MR cholangiopancreatographic differentiation of benign and malignant intraductal mucin-producing tumors of the pancreas

OBJECTIVE: The purpose of this study was to establish MR cholangiopancreatographic criteria for discriminating benign from malignant intraductal mucin-producing tumors of the pancreas. MATERIALS AND METHODS: Thirty-one patients with 34 intraductal mucin-producing tumors underwent MR cholangiopancreatography. Tumors were classified as either main duct type (n = 10) or branch duct type (n = 24). In patients with the main duct type, the maximum diameter and the location of the main pancreatic duct, the extent of main pancreatic duct dilatation, and the presence of a filling defect were evaluated. For branch duct type, the location and maximum diameter of the cystic lesion, the presence of a filling defect, and the presence of associated main pancreatic duct dilatation were evaluated. RESULTS: In patients with the main duct type, the main pancreatic duct was significantly narrower when associated with benign rather than malignant tumors. All malignant tumors showed diffuse main pancreatic duct dilatation, whereas all benign tumors showed segmental dilatation. Among patients with branch duct type, the cyst was smaller when it was a benign rather than malignant tumor. All but one malignant tumor showed mild associated main pancreatic duct dilatation, whereas benign tumors were not associated with main pancreatic duct dilatation. Filling defects suggested malignancy, although half of the malignant tumors had no filling defects. CONCLUSION: In patients with intraductal mucin-producing tumors of the pancreas, filling defects are indicative of malignancy. Diffuse main pancreatic duct dilatation greater than 15 mm (main duct type), or any main pancreatic duct dilatation (branch duct type), is strongly associated with malignancy.     

Homogeneously enhancing breast lesions on contrast enhanced US: differential diagnosis by conventional and contrast enhanced US findings

Objective

To clarify the details of homogeneously enhancing lesions on contrast-enhanced ultrasonography (CEUS) and also to elucidate whether their differential diagnosis is possible.

Methods

Seventy-three homogeneously enhancing lesions on CEUS were retrospectively selected. Two radiologists first assessed conventional US findings alone in consensus to differentiate malignant vs. benign lesions. Then, qualitative and quantitative CEUS findings were analyzed to determine the useful findings for the differential diagnosis. Determined CEUS findings were applied to the indeterminate lesions based on conventional US findings to see whether CEUS can improve the diagnostic performance.

Results

There were 42 cancers (58 %) out of 73. Sensitivity and specificity using conventional US findings alone were 91 and 55 %, respectively. Among the CEUS findings tested, multivariate analysis revealed only the type 3 enhancement pattern, which indicates a larger enhancing area than the precontrast hypoechoic lesion, was related to malignancy (p < 0.05). By adding this information, however, no improvement was achieved in the diagnostic performance as determined by conventional US findings.

Conclusions

Approximately half of the homogeneously enhancing lesions on CEUS are malignant, and differentiation of malignant from benign lesions may be possible, at least to some extent, by meticulous assessment of the conventional US rather than CEUS findings.

     

Significance of mesenteric lymphadenopathy after pancreaticoduodenectomy for periampullary carcinomas: evaluation with serial MDCT studies

OBJECTIVE: To evaluate the significance of mesenteric lymphadenopathy arising after pancreaticoduodenectomy (PD) for periampullary carcinomas. MATERIALS AND METHODS: Serial multidetector CT (MDCT) studies in 44 patients after PD for periampullary carcinomas (Group A) were retrospectively reviewed, the incidence and interval changes of mesenteric lymphadenopathy were evaluated, and comparisons were made with 21 patients who underwent PD for benign diseases (Group B). RESULTS: In Group A, mesenteric lymphadenopathy was seen in 31 of 44 (70.5%) patients. The short axis diameter of the largest lymph node ranged from 6.2 to 11.5mm (mean+/-S.D.: 8.6+/-1.4mm), and the short-axis-to-long-axis (S/L) ratio ranged from 0.46 to 0.99 (mean+/-S.D.: 0.69+/-0.12). Six of the 31 (19.4%) mesenteric lymphadenopathy cases showed interval increases in size on follow-up studies, and three cases showed new development of mesenteric lymphadenopathy: all of these nine cases had concurrent recurrence in the mesenteric root. In Group B, 11 (52.4%) had mesenteric lymphadenopathy. The short axis diameter of the largest lymph node ranged from 5.6 to 10.9mm (mean+/-S.D.: 8.0+/-1.9mm) and the S/L ratio ranged from 0.48 to 0.93 (mean+/-S.D.: 0.67+/-0.12). Differences in the incidence, short axis diameter and S/L ratio were not significant between Groups A and B (p=0.154, 0.271 and 0.654, respectively). CONCLUSION: Mesenetric lymphadenopathy after PD less likely reflects recurrence. Lymph node metastasis may be suggested only when coexisting recurrent mass is found in the proximal mesenteric root.     

