Purpose: The purpose of this study was to elucidate whether contrast-enhanced ultrasonography (CEUS) can visualize orally administered Sonazoid leaking into the peritoneal cavity in a postoperative stomach leakage mouse model. Methods: Adult female mice (n=33, 9-10 weeks old) were used. Preoperative CEUS was performed after delivering Sonazoid via intraperitoneal injection and the per oral route. A gastric leakage model was then generated by making a surgical incision of about 0.5 cm at the stomach wall, and CEUS with per oral Sonazoid administration was performed. A region of interest was drawn on the CEUS images and the signal intensity was quantitatively measured. Statistical analysis was performed using a mixed model to compare the signal intensity sampled from the pre-contrast images with those of the post-contrast images obtained at different time points. Results: CEUS after Sonazoid intraperitoneal injection in normal mice and after oral administration in mice with gastric perforation visualized the contrast medium spreading within the liver interlobar fissures continuous to the peritoneal cavity. A quantitative analysis showed that in the mice with gastric perforation, the orally delivered Sonazoid leaking into the peritoneal cavity induced a statistically significant (P<0.05) increase in signal intensity in all CEUS images obtained 10 seconds or longer after contrast delivery. However, enhancement was not observed before gastric perforation surgery (P=0.167). Conclusion CEUS with oral Sonazoid administration efficiently visualized the contrast medium spreading within the peritoneal cavity in a postoperative stomach leakage mouse model.

PURPOSE: Extraosseous Ewing's sarcoma (EOE) of the rectum is extremely rare: only three cases have been reported in the literature and none of these reports described their imaging findings in detail. Herein, we describe the tumor imaging and pathological features in detail. MATERIALS AND METHODS: We report a case of rectal EOE in a 72-year-old female who received local excision and was provisionally diagnosed with a rectal submucosal spindle cell tumor. We used immunohistochemistry, histopathology, and fluorescence in situ hybridization to characterize the tumor and provide a definitive diagnosis of EOE. RESULTS: MRI revealed a well-demarcated submucosal tumor with heterogeneous enhancement and hemorrhagic foci in rectum. EOE was diagnosed by positive staining of tumor cells for CD99 and Fli-1 by immunohistochemistry and the presence of the EWSR1 gene translocation by fluorescence in situ hybridization. Although the patient underwent radiation treatment and surgery, the tumor recurred after 4 months as revealed by computed tomography and magnetic resonance imaging. CONCLUSION: Rectal EOE may present as a rectal submucosal tumor. The understanding of imaging and histological characteristics of this tumor are critical for accurate diagnosis and appropriate aggressive treatment.
Aged ; Diagnosis ; Female ; Fluorescence ; Humans ; Immunohistochemistry ; In Situ Hybridization ; Magnetic Resonance Imaging ; Rectum ; Sarcoma, Ewing*

PURPOSE: To investigate whether histogram analysis of the hepatobiliary phase on gadoxetate enhanced-MRI could be used as a quantitative index for determination of liver cirrhosis. MATERIALS AND METHODS: A total of 63 patients [26 in a normal liver function (NLF) group and 37 in a cirrhotic group] underwent gadoxetate-enhanced MRI, and hepatobiliary phase images were obtained at 20 minutes after contrast injection. The signal intensity of the hepatic parenchyma was measured at four different regions of interest (ROI) of the liver, avoiding vessels and bile ducts. Standard deviation (SD), coefficient of variation (CV), and corrected CV were calculated on the histograms at the ROIs. The distributions of CVs calculated from the ROI histogram were examined and statistical analysis was carried out. RESULTS: The CV value was 0.041+/-0.009 (mean CV+/-SD) in the NLF group, while that of cirrhotic group was 0.071+/-0.020. There were statistically significant differences in the CVs and corrected CV values between the NLF and cirrhotic groups (p<0.001). The most accurate cut-off value among CVs for distinguishing normal from cirrhotic group was 0.052 (sensitivity 83.8% and specificity 88.5%). There was no statistically significant differences in SD between NLF and cirrhotic groups (p=0.307). CONCLUSION: The CV of histograms of the hepatobiliary phase on gadoxetate-enhanced MRI may be useful as a quantitative value for determining the presence of liver cirrhosis.
Adult ; Aged ; Aged, 80 and over ; Contrast Media/diagnostic use ; Female ; Gadolinium DTPA/diagnostic use ; Humans ; Liver Cirrhosis/*diagnosis ; Magnetic Resonance Imaging/methods ; Male ; Middle Aged ; Retrospective Studies ; Young Adult

