Beschreibung: Purpose Reducing blood flow in the liver during radiofrequency ablation causes enlargement of the ablation area. In this animal study, we evaluated the extended effects of radiofrequency ablation combined with transarterial embolization using various embolic agents. Methods We treated 38 radiofrequency ablation lesions after embolization in 13 pigs using the following embolic agents: gelatin sponge (Group A); iodized oil followed by gelatin sponge (Group B); 700–900 µm calibrated microspheres (Group C); and 100–300 µm calibrated microspheres (Group D). Lesion size and pathological evaluations of these ablation lesions were compared with those receiving radiofrequency ablation alone (control). Results Both the long- and short-axis diameters of the ablation lesions for Groups A, B, C, and D were significantly longer than those of controls (long axis/short axis for Groups A, B, C, D, and controls were 27.2/23.2, 30.2/26.0, 28.2/22.2, 32.0/24.4, and 23.2 mm/18.5 mm, respectively) ( P  〈 0.05). The long-axis of the ablation lesion for Group D was significantly longer than those for both Groups A and C ( P  〈 0.05). At pathological examination, the central ablation lesions showed coagulative necrosis with a surrounding hemorrhagic rim, and the microspheres were fitted to occlude the small arteries in peripheral liver parenchyma in Groups C and D. Conclusions The extended effects of embolization with small microspheres may be stronger than those with large microspheres and were equal to those with iodized oil followed by gelatin sponge.

Beschreibung: We report here a rare case of undifferentiated carcinoma of the pancreas mimicking main-duct intraductal papillary mucinous neoplasm. In an 80-year-old woman, an approximately 8-mm papillary mass was incidentally detected at the downstream edge of a dilatated main pancreatic duct lumen on CT and MRI. Main pancreatic duct dilatation in the pancreatic body and tail and parenchymal atrophy were observed in the upstream of the mass. Histopathologically, the tumor protruded into the downstream edge of the dilatated main pancreatic duct lumen in the pancreatic body. The tumor cells had highly atypical nuclei and abundant polymorphic structures, and showed positive staining for granulocyte colony-stimulating factor, which led to the diagnosis of undifferentiated carcinoma. A total of 13 cases of undifferentiated carcinoma with intraductal tumor growth have been reported to date. The case report by Bergmann et al. has been the smallest in histopathological specimen, and the present case is the smallest in size detected by radiological images. Since early undifferentiated carcinoma of the pancreas can resemble those of main-duct intraductal papillary mucinous neoplasm in cross-sectional images, we have to consider undifferentiated carcinoma in the differential diagnosis of the solitary and papillary mass with low contrast enhancement in early phase in the main pancreatic duct.

Beschreibung: Purpose The purpose of the study is to evaluate the influence of the adaptive iterative dose reduction (AIDR 3D) algorithm on the detectability of low-contrast focal liver lesions (FLLs) and the radiation dose repeatability of automatic tube current modulation (ATCM) in abdominal CT scans using anthropomorphic phantoms. Materials and Methods Three different sizes of anthropomorphic phantoms, each with 4 low-contrast FLLs, were scanned on a 320-channel CT scanner using the ATCM technique and AIDR 3D, at different radiation doses: full-dose, half-dose, and quarter-dose. Scans were repeated three times and reconstructed with filtered back projection (FBP) and AIDR 3D. Radiation dose repeatability was assessed using the intraclass correlation coefficient (ICC). Image noise, quality, and lesion conspicuity were assessed by four reviewers and the number of invisible FLLs was compared among different radiation doses and reconstruction methods. Results ICCs of radiation dose among the three CT scans were excellent in all phantoms (0.99). Image noise, quality, and lesion conspicuity in the half-dose group were comparable with full-dose FBP after applying AIDR 3D in all phantoms. In small phantoms, the half-dose group reconstructed with AIDR 3D showed similar sensitivity in visualizing low-contrast FLLs compared to full-dose FBP ( P  = 0.77–0.84). In medium and large phantoms, AIDR 3D reduced the number of missing low-contrast FLLs [3.1% (9/288), 11.5% (33/288), respectively], compared to FBP [10.4% (30/288), 21.9% (63/288), respectively] in the full-dose group. Conclusion By applying AIDR 3D, half-dose CT scans may be achievable in small-sized patients without hampering diagnostic performance, while it may improve diagnostic performance in medium- and large-sized patients without increasing the radiation dose.