Synthesis and evaluation of PET probes for the imaging of I2 imidazoline receptors in peripheral tissues

IntroductionTo explore the possible use of positron emission tomography (PET) probes for imaging of I₂-imidazoline receptors (I₂Rs) in peripheral tissues, we labeled two new I₂R ligands, 2-[2-(o-tolyl)vinyl]-4,5-dihydro-1H-imidazole (K_i for I₂Rs, 3.7 nM) and 2-[2-(o-tolyl)ethyl]-4,5-dihydro-1H-imidazole (K_i for I₂Rs, 1.7 nM) with ¹¹C ([¹¹C]metrazoline and [¹¹C]TEIMD), respectively, and evaluated these ligands and the recently developed I₂R ligand 2-[3-fluoro-[4-¹¹C]tolyl]-4,5-dihydro-1H-imidazole ([¹¹C]FTIMD) by in vivo studies.Methods[¹¹C]Metrazoline and [¹¹C]TEIMD were prepared by a palladium-promoted cross-coupling reaction of the tributylstannyl precursor and [¹¹C]methyl iodide. Their biodistribution in mice was investigated by tissue dissection. In addition, PET scans and metabolite analysis were performed.Results[¹¹C]Metrazoline and [¹¹C]TEIMD were successfully synthesized with a suitable radioactivity for injection. In the liver and pancreas expressing I₂Rs, coinjection with the high-affinity I₂R ligand, BU224, induced a reduction in the radioactivity level at 30 min after injection of [¹¹C]metrazoline and [¹¹C]FTIMD. However, the radioactivity level after injection of [¹¹C]TEIMD was unchanged. In the PET study, coinjection with BU224 induced a decrease in the radioactivity level in the liver and pancreas after more than 15 min of injection of [¹¹C]metrazoline and [¹¹C]FTIMD as compared with the results obtained for controls. In metabolite analysis, coinjection with BU224 induced a significant reduction in the percentage of unchanged [¹¹C]metrazoline at 30 min after injection as compared with that in the control, although no significant difference was observed in the percentage of unchanged [¹¹C]FTIMD.Conclusion[¹¹C]Metrazoline may be a more useful PET probe than [¹¹C]FTIMD for imaging of I₂Rs in peripheral tissues.     

Enhanced CT in the diagnosis of acute appendicitis to evaluate the severity of disease: comparison of CT findings and histological diagnosis

PURPOSE: To assess the potential of CT in evaluating the histological severity of acute appendicitis in comparison with surgical and pathological findings. METHOD: The CT images of 75 patients with surgically proven appendicitis, including 10 cases of catarrhal, 34 of phlegmonous, and 31 of gangrenous appendicitis, were retrospectively analyzed for the following five CT findings: (1) hazy periappendiceal densities, (2) enlarged appendix, (3) increased enhancement of the appendiceal wall, (4) increased enhancement of the periappendiceal intestinal wall, and (5) deficiency of the appendiceal wall. By comparing all the CT findings and the pathological severity of appendicitis (catarrhal, phlegmonous, and gangrenous), the prevalence of the five CT findings was calculated for each pathological category. RESULTS: Abnormal CT findings were noted in only one case of catarrhal appendicitis. Increased enhancement of the appendiceal wall was observed in all 29 cases of phlegmonous appendicitis (100%), but in only 66.7% (18 cases) of gangrenous appendicitis. Deficiency of the appendiceal wall was more frequently observed in gangrenous (19/27, 70.4%) than phlegmonous appendicitis (4/29, 13.8%). CONCLUSION: Findings of enhanced CT provide useful information in evaluating the pathological severity of acute appendicitis.     

Japanese Dermatological Association Guidelines: Guidelines for the treatment of acne vulgaris 2017

The Guidelines for the Treatment of Acne Vulgaris of the Japanese Dermatological Association was first published in Japanese in 2008 and revised in 2016 and 2017. These guidelines (GL) indicate the standard acne treatments in Japan and address pharmaceutical drugs and treatments applicable or in use in Japan. In these GL, the strength of the recommendation is based on clinical evidences as well as availability in Japanese medical institutions. In the 2016 and 2017 GL, some of the clinical questions were revised, and other questions were added in accordance with approval of topical medicines containing benzoyl peroxide (BPO). Rather than monotherapies of antibiotics, the 2017 GL more strongly recommend combination therapies, especially fixed‐dose combination gels including BPO in the aspects of pharmacological actions and compliance in the acute inflammatory phase to achieve earlier and better improvements. The 2017 GL also indicate to limit the antimicrobial treatments for the acute inflammatory phase up to approximately 3 months and recommend BPO, adapalene, and a fixed‐dose combination gel of 0.1% adapalene and 2.5% BPO for the maintenance phase to avoid the emergence of antimicrobial‐resistant Propionibacterium acnes. The 2017 GL also discuss rosacea, which requires discrimination from acne and a different treatment plan.     

A novel prostanoid EP1 receptor antagonist,ONO-8539, reduces acid-induced heartburn symptoms in healthy male volunteers: a randomized clinical trial

Journal of Gastroenterology - Patients with proton pump inhibitor (PPI)-refractory gastroesophageal reflux disease (GERD) have unmet clinical needs. Recently, we reported that esophageal...