Risk Factors for Liver Function Deterioration after Transarterial Chemoembolization Refractoriness in Child-Pugh Class A Hepatocellular Carcinoma Patients.

Background/Aims: A switch to systemic therapy, such as sorafenib, should be considered for hepatocellular carcinoma (HCC) patients refractory to transarterial chemoembolization (TACE). On the other hand, treatment changes are difficult if the liver function worsens to Child-Pugh B or C. Therefore, predicting the risk factors for non-responsiveness to TACE and deteriorating liver function may be helpful. Methods: Newly diagnosed Child-Pugh A HCC patients who underwent TACE from January 2012 to June 2018 were included. After 1 year, this study evaluated whether there was a treatment response to TACE and whether the Child-Pugh class had worsened. Results: Among 121 patients, 65 were refractory and 56 responded to TACE. In multivariable logistic regression analysis, the tumor size, tumor number, and albumin at the time of the diagnosis of HCC were significant prognostic factors for the treatment response to TACE. Among 65 patients who presented TACE-refractoriness, 27 showed liver function deterioration from Child-Pugh class A to class B or C after TACE. In multivariable logistic regression analysis, bilirubin at the diagnosis of HCC was a significant prognostic factor for liver function deterioration. A predictive algorithm based on the regression equations revealed a sensitivity, specificity, positive predictive value, and negative predictive value of 74.1%, 74.5%, 45.5%, and 90.9%, respectively, for TACE-refractoriness and liver function deterioration. Conclusions: The prognostic model incorporating the tumor size, tumor number, albumin, and bilirubin at the diagnosis of HCC may help identify patients who show a poor response to TACE and aggravation of liver function after TACE, who may benefit from early switching into systemic therapy before liver function aggravation.

Value of Fluoroscopic Defecography in Constipated Children With Abnormal Colon Transit Time Test Results.

BACKGROUND/AIMS: Colon transit time (CTT) test is regarded as the gold standard for evaluating colon transit function. Fluoroscopic defecography (FD) is a dynamic radiologic test to assess anorectal function. The aim is to evaluate the value of FD in constipated children with abnormal CTT test results. METHODS: Fifty-one children (27 girls) with a mean age of 9.8 ± 3.2 years who met Rome III criteria for constipation and older than 5 years with abnormal CTT test results underwent FD. RESULTS: Of 51 children, 27 (52.9%) showed positive findings on FD, including pelvic floor dyssynergia (PFD) (10/27, 37.0%), structural abnormality (15/27, 55.6%) (rectocele 53.3%, intussusception 33.3%, and both 13.4%), and both PFD and rectocele (2/27, 7.4%). In terms of CTT test subtype, of 35 children who had outlet obstruction type in CTT test, 19 (54.2%) had positive findings, including PFD (8/19, 42.1%), structural abnormality (9/19, 47.4%) (rectocele 55.6%, intussusception 22.2%, and both 22.2%), and both PFD and rectocele (2/19, 10.5%). Of the 16 children who had slow transit type of CTT test, 8 (50.0%) had positive findings, including PFD (2/8, 25.0%) and structural abnormality (6/8, 75.0%). Of the 6 children who had structural abnormality, 3 (50.0%) had rectocele and 3 (50.0%) had intussusception. For the 2 children (2/16, 12.5%) who had PFD, puborectalis muscle relax failure was found on FD. Puborectalis muscle relax failure was treated with biofeedback and medication. In the minor abnormalities, medication continued without additional therapeutic modalities. CONCLUSIONS: FD was valuable for both diagnoses of underlying causes and interpretation of CTT test results in children with abnormal CTT test results. Therefore, this study suggests that FD and CTT tests should be incorporated into logical thinking for constipation in children.

Efficacy and Safety of Combined Radiofrequency Ablation with Transarterial Chemoembolization in Patients with Barcelona Clinic Liver Cancer Stage A Hepatocellular Carcinoma Ineligible for Curative Treatment.

