See Hyung Kim

Low-Risk Prostate Cancer: The Accuracy of Multiparametric MR Imaging for Detection

PURPOSE To retrospectively determine diagnostic performance with multiparametric magnetic resonance (MR) imaging for detection of cancer of different tumor volumes and Gleason grades in patients with clinically low-risk prostate cancer. MATERIALS AND METHODS The local ethical committee and institutional review board approved this study. Consecutive patients with clinically determined low-risk cancer (n = 100) were examined with multiparametric MR imaging (T2 weighted, diffusion weighted, and dynamic contrast material enhanced) by using a 3.0-T imager before prostatectomy. Two radiologists independently assessed the likelihood of cancer per sextant. Cancers with a volume of 0.5 cm(3) or more identified at histopathologic examination were compared with multiparametric MR images. Cancer detection with multiparametric MR imaging was assessed for tumors of different volumes and Gleason grades by using a logistic generalized estimating equation model with 95% confidence intervals (CIs) with two optimal dichotomized cutoff scores. RESULTS For cancers greater than or equal to 0.5 cm(3), with respect to cancer volume and Gleason grade, multiparametric MR imaging showed high diagnostic performance for the detection of cancer. Diagnostic accuracy with multiparametric MR imaging was significantly higher for cancers with a volume greater than 1 cm(3) than for those with a volume of 0.5-1 cm(3) (87.7%; 95% CI: 82.4%, 94.3% vs 82.6%; 95% CI: 79.0%, 88.7%; P = .02) and for cancers with Gleason grades of 7 or more than for those with grades of 6 or less (89.2%; 95% CI: 85.4%, 93.8% vs 80.6%; 95% CI: 71.2%, 89.8%; P = .01). Detection rates for cancers with a volume more than 1 cm(3) and a Gleason grade of 7 or more were significantly higher than for those with a volume of 0.5-1 cm(3) and a Gleason grade of 6 or less(87.8%; 95% CI: 85.3%, 93.7% vs 82.0%; 95% CI: 75.6%, 86.1%; P = .01). CONCLUSION Detection of prostate cancer in patients with clinically low-risk cancer with multiparametric MR imaging is highly accurate, and larger cancer volume and higher Gleason grade are associated with higher detection accuracy.

Locally advanced rectal cancer: post-chemoradiotherapy ADC histogram analysis for predicting a complete response

Background The value of diffusion-weighted imaging (DWI) for reliable differentiation between pathologic complete response (pCR) and residual tumor is still unclear. Recently, a few studies reported that histogram analysis can be helpful to monitor the therapeutic response in various cancer research. Purpose To investigate whether post-chemoradiotherapy (CRT) apparent diffusion coefficient (ADC) histogram analysis can be helpful to predict a pCR in locally advanced rectal cancer (LARC). Material and Methods Fifty patients who underwent preoperative CRT followed by surgery were enrolled in this retrospective study, non-pCR (n = 41) and pCR (n = 9), respectively. ADC histogram analysis encompassing the whole tumor was performed on two post-CRT ADC600 and ADC1000 (b factors 0, 600 vs. 0, 1000 s/mm2) maps. Mean, minimum, maximum, SD, mode, 10th, 25th, 50th, 75th, 90th percentile ADCs, skewness, and kurtosis were derived. Diagnostic performance for predicting pCR was evaluated and compared. Results On both maps, 10th and 25th ADCs showed better diagnostic performance than that using mean ADC. Tenth percentile ADCs revealed the best diagnostic performance on both ADC600 (AZ 0.841, sensitivity 100%, specificity 70.7%) and ADC1000 (AZ 0.821, sensitivity 77.8%, specificity 87.8%) maps. In comparison between 10th percentile and mean ADC, the specificity was significantly improved on both ADC600 (70.7% vs. 53.7%; P = 0.031) and ADC1000 (87.8% vs. 73.2%; P = 0.039) maps. Conclusion Post-CRT ADC histogram analysis is helpful for predicting pCR in LARC, especially, in improving the specificity, compared with mean ADC.

Angiomyolipoma with minimal fat: differentiation of morphological and enhancement features from renal cell carcinoma at CT imaging.

