Jeong Yeon Cho

Segmental Enhancement Inversion at Biphasic Multidetector CT: Characteristic Finding of Small Renal Oncocytoma

PURPOSE To retrospectively determine the usefulness of segmental enhancement inversion during the corticomedullary phase (CMP) and early excretory phase (EEP) of biphasic multidetector computed tomography (CT) in differentiating small renal oncocytoma from renal cell carcinoma (RCC). MATERIALS AND METHODS This retrospective study was institutional review board approved; informed consent was waived. Between January 2004 and December 2006, 98 patients with pathologically confirmed renal masses smaller than 4 cm (10 renal oncocytomas and 88 RCCs) were included in this study. Segmental enhancement inversion was defined as follows: In a mass with two segments showing different degrees of enhancement during CMP, the relatively highly enhanced segment became less enhanced during EEP, whereas the less-enhanced segment during CMP became highly enhanced during EEP. Two experienced radiologists retrospectively assessed the presence of segmental inversion in all masses and measured attenuation with consensus. The Fisher exact test was used to determine the significance of segmental enhancement inversion in differentiating small renal oncocytoma from RCC. RESULTS Eight of 10 renal oncocytomas and only one of 88 RCCs showed segmental inversion during CMP and EEP, which significantly differentiated small renal oncocytomas and RCCs (P < .0001). For differentiating oncocytoma from RCC, segmental inversion was found to have a sensitivity of 80% (eight of 10), a specificity of 99% (87 of 88), a positive predictive value of 89% (eight of nine), and a negative predictive value of 98% (87 of 89). The mean values of the attenuation differences shown by two segments during CMP and EEP were 62.75 HU +/- 36.96 (standard deviation) and -36.88 HU +/- 20.02, respectively. CONCLUSION Segmental enhancement inversion during CMP and EEP was found to be a characteristic enhancement pattern of small renal oncocytoma at biphasic multidetector CT and it may help in differentiating small oncocytoma from RCC. SUPPLEMENTAL MATERIAL http://radiology.rsnajnls.org/cgi/content/full/2522081180/DC1.

Diffuse prostatic lesions: role of color Doppler and power Doppler ultrasonography.

The purpose of this study was to assess the role of color Doppler ultrasonography and power Doppler ultrasonography in the identification of diffuse prostatic lesions. Forty male patients underwent gray scale transrectal ultrasonography, color and power Doppler sonography, and transrectal ultrasonographically guided biopsy. Transrectal ultrasonographically guided biopsy revealed cancer in 23 patients and benign lesions in 17 patients. Among the prostatic cancers 82.6% (19 of 23) showed increased flow signals, whereas 23.5% (four of 17) of benign lesions showed increased flow signals on color or power Doppler ultrasonography. If we consider increased flow signal on color or power Doppler sonography as a sign of a prostate cancer in diffuse prostatic lesions, these modalities have a sensitivity of 82.6%, specificity of 76.5%, and positive predictive value of 82.6%. On the basis of our study, we may conclude that color and power Doppler ultrasonography are useful in the identification of diffuse prostatic lesions.

Histogram analysis of apparent diffusion coefficient map of diffusion-weighted MRI in endometrial cancer: a preliminary correlation study with histological grade.

Background Until now, several investigators have explored the value of diffusion-weighted magnetic resonance imaging (DWI) for the preoperative tumor grading of endometrial cancer. However, the diagnostic value of DWI with quantitative analysis of apparent diffusion coefficient (ADC) has been controversial. Purpose To explore the role of histogram analysis of ADC maps based on entire tumor volume in determining the grade of endometrial cancer. Material and Methods This study was IRB-approved with waiver of informed consent. Thirty-three patients with endometrial cancer underwent DWI (b = 0, 600, 1000 s/mm2), and corresponding ADC maps were acquired. Regions of interest (ROIs) were drawn on all slices of the ADC map in which the tumor was visualized including areas of necrosis to derive volume-based histographic ADC data. Histogram parameters (5th–95th percentiles, mean, standard deviation, skewness, kurtosis) were correlated with histological grade using one-way ANOVA with Tukey-Kramer test for post hoc comparisons, and were compared between high (grade 3) and low (grades 1/2) grade using Student t-test. ROC curve analysis was performed to determine the optimum threshold value for each parameter, and their corresponding sensitivity and specificity. Results The standard deviation, quartile, 75th, 90th, and 95th percentiles of ADC showed significant differences between grades (P ≤ 0.03 for all) and between high and low grades (P ≤ 0.024 for all). There were no significant correlations between tumor grade and other parameters. ROC curve analysis yielded sensitivities and specificities of 75% and 96%, 62.5% and 92%, 100% and 52%, 100% and 72%, and 100% and 88%, using standard deviation, quartile, 75th, 90th, and 95th percentiles for determining high grade with corresponding areas under the curve (AUCs) of 0.787, 0.792, 0.765, 0.880, and 0.925, respectively. Conclusion Histogram analysis of ADC maps based on entire tumor volume can be useful for predicting the histological grade of endometrial cancer. The 90th and 95th percentiles of ADC were the most promising parameters for differentiating high from low grade.

