Accurate prediction of cancer prognosis before the start of treatment is important since these predictions often affect the choice of treatment. Prognosis is usually based on anatomical staging and other clinical factors. However, the conventional system is not sufficient to accurately and reliably determine prognosis. Metabolic parameters measured by $^{18}F$-fluorodeoxyglucose (FDG) positron emission tomography (PET) have the potential to provide valuable information regarding prognosis and treatment response evaluation in cancer patients. Among these parameters, volume-based PET parameters such as metabolic tumor volume and total lesion glycolysis are especially promising. However, the measurement of these parameters is significantly affected by the imaging methodology and specific image characteristics, and a standard method for these parameters has not been established. This review introduces volume-based PET parameters as potential prognostic indicators, and highlights methodological considerations for measurement, potential implications, and prospects for further studies.

Objective: To compare the diagnostic performance in evaluating the response of neoadjuvant chemotherapy (NAC), between the response evaluation criteria in solid tumor (RECIST) 1.0 and RECIST 1.1, on magnetic resonance imaging (MRI) for advance breast cancer patients. Materials and Methods: Breast cancer patients, who underwent NAC between 2005 and 2010, were included. Both prechemotherapy and post-chemotherapy MRIs were performed within 1-4 weeks before and after NAC. Only the patients with subsequent surgery were included. The response to NAC was assessed by using RECIST 1.0 and RECIST 1.1. Patients with a complete or partial response on MRI were considered as responders, and those with stable or progressive disease were considered as non-responders. Tumor necrosis > 50% on pathology was defined as responders and necrosis < 50% was defined as non-responders. The diagnostic accuracy of both RECIST 1.0 and RECIST 1.1 was analyzed and compared by receiver operating characteristic curve analysis. Results: Seventy-nine females (mean age 51.0 ${\pm}$ 9.3 years) were included. Pathology showed 45 responders and 34 nonresponders. There were 49 responders and 30 non-responders on RECIST 1.0, and in 55 patients, RECIST 1.0 results agreed with pathologic results (69.6%). RECIST 1.1 showed 52 responders and 27 non-responders. In 60 patients, RECIST 1.1 results were in accordance with pathology results (75.9%). The area under the ROC curve was 0.809 for RECIST 1.0 and 0.853 for RECIST 1.1. Conclusion: RECIST 1.1 showed better diagnostic performance than RECIST 1.0, although there was no statistically significant difference between the two.

Objective: We aimed to evaluate the time efficiency and diagnostic accuracy of automated myocardial computed tomography perfusion (CTP) image analysis software. Materials and Methods: 320-row CTP was performed in 30 patients, and analyses were conducted independently by three different blinded readers by the use of two recent software releases (version 4.6 and novel version 4.71GR001, Toshiba, Tokyo, Japan). Analysis times were compared, and automated epi- and endocardial contour detection was subjectively rated in five categories (excellent, good, fair, poor and very poor). As semi-quantitative perfusion parameters, myocardial attenuation and transmural perfusion ratio (TPR) were calculated for each myocardial segment and agreement was tested by using the intraclass correlation coefficient (ICC). Conventional coronary angiography served as reference standard. Results: The analysis time was significantly reduced with the novel automated software version as compared with the former release (Reader 1: 43:08 ${\pm}$ 11:39 min vs. 09:47 ${\pm}$ 04:51 min, Reader 2: 42:07 ${\pm}$ 06:44 min vs. 09:42 ${\pm}$ 02:50 min and Reader 3: 21:38 ${\pm}$ 3:44 min vs. 07:34 ${\pm}$ 02:12 min; p < 0.001 for all). Epi- and endocardial contour detection for the novel software was rated to be significantly better (p < 0.001) than with the former software. ICCs demonstrated strong agreement (${\geq}$ 0.75) for myocardial attenuation in 93% and for TPR in 82%. Diagnostic accuracy for the two software versions was not significantly different (p = 0.169) as compared with conventional coronary angiography. Conclusion: The novel automated CTP analysis software offers enhanced time efficiency with an improvement by a factor of about four, while maintaining diagnostic accuracy.