Background Angiomyolipoma (AML) with minimal fat may mimic renal cell carcinoma (RCC) and is difficult to distinguish from RCC with imaging studies alone. Precise diagnostic strategies have been explored to discern AML with minimal fat from RCC. Purpose To compare the morphological and enhancement features of AML with minimal fat with those of size-matched RCC on computed tomography (CT). Material and Methods Our study included 143 pathologically proved renal tumors (29 AML with minimal fat: mean diameter, 2.5 cm; range, 1.2–4 cm; 114 RCC: mean diameter, 2.8 cm; range, 1.3–4 cm). All patients underwent biphasic helical CTs. Two radiologists retrospectively evaluated the morphological (i.e. non-round and round appearances, with or without capsule) and enhancement features (i.e., wash-out, gradual, or prolonged). For the parameters that had statistically significance between the two groups, we calculated the positive and negative predictive values by using the univariate χ2 test. P < 0.05 indicated a significant difference. Results AML with minimal fat showed a non-round appearance without a capsule (n = 24, 83%) and prolonged enhancement (n = 20, 69%). The positive and negative predictive values of the non-round appearance without capsule for differentiating AML with minimal fat from RCC were 82.8% and 95.6%, respectively. The positive and negative predictive values of prolonged enhancement were 62.5% and 90.8%, respectively. These features were valuable predictors for AML with minimal fat from RCC. Conclusion CT images with non-round shape without capsule and prolonged enhancements may be used to differentiate AML with minimal fat from RCC.

Differentiation of Clear Cell Renal Cell Carcinoma From Other Subtypes and Fat-Poor Angiomyolipoma by Use of Quantitative Enhancement Measurement During Three-Phase MDCT

OBJECTIVE The purpose of this study was to retrospectively assess whether measurement of quantitative enhancement during three-phase MDCT can help differentiate clear cell renal cell carcinoma (RCC) from papillary RCC, chromophobe RCC, and fat-poor angiomyolipoma. MATERIALS AND METHODS During preoperative three-phase MDCT (unenhanced, corticomedullary, and early excretory phases), 563 lesions were identified in 552 consecutively registered patients. The lesions were assessed for attenuation in each phase, and the attenuation values were compared by t test. Cutoff analysis of enhancement values (percentage enhancement ratio, enhancement change, and absolute washout ratio) was performed to determine optimal thresholds for the four types of lesions. RESULTS The mean attenuation of clear cell RCC was significantly greater than that of papillary RCC and chromophobe RCC in the corticomedullary phase (clear cell, 139.7 HU; papillary, 56.8 HU [p = 0.003]; chromophobe, 85.4 HU [p = 0.005]) and early excretory phase (clear cell, 86.9 HU; papillary, 73.4 HU [p = 0.03]; chromophobe, 68.2 HU [p = 0.02]). It was also significantly greater than that of fat-poor angiomyolipoma in the corticomedullary phase (139.7 vs 99.6 HU, p = 0.02). Establishment of threshold enhancement values helped to differentiate clear cell RCC from papillary RCC, chromophobe RCC, and fat-poor angiomyolipoma with the following accuracies: percentage enhancement ratio, 84.7% (399/471) for papillary RCC, 71.1% (325/457) for chromophobe RCC, and 81.9% (377/460) for fat-poor angiomyolipoma; enhancement change, 80.9% (381/471) for papillary RCC, 70.2% (321/457) for chromophobe RCC, and 80.6% (371/460) for fat-poor angiomyolipoma; absolute washout ratio, 88.5% (417/471) for papillary RCC, 74.1% (339/457) for chromophobe RCC, and 85.0% (391/460) for fat-poor angiomyolipoma. CONCLUSION Quantitative enhancement measurement may be useful for differentiating clear cell RCC from papillary RCC, chromophobe RCC, and fat-poor angiomyolipoma.

Serious acute pyelonephritis: a predictive score for evaluation of deterioration of treatment based on clinical and radiologic findings using CT

Background Acute pyelonephritis (APN) requires prompt diagnosis and immediate treatment. Purpose To develop a simple score to assist in diagnosing treatment deterioration in patients with serious APN. Material and Methods Using data from a retrospective cohort of 193 patients with APN, we developed scores based on multivariate logistic regression after the jackknife procedure. We validated the scores in a prospective cohort of 40 patients. Results Nine criteria were independently associated with our investigation: Abscess (adjusted odds ratio [OR], 19.8; 95% confidence interval [95% CI] 4.5–72.1), pyonephrosis with or without stone (18.3; 4.8–70.9), pelvicalyceal air (15.5; 3.2–26.9), poor global excretion of contrast (12.3; 2.9–68.5), tachycardia or hypotension (10.1; 2.5–28.0), obliteration of the renal sinus (9.6; 2.5–45.2), persistent fever or pyuria (9.8; 1.9–25.8), diabetes (9.4; 2.0–31.8), and global renal enlargement (7.5; 2.1–35.8). The APN score was based on these nine criteria. Low-risk and high-risk groups were derived from the score (probability, 3.5% [95% CI 0–7.5] and 67% [51–83]). Application of these criteria to the prospective cohort confirmed the diagnostic accuracy of the score (probability 0% [0–15] and 71% [25–100] in the low-risk and high-risk groups, respectively). Conclusion This easy-to-calculate score may prove useful for diagnosing patients with serious APN who deteriorate with treatment.

