Urothelial Carcinoma of the Renal Pelvis with Synchronous Ipsilateral Collecting Duct Carcinoma: Two Case Reports.

Synchronous renal malignancies are seldom encountered or diagnosed post-renal resection. A combination of renal cell carcinoma (RCC) and urothelial carcinoma (UC) is most commonly reported. Typically, the RCC subtype is clear-cell RCC; however, a combination of collecting duct carcinoma (CDC) and UC has rarely been reported in the existing literature. Here, we present two cases of synchronous renal malignancy, specifically a combination of CDC and UC, in the ipsilateral kidney.

Variability of Transrectal Shear Wave Elastography in a Phantom Model.

Purpose: This study aimed to assess the variability of transrectal shear wave elastography (SWE) using a designed phantom. Materials and Methods: In a phantom, the SWE values were examined by two radiologists using agarose and emulsion silicone of different sizes (1, 2, and 3 cm) and shapes (round, cubic) at three depths (1, 2, and 3 cm), two region of interest (ROI) and locations (central, peripheral) using two ultrasound machines (A, B from different vendors). Variability was evaluated using the coefficient of variation (CV). Results: The CVs decreased with increasing phantom size. Significant changes in SWE values included; agarose phantom at 3 cm depth (p < 0.001; machine A), 1 cm depth (p = 0.01; machine B), emulsion silicone at 2 cm depth (p = 0.047, p = 0.020; both machines). The CVs increased with increasing depth. Significant changes in SWE values included; 1 cm agarose (p = 0.037, p = 0.021; both machines) and 2 cm agarose phantom (p = 0.047; machine A). Significant differences in SWE values were observed between the shapes for emulsion silicone phantom (p = 0.032; machines A) and between ROI locations on machine B (p ≤ 0.001). The SWE values differed significantly between the two machines (p < 0.05). The intra-/inter-operator agreements were excellent (intraclass correlation coefficient > 0.9). Conclusion: The phantom size, depth, and different machines affected the variability of transrectal SWE.

Multilocular Cystic Renal Neoplasm of Low Malignant Potential: A Case Report and Literature Review.

Multilocular cystic renal neoplasm of low malignant potential (MCRNLMP) is a rare subtype of renal cell carcinoma that has a favorable outcome. Most cases of MCRNLMP usually present as distinct multilocular cystic lesions; however, they may appear as small complicated cysts with hemorrhagic components. Herein, we present a case of MCRNLMP and provide a review of the literature.

Risk Factors for Renal Function Impairment Following Radiofrequency Ablation of Renal Tumors.

Purpose: To evaluate the various factors that affect renal function following percutaneous radiofrequency ablation (RFA) therapy in patients with renal tumors. Materials and Methods: Between 2010 and 2018, 91 patients diagnosed with renal tumors using ultrasonography and CT-guided RFA were enrolled. We retrospectively investigated the serum creatinine (SCr) level and estimated glomerular filtration rates immediately prior to RFA and during post-treatment follow-up. The patients were divided into two groups based on the degree of change in SCr level (0.3 mg/dL). Group comparisons were performed using univariable and multivariable logistic regression analyses to determine the factors impacting renal function. Results: Impaired renal function was associated with solitary kidney, chronic kidney disease (CKD) over stage 3, and pyeloureteral injury. Sex, age, other cancers, tumor size, location, growth pattern, and proximity to the collecting system were not significantly associated with impaired renal function. There was a difference in the overall change over time between the association with and without solitary kidney, CKD stage 3, and pyeloureteral injury. Conclusion: Among the medical conditions present prior to RFA, solitary kidney and CKD over stage 3 could be considered as risk factors for impaired renal function. Post-procedural pyeloureteral injury can also be considered a risk factor.

[Urothelial Carcinoma of the Bladder: Radiologic Perspective]. / 방광 요로상피세포암: ì˜ìƒì˜í•™ì  ê´€ì .

Bladder cancer is a relatively common cancer type, with a high recurrence rate, that can be often encountered in the imaging study. Accurate diagnosis and staging have a significant impact on determining treatment and evaluating prognosis. Bladder cancer has been evaluated by transurethral resection of bladder tumor for clinical staging and treatment, but it is often understaged when compared with final pathologic result by radical cystectomy. If the location, size, presence of muscle invasion, lymph node metastasis, distant metastasis, and presence of upper urinary tract cancer can be accurately diagnosed and evaluated in an imaging study, it can be treated and managed more appropriately. For an accurate diagnosis, radiologists who evaluate the images must be aware of the characteristics of bladder cancer as well as its types, imaging techniques, and limitations of imaging studies. Recent developments in MRI with functional imaging have improved the quality of bladder imaging and the evaluation of cancer. In addition, the Vesical Imaging Reporting and Data System was published to objectively assess the possibility for muscle invasion of cancer. Radiologists need to know the types of bladder cancer treatment and how to evaluate the changes after treatment. In this article, the characteristics of bladder urothelial carcinoma, various imaging studies, and findings are reviewed.