Correlation between prostatic urethral angle and bladder outlet obstruction index in patients with lower urinary tract symptoms.

OBJECTIVES To evaluate the association of prostatic urethral angle (PUA) with bladder outlet obstruction (BOO) index in men with lower urinary tract symptoms (LUTS) suggestive of benign prostatic hyperplasia (BPH). METHODS A retrospective analysis was made of 260 men with LUTS and/or BPH aged>50 years (median: 65.9, range: 50-87). Patients underwent an evaluation including the International Prostatic Symptom Score, serum prostate-specific antigen levels, transrectal ultrasonography, frequency-volume chart, uroflowmetry, and measurement of postvoid residual, and multichannel video urodynamic study with a pressure-flow study. RESULTS Patients with higher PUA (PUA>or=35 degrees) had higher prostate-specific antigen levels (P=.043), larger prostate volume (P<.001), higher maximal urethral closure pressure (P=.004), higher detrusor pressure at maximum flow rate (P=.008), and higher BOO index (P=.032), in comparison with those who had lower PUA (PUA<35 degrees). There was no significant difference of PUA values according to the degree of intravesical prostatic protrusion. When we compared BOO index according to PUA, patients with higher PUA had higher BOO index than those with lower PUA (30.6+/-1.8 vs 23.6+/-1.8, P=.006). The area under the curve of PUA was significant for BOO (area, 63.0%; 95% confidence interval, 55.1%-70.9%; P=.002). CONCLUSIONS PUA may be one method to asses the presence of BOO in men with LUTS and/or BPH. Our findings suggest that PUA may help in the treatment of individuals by better predicting their likely classification from a pressure-flow study.

Diagnostic Performance of Prostate Imaging Reporting and Data System Version 2 for Detection of Prostate Cancer: A Systematic Review and Diagnostic Meta-analysis

CONTEXT In 2015, the updated Prostate Imaging Reporting and Data System version 2 (PI-RADSv2) for the detection of prostate cancer (PCa) was established. Since then, several studies assessing the value of PI-RADSv2 have been published. OBJECTIVE To review the diagnostic performance of PI-RADSv2 for the detection of PCa. EVIDENCE ACQUISITION MEDLINE and EMBASE databases were searched up to December 7, 2016. We included diagnostic accuracy studies that used PI-RADSv2 for PCa detection, using prostatectomy or biopsy as the reference standard. The methodological quality was assessed by two independent reviewers using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. Sensitivity and specificity of all studies were calculated. Results were pooled and plotted in a hierarchical summary receiver operating characteristic plot with further exploration using meta-regression and multiple subgroup analyses. Head-to-head comparison between PI-RADSv1 and PI-RADSv2 was performed for available studies. EVIDENCE SYNTHESIS Twenty-one studies (3857 patients) were included. The pooled sensitivity was 0.89 (95% confidence interval [CI] 0.86-0.92) with specificity of 0.73 (95% CI 0.60-0.83) for PCa detection. Proportion of patients with PCa, magnetic field strength, and reference standard were significant factors affecting heterogeneity (p<0.01). Multiple subgroup analyses showed consistent results. In six studies performing head-to-head comparison, PI-RADSv2 demonstrated higher pooled sensitivity of 0.95 (95% CI 0.85-0.98) compared with 0.88 (95% CI 0.80-0.93) for PI-RADSv1 (p=0.04). However, the pooled specificity was not significantly different (0.73 [95% CI 0.47-0.89] vs 0.75 [95% CI 0.36-0.94], respectively; p=0.90). CONCLUSIONS PI-RADSv2 shows good performance for the detection of PCa. PI-RADSv2 has higher pooled sensitivity than PI-RADSv1 without significantly different specificity. PATIENT SUMMARY We reviewed all previous studies using Prostate Imaging Reporting and Data System version 2 (PI-RADSv2) for prostate cancer detection. We found that the updated PI-RADSv2 shows significant improvement compared with the original PI-RADSv1.