Purpose: Expression of organic anion transporting polypeptides (OATPs) 1B1/1B3 in hepatocellular carcinoma (HCC) induces a paradoxical enhancement of gadoxetic acid on liver magnetic resonance imaging (MRI). We examined the expression profile of OATPs with regard to tumor differentiation in a genetically modified H-Ras 12V mouse model of spontaneous HCC that undergoes multistep hepatocarcinogenesis with minimal inter-individual variation. Materials and Methods: Tumor nodules were harvested from transgenic H-Ras 12V mice. Hematoxylin and eosin-stained slides were examined for tumor differentiation and high-grade pathological components (tumor necrosis, thickened trabeculae, or vascular invasion). Immunohistochemistry of OATP 1B1/1B3 was performed, and OATP expression was assessed. Results: We examined well-differentiated HCCs (n=59) in which high-grade pathological components were absent (n=49) or present (n=10). Among the well-differentiated HCCs without high-grade pathological components (n=49), OATP expression was negative, weak positive, and moderate positive in 23, 17, and nine cases, respectively. Among the well-differentiated HCCs with highgrade pathological components (n=10), OATP expression was negative, weak positive, and moderate positive in one, two, and seven cases, respectively. The ratio of positive OATP 1B1/1B3 expressing tumors was higher in HCCs with high-grade pathological components than in those without high-grade pathological components (p=0.004). Conclusion Our findings support those of previous clinical studies that have reported the frequent appearance of gadoxetic acidenhanced MRI in moderately differentiated HCC.

Purpose: Expression of organic anion transporting polypeptides (OATPs) 1B1/1B3 in hepatocellular carcinoma (HCC) induces a paradoxical enhancement of gadoxetic acid on liver magnetic resonance imaging (MRI). We examined the expression profile of OATPs with regard to tumor differentiation in a genetically modified H-Ras 12V mouse model of spontaneous HCC that undergoes multistep hepatocarcinogenesis with minimal inter-individual variation. Materials and Methods: Tumor nodules were harvested from transgenic H-Ras 12V mice. Hematoxylin and eosin-stained slides were examined for tumor differentiation and high-grade pathological components (tumor necrosis, thickened trabeculae, or vascular invasion). Immunohistochemistry of OATP 1B1/1B3 was performed, and OATP expression was assessed. Results: We examined well-differentiated HCCs (n=59) in which high-grade pathological components were absent (n=49) or present (n=10). Among the well-differentiated HCCs without high-grade pathological components (n=49), OATP expression was negative, weak positive, and moderate positive in 23, 17, and nine cases, respectively. Among the well-differentiated HCCs with highgrade pathological components (n=10), OATP expression was negative, weak positive, and moderate positive in one, two, and seven cases, respectively. The ratio of positive OATP 1B1/1B3 expressing tumors was higher in HCCs with high-grade pathological components than in those without high-grade pathological components (p=0.004). Conclusion Our findings support those of previous clinical studies that have reported the frequent appearance of gadoxetic acidenhanced MRI in moderately differentiated HCC.

Baseline magnetic resonance imaging (MRI) has become the primary staging modality for surgical plans and stratification of patient populations for more efficient neoadjuvant treatment. Patients who exhibit a complete response to chemoradiotherapy (CRT) may achieve excellent local tumor control and better quality of life with organ-preserving treatments such as local excision or even watch-and-wait management. Therefore, the evaluation of tumor response is a key factor for determining the appropriate treatment following CRT. Although post-CRT MRI is generally accepted as the first-choice method for evaluating treatment response after CRT, its application in the clinical decision process is not fully validated. In this review, we will discuss various oncologic treatment options from radical surgical technique to organ-preservation strategies for achieving better cancer control and improved quality of life following CRT. In addition, the current status of post-CRT MRI in restaging rectal cancer as well as the main imaging features that should be evaluated for treatment planning will also be described for the tailored treatment.
Chemoradiotherapy ; Humans ; Magnetic Resonance Imaging ; Methods ; Neoadjuvant Therapy ; Quality of Life ; Rectal Neoplasms

Locoregional recurrence after breast conservative surgery is not a rare event. However, a metastatic nodule solely at the surgical drain site seems to be extremely unusual. In this report, we present a patient who received a lumpectomy for breast cancer but a metastatic nodule developed at the drain site more than two years after her surgery.
Adult ; Breast Neoplasms/*pathology/*surgery ; Female ; Humans ; *Mastectomy, Segmental/adverse effects ; Neoplasm Recurrence, Local/*diagnosis

