test showed a difference between the ADC values of the normal testicular parenchyma and testicular malignancies (P=0.000), the ADC values of benign and malignant intratesticular lesions (P=0.000), and between the measurements of the normal testis and benign intratesticular lesions (P=0.004). DW images and ADC map using a cut-off value (≤0.99) had a sensitivity of 93.3%, specificity of 90%, positive predictive value of 87.5%, and negative predictive value of 94.7% in the characterization of intratesticular masses (Table 5). The combined evaluation of both conventional and DW images proved accurate in differentiating malignant from benign intratesticular mass lesions in all (100%) cases in this series.


Advantage of Adding Diffusion Weighted Imaging to Routine MRI Examinations in the Diagnostics of Scrotal Lesions.

Algebally AM, Tantawy HI, Yousef RR, Szmigielski W, Darweesh A - Pol J Radiol (2015)

Male, 31 years old, with right testicular swelling due to seminoma. (A) T2WI with fat saturation: Hypointense signal (arrow), (B) DWI b800: Restriction, (C) ADC map: Low signal.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4588671&req=5

f3-poljradiol-80-442: Male, 31 years old, with right testicular swelling due to seminoma. (A) T2WI with fat saturation: Hypointense signal (arrow), (B) DWI b800: Restriction, (C) ADC map: Low signal.
Mentions: The study included 100 testes of 50 patients with a unilateral testicular disease. Fifty normal contralateral testes (50%) were used as a control group. The normal testicular parenchyma appeared hyperintense on both T2-weighted and DW images, and slightly hypointense on the ADC maps. The mean ±s.d. of (ADC value 10−3mm2·s−1) of the normal testis was (1.12±0.67). The other 50 testes (50%) were abnormal with scrotal disorders. The study included 35 intratesticular lesions (70%), of which 15 (43%) were malignant and 20 (57%) benign. Extratesticular lesions were 15 cases, which all (100%) proved to be benign (Table 1). A total of 35 cases had benign-nature lesions of both intra- and extratesticular locations (70%) and 15 cases were histopathologically proved as malignant lesions (30%) all of intratesticular location. The conventional MRI features of 3 cases of tubular ectasia of rete testis and 3 cases of testicular cysts were typical in this series, in the form of the presence of testicular cyst or multicystic lesions involving the mediastinum of the testis, with fluid signal intensity, not enhancing after intravenous contrast material administration [31,32]. Seven cases of epididymo-orchitis were also correctly characterized by conventional MR images. Enlargement and contrast enhancement of the epididymis and the testis, combined with signal hyperintensity on T2-weighted images, were findings proved to correspond with acute inflammation on clinical and sonographic follow-up in this study. This study also included four cases of post-traumatic/post-infective heterogeneity which was seen by ultrasound and MRI, and the latter was aimed to rule out malignancy. The cases showed heterogeneous T2 signal with no mass effect or signs of pathological contrast enhancement. Three cases of pathologically proved testicular granulomas were included in this study, one case showed low signal in T2 and other two cases showed mixed hyperintense signals in T2 images; all three cases showed peripheral delayed enhancement. All benign 20 testicular lesions in this study (100%), were detected without causing significant restricted diffusion, therefore of low signal intensity on DW sequences. The mean ±s.d. of ADC values of benign intratesticular lesions was 1.58±0.63. This study included 15 cases of paratesticular lesions. MR imaging identified normal epididymis at T2-weighted and DW sequences as relatively hypointense, when compared to the normal testicular parenchyma. Three cases of acute epididymitis showed enlargement and post-contrast enhancement of the epididymis combined with heterogeneous low signal intensity. Two cases of chronic granulomatous epididymitis with enlarged heterogeneous epididymis, showed a T2 heterogeneous low signal pattern with delayed heterogeneous enhancement. The study included four cases of adenomatoid tumors of the tunica and epididymis (Figure 1), which presented as an isointense-signal lesion in a T2-weighted image with early post-contrast enhancement. Also two cases of epididymal fibrous tumors showed a hypointense signal in both T1- and T2-weighted images and post- contrast enhancement. Two cases of spermatocele with a typical fluid signal and no post-contrast enhancement were detected (Figure 2). Both extratesticular benign neoplastic and inflammatory lesions showed signal hypointensity and hyperintensity on DW sequences and ADC maps, respectively. The mean ±s.d. of ADC values of normal epididymis was 1.08±0.033. The mean ±s.d. of ADC values of benign paratesticular lesions including both neoplastic and inflammatory ones was 1.17±0.48. The statistical difference between the ADC values of the normal epididymis and those of benign paratesticular lesions was noted (P=0.49), which was insignificant (Table 2). The mean ±s.d. of the ADC value of a benign paratesticular neoplasm was 0.99±1.53 and the mean ±s.d. of the ADC value of paratesticular inflammatory lesions was 1.29±0.59. Statistical difference between the ADC values of the benign neoplastic and inflammatory paratesticular lesions was noted (P=0.25), which was insignificant (Table 3). Two false positive cases for malignancy, based on the DW data alone, with acute post-traumatic epididymal hematoma were detected with restricted diffusion on DW images and very low ADC values. However, conventional MR sequences enabled the correct characterization in those patients. Both conventional and DW images proved accurate in characterizing the benign nature of all (100%) paratesticular lesions in this series. We had 15 malignant cases, all were intratesticular. There were 8 cases of seminoma (53%), (Figure 3) and 7 (47%) non-seminoma cases (Figure 4), (47%). Testicular malignancies were detected on T2-weighted images as either low signal in 9 cases or heterogeneous signal intensity in 6 cases, with areas of hemorrhage in 2 cases and necrosis in 4 cases, all heterogeneously enhancing after intravenous contrast material administration, except for three cases with mainly cystic components that showed peripheral enhancement. Invasion of the testicular tunica by a neoplasm in 5 cases, invasion of the epididymis in 2 cases and extension of the tumor to the spermatic cord in two cases were detected. When assessed by DW imaging, 12 cases (80%) of all testicular malignancies including seminoma (Figure 3) and non-seminoma (Figure 4), were depicted as areas of restricted diffusion, appearing hyperintense when compared to the normal testicular parenchyma and hypointense on the ADC maps, respectively. Three cases (20%) of malignancy with mainly cystic/necrotic components and a thin peripheral soft tissue rim showed no restriction in the cystic parts in DW images, appearing as a hyperintense signal in ADC maps. The mean ±s.d. of ADC values of intratesticular malignancies was 0.79±0.16. Conventional MR had a sensitivity of 100%, specificity of 80%, positive predictive value of 86.5%, negative predictive value of 100% and overall accuracy of 90% in differentiating malignant from benign testicular lesions. The ANOVA analysis between normal testis, benign and malignant intratesticular lesions showed that the mean ADC values were different (F23.0, P 0.00) (Table 4). The least significance difference test showed a difference between the ADC values of the normal testicular parenchyma and testicular malignancies (P=0.000), the ADC values of benign and malignant intratesticular lesions (P=0.000), and between the measurements of the normal testis and benign intratesticular lesions (P=0.004). DW images and ADC map using a cut-off value (≤0.99) had a sensitivity of 93.3%, specificity of 90%, positive predictive value of 87.5%, and negative predictive value of 94.7% in the characterization of intratesticular masses (Table 5). The combined evaluation of both conventional and DW images proved accurate in differentiating malignant from benign intratesticular mass lesions in all (100%) cases in this series.