Diagnostic value of computed tomographic findings of nutcracker syndrome: Correlation with renal venography and renocaval pressure gradients

PURPOSE To evaluate the diagnostic values of CT findings of nutcracker syndrome (NCS). METHODS AND MATERIALS Twenty seven subjects that underwent CT and renal venography, were divided into three groups based on the venographic renocaval pressure gradient (PG) and collateral veins of the left renal vein (LRV): non-compensated NCS patients with PG≥3 mm Hg (group 1, n=12), partially compensated NCS patients with borderline PG (1<3 mm Hg) and collateral veins (group 2, n=6), and control group with low PG (0-1 mm Hg) without collateral veins (group 3, n=9). The CT findings were analyzed with regard to abrupt narrowing of the LRV with an acute angle (beak sign), aortomesenteric angle between the superior mesenteric artery and aorta on sagittal images, and LRV diameter ratio (hilar-aortomesenteric). RESULTS Beak sign of the LRV was found in 91.7% (11/12) of group 1, 50% (3/6) of group 2, and in 11.1% (1/9) of group 3 with the significant difference between groups 1 and 3 (P<.05, χ2 test). Mean values of all quantitative CT parameters differed significantly only between groups 1 and 3 (P<.05, one-way ANOVA test). For differentiating the non-compensated NCS from the control group, the beak sign showed 91.7% sensitivity and 88.9% specificity. Of the various CT parameters, the beak sign and LRV diameter ratio of ≥4.9 showed the greatest diagnostic accuracy (AUC 0.903, ROC analysis). CONCLUSION Beak sign of the LRV and CT findings can be useful in diagnosing the non-compensated NCS.

Role of magnetic resonance imaging and positron emission tomography/computed tomography in preoperative lymph node detection of uterine cervical cancer

OBJECTIVE The aim of this study was to compare magnetic resonance imaging (MRI) with positron emission tomography/computed tomography (PET/CT) in the preoperative detection of lymph node metastases in patients with uterine cervical cancer. STUDY DESIGN This retrospective study reviewed patients with cervical cancer who had undergone both preoperative MRI and PET/CT before radical surgery, including lymphadenectomy between 2004-2008. RESULTS Eighty-three patients were identified, of whom 28 (33.7%) had pelvic lymph node metastasis. The sensitivity, specificity, and accuracy for detecting lymph node metastasis were 64.3%, 69.1%, and 67.5% for MRI, and 28.6%, 83.6%, and 65.1% for PET/CT, respectively. The area under the receiver operating characteristics for the MRI and PET/CT were 0.667 and 0.561, respectively (P = .013). MRI showed significantly higher sensitivity for detecting metastatic lymph nodes than PET/CT (P = .006). CONCLUSION MRI was more sensitive than PET/CT for detecting metastatic lymph node in patients with cervical cancer.

Collision tumors of the ovary associated with teratoma : clues to the correct preoperative diagnosis

PURPOSE Collision tumors represent a coexistence of two adjacent but histologically distinct tumors without histologic admixture in an organ. The purpose of this study was to describe the imaging findings of collision tumors of the ovary associated with teratoma and to look for clues that might lead to the correct preoperative diagnosis. METHOD Seven pathologically proven cases of collision tumor of the ovary associated with teratoma were retrospectively reviewed. Ovarian teratomas were coexistent with mucinous cystadenoma (n = 4), borderline mucinous tumor (n = 1), mucinous cystadenocarcinoma (n = 1), and dysgerminoma (n = 1). US (n = 5), CT (n = 3), and/or MRI (n = 4) findings were evaluated. RESULTS In addition to the typical findings of teratoma, the mass contained a multiloculated cystic portion filled with nonfatty fluid, suggesting the coexistent epithelial tumor in five cases. In one case, the mass contained a large solid component, suggesting the possibility of collision tumor. In the remaining one case, coexistent small mucinous cystadenoma could not be identified. CONCLUSION Preoperative imaging for ovarian teratoma revealed a collision tumor in six of seven cases. The possibility of a collision tumor should be considered when an ovarian teratoma has imaging findings that cannot be explained solely by an ovarian teratoma.