Background/Aims: Surgical resection or ablation is recommended for the treatment of early hepatocellular carcinoma (HCC), whereas transarterial chemoembolization (TACE) is frequently used in early HCC ineligible for curative resection. We evaluated the clinical effects and safety of radiofrequency ablation (RFA) shortly after TACE in patients with Barcelona clinic liver cancer (BCLC) stage A HCC. Methods: Sixty-seven BCLC stage A HCC patients who failed to achieve complete response to TACE as either a first line treatment and who subsequently received RFA at the Konkuk University Medical Center from January 2005 to December 2017 were included. Evaluation indices included treatment response, overall survival rate, recurrence-free survival, prognostic factors, and procedure-related complications. Results: Median follow-up was 46.9 months. Fifty-four (80.6%) patients were of Child-Pugh class A, and 13 (19.4%) were of class B. Modified UICC stages were I in 10 (14.9%), II in 46 (68.7%), and III in 11 (16.4%) patients. In the 67 study subjects, cumulative recurrence-free survival rates were 86.8%, 55.9% and 29.7% at 1, 3, and 5 years, respectively, and overall survival rates were 100%, 93.4%, and 83.5% at 1, 3, and 5 years, respectively. Tumor size significantly predicted recurrence. No treatment-related death occurred. Conclusions: Combination of RFA was an efficient and safe treatment for BCLC stage A HCC patients that failed to achieve complete response to initial TACE. We suggest TACE plus RFA be considered as a curative option for early HCC patients ineligible for curative resection of RFA.

Shrinkage of hepatocellular carcinoma after radiofrequency ablation following transcatheter arterial chemoembolization: Analysis of contributing factors.

OBJECTIVE: This study was conducted to investigate tumor shrinkage and influencing factors in patients with hepatocellular carcinoma (HCC) from radiofrequency (RF) ablation following transcatheter arterial chemoembolization (TACE). METHODS: A total of 222 patients underwent combined sequential treatment of TACE and RF ablation for HCC at our institution between 2008 and 2014. Of those, 86 patients (men, 68; women, 18) who achieved compact iodized oil tagging and complete ablation were included for this retrospective study. We measured three-dimensional tumor diameters and calculated tumor volumes on pre-treatment CT/MRI and follow-up CT scans performed post-TACE, post-ablation, and 1 month post-treatment, respectively. To compare periodically generated tumor diameters and volumes, repeated measures analysis of variance (ANOVA) was applied. Multiple linear regression analysis was performed to identify factors impacting tumor shrinkage after RF ablation. RESULTS: Diameters and volumes of HCCs declined significantly in the immediate aftermath of RF ablation (i.e., between post-TACE and post-ablation CT scans) (p < 0.001, for both). Mean reduction rates in tumor diameter and volume immediately after RF ablation were 18.2 ± 9.1% and 44.4 ± 14.6%, respectively. Of note, tumors of left hepatic lobe and in subphrenic or perivascular locations showed lower rates of post-ablative volume reduction than those in counterpart locations (p = 0.002, 0.046, 0.024, respectively). Tumor size and liver function did not influence tumor shrinkage after RF ablation. CONCLUSION: In patients with HCC, significant tumor shrinkage occurs immediately after RF ablation. The degree of shrinkage in response to ablative treatment seems to vary by tumor location.

Multiparametric MR imaging of peripheral zone prostate cancer: effect of postbiopsy hemorrhage on cancer detection according to Gleason score and tumour volume.