Ultrasonographic indications for conservative treatment in pregnancy-related uterine arteriovenous malformations.

Background Uterine arteriovenous malformations (AVMs) are known to spontaneously regress. Purpose To assess the predictive value of ultrasonography for patients requiring conservative treatment for pregnancy related to AVMs. Material and Methods Our prospective study included 75 patients (conservative management:therapeutic management = 45:30) with vaginal bleeding from pregnancy-related AVM. Clinical and ultrasonography examinations were reviewed, and the following information was gathered: complete blood count, AVM maximal diameter, AVM echogenicity, retained product of conception, number of blood vessels, and spectral Doppler (pulsatility index [PI], resistance index [RI], peak systolic velocity [PSV], time-averaged maximum velocity [TAMXV]). The Doppler criteria by Timmerman (mean PSV >70 cm/s: therapeutic management, mean PSV < 52 cm/s: conservative management) were used for the initial management selection. The association between experimental variables and outcomes was assessed to determine their usefulness for predicting conservative management. Results Features strongly associated with conservative management and their accuracy were PSV 89.6%, hemoglobin 84.7%, RI 83.1%, TAMXV 79.3%, and PI 78.6%. The overall accuracy for correct outcome classification was 64 (85.3%) of 75 patients. Most patients with conservative management had quicker improvement of symptoms and spontaneous regression at follow-up. Conclusion Ultrasonography can accurately predict selection of conservative management.

Is CA-125 an additional help to radiologic findings for differentiation borderline ovarian tumor from stage I carcinoma?

Background Borderline ovarian tumors (BOTs) are difficult to differentiate from stage I carcinoma using radiological findings. Little is known about the correlation between CA-125 levels and radiological findings for predicting BOTs or carcinoma. Purpose To assess the role of CA-125, in addition to that of radiological findings, in differentiating BOTs from stage I carcinoma. Material and Methods The study received institutional review board approval, with waiver of informed consent. We evaluated 100 patients (two groups: BOT, 58 patients; stage I carcinoma, 42 patients) using radiological findings, including location and size of each tumor, number and size of septations, papillary projections and vegetations, peritoneal implants, ascites, and preoperative CA-125 levels. The differences in CA-125 levels according to bilateral location, solid components, and thickness of septations between the two groups were evaluated using the McNemar test. Correlations of CA-125 level to size and number of septations were evaluated by the independent sample t test. Results No statistical correlation was found between CA-125 level and location, size, and number of septations between the two groups. Solid components within the tumors were similar in the two groups, but the CA-125 level was significantly higher in stage I carcinoma than in BOTs. The number of septations per tumor was similar in the two groups; thick septations were more frequent in stage I carcinoma than in BOTs, and a significantly higher titer of CA-125 was found in stage I carcinoma. Discriminant analysis of solid components and thickness of septations resulted in accurate diagnosis of 70.6% of the tumors (80.6% of BOTs and 69.7% of stage I carcinomas). Conclusion CA-125 levels for solid components and thickness of septations are lower in BOTs. These may be helpful in predicting the risk of carcinoma, even if BOTs cannot be conclusively differentiated from stage I carcinoma.

Validation of Prostate Imaging Reporting and Data System Version 2 Using an MRI-Ultrasound Fusion Biopsy in Prostate Cancer Diagnosis