Beschreibung: A 50-year-old postmenopausal woman, who underwent ultrasonography at a periodic medical checkup, was found to have bilateral ovarian masses. Pelvic magnetic resonance imaging (MRI) showed bilateral multilocular cystic ovarian masses. The cyst walls and septal structure demonstrated contrast enhancement. She underwent bilateral salpingo-oophorectomy. Microscopic examination revealed that the cysts were lined with cuboidal or columnar epithelial cells, and some of the cells were ciliated. The final histopathological diagnosis was endosalpingiosis. Endosalpingiosis is defined as the presence of ectopic ciliated epithelium, resembling the normal endosalpinx, without endometrial stroma. It rarely presents as a tumor-like mass on MRI.

Beschreibung: Purpose Polypoid adenomyoma (PA) is an uncommon benign tumor of the uterus appearing as a submucosal polypoid mass, or rarely as a subserosal polypoid mass. PA should be differentiated from atypical polypoid adenomyoma or malignant uterine tumors. The purpose of our case series is to evaluate magnetic resonance (MR) manifestations of PA for the differential diagnosis. Methods Seven cases with surgically proven PA, five submucosal, and two subserosal, were evaluated. MR imaging findings including contrast enhancement in six cases (four cases with dynamic contrast-enhanced MR study), diffusion-weighted imaging (DWI) in five cases, and susceptibility weighted imaging (SWI) in two cases were retrospectively reviewed. Results All seven lesions exhibited isointensity compared with the myometrium and 4 of 7 lesions (57%) contained high signal intensity hemorrhagic areas on T1-weighted images. On T2-weighted images, signal intensity was variable and all seven lesions contained cysts. None of five lesions with DWI exhibited high signal intensity compared with the normal myometrium. All six lesions showed intense contrast enhancement similar to that of the myometrium on post-contrast T1-weighted images. Punctate low intensity areas reflecting blood contents were revealed in all two lesions with SWI. Conclusions Submucosal or subserosal polypoid masses containing hemorrhagic areas, and cysts reflecting functional endometrium and dilatation of endometrial glands are suggestive for PA. Intense contrast enhancement similar to that of the myometrium may be another characteristic finding for PA.

Beschreibung: Purpose Portacaval lymphadenopathy (PCLA) is common in cirrhosis and chronic viral hepatitis and is frequently an incidental finding on abdominal CT scans. We aimed to detect the incidence of malignancy in organs drained by portacaval nodes in patients with PCLA associated with cirrhosis or chronic viral hepatitis, or incidentally detected PCLA. Methods We searched CT reports from 2005 to 2007 for the phrases “periportal node” and “portacaval node.” MDCTs of patients with portacaval nodes ≥10 mm in maximal short-axis size on contrast-enhanced MDCTs, were included. Records were reviewed for presence of malignancy, liver metastases, chronic viral hepatitis, and cirrhosis. Clinical or imaging follow-up ≥6 months was performed to detect if malignancy developed in organs drained by portacaval nodes in patients with incidental PCLA, cirrhosis, or chronic viral hepatitis. Results 479 patients met inclusion criteria [298 males (62%), mean age 61.4 years]. In 285 (59.5%) patients, PCLA was explained by local pathology or systemic lymphadenopathy. PCLA was incidental in 146 (30.5%) patients. Of these, 112 (76.7%) had ≥6 months of follow-up (median 26 months). No patient with incidental PCLA developed malignancy in organs drained by these nodes. Cirrhosis or chronic viral hepatitis was present in 48 (10.0%) patients. Of these, 42 (87.5%) had ≥6 months follow-up (median 28 months), and only 1 patient developed cholangiocarcinoma (positive predictive value 2.4%). Conclusions Development of malignancy is rare in patients with PCLA, either incidental or secondary to cirrhosis or chronic viral hepatitis. Our study suggests that no follow-up of PCLA is required in these settings.

Beschreibung: Purpose To determine (1) the sensitivity for detection of small polyps with varying MR slice thicknesses using a resolution phantom; (2) reader confidence in polyp detection; and (3) image acquisition time. Methods A resolution phantom was created using a 3D printer. Polyp morphologies were sessile (height = diameter), flat (height = 1/2 diameter of the base), and pedunculated (stalk length = polyp diameter). Polyp diameters were 5, 7, 10, and 12 mm. Images were acquired with section thicknesses of 5, 3, and 1 mm. Images were independently reviewed by 4 board-certified radiologists who were blinded to phantom design and sequences parameters. Readers recorded maximal polyp diameter and confidence level that a polyp was present on a 1–100 point scale. Image acquisition time was also recorded. Results All polyps were detected by all 4 readers in the 5-mm-section thickness series. All polyps were detected by 3 readers in the 3- and 1-mm-section thickness series. The fourth reader identified 11/12 polyps in the 3- and 1-mm-section thickness series. Confidence levels were not statistically significantly different for the different section thicknesses ( p  = 0.28). Increasing the section thickness from 1 to 5 mm decreased image acquisition time from 3 min 54 s to 41 s. Conclusions Five-millimeter-section thickness was adequate for identification of 5–12 mm polyps regardless of shape. Pending further reduction in acquisition time, this prototype sequence holds promise for segmental imaging of the colon with MR colonography.