Assessment of clinical and radiologic differences between small and large adrenal pheochromocytomas.

OBJECTIVE: To evaluate differences in clinical and radiologic features of small and large pheochromocytomas. MATERIALS AND METHODS: This study included 39 patients with adrenal pheochromocytomas. Several clinical and radiologic features were statistically analyzed and compared between small and large pheochromocytomas. RESULTS: No significant differences were found in clinical features between them. Small pheochromocytomas had more relatively homogeneous attenuation although large pheochromocytomas had more cystic or necrotic changes. CONCLUSIONS: Pheochromocytomas tend to have different CT imaging features mimicking other tumors according to the size of the tumors. However, clinical features, CT imaging characteristics, and radioisotope activity are not different between small and large pheochromocytomas.

Measurement of arterial transit time and renal blood flow using pseudocontinuous ASL MRI with multiple post-labeling delays: Feasibility, reproducibility, and variation.

PURPOSE: To evaluate the feasibility, reproducibility, and variation of renal perfusion and arterial transit time (ATT) using pseudocontinuous arterial spin labeling magnetic resonance imaging (PCASL MRI) in healthy volunteers. MATERIALS AND METHODS: PCASL MRI at 3T was performed in 25 healthy volunteers on two different occasions. The ATT and ATT-corrected renal blood flow (ATT-cRBF) were calculated at four different post-labeling delay points (0.5, 1.0, 1.5, and 2.0 s) and evaluated for each kidney and subject. The intraclass correlation (ICC) and Bland-Altman plot were used to assess the reproducibility of the PCASL MRI technique. The within-subject coefficient of variance was determined. RESULTS: Results were obtained for 46 kidneys of 23 subjects with a mean age of 38.6 ± 9.8 years and estimated glomerular filtration rate (eGFR) of 89.1 ± 21.2 ml/min/1.73 m2 . Two subjects failed in the ASL MRI examination. The mean cortical and medullary ATT-cRBF for the subjects were 215 ± 65 and 81 ± 21 ml/min/100 g, respectively, and the mean cortical and medullary ATT were 1141 ± 262 and 1123 ± 245 msec, correspondingly. The ICC for the cortical ATT-cRBF was 0.927 and the within-subject coefficient of variance was 14.4%. The ICCs for the medullary ATT-cRBF and the cortical and medullary ATT were poor. The Bland-Altman plot for cortical RBF showed good agreement between the two measurements. CONCLUSION: PCASL MRI is a feasible and reproducible method for measuring renal cortical perfusion. In contrast, ATT for the renal cortex and medulla has poor reproducibility and high variation. LEVEL OF EVIDENCE: 2 Technical Efficacy: Stage 2 J. MAGN. RESON. IMAGING 2017;46:813-819.

Noninvasive detection of coronary vasospastic angina using a double-acquisition coronary CT angiography protocol in the presence and absence of an intravenous nitrate: a pilot study.

OBJECTIVES: To evaluate the feasibility of a double-acquisition coronary CT angiography (CCTA) protocol in the presence and absence of an intravenous (IV) vasodilator infusion for detecting vasospastic angina. METHODS: Twenty patients with a high clinical probability of vasospastic angina were enrolled. All subjects underwent baseline CCTA without a vasodilator in the early morning followed by a catheterized coronary angiography with ergonovine provocation test. Within 3 days, all subjects underwent repeat CCTA during a continuous IV infusion of nitrate. Vasospastic angina as detected by CCTA was defined as significant stenosis (≥50 %) with negative remodelling without definite plaques or diffuse small diameter (<2 mm) of a major coronary artery with a beaded appearance on baseline CT that completely dilated on IV nitrate CT. The CCTA results were compared to the catheterized ergonovine provocation test as the reference standard. RESULTS: Among 20 patients, the catheterized ergonovine provocation test detected vasospasm in 15 patients. The sensitivity, specificity, positive predictive value and negative predictive value of CCTA in a per-patient-based analysis were 73, 100, 100 and 56 %, respectively. CONCLUSIONS: Double-acquisition CCTA in the presence and absence of IV infusion of nitrate allows noninvasive detection of vasospastic angina with moderate sensitivity and high specificity. KEY POINTS: • Limited data exist regarding the efficacy of CCTA in detecting vasospastic angina. • We propose a double-acquisition CCTA protocol with and without IV nitrate injections. • This protocol provides 100% specificity and moderate sensitivity (73%) in spasm detection.