Peripheral Hypoechoic Lesions of the Prostate: Evaluation with Color and Power Doppler Ultrasound

Objective: To assess the usefulness of color and power Doppler ultrasound in predicting the benignity and malignancy of the peripheral hypoechoic lesion of the prostate.Methods: Thirty–nine patients who had peripheral hypoechoic lesions on transrectal ultrasound were evaluated with color and power Doppler ultrasound followed by lesion–specific transrectal ultrasound–guided biopsies. The interpretation of color and power Doppler ultrasound was not performed separately and flow signals were categorized using a combination of the two modalities. The amount of flow signals within the lesion was evaluated and categorized into three groups: increased/equal/decreased flow compared to surrounding normal tissue on ultrasound. Doppler spectra could be obtained from the lesions in 23 patients. The amount of flow signals and resistive indexes of the spectra of the lesions were compared with those of surrounding normal tissue using the Mann–Whithney U test.Results: Transrectal ultrasound–guided biopsy of the hypoechoic lesions revealed prostate cancer in 20 patients and benign prostatic diseases in 19. Flow signals within the lesions were of increasded/equal/decreased flow compared to surrounding normal tissue in 16/2/2 in the prostate cancer group and 3/9/7 in the benign disease group, respectively. The difference was statistically significant (p = 0.0003). Resistive indexes of the lesion were 0.58–1.0 (mean 0.75) in the prostate cancer group and 0.57–1.0 (mean 0.80) in the benign disease group, and there was no significant difference between the two groups (p = 0.82). If we consider an increased flow signal within a peripheral hypoechoic lesion as a sign of prostate cancer, color power Doppler ultrasound has a sensitivity of 80%, a specificity of 84%, and an accuracy of 82%.Conclusion: Evaluation of peripheral hypoechoic lesions of the prostate with color and power Doppler may enhance the diagnostic capability of transrectal ultrasound.

Extracapsular Extension in Prostate Cancer: Added Value of Diffusion-Weighted MRI in Patients With Equivocal Findings on T2-Weighted Imaging

OBJECTIVE. The objective of our study was to evaluate diffusion-weighted imaging (DWI) and T2-weighted imaging for predicting extracapsular extension (ECE) in patients with prostate cancer. MATERIALS AND METHODS. One hundred seventeen patients underwent preoperative 3-T MRI and radical prostatectomy. Two radiologists evaluated ECE with T2-weighted imaging based on the Prostate Imaging Reporting and Data System (PI-RADS). Then, the apparent diffusion coefficient (ADC) of the tumor calculated from two b values (0, 1000 s/mm(2)) was measured. Interreader agreement of T2-weighted imaging scores was assessed with weighted kappa statistics. We compared T2-weighted imaging scores and ADC values between patients with ECE and those without ECE using the unpaired Student t test and evaluated their association with ECE using logistic regression analyses and ROC curves incorporating prostate-specific antigen value, Gleason score, clinical stage, and greatest percentage involved core length. The ADC values were also tested for differences between patients with ECE and those without ECE in subgroups stratified by the T2-weighted imaging criteria shown to have a high specificity for ECE. RESULTS. Fifty (42.7%) patients had ECE. There was substantial agreement for T2-weighted imaging scores (κ = 0.613). T2-weighted imaging scores and ADCs were significantly different in patients with ECE and those without ECE (p < 0.001). Multivariate analysis showed that the greatest percentage involved core length, T2-weighted imaging score, and ADC (p < 0.05) were independently predictive of ECE. The AUCs for these variables (range, 0.733-0.770) were not significantly different except for the AUC for clinical stage (0.552). The use of a high specificity (92.5%) setting for ECE divided the patients into the following groups: patients with a T2-weighted imaging score of ≥ 4 (n = 20) and patients with a T2-weighted imaging score of < 4 (n = 97). In patients with a T2-weighted imaging score of ≥ 4, the ADC was not significantly different between patients with ECE and those without ECE (p = 0.555). However, among patients with a T2-weighted imaging score of ≤ 3, the ADC value was significantly lower in patients with ECE (mean ± SD, 0.794 ± 0.116) than in those without ECE (1.027 ± 0.339) (p < 0.001). CONCLUSION. T2-weighted imaging scores and ADCs were independently associated with ECE, and the ADC had incremental value in patients without a high suspicion of ECE on T2-weighted imaging.