Bottom Line: The results of MRI and DWI of the group of patients treated surgically were correlated with histopathological findings.There was a significant difference between ADC values of malignant testicular lesions and normal testicular tissues as well as benign testicular lesions (P=0.000).At a cut-off ADC value of ≤0.99, it had a sensitivity of 93.3%, specificity of 90%, positive predictive value of 87.5%, and negative predictive value of 94.7% in the characterization of intratesticular masses.

View Article: PubMed Central - PubMed

Affiliation: Department of Diagnostic Imaging, Zagazig University, Zagazig, Egypt.

ABSTRACT

Background: The purpose of the study is to identify the diagnostic value of adding diffusion weighted images (DWI) to routine MRI examinations of the scrotum.

Material/methods: The study included 100 testes of 50 patients with a unilateral testicular disease. Fifty normal contralateral testes were used as a control group. All patients underwent conventional MRI and DWI examinations of the scrotum. The results of MRI and DWI of the group of patients treated surgically were correlated with histopathological findings. The MRI and DWI results of non-surgical cases were correlated with the results of clinical, laboratory and other imaging studies. Comparison of the ADC value of normal and pathological tissues was carried out followed by a statistical analysis.

Results: There was a significant difference between ADC values of malignant testicular lesions and normal testicular tissues as well as benign testicular lesions (P=0.000). At a cut-off ADC value of ≤0.99, it had a sensitivity of 93.3%, specificity of 90%, positive predictive value of 87.5%, and negative predictive value of 94.7% in the characterization of intratesticular masses.

Conclusions: Inclusion of DWI to routine MRI has a substantial value in improving diagnosis in patients with scrotal lesions and consequently can reduce unnecessary radical surgical procedures in these patients.

No MeSH data available.


Related in: MedlinePlus