OBJECTIVE: To evaluate effect of postbiopsy hemorrhage on detection of peripheral zone (PZ) prostate cancer by multiparametric MR imaging according to Gleason score and tumor volume. METHODS: This retrospective study included 54 biopsy-proven prostate cancer patients (median age, 67.0 years) who underwent multiparametric MR imaging. Two independent readers evaluated each sextant of the PZ using the PI-RADS v2. One reader recorded the presence or absence of hemorrhage per sextant on T1 weighted MR images. Areas under the receiver operating characteristic curves (AUCs) were used to evaluate cancer detection accuracy. RESULTS: Postbiopsy hemorrhage was noted in 122 (37.7%) of 324 sextants of all patients. There was no significant difference in the AUC for detection of cancer with Gleason score ≥3 + 4 or volume ≥0.5 ml between sextants with and without hemorrhage (with hemorrhage, reader 1, 0.83 for Gleason score ≥3 + 4, 0.84 for tumor volume ≥0.5 ml; reader 2, 0.74 for Gleason score ≥3 + 4, 0.77 for tumor volume ≥0.5 ml; without hemorrhage, reader 1, 0.86 for Gleason score ≥3 + 4, 0.88 for tumor volume ≥0.5 ml; reader 2, 0.79 for Gleason score ≥3 + 4, 0.83 for tumor volume ≥0.5 ml; p > 0.2 for all). CONCLUSION: Postbiopsy hemorrhage did not negatively affect the detection of clinically significant PZ prostate cancer on multiparametric MR imaging. Advances in knowledge: Under influence of postbiopsy hemorrhage, multiparametric MR can be useful for the detection of clinically significant PZ prostate cancer.

Estimation of hepatic fat fraction using modified Dixon magnetic resonance imaging techniques: effect of liver cirrhosis.

PURPOSE: To evaluate modified Dixon MRI techniques in hepatic fat estimation and to assess the effect of cirrhosis. METHODS: 235 patients who underwent liver MRI were included. Correlation between modified Dixon techniques with MRS was assessed. Accuracy of MR techniques in hepatic fat estimation was calculated, and the result was compared between patients with/without liver cirrhosis. RESULTS: Correlation between modified Dixon and MRS was better in group without liver cirrhosis, and accuracy of modified Dixon method was higher in group without liver cirrhosis. CONCLUSIONS: Modified Dixon techniques estimate hepatic fat fraction noninvasively, but the result can be influenced by the presence of liver cirrhosis.

Comparison of Nonspherical Polyvinyl Alcohol Particles and Microspheres for Prostatic Arterial Embolization in Patients with Benign Prostatic Hyperplasia.

PURPOSE: To report early results following prostatic artery embolization (PAE) and compare outcomes between nonspherical polyvinyl alcohol (PVA) particles and microspheres to treat lower urinary tract symptoms (LUTS) due to benign prostatic hyperplasia (BPH). METHODS: PAE was performed in nine patients (mean age: 78.1 years) with symptomatic BPH. Embolization was performed using nonspherical PVA particles (250-355 µm) in four patients and microspheres (300-500 µm) in five patients. RESULTS: PAE was technically successful in all nine patients (100%). During a mean follow-up of 10.1 months, improvements in mean International Prostate Symptom Score (IPSS), Quality of Life (QoL), prostatic volume (total volume and transition zone), and peak urinary flow (Qmax) were 9.8 points, 2.3 points, 28.1 mL, 17.8 mL, and 4.5 mL/s, respectively. Clinical success was obtained in seven of nine patients (78%). Patients in the microsphere group showed greater improvement in IPSS, QoL, prostatic volume, and Qmax compared to patients in the nonspherical PVA particle group. However, significant difference was noted only in the prostatic volume. CONCLUSION: PAE is a feasible, effective, and safe treatment option for BPH with LUTS. Use of microspheres showed greater prostatic volume reduction compared to nonspherical PVA particles.

Visibility of focal liver lesions: Comparison between kupffer phase of CEUS with sonazoid and hepatobiliary phase of gadoxetic acid-enhanced MRI.