CT-based assessment of renal function impairment in patients with acute unilateral ureteral obstruction by urinary stones.

PURPOSE: The purpose of our study was to evaluate computed tomography (CT) imaging factors related to renal function impairment in patients with acute unilateral ureteral obstruction by urinary stones. MATERIALS AND METHODS: The study included 94 patients who had acute unilateral ureteral obstruction due to a urinary stone and a normal contralateral kidney. We retrospectively investigated the serum creatinine (SCr) levels immediately prior to CT examination and at least 1 week after treatment. CT examinations were performed using a CT urography protocol, including pre- and post-contrast images. The 67 patients with a SCr change of less than 0.3 mg/dL constituted group A. The other 27 patients with a SCr decrease of more than 0.3 mg/dL constituted group B. To evaluate factors related to renal function impairment, differences in CT imaging factors between the two groups, including the cortical and medullary density, renal and pelvic anteroposterior diameter, and perinephric fluid, were statistically analyzed. RESULTS: The SCr immediately prior to CT examination significantly differed between the two groups. The follow-up SCr after resolution did not significantly differ between the two groups. The difference in the mean cortical and medullary HU on the nephrographic phase between the obstructed kidney and normal kidney was higher in group B than in group A (27.1 ± 23.1 and 69.4 ± 59.1 vs. 5.7 ± 8.8 and 31.8 ± 34.8; p < 0.001 and p = 0.004, respectively). The cut-off point for the difference in the mean cortical HU on the nephrographic phase between the obstructed kidney and normal kidney for renal function impairment was 15 HU, as determined by a receiver operating characteristic curve analysis. CONCLUSIONS: Patients with significantly impaired renal function due to an acute unilateral ureteral obstruction may show a decreased nephrogram of the affected kidney and a significant difference in the HU on the nephrographic phase between the obstructed and normal kidney.

Contrast-induced nephropathy in patients undergoing intravenous contrast-enhanced computed tomography in Korea: a multi-institutional study in 101487 patients.

OBJECTIVE: To evaluate the prevalence of known risk factors for contrast-induced nephropathy (CIN) and their association with the actual occurrence of CIN in patients undergoing intravenous contrast-enhanced computed tomography (CECT) in Korea. MATERIALS AND METHODS: Patients who underwent CECT in 2008 were identified in the electronic medical records of 16 tertiary hospitals of Korea. Data on demographics, comorbidities, prescriptions and laboratory test results of patients were collected following a standard data extraction protocol. The baseline renal function was assessed using the estimated glomerular filtration rate (eGFR). We identified the prevalence of risk factors along the eGFR strata and evaluated their influence on the incidence of CIN, defined as a 0.5 mg/dL or 25% increase in serum creatinine after CECT. RESULTS: Of 432425 CECT examinations in 272136 patients, 140838 examinations in 101487 patients met the eligibility criteria for analysis. The mean age of the participants was 57.9 ± 15.5 years; 25.1% of the patients were older than 70 years. The prevalence of diabetes mellitus was 11.9%, of hypertension 13.7%, of gout 0.55% and of heart failure was 1.7%. Preventive measures were used in 40238 CECT examinations (28.6%). The prevalence of risk factors and use of preventive measures increased as the renal function became worse. A CIN was occurred after 3103 (2.2%) CECT examinations, revealing a significant association with decreased eGFR, diabetes mellitus, and congestive heart failure after adjustment. CONCLUSION: Risk factors for CIN are prevalent among the patients undergoing CECT. Preventive measures were seemingly underutilized and a system is needed to improve preventive care.

Computed tomography and magnetic resonance images of adrenocortical oncocytoma cases.

We present two cases of adrenocortical oncocytomas that were well-delineated on multi-detector computed tomography and magnetic resonance imaging. The images showed a well-enhanced large mass with multiple stippled calcifications in a 10-yr-old girl who was consulted due to precocious puberty. A well-enhanced solid mass with necrotic components was incidentally noticed in a 54-yr-old man. These lesions were resected and diagnosed as adrenocortical oncocytomas through immunohistochemical studies and electron microscopy. Adrenocortical oncocytomas are rare disease entities, therefore, we report these interesting, rare adrenocortical oncocytomas here with radiologic findings, and discuss differential diagnosis.

Focal thickening at the fundus of the gallbladder: computed tomography differentiation of fundal type adenomyomatosis and localized chronic cholecystitis.