Objective: Authors aimed to determine the targeting ability of vascular endothelial growth factor receptor 2 (VEGFR2)- conjugated quantum dots (QDs) in vitro, and apply it for a xenograft prostate cancer mouse model. Materials and Methods: Conjugation reaction of QDs was performed by using the N-(3-dimethylaminopropyl)-N'- ethylcarbodiimide (EDC) and sulfo-(N-hydroxysulfosuccinimide) (Sulfo-NHS). The human umbilical vein cord endothelial cells (HUVECs) were incubated with QDs, conjugated with antiVGFR2, to see a specific binding in vitro. Fluorescent cell images were taken by a confocal microscope. The human prostate cancer cells (PC3) were injected to five nude mice on hind limbs to make the xenograft tumor model. QD-antiVEGFR2 antibody complex was injected into the tumor model and fluorescence measurements were performed at 1, 4, 9, 12, 15, and 24 hours after the injection. Results: The specific interaction between HUVECs and QD-antiVEGFR2 antibody was clearly shown in vitro. The in vivo fluorescence image disclosed that there was an increased signal of tumor, 12 hours after the injection of QDs. Conclusion: By showing endothelial cells binding with QDs-antiVEGFR2 antibodyand an experimental application of the antibody for VEGFR2 imaging in the prostate cancer xenograft mouse model, we suggests that the antibody-conjugated QDs can be a potential imaging tool for angiogenesis of the cancer.

Objective: To compare the ancillary CT findings between superior mesenteric artery thromboembolism (SMAT) and superior mesenteric vein thrombosis (SMVT), and to determine the independent CT findings of life-threatening mesenteric occlusion. Materials and Methods: Our study was approved by the institution review board. We included 43 patients (21 SMAT and 22 SMVT between 1999 and 2008) of their median age of 60.0 years, and retrospectively analyzed their CT scans. Medical records were reviewed for demographics, management, surgical pathology diagnosis, and outcome. We compared CT findings between SMAT and SMVT groups. Multivariate analysis was conducted to determine the independent CT findings of life-threatening mesenteric occlusion. Results: Of 43 patients, 24 had life-threatening mesenteric occlusion. Death related to mesenteric occlusion was 32.6%. A thick bowel wall (p < 0.001), mesenteric edema (p < 0.001), and ascites (p = 0.009) were more frequently associated with SMVT, whereas diminished bowel enhancement (p = 0.003) and paralytic ileus (p = 0.039) were more frequent in SMAT. Diminished bowel enhancement (OR = 20; p = 0.007) and paralytic ileus (OR = 16; p = 0.033) were independent findings suggesting life-threatening mesenteric occlusion. Conclusion: The ancillary CT findings occur with different frequencies in SMAT and SMVT. However, the independent findings indicating life-threatening mesenteric occlusion are diminished bowel wall enhancement and paralytic ileus.

Objective: The purpose of this study was to establish a minimally invasive and reproducible protocol for estimating the gastrointestinal (GI) transit time in mice using barium and radiopaque markers. Materials and Methods: Twenty 5- to 6-week-old Balb/C female mice weighing 19-21 g were used. The animals were divided into three groups: two groups that received loperamide and a control group. The control group (n = 10) animals were administered physiological saline (1.5 mL/kg) orally. The loperamide group I (n = 10) and group II (n = 10) animals were administered 5 mg/kg and 10 mg/kg loperamide orally, respectively. Thirty minutes after receiving the saline or loperamide, the mice was administered 80 ${\mu}L$ of barium solution and six iron balls (0.5 mm) via the mouth and the upper esophagus by gavage, respectively. Afterwards, the mice were continuously monitored with fluoroscopic imaging in order to evaluate the swallowing of the barium solution and markers. Serial fluoroscopic images were obtained at 5- or 10-min intervals until all markers had been excreted from the anal canal. For analysis, the GI transit times were subdivided into intestinal transit times (ITTs) and colon transit times (CTTs). Results: The mean ITT was significantly longer in the loperamide groups than in the control group (p < 0.05). The mean ITT in loperamide group II (174.5 ${\pm}$ 32.3) was significantly longer than in loperamide group I (133.2 ${\pm}$ 24.2 minute) (p < 0.05). The mean CTT was significantly longer in loperamide group II than in the control group (p < 0.05). Also, no animal succumbed to death after the experimental procedure. Conclusion: The protocol for our study using radiopaque markers and barium is reproducible and minimally invasive in determining the GI transit time of the mouse model.