BACKGROUND: To investigate the agreement between Kupffer phase of Sonazoid contrast-enhanced sonography (CEUS) and hepatobiliary phase of gadoxetic acid-enhanced MRI in the evaluation of focal liver lesions (FLLs). METHODS: One hundred fifty-four FLLs in 154 patients who underwent both Sonazoid CEUS and gadoxetic acid-enhanced liver MRI were included in this retrospective study. FLL visibility on the Kupffer-phase images was graded as one (invisible or isoenhancing), two (vaguely visible or vaguely hypoenhancing), or three (clearly visible or clearly hypoenhancing), and that on the hepatobiliary-phase images of MRI was graded as one (invisible or hyper/isointense), two (vaguely visible or weakly hypointense), or three (clearly visible or strongly hypointense). Pairwise comparison of lesion visibility between the two modalities was performed, and intermodality agreement was assessed. RESULTS: On Kupffer-phase CEUS, 31 (20.1%) lesions were invisible, 17 (11.1%) were vaguely visible, and 106 (68.9%) were clearly visible. On the hepatobiliary-phase MRI, 9 (5.9%) lesions were invisible, 45 (29.2%) were vaguely visible, and 100 (64.9%) were clearly visible. Overall, lesion visibility scores were not significantly different between the two modalities (p = 0.121), but the visibility was significantly better on MRI in smaller lesions. Twenty-eight lesions (18.2%) showed discrepancy in the visibility on CEUS and MRI, and most of the cases (89.7%) were lesions that were invisible on CEUS but visible on MRI. CONCLUSIONS: The overall visibility of FLLs was comparable between the Kupffer phase of Sonazoid-CEUS and the hepatobiliary-phase images of gadoxetic acid-enhanced MRI, with a discrepancy between the two modalities in 18% of the cases. © 2017 Wiley Periodicals, Inc. J Clin Ultrasound 45:542-550, 2017.

Imaging Patterns of Intratumoral Calcification in the Abdominopelvic Cavity.

Intratumoral calcification is one of the most noticeable of radiologic findings. It facilitates detection and provides information important for correctly diagnosing tumors. In the abdominopelvic cavity, a wide variety of tumors have calcifications with various imaging features, though the majority of such calcifications are dystrophic in nature. In this article, we classify the imaging patterns of intratumoral calcification according to number, location, and morphology. Then, we describe commonly-encountered abdominopelvic tumors containing typical calcification patterns, focusing on their differentiable characteristics using the imaging patterns of intratumoral calcification.

Serial Changes of Tendon Histomorphology and Strain Elastography After Induced Achilles Tendinopathy in Rabbits: An In Vivo Study.

OBJECTIVES: The purpose of this study was to investigate and compare the serial changes of morphology and strain in the early process of Achilles tendinopathy in a rabbit model. METHODS: A total of 10 New Zealand white rabbits underwent ligation of one of their Achilles tendons to induce ischemic injury. Both inflamed and contralateral Achilles tendons were serially evaluated with 3 follow-ups: the first on days 3 to 5, the second on days 9 to 13, and the third and last follow-up on days 15 to 20 after surgery. During each examination, tendon thickness was measured and red, green, and blue pixel intensities of the elastogram were analyzed using color histogram analysis software. Differences between the inflamed and control group were compared. RESULTS: The mean thickness of the inflamed tendons increased during consecutive follow-ups and was significantly larger than that of control tendons (P < .01). The mean red pixel intensity ratio of the inflamed tendons was also serially increased and was higher than that in the control tendons, indicating softening. However, the difference was significant only in the second and third follow-ups (P < .01). CONCLUSIONS: Tendon thickening and softening developed during the early process of Achilles tendinopathy in a rabbit model. Tendon softening may present later than thickening.

CT predictors for selecting conservative surgery or adnexectomy to treat adnexal torsion.

PURPOSE: To identify computed tomography (CT) findings for selection between conservative surgery and adnexectomy in patients of reproductive age with adnexal torsion. METHODS: This retrospective study included 54 consecutive patients who underwent preoperative CT imaging before undergoing either conservative surgery or adnexectomy to treat adnexal torsion. RESULTS: By multivariate analysis, CT finding of tubal thickening was significantly associated with the patients treated with adnexectomy (odds ratio=7.6, P=.008). CONCLUSION: Although the majority of patients of reproductive age with adnexal torsion can be treated with conservative surgery, patients who require adnexectomy tend to have a tubal thickening on CT.

Added Value of Using a CT Coronal Reformation to Diagnose Adnexal Torsion.

