Relationship between patient centering,mean computed tomography numbers and noise in abdominal computed tomography:Influence of anthropomorphic parameters

AIM:To determine the influence of anthropomorphic parameters on the relationship between patient centering,mean computed tomography(CT) numbers and quantitative image noise in abdominal CT.METHODS:Our Institutional Review Board approved study included 395 patients(age range 21-108,years;male:female = 195:200) who underwent contrast-enhanced abdominal CT on a 16-section multi-detector row scanner(GE LightSpeed 16).Patient centering in the gantry isocenter was measured from the lateral localizer radiograph(off center S = patient off centered superior to isocenter;off center I = patient off centered inferior to isocenter).Mean CT numbers(Hounsfield Units:HU) and noise(standard deviation of CT numbers:SD) were measured in the anterior(aHU,aSD) and posterior(pHU,pSD) abdominal wall subcutaneous fat and liver parenchyma(LivHU,LivSD) at the level of the porta hepatis.Patients' age,gender,weight,body mass index and maximal anteroposterior diameter were recorded.The data were analyzed using linear regression analysis.RESULTS:Most patients(81%;320/395) were not correctly centered in the gantry isocenter for abdominal CT scanning.Mean CT numbers in the abdominal wall increased significantly with an increase in the offcentering distance,regardless of the direction of the off-center(P < 0.05).There was a substantial increase in pSD(P = 0.01) and LivSD(P = 0.017) with off-centering.Change in mean CT numbers and image noise along the off-center distance was influenced by the patient size(P < 0.01).CONCLUSION:Inappropriate patient centering for CT scanning adversely affects the reliability of mean CT numbers and image noise.

Cryptogenic multifocal ulcerous stenosing enteritis: Radiologic features and clinical behavior

AIM To investigate the characteristic radiologic findings of cryptogenic multifocal ulcerous stenosing enteritis(CMUSE) which can be differentiated from other similar bowel disease and to assess their clinical behavior.METHODS Twenty pathologically and clinically confirmed CMUSE patients(males:females = 8:12; mean age: 40.4 years) between March 2002 and August 2015 from seven academic centers in South Korea were retrospectively reviewed. We evaluated small bowel series(SBS; n = 25), computed tomography(CT) enterography(n = 21), magnetic resonance(MR) enterography(n = 2), and abdominopelvic CT(n = 18) images, focusing on enteric and perienteric manifestations. Any change in radiologic features during followup period was recorded. We evaluated clinical data including presenting symptoms, laboratory finding and presence of relapse from electronic medical records. Histopathologic findings were also evaluated. RESULTS The main symptoms were abdominal pain(n = 12) and anemia(n = 10). All patients showed small bowel strictures(n = 52, mean: 2.6 per patient) on initial CT/MR, located in the ileum(n = 47) or jejunum(n = 5). Strictures showed short-length(mean: 10.44 mm) and circumferential bowel wall thickening(mean: 5.56 mm) with layered enhancement(n = 48) that were also noted on initial SBS(n = 36) with shallow ulcers(n = 10). Some ulcerative lesions or wall thickening progressed into strictures on follow-up SBS/CT, and some strictures revealed recurrent ulceration on followup SBS. There were no penetrating disease features like fistula or abscess and no gastrointestinal tract involvement except the small bowel. Nine patients experienced disease recurrence(median relapse-free period: 32 mo) even post-operatively. Histopathologic features of surgically resected specimens were characterized as multiple superficial ulcerations confined to mucosa or submucosa and multiple strictures.CONCLUSION Under characteristic radiologic findings with multiple short-segmental strictures and/or shallow ulcers of the small intestine, CMUSE should be considered when assessing patients with recurrent abdominal pain and anemia.

A case of a duodenal duplication cyst presenting as melena

Duodenal duplication cysts are benign rare congenital anomalies reported mainly in the pediatric population,but seldom in adults.Symptoms depend on the type and location and can present as abdominal pain,distension,dysphagia or dyspepsia.They have been reported to be responsible for duodenal obstruction,pancreatitis and,in rare cases,gastrointestinal bleeding.We present a case of a duodenal duplication cyst in a 43-year-old man presenting as melena.Initial gastroduodenoscopy and colonoscopy did not reveal any bleeding focus.However,the patient began passing melena after 3 d,with an acute decrease in hemoglobin levels.Subsequent studies revealed a duplication cyst in the second portion of the duodenum which was surgically resected.Histology revealed a duodenal duplication cyst consisting of intestinal mucosa.There was no further bleeding and the patient recovered completely.In rare cases,duodenal duplication cysts might cause gastrointestinal bleeding and should be included in the differential diagnosis.