Objective: To investigate the additional diagnostic value of color mapping of the hepatic arterial enhancement fraction (AEF) for detecting recurrent or residual hepatocellular carcinoma (HCC) in patients treated with transcatheter arterial chemoembolization (TACE). Materials and Methods: Seventy-six patients with 126 HCCs, all of whom had undergone previous TACE, and subsequently, underwent follow-up multiphasic liver CT scans, were included in this study. Quantitative color maps of the AEF of the whole liver were created, by using prototype software with non-rigid registration. The AEF was defined as the ratio of the attenuation increment during the arterial phase to the attenuation increment during the portal phase. Two radiologists independently analyzed the two image sets at a two-week interval, i.e., the multiphasic CT image set and the second image set of the AEF color maps and the CT images. The additional diagnostic value of the AEF color mapping was determined, by the use of the jackknife-alternative free-response receiver-operating-characteristic analysis. The sensitivity and positive predictive values for detecting HCCs of each image set were also evaluated and compared. Results: The reader-averaged figures of merit were 0.699 on the initial interpretation of the MDCT image set, and 0.831 on the second interpretation of the combined image set; the difference between the two interpretations was significant (p value < 0.001). The mean sensitivity for residual or recurrent HCC detection increased from 62.7% on the initial analysis to 82.1% on the second analysis using the AEF color maps (p value < 0.001). The mean positive predictive value for HCC detection was 74.5% on the initial analysis using MDCT, and 71.6% on the second analysis using AEF color mapping. Conclusion: Quantitative color mapping of the hepatic AEF may have the possibility to increase the diagnostic performance of MDCT for the detection of recurrent or residual HCC without the potential risk of radiation-related hazards.

Objective: To retrospectively determine the optimal b value of diffusion-weighted imaging (DWI) for predicting the presence of localized prostate cancer, and to evaluate the utility of DWI under different b values in differentiating between cancers and benign prostatic tissues. Materials and Methods: Eighty patients with suspected prostate cancer underwent MRI including DWI at 3T, followed by radical prostatectomy. DWI was examined under different b values. Apparent diffusion coefficient (ADC) maps were generated by using b = 0, and other b values of 300, 700, 1000 or 2000 $s/mm^2$. For predicting the presence of cancers, four different ADC maps were analyzed independently by two blinded readers. ADCs were measured in benign and malignant tissues. Results: For predicting the presence of 110 prostate cancers, the sensitivity and area under the curve (AUC) for an experienced reader was significantly greater at b = 1000 (85% and 0.91) than b = 300, 700 or 2000 $s/mm^2$ (p < 0.01). For a less-experienced reader, the AUC was significantly greater at b = 700, 1000 or 2000 than b = 300 $s/mm^2$ (p < 0.01). Mean ADCs of the cancers in sequence from b = 300 to 2000 $s/mm^2$ were 1.33, 1.03, 0.88 and $0.68{\times}10^{-3}mm^2/s$, which were significantly lower than those of benign tissues (p < 0.001). Conclusion: The optimal b value for 3T DWI for predicting the presence of prostate cancer may be 1000 $s/mm^2$.

Objective: The current study retrospectively evaluated whether the percutaneous N-butyl cyanoacrylate (NBCA) seal-off technique is an effective treatment for controlling the angioplasty-related ruptures, which are irresponsive to prolonged balloon tamponade, during interventions for failed or failing hemodialysis vascular accesses. Materials and Methods: We reviewed 1588 interventions performed during a 2-year period for dysfunction and/or failed hemodialysis vascular access sites in 1569 patients. For the angioplasty-related ruptures, which could not be controlled with repeated prolonged balloon tamponade, the rupture sites were sealed off with an injection of a glue mixture (NBCA and lipiodol), via a needle/needle sheath to the rupture site, under a sonographic guidance. Technical success rate, complications and clinical success rate were reported. The post-seal-off primary and secondary functional patency rates were calculated by a survival analysis with the Kaplan-Meier method. Results: Twenty ruptures irresponsive to prolonged balloon tamponade occurred in 1588 interventions (1.3%). Two technical failures were noted; one was salvaged with a bailout stent-graft insertion and the other was lost after access embolization. Eighteen accesses (90.0%) were salvaged with the seal-off technique; of them, 16 ruptures were completely sealed off, and two lesions were controlled as acute pseudoaneurysms. Acute pseudoaneurysms were corrected with stentgraft insertion in one patient, and access ligation in the other. The most significant complication during the follow-up was delayed pseudoaneurysm, which occurred in 43.8% (7 of 16) of the completely sealed off accesses. Delayed pseudoaneurysms were treated with surgical revision (n = 2), access ligation (n = 2) and observation (n = 3). During the follow-up, despite the presence of pseudoaneurysms (acute = 1, delayed = 7), a high clinical success rate of 94.4% (17 of 18) was achieved, and they were utilized for hemodialysis at the mean of 411.0 days. The post-seal-off primary patency vs. secondary patency at 90, 180 and 360 days were 66.7 ${\pm}$ 11.1% vs. 94.4 ${\pm}$ 5.4%; 33.3 ${\pm}$ 11.1% vs. 83.3 ${\pm}$ 8.8%; and 13.3 ${\pm}$ 8.5% vs. 63.3 ${\pm}$ 12.1%, respectively. Conclusion: Our results suggest that the NBCA seal-off technique is effective for immediate control of a venous rupture irresponsive to prolonged balloon tamponade, during interventions for hemodialysis accesses. Both high technical and clinical success rates can be achieved. However, the treatment is not durable, and about 40% of the completely sealed off accesses are associated with developed delayed pseudoaneurysms in a 2-month of follow-up. Further repair of the vascular tear site, with surgery or stent-graft insertion, is often necessary.