OBJECTIVE The purpose of our study was to prospectively assess Prostate Imaging Reporting and Data System (PI-RADS) version 2 using an MRI-ultrasound fusion biopsy. SUBJECTS AND METHODS This study included 295 consecutive patients with 478 lesions who underwent multiparametric MRI and subsequent MRI-ultrasound fusion biopsy between December 2014 and September 2016. Lesions were assessed by using an overall score of PI-RADS version 2. One radiologist assessed the presence or absence of clinically significant prostate cancer in the whole gland and in subgroups of the peripheral zone and transition zone by using cutoff values of ≥ 4 and ≥ 3. Histologic examination of MRI-ultrasound fusion biopsy specimens was used as the reference standard. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were calculated to assess the utility of PI-RADS version 2 for the diagnosis of clinically significant prostate cancer. RESULTS The overall PI-RADS version 2 scores showed an accuracy of 82.2% (393/478) for the whole gland, with a cutoff value of ≥ 4 granting sensitivity of 90.0% (90/100), specificity of 80.1% (303/378), PPV of 83.3% (90/108), and NPV of 81.8% (303/370). The overall scores showed accuracies of 84.7% (301/355) in the peripheral zone and 74.7% (92/123) in the transition zone. When we applied an arbitrary overall score of ≥ 3, accuracy was 68.6% (328/478), sensitivity was 94.6% (124/131), specificity was 58.7% (204/347), PPV was 51.6% (124/240), and NPV was 85.7% (204/238). CONCLUSION PI-RADS version 2 has an overall good performance for the diagnosis of clinically significant prostate cancer.

Long-term outcomes of surgery alone versus surgery following preoperative chemoradiotherapy for early T3 rectal cancer A propensity score analysis

Abstract Recently, a few studies have raised the question of whether preoperative chemoradiotherapy (PCRT) is essential for all T3 rectal cancers. This case-matched study aimed to compare the long-term outcomes of surgery alone with those of PCRT + surgery for magnetic resonance imaging (MRI)-assessed T3ab (extramural depth of invasion ⩽5 mm) and absent mesorectal fascia invasion (clear MRF) in mid/lower rectal cancer patients. From January 2006 to November 2012, 203 patients who underwent curative surgery alone (n = 118) or PCRT + surgery (n = 85) were enrolled in this retrospective study. A 1:1 propensity score-matched analysis was performed to eliminate the inherent bias. Case-matching covariates included age, sex, body mass index, histologic grade, carcinoembryonic antigen, operation method, follow-up period, tumor height, and status of lymph node metastasis. The end-points were the 5-year local recurrence (LR) rate and disease-free-survival (DFS). After propensity score matching, 140 patients in 70 pairs were included. Neither the 5-year LR rate nor the DFS was significantly different between the 2 groups (the 5-year LR rate, P = 0.93; the 5-year DFS, P = 0.94). The 5-year LR rate of the surgery alone was 2% (95% confidence interval [CI] 0.2%–10.9%) versus 2% (95% CI 0.2%–10.1%) in the PCRT + surgery group. The 5-year DFS of the surgery alone was 87% (95% CI 74.6%–93.7%) versus 88% (95% CI 77.8%–93.9%) in the PCRT + surgery group. In patients with MRI-assessed T3ab and clear MRF mid/lower rectal cancer, the long-term outcomes of surgery alone were comparable with those of the PCRT + surgery. The suggested MRI-assessed T3ab and clear MRF can be used as a highly selective indication of surgery alone in mid/lower T3 rectal cancer. Additionally, in those patients, surgery alone can be tailored to the clinical situation.

Diagnostic efficiency of split-bolus dual-energy computed tomography for patients with suspected urinary stones.

Objective The objective of this study was to evaluate the efficiency of virtual noncontrast image (VNCI) generated from dual-energy split-bolus computed tomographic urography (DE-SBCTU) for urinary stones detection. Methods Three hundred fifty-six patients underwent true noncontrast image (TNCI) and DE-SBCTU. Two radiologists evaluated opacification scores of DE-SBCTU as well as iodine subtractions and image noise on VNCI. Diagnostic performance of the VNCI was evaluated using TNCI as a reference standard, according to diameter and image quality. The results were compared between patient groups with body mass index of less than 25 and 25 kg/m2 or greater. Results Agreements for opacification, iodine subtraction, and image noise between the radiologists were excellent, and there were no significant difference in the 2 patients groups. A total of 499 stones were detected on VNCI, with a sensitivity and diagnostic accuracy of 95.1% (468/492) and 92.9% (499/537). Mean (SD) diameter was significantly smaller on VNCI (3.6 [2.3] mm) than on TNCI (4.4 [2.0] mm) (P = 0.01). The stone diameter with false interpretation was less than 4 mm in 48 of 51 patients. The diameter and image quality on VNCI had no significant difference between the 2 patients groups. Conclusions Virtual noncontrast image displays high accuracy for detecting urinary stones, regardless of body mass index.