BACKGROUND/AIMS: The objective of our study was to identify useful computed tomography (CT) findings for differentiating fundal type adenomyomatosis from localized chronic cholecystitis involving the fundus of the gallbladder. METHODS: We retrospectively identified cases of 41 patients with pathologically proven adenomyomatosis (n=21) or chronic cholecystitis (n=20) who had fundal thickening of the gallbladder on preoperative abdominal CT. Analysis of the CT findings included evaluation of the thickness, contour, border, intralesional cystic area, adjacent gallbladder wall thickening, presence of inner layer enhancement, enhancement grade, enhancement pattern, and presence of stones. Statistical analyses were performed using the Mann-Whitney U test and Fisher exact test. RESULTS: Oval contour, inner layer enhancement and intralesional cystic area were more frequently noted in adenomyomatosis than in chronic cholecystitis (p<0.05 for each finding). Flat contour and adjacent gallbladder wall thickening were more frequently observed in chronic cholecystitis than in adenomyomatosis. No differences between adenomyomatosis and chronic cholecystitis in terms of the thickness, enhancement grade, enhancement pattern and presence of stones were apparent. CONCLUSIONS: CT may help to differentiate fundal type adenomyomatosis from localized chronic cholecystitis involving the fundus of the gallbladder.

Epididymal lymphoma: report of two cases and imaging findings.

Epididymal lymphoma is a very rare tumor that is difficult to differentiate radiologically from other paratesticular tumors. Most cases of epididymal lymphoma are secondary involvement of the epididymis in patients with testicular lymphoma. However, isolated epididymal lymphoma is very rare. We herein report two cases of isolated epididymal lymphoma with different imaging findings. Patient 1 was a 52-year-old man who presented with a painless scrotal mass. Patient 2 was a 65-year-old man who presented with painless scrotal swelling. Ultrasound (US) demonstrated different imaging findings: US in patient 1 showed a well-defined round mass in the tail of the epididymis with hypervascularity confined to the epididymis, while US in patient 2 showed diffuse infiltrative enlargement with hypervascularity confined to the epididymis. Orchiectomy performed in both patients revealed diffuse large B-cell lymphoma confined to the epididymis.

Application of 31P MR spectroscopy to the brain tumors.

OBJECTIVE: To evaluate the clinical feasibility and obtain useful parameters of (31)P magnetic resonance spectroscopy (MRS) study for making the differential diagnosis of brain tumors. MATERIALS AND METHODS: Twenty-eight patients with brain tumorous lesions (22 cases of brain tumor and 6 cases of abscess) and 11 normal volunteers were included. The patients were classified into the astrocytoma group, lymphoma group, metastasis group and the abscess group. We obtained the intracellular pH and the metabolite ratios of phosphomonoesters/phosophodiesters (PME/PDE), PME/inorganic phosphate (Pi), PDE/Pi, PME/adenosine triphosphate (ATP), PDE/ATP, PME/phosphocreatine (PCr), PDE/PCr, PCr/ATP, PCr/Pi, and ATP/Pi, and evaluated the statistical significances. RESULTS: The brain tumors had a tendency of alkalization (pH = 7.28 ± 0.27, p = 0.090), especially the pH of the lymphoma was significantly increased (pH = 7.45 ± 0.32, p = 0.013). The brain tumor group showed increased PME/PDE ratio compared with that in the normal control group (p = 0.012). The ratios of PME/PDE, PDE/Pi, PME/PCr and PDE/PCr showed statistically significant differences between each brain lesion groups (p < 0.05). The astrocytoma showed an increased PME/PDE and PME/PCr ratio. The ratios of PDE/Pi, PME/PCr, and PDE/PCr in lymphoma group were lower than those in the control group and astrocytoma group. The metastasis group showed an increased PME/PDE ratio, compared with that in the normal control group. CONCLUSION: We have obtained the clinically applicable (31)P MRS, and the pH, PME/PDE, PDE/Pi, PME/PCr, and PDE/PCr ratios are helpful for differentiating among the different types of brain tumors.

Actinomycosis of the appendix mimicking appendiceal tumor: a case report.

Actinomycosis is an uncommon chronic infectious disease. Common sites of involvement include the cervicofacial, thoracic and abdominopelvic regions. In abdominopelvic actinomycosis, the ileocecal region, including the appendix, is the most commonly involved site. In some reports, limited appendiceal actinomycosis has revealed a thickened appendiceal wall with peri-appendiceal inflammation as acute appendicitis or perforated appendicitis. We experienced pathologically confirmed intraluminal limited appendiceal actinomycosis without peri-appendiceal infiltration. Here, we report the computed tomography and ultrasound findings.

Vascular calcification score on plain radiographs of the feet as a predictor of peripheral arterial disease in patients with chronic kidney disease.