We report a case of erectile dysfunction caused by external iliac artery occlusion, associated with pelvic steal syndrome; bilateral internal iliac arteries were patent. The patient stated that he had experienced erectile dysfunction at similar times along with claudication, but he did not mention it before angiography. He expressed that the erectile dysfunction did not last long and that he felt completely okay after the interventional procedure, in addition to his claudication. Successful treatment of the occlusion, by percutaneous transluminal angioplasty and stent implantation, helped resolve erectile dysfunction completely and treat the steal syndrome.

Vascular involvement in neurofibromatosis type 1 is rare but has the potential to be fatal. We report a case of a patient with spontaneous rupture of a left intercostal artery aneurysm, which presented as a massive left hemothorax and was successfully treated by transarterial coil embolization.

A 46-year-old Vietnamese woman received embolization therapy in order to control postpartum hemorrhage. Angiography revealed an aberrant ovarian artery arising from the right common iliac artery. Superselective catheterization and subsequent embolization of the aberrant ovarian artery and bilateral uterine arteries were performed. Precise knowledge of the anatomic variations of the ovarian artery is important for successful embolization.

Gross hematuria secondary to vesical varices is an unusual presentation. We report such a case recurrent gross hematuria in a male patient who had a history of bladder substitution with ileal segments that had been treated by balloon-occluded percutaneous transhepatic obliteration of vesical varices.

We report a case in an inoperable patient with the hilar malignant biliary obstruction treated palliatively by the use of a newly designed Y-shaped covered stent without interfering contra-lateral bile duct. We percutaneously inserted a newly designed Y-shaped covered stent into a biliary tree in an inoperable patient with Bismuth Type II cholangiocarcinoma. We checked tubograms, enhanced CT studies, and blood bilirubin levels before, one week after, and at every three month after the stenting, by observing closely the signs of clinical infection as well. The follow-up period was about 12 months. The placement of the Y-shaped covered stent was successful and resulted in adequate biliary drainage in the immediate post-procedural tubogram and in the follow-up abdominal CT. The serum bilirubin levels did not show elevation after the insertion of the Y-shaped covered stent.

Objective: We aimed to evaluate the use of dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) at 3.0 T for differentiating the benign from malignant soft tissue tumors. Also we aimed to assess whether the shorter length of DCEMRI protocols are adequate, and to evaluate the effect of temporal resolution. Materials and Methods: Dynamic contrast-enhanced magnetic resonance imaging, at 3.0 T with a 1 second temporal resolution in 13 patients with pathologically confirmed soft tissue tumors, was analyzed. Visual assessment of time-signal curves, subtraction images, maximal relative enhancement at the first (maximal peak enhancement [Emax]/1) and second (Emax/2) minutes, Emax, steepest slope calculated by using various time intervals (5, 30, 60 seconds), and the start of dynamic enhancement were analyzed. Results: The 13 tumors were comprised of seven benign and six malignant soft tissue neoplasms. Washout on time-signal curves was seen on three (50%) malignant tumors and one (14%) benign one. The most discriminating DCE-MRI parameter was the steepest slope calculated, by using at 5-second intervals, followed by Emax/1 and Emax/2. All of the steepest slope values occurred within 2 minutes of the dynamic study. Start of dynamic enhancement did not show a significant difference, but no malignant tumor rendered a value greater than 14 seconds. Conclusion: The steepest slope and early relative enhancement have the potential for differentiating benign from malignant soft tissue tumors. Short-length rather than long-length DCE-MRI protocol may be adequate for our purpose. The steepest slope parameters require a short temporal resolution, while maximal peak enhancement parameter may be more optimal for a longer temporal resolution.