OBJECTIVE: To evaluate the performance of predicting early recurrence using preoperative factors only in comparison with using both pre-/postoperative factors.MATERIALS AND METHODS: We retrospectively reviewed 549 patients who had undergone curative resection for single hepatcellular carcinoma (HCC) within Milan criteria. Multivariable analysis was performed to identify pre-/postoperative high-risk factors of early recurrence after hepatic resection for HCC. Two prediction models for early HCC recurrence determined by stepwise variable selection methods based on Akaike information criterion were built, either based on preoperative factors alone or both pre-/postoperative factors. Area under the curve (AUC) for each receiver operating characteristic curve of the two models was calculated, and the two curves were compared for non-inferiority testing. The predictive models of early HCC recurrence were internally validated by bootstrap resampling method.RESULTS: Multivariable analysis on preoperative factors alone identified aspartate aminotransferase/platelet ratio index (OR, 1.632; 95% CI, 1.056–2.522; p = 0.027), tumor size (OR, 1.025; 95% CI, 0.002–1.049; p = 0.031), arterial rim enhancement of the tumor (OR, 2.350; 95% CI, 1.297–4.260; p = 0.005), and presence of nonhypervascular hepatobiliary hypointense nodules (OR, 1.983; 95% CI, 1.049–3.750; p = 0.035) on gadoxetic acid-enhanced magnetic resonance imaging as significant factors. After adding postoperative histopathologic factors, presence of microvascular invasion (OR, 1.868; 95% CI, 1.155–3.022; p = 0.011) became an additional significant factor, while tumor size became insignificant (p = 0.119). Comparison of the AUCs of the two models showed that the prediction model built on preoperative factors alone was not inferior to that including both pre-/postoperative factors {AUC for preoperative factors only, 0.673 (95% confidence interval [CI], 0.623–0.723) vs. AUC after adding postoperative factors, 0.691 (95% CI, 0.639–0.744); p = 0.0013}. Bootstrap resampling method showed that both the models were valid.CONCLUSION: Risk stratification solely based on preoperative imaging and laboratory factors was not inferior to that based on postoperative histopathologic risk factors in predicting early recurrence after curative resection in within Milan criteria single HCC patients.

Seventeen months after kidney transplantation for the treatment of nephrotic syndrome, a retroperitoneal mass was incidentally detected in a 30-year-old man during routine follow-up. Ultrasonography revealed a mass measuring 5.5 cmx4.3 cm located between the liver and the atrophic right kidney, which showed markedly heterogeneous internal echogenicity. Contrast-enhanced computed tomography displayed a mild degree of enhancement only at the periphery of the mass, while the center lacked perceivable intensification. The patient underwent surgical resection. The final pathological diagnosis was non-Hodgkin lymphoma (diffuse large B-cell lymphoma), and extensive necrosis was observed on microscopic examination. We found that the prominent heterogeneous echogenicity of the mass (an unusual finding of lymphoma) demonstrated on ultrasonography is a result of extensive necrosis, which may sometimes occur in patients with post-transplantation lymphoproliferative disorder.
Adult ; B-Lymphocytes ; Diagnosis ; Follow-Up Studies ; Humans ; Immunocompromised Host ; Kidney ; Kidney Transplantation ; Liver ; Lymphoma* ; Lymphoma, Non-Hodgkin ; Lymphoproliferative Disorders* ; Necrosis ; Nephrotic Syndrome ; Ultrasonography*

A 53-year-old male with hepatocellular carcinoma underwent orthotopic liver transplantation. Preoperative computed tomography revealed main portal vein luminal narrowing by flat thrombi and the development of cavernous transformation. On post-transplantation day 1, thrombotic portal venous occlusion occurred, and emergency thrombectomy was performed. Subsequent Doppler ultrasonography and contrast-enhanced ultrasonography confirmed the restoration of normal portal venous flow. The next day, however, decreased portal venous velocity was observed via Doppler ultrasonography, and serum liver enzymes and bilirubin levels remained persistently elevated. Direct portography identified massive perfusion steal through prominent splenorenal collateral veins. Stent insertion and balloon angioplasty of the portal vein were performed, and subsequent Doppler ultrasonography demonstrated normalized portal flow parameters. Afterwards, the serum liver enzymes and bilirubin levels rapidly normalized.
Angioplasty, Balloon ; Bilirubin ; Carcinoma, Hepatocellular ; Emergencies ; Humans ; Liver Transplantation* ; Liver* ; Male ; Middle Aged ; Perfusion* ; Phenobarbital ; Portal Vein ; Portasystemic Shunt, Surgical ; Portography ; Stents ; Thrombectomy ; Transplants* ; Ultrasonography ; Ultrasonography, Doppler ; Veins