OBJECTIVE: To evaluate the increased value of using coronal reformation of a transverse computed tomography (CT) scan for detecting adnexal torsion. MATERIALS AND METHODS: This study included 106 woman suspected of having adnexal torsion who underwent CT with coronal reformations and subsequent surgical exploration. Two readers independently recorded the CT findings, such as the thickening of a fallopian tube, twisting of the adnexal pedicle, eccentric smooth wall thickening of the torsed adnexal mass, eccentric septal thickening of the torsed adnexal mass, eccentric poor enhancement of the torsed adnexal mass, uterine deviation to the twisted side, ascites or infiltration of pelvic fat, and the overall impression of adnexal torsion with a transverse scan alone or combined with coronal reformation and a transverse scan. The areas under the receiver operating characteristic curves (AUCs), sensitivity, specificity, and positive predictive value were used to compare diagnostic performance. RESULTS: Fifty-two patients were confirmed to have adnexal torsion. The addition of coronal reformations to the transverse scan improved AUCs for readers 1 and 2 from 0.74 and 0.75 to 0.92 and 0.87, respectively, for detecting adnexal torsion (p < 0.001 and p = 0.004, respectively). Sensitivity of CT for detecting twisting of the adnexal pedicle increased significantly for readers 1 and 2 from 0.27 and 0.29 with a transverse scan alone to 0.79 and 0.77 with a combined coronal reformation and a transverse scan, respectively (p < 0.001 and p < 0.001, respectively). CONCLUSION: Use of a coronal reformation with transverse CT images improves detection of adnexal torsion.

Shear Wave Elastography of Focal Liver Lesion: Intraobserver Reproducibility and Elasticity Characterization.

PURPOSE: The aim of the study was to evaluate the intraobserver reproducibility and to determine the elasticity characteristics of focal liver lesions (FLLs) by shear wave elastography (SWE). METHODS: One hundred thirty-six FLLs in 118 patients were examined with SWE for quantitative and qualitative assessment of stiffness. Three SWE images were obtained for each lesion and liver parenchyma by 1 radiologist. Intraobserver reproducibility was assessed by intraclass correlation coefficients (ICCs). Patient and lesion factors that can affect the reproducibility were evaluated. For characterization of the lesion elasticity, the difference in stiffness between the groups of lesions was evaluated. RESULTS: The mean (SD) diameter and depth of the lesions were 3.98 (2.07) and 4.4 (1.59) cm, respectively. The ICC of intraobserver reproducibility was 0.763. Deep-seated lesions (≥6 cm; ICC, 0.621) showed significantly lower intraobserver reproducibility compared with superficial lesions (ICC, 0.793; P = 0.047). Stiffness values of malignant lesions (n = 85, 60.41 [47.81] kPa) were significantly higher than those of benign lesions (n = 51, 22.05 [17.24] kPa, P < 0.0001). Mean (SD) stiffness of hepatocellular carcinoma (45.72 [35.65] kPa) was significantly lower than that of metastasis (67.43 [43.39] kPa) and was significantly higher than benign FLLs (22.05 [17.24] kPa). However, mean (SD) lesion-parenchyma ratio of hepatocellular carcinoma (3.76 [4]) was not significantly different from that of benign FLLs (3.7 [3.77]). CONCLUSIONS: Overall, intraobserver reproducibility of SWE in evaluation of FLLs was excellent, but it can be affected by lesion depth. In addition, SWE is helpful in elasticity characterization of FLLs.

Diagnosis of esophageal varices on liver CT: is thin-section reconstruction necessary?