Objective: The objective of this retrospective study was to develop and validate a simple diagnostic prediction model by using ultrasound (US) features of thyroid nodules obtained from multicenter retrospective data. Materials and Methods: Patient data were collected from 20 different institutions and the data included 2000 thyroid nodules from 1796 patients. For developing a diagnostic prediction model to estimate the malignant risk of thyroid nodules using suspicious malignant US features, we developed a training model in a subset of 1402 nodules from 1260 patients. Several suspicious malignant US features were evaluated to create the prediction model using a scoring tool. The scores for such US features were estimated by calculating odds ratios, and the risk score of malignancy for each thyroid nodule was defined as the sum of these individual scores. Later, we verified the usefulness of developed scoring system by applying into the remaining 598 nodules from 536 patients. Results: Among 2000 tumors, 1268 were benign and 732 were malignant. In our multiple regression analysis models, the following US features were statistically significant for malignant nodules when using the training data set: hypoechogenicity, marked hypoechogenicity, non-parallel orientation, microlobulated or spiculated margin, ill-defined margins, and microcalcifications. The malignancy rate was 7.3% in thyroid nodules that did not have suspicious-malignant features on US. Area under the receiver operating characteristic (ROC) curve was 0.867, which shows that the US risk score help predict thyroid malignancy well. In the test data set, the malignancy rates were 6.2% in thyroid nodules without malignant features on US. Area under the ROC curve of the test set was 0.872 when using the prediction model. Conclusion: The predictor model using suspicious malignant US features may be helpful in risk stratification of thyroid nodules.

A case of intracranial ganglioneuroma arising from the trigeminal nerve in the pontine and cerebellopontine angle cistern, in a 44-year-old female, is presented with an emphasis on diffusion-weighted imaging findings. We will discuss on how the tumor in the very unusual location should be differentiated particularly focused on diffusion-weighted imaging findings.

We report a case of intraocular lymphoma in a 65-year-old man, 15 months after cardiac transplantation. On Magnetic Resonance (MR) images, the iris and the anterior chamber of the right eye were found to be involved with an enhancing soft-tissue lesion. To our knowledge, this is the first case of post-transplantation intraocular lymphoma evaluated with MR imaging.

Objective: The quality and radiation dose of different tube voltage sets for chest digital radiography (DR) were compared in a series of pediatric age groups. Materials and Methods: Forty-five hundred children aged 0-14 years (yr) were randomly divided into four groups according to the tube voltage protocols for chest DR: lower kilovoltage potential (kVp) (A), intermediate kVp (B), and higher kVp (C) groups, and the fixed high kVp group (controls). The results were analyzed among five different age groups (0-1 yr, 1-3 yr, 3-7 yr, 7-11 yr and 11-14 yr). The dose area product (DAP) and visual grading analysis score (VGAS) were determined and compared by using one-way analysis of variance. Results: The mean DAP of protocol C was significantly lower as compared with protocols A, B and controls (p < 0.05). DAP was higher in protocol A than the controls (p <0.001), but it was not statistically significantly different between B and the controls (p = 0.976). Mean VGAS was lower in the controls than all three protocols (p < 0.001 for all). Mean VGAS did not differ between protocols A and B (p = 0.334), but was lower in protocol C than A (p = 0.008) and B (p = 0.049). Conclusion: Protocol C (higher kVp) may help optimize the trade-off between radiation dose and image quality, and it may be acceptable for use in a pediatric age group from these results.

CT scans in four cases of chronic superior vena cava or left brachiocephalic vein obstruction demonstrate a systemic-to-cardiac collateral venous pathway through anastomoses between the pericardial branches of systemic veins and the presumed adventitial veins of the ascending aorta and pulmonary trunk. These adventitial veins then drain into tributaries of the anterior cardiac veins or ventricular coronary veins.