Beschreibung: Gastric-type adenocarcinoma (GAS) of the uterine cervix is a recently defined subtype of mucinous adenocarcinoma. GAS is proposed to include minimal deviation adenocarcinoma (MDA) as a very well-differentiated form and has been suggested to arise from lobular endocervical glandular hyperplasia (LEGH). We report the magnetic resonance imaging (MRI) findings of a GAS associated with LEGH. On MRI, the LEGH component was detected as multiple cystic lesions arranged in a “cosmos pattern”, while the GAS was depicted as a predominantly solid lesion containing obvious adenocarcinoma and MDA components, which appeared as mass-like and infiltrative components, respectively. The GAS exhibited tiny cysts on three-dimensional T2-weighted images, high intensity on diffusion-weighted images mostly due to T2 shine-through effect according to apparent diffusion coefficient (ADC) map, and reticular enhancement on dynamic contrast-enhanced MRI, which reflected numerous dilated glandular structures of the tumor. Low ADC was only observed at the deepest invasion front of the obvious adenocarcinoma component. Our case suggests that the MRI features of GAS vary depending on the tumor’s histological components, and it is important to be aware of these imaging features when evaluating LEGH on MRI.

Beschreibung: We present a rare case of testicular seminoma in persistent Mullerian duct syndrome (PMDS) with transverse testicular ectopia (TTE). A 42-year-old man noticed scrotal swelling a few weeks earlier and underwent magnetic resonance imaging (MRI) on suspicion of testicular tumor. MRI revealed a normal left testis on the left side of the left scrotum and a heterogeneous mass on the right side within the left scrotum. No right testis was found in the right scrotum. A blind-ending tubular structure with thickened wall showed a three-layer appearance on T2-weighted imaging and extended from the prostate through the left inguinal canal to the left scrotum. Findings during surgery suggested right testicular tumor associated with right TTE. The histopathological and immunohistochemical diagnoses of the testicular tumor and blind-ending tubular structure were seminoma and persistent Mullerian duct, respectively. Testicular tumor in PMDS with TTE is rare but may possess a characteristic appearance on imaging. Proper knowledge of these diseases will allow correct preoperative diagnosis.

Beschreibung: The aim of this study is to compare the clinical outcomes of transjugular intrahepatic portosystemic shunt (TIPS) and endoscopic band ligation (EBL) in patients with cirrhosis and portal vein thrombosis (PVT). We retrospectively reviewed the January to September 2010 data from our database and included 25 patients with cirrhosis and PVT who underwent successful TIPS creation. We selected another 25 patients who underwent EBL matching for age, sex, and Child-Pugh-Turcotte class. The outcome measures included changes in the PVT status before and after the treatments, the rebleeding rate, and the overall survival. The mean follow-up was 25.1 ± 8.7 months in the EBL group and 25.6 ± 8.5 months in the TIPS group ( P  = 0.85). After treatments, the PVT severity improved in 40% and worsened in 25% of patients who did not undergo TIPS, compared with 87% and none of the patients who underwent TIPS ( P  〈 0.001). Previous splenectomy (OR 0.13, 95% CI 0.02–0.76, P  = 0.024) and patency status of TIPS (OR 20.8, 95% CI 3.0–141.8, P  = 0.002) were the independent factors associated with PVT disappearance. The 1- and 2-year rebleeding rates were, respectively, 44.6% and 59.0% in the EBL group, and 12.5% and 25.2% in the TIPS group ( P  = 0.002). The 1- and 2-year survival rates were, respectively, 95.7% and 85.2% in the EBL group, and 96% and 78.7% in the TIPS group ( P  = 0.203). The MELD score was the only independent predictive factor for survival (HR 1.73, 95% CI 1.27–2.37, P  = 0.001). Compared with EBL, TIPS contributed to PVT improvement and reduced the risk of rebleeding without providing a survival benefit for patients with PVT.