BACKGROUND/AIMS: The aim of this study was to evaluate the effect of 1 mm, 3 mm, and 5 mm section thicknesses of liver CT on the detection and grading of esophageal varices in cirrhotic patients. METHODOLOGY: A total of 219 consecutive cirrhotic patients who had undergone both upper endoscopy and 64-channel liver CT were included. Portal phase images of each CT were reconstructed with a section thickness of 1 mm, 3 mm, and 5 mm. Four radiologists independently reviewed the 3 image sets. The observers evaluated the presence of esophageal varices on a 5-point confidence scale and measured the maximal short diameter of the largest varix identified. Sensitivity, specificity and predictive value calculation and receiver operating characteristic analysis were performed. Correlation between CT measurements and endoscopic grading as the reference standard was assessed. RESULTS: The averaged Az values at 1 mm, 3 mm, and 5 mm image sets were 0.936, 0.946, and 0.935, respectively, and they were not significantly different among the 4 observers. When a 3 mm cut-off criterion for large varices was applied, sensitivity, specificity, and predictive values were comparable among the 3 image datasets. CONCLUSIONS: Routine liver CT protocol is sufficient for evaluation of esophageal varices in cirrhotic patients without adding thin section reconstruction images.

Real-time contrast-enhanced sonographically guided biopsy or radiofrequency ablation of focal liver lesions using perflurobutane microbubbles (sonazoid): value of Kupffer-phase imaging.

OBJECTIVES: To evaluate the utility of Kupffer-phase imaging by real-time contrast-enhanced sonography using the perflurobutane microbubble contrast agent Sonazoid (GE Healthcare, Oslo, Norway) in guiding biopsy or radiofrequency (RF) ablation of focal liver lesions. METHODS: A total of 75 patients (mean age, 59.7 years) who were referred for percutaneous biopsy (n = 42) or RF ablation (n = 33) were included in the study. Grayscale sonography and contrast-enhanced sonography using Sonazoid were performed in all patients before the procedure. The conspicuity of each targeted liver lesion on grayscale sonography, vascular-phase contrast-enhanced sonography, and Kupffer-phase contrast-enhanced sonography was graded using a 5-point scale. Lesion detection rates were calculated, and the conspicuity of the lesions among the imaging modalities was compared. The technical success of the procedures was also assessed. RESULTS: The procedures were conducted in 66 patients (biopsy in 41 and RF ablation in 25) under real-time guidance by Kupffer-phase contrast-enhanced sonography. Lesion detection rates were 77.3% (58 of 75), 84.0% (63 of 75), and 92.0% (69 of 75) on grayscale sonography, vascular-phase contrast-enhanced sonography, and Kupffer-phase contrast-enhanced sonography, respectively, and were significantly different among the 3 modalities (P= .034). Overall, lesion conspicuity was significantly increased on vascular-phase and Kupffer-phase contrast-enhanced sonography compared to grayscale sonography (P < .001). Technical success rates for the procedures were 95.2% (40 of 42) for biopsy and 69.7% (23 of 33) for RF ablation. CONCLUSIONS: Kupffer-phase imaging by contrast-enhanced sonography using Sonazoid increases the conspicuity of the liver lesions compared to grayscale sonography, and it is useful for real-time guidance of percutaneous biopsy or RF ablation of focal liver lesions.

Three-Tesla magnetic resonance elastography for hepatic fibrosis: comparison with diffusion-weighted imaging and gadoxetic acid-enhanced magnetic resonance imaging.

AIM: To evaluate the feasibility of 3-Tesla magnetic resonance elastography (MRE) for hepatic fibrosis and to compare that with diffusion-weighted imaging (DWI) and gadoxetic acid-enhanced magnetic resonance (MR) imaging. METHODS: Forty-two patients were included in the study. On MRE, mean stiffness values were measured on the elastograms in kilopascals. The apparent diffusion coefficient (ADC) of the liver was measured using DWI. On gadoxetic acid enhanced MR, the contrast enhancement index (CEI) was calculated as signal intensity (SI)post/SIpre, where SIpost is liver-to-muscle SI ratio on hepatobiliary phase images and SIpre is that on nonenhanced images. Correlation between aspartate aminotransferase to the platelet ratio index (APRI) and three MR parameters was assessed. Each MR parameter was compared between a hepatic fibrosis (HF) group and non-hepatic fibrosis (nHF) group. RESULTS: Liver stiffness showed strong positive correlation with APRI [Spearman correlation coeffiecient (r) = 0.773, P < 0.0001], while ADC and CEI showed weak or prominent negative correlation (r = -0.28 and -0.321, respectively). In the HF group, only liver stiffness showed strong correlation with APRI (r = 0.731, P < 0.0001). Liver stiffness, ADC, and APRI were significantly different between the HF group and nHF group. CONCLUSION: MRE at 3-Tesla could be a feasible method for the assessment of hepatic fibrosis.