BACKGROUND: The incidence of lower extremity amputation is increasing in patients with chronic kidney disease (CKD), but symptoms of peripheral arterial disease (PAD) in patients with CKD are uncommon. The aim of the current study was to assess the value of the vascular calcification (VC) score on plain radiographs of the feet for the prediction of PAD in patients with CKD. METHODS: We recruited 102 patients with CKD (24 pre-dialysis, 58 hemodialysis [HD], and 20 peritoneal dialysis [PD]). We defined the VC score on the plain radiographs of the feet as follows: score 0, no calcification; score 1, the length of the VC is <5 cm in a single foot or <2 cm in both feet; and score 2, the length of the VC is >5 cm in a single foot or >2 cm in both feet. We evaluated the atherosclerotic calcified plaques of the femoral or popliteal artery with Doppler ultrasonography and compared it with the VC score. RESULTS: Patients with high VC scores showed more atherosclerotic calcified plaques in the femoral or popliteal artery (P < 0.01). The prevalence of PAD in patients with CKD was closely related with the VC score (P < 0.01). PAD was associated with diabetes, a higher hsCRP, and a lower total cholesterol level (P < 0.01). The VC score was a significant predictor of the presence of PAD (odds ratio: 6.66, P < 0.001). CONCLUSIONS: Asymptomatic CKD patients, including those on HD and PD, may have PAD and routine testing by plain radiographs of the feet followed by Doppler ultrasonography are of pivotal significance, especially if the patients are diabetic.

Radiofrequency ablation of renal VX2 tumors with and without renal artery occlusion in a rabbit model: feasibility, therapeutic efficacy, and safety.

The purpose of this study was to determine the therapeutic efficacy of radiofrequency ablation for treating renal VX2 tumors with and without renal artery occlusion in a rabbit model. Twenty-four New Zealand White rabbits were percutaneously implanted with renal VX2 tumors. Fifteen days after implantation, both kidneys were surgically exposed, and radiofrequency ablation was conducted. Group A (n=12) was treated with renal artery occlusion, and group B (n=12) was treated without occlusion. In each rabbit, the serum creatinine was measured to evaluate renal damage after arterial occlusion. Two days after radiofrequency ablation, computed tomography was performed to evaluate the difference in therapeutic results between the two groups. We also compared histopathologic findings after radiofrequency ablation. The mean tumor size was 2.4 cm (range, 1.2-3.1 cm). Radiofrequency ablation of renal tumors was technically feasible in all cases. Complete ablation was achieved in 11 of the 12 rabbits (92%) in group A but in only eight of the 12 rabbits (67%) in group B (P<0.05). The average time of radiofrequency application was shorter in group A (mean, 547 s) than in group B (mean, 826 s) (P<0.05). After radiofrequency ablation, the serum creatinine increased from 1.54 to 1.82 mg/dl in group A and from 1.46 to 1.78 mg/dl in group B. However, there was no significant difference between the two groups (P>0.05). In conclusion, radiofrequency ablation with renal artery occlusion can decrease the duration of treatment and increase the therapeutic efficacy for renal VX2 tumors.

Radiofrequency ablation treatment for renal cell carcinoma: early clinical experience.

OBJECTIVE: To evaluate the early clinical experience associated with radiofrequency (RF) ablation in patients with renal cell carcinoma (RCC). MATERIALS AND METHODS: The RF ablation treatment was performed on 17 tumors from 16 patients (mean age, 60.5 years; range, 43-73 years) with RCC. The treatment indications were localized, solid renal mass, comorbidities, high operation risk, and refusal to perform surgery. All tumors were treated by a percutaneous CT (n = 10), followed by an US-guided (n = 2), laparoscopy-assisted US (n = 2), and an open (n = 2) RF ablation. Furthermore, patients underwent a follow-up CT at one day, one week, one month, three and six months, and then every six months from the onset of treatment. We evaluated the technical success, technical effectiveness, ablation zone, benign periablation enhancement, irregular peripheral enhancement, and complications. RESULTS: All 17 exophytic tumors (mean size, 2.2 cm; range, 1.1-5.0 cm) were completely ablated. Technical success and effectiveness was achieved in all cases and the mean follow-up period was 23.8 months (range, 17-33 months). A local recurrence was not detected in any of the cases; however, five patients developed complications as a result of treatment, including hematuria (n = 2), mild thermal injury of the psoas muscle (n = 1), mild hydronephrosis (n = 1), and fistula formation (n = 1). CONCLUSION: The RF ablation is an alternative treatment for exophytic RCCs and represents a promising treatment for some patients with small RCCs.