Delayed hepatic rupture after radiofrequency ablation for colorectal hepatic metastasis: management with transcatheter arterial embolization.

Intraperitoneal bleeding after radiofrequency ablation (RFA) is the most common major vascular complication due to direct needle injury to a vessel or liver capsule. However, intraperitoneal bleeding as a result of a delayed hepatic rupture after RFA for liver tumors is an extremely rare complication. The present report describes a case of intraperitoneal hemorrhage caused by delayed hepatic rupture resulting from arterioportal fistula after RFA for hepatic metastasis from colorectal cancer and successful management using transcatheter embolization.

Multidetector computed tomography for the assessment of adnexal mass: is unenhanced CT scan necessary?

OBJECTIVE: To compare the diagnostic performance and radiation dose between contrast-enhanced CT (ECT) alone, and combined unenhanced and contrast-enhanced CT (UE + ECT) for the assessment of adnexal mass. MATERIALS AND METHODS: This retrospective study was approved by the Institutional Review Board. A total of 146 consecutive patients (mean age, 41.1 years) who underwent preoperative unenhanced and contrast-enhanced multidetector CT of the pelvis and had adnexal masses found at surgery were included. Two readers independently evaluated the likelihood of adnexal malignancy on a 5-point scale on two different imaging datasets (ECT alone and UE + ECT). The area under the receiver operating characteristic curve (AUC) was used to evaluate diagnostic performance. Radiation dose to patients was calculated by the volume CT dose index (CTDIvol) and the dose length products (DLP) on each dataset. RESULTS: Of the total 178 adnexal masses, 133 masses were benign and 45 masses were malignant. For both readers, there is no significant difference of AUC values between ECT alone and UE + ECT for the detection of adnexal malignancy (reader 1, 0.93 vs. 0.95; reader 2, 0.92 vs. 0.91) (p > 0.05). The mean CTDIvol (12.6 ± 2.2 mGy) and DLP (641.2 ± 137.2 mGy) of ECT alone was significantly lower than the mean CTDIvol (21.5 ± 2.7 mGy) and DLP (923.6 ± 158.8 mGy) of UE + ECT (p < 0.0001). CONCLUSION: The use of unenhanced CT scan in addition to contrast-enhanced CT scan does not improve the detection of adnexal malignancy, but increases radiation exposure.

Unenhanced CT for the detection of renal cell carcinoma: effect of tumor size and contour type.

PURPOSE: To evaluate effect of tumor size and contour type for the detection of renal cell carcinoma (RCC) on unenhanced CT. METHODS: This retrospective institutional review board approved study that includes 111 patients with RCC and 100 patients without RCC who underwent unenhanced CT. Two readers performed a blinded and independent review of the presence of RCC on unenhanced CT. The area under the receiver operating characteristic curves (AUC) was compared by tumor size (<3 cm: small, or ≥3 cm: large) and contour type (endophytic, mesophytic, or exophytic). RESULTS: For tumor size, the AUC for small RCC (0.70 and 0.78, for reader 1 and reader 2) was significantly lower than that for large RCC (0.97 and 0.99, for reader 1 and reader 2) (p < 0.001). As for contour type of tumor, the AUC for endophytic RCC (0.60 and 0.71, for reader 1 and reader 2) was significantly lower than that for mesophytic RCC (0.95 and 0.98, for reader 1 and reader 2) and exophytic RCC (0.98 and 0.99, reader 1 and reader 2) (p < 0.001). CONCLUSION: On unenhanced CT, tumor size and contour type can affect the detection of RCC. While most large or exophytic RCC can be easily detected, the detection of small and endophytic RCC is highly limited.