小肠粪石的CT表现

小肠粪石很少见,以往影像学报道多见于消化道X线造影检查和超声检查。笔者观察小肠粪石在CT上有典型表现,报道如下,以提高认识。1材料与方法搜集经手术病理证实的小肠粪石3例,其中男2例,女1例。年龄分别为30岁、65岁、69岁。1例因胃癌曾行胃大部切除手术,其余2例无胃肠道手术史。患者均以肠梗阻就诊,均行小肠切开取石术证实为小肠粪石。使用SiemensPlus4型螺旋CT机行全腹部平扫,上至膈顶,下至耻骨联合。层厚10mm,间距10mm.2例患者检查前2h分次口服2%～3%浓度的泛影葡胺水溶液1000ml。1例患者未口服造影剂,直接行SCT检查。2结果3例均表现…     

Restricted diffusion within ring enhancement is not pathognomonic for brain abscess.

BACKGROUND AND PURPOSE: Recent experience suggests that diffusion-weighted MR imaging may be decisive in the differential diagnosis of ring-enhancing cerebral lesions. Whether restricted diffusion within a ring-enhancing cerebral mass lesion is pathognomonic for abscess was studied. METHODS: Seventeen patients with ring-enhancing cerebral lesions (three abscesses, six glioblastomas, eight metastases) on conventional contrast-enhanced T1-weighted images were examined with echo-planar diffusion-weighted MR imaging. Apparent diffusion coefficient (ADC) maps and the ADCs were calculated for all lesions. Lesions with signs of intralesional hemorrhage on unenhanced T1-weighted images were excluded. RESULTS: The central portion of all six glioblastomas and seven of eight metastases showed unrestricted diffusion, whereas two of three abscesses showed restricted diffusion (low ADC values) in their cavity. However, restricted diffusion also was found in one metastasis, and one abscess within a postoperative cavity showed unrestricted diffusion within a larger nondependent portion. CONCLUSION: In patients with ring-enhancing cerebral mass lesions, restricted diffusion might be characteristic but is not pathognomonic for abscess, as low ADC values also may be found in brain metastases.     

Closed-loop obstruction of the small bowel: CT and sonographic appearance

Two patients with closed loop obstruction diagnosed by CT and sonography are reported. Abdominal radiograph was nonspecific. The characteristic CT and sonographic features included (a) isolated conglomerate of dilated, fluid-filled bowel loops; (b) fixation of these "U" shaped distended loops; (c) thickened bowel wall; and (d) extraluminal fluid.     

Ectopic pancreas located in the small bowel: CT-endoscopic appearance. Apropos of two cases

Two patients have been diagnosed preoperatively with ectopic pancreas located within the small bowel using CT-enteroclysis. This technique, combining helical CT and small bowel opacification through a naso-jejunal tube, allows detection of small tumors.     

Normal anatomy and pathologic changes of the small bowel mesentery: US appearance

The ultrasonographic (US) appearance of the normal small bowel mesenteric leaves was evaluated in two in vitro studies and in 30 patients. Such structures had an elongated shape, echogenic surfaces, and small vessels in their center and could be recognized in 28 of the 30 patients. They did not show active movements, and at their distal end, the small bowel loops could be seen and peristalsis detected. Doppler signals were obtained from the small vascular structures in their center in three additional cases. On the basis of these anatomic findings, pathologic changes such as lymphoma, desmoid tumor, metastatic lesions, dilated vessels, and edema could be detected in 15 patients. When examining with US patients with diseases prone to involve the mesentery, careful attention should be given to this structure, since useful information about the abdominal spread of the disease can be obtained.     

Malignant small bowel obstruction and ascites: not a contraindication to percutaneous gastrostomy.

Percutaneous gastrostomy (PG) with gastropexy was performed for relief of malignant small bowel obstruction in 12 patients with extensive ascites. Abdominal paracentesis was performed before PG in nine patients and after PG in one patient. Gastrostomy catheters were inserted without complication in all patients. Clinical follow up revealed that pericatheter leakage of ascitic fluid and skin excoriation occurred only in the three patients who did not have paracentesis performed before PG. No dislodgement of gastrostomy catheters occurred but mild peritonitis was noted in one patient. Our experience suggests that although in the past extensive ascites was a relative contraindication for PG, these patients can now be successfully treated with a combination of ultrasound-guided paracentesis to reduce pericatheter leakage of ascitic fluid, and gastropexy to prevent catheter dislodgement.     

Ultrasound findings in small bowel infarction.

A patient with small bowel infarction was studied using grey-scale ultrasound. The appearance was that of a lobulated abdominal mass consisting of smaller masses with a central sonolucent area and a peripheral echogenic rind. This is the reverse of what has been described in intramural intestinal hematoma, intussusception, and inflammatory and neoplastic bowel masses.     

Multidetector CT appearance of adhesion-induced small bowel obstructions: matted adhesions versus single adhesive bands

Adhesive small bowel obstruction (SBO) is a common cause of abdominal pain after surgery or peritonitis. The role of computed tomography (CT) in the evaluation of SBO has expanded. Diagnosis of adhesive SBO, however, remains challenging. Adhesions causing SBO are classified as either matted adhesions or single adhesive bands, and both types have different mechanisms that lead to SBO. In patients with matted adhesions, SBO results from angulation and kinking or from torsion of the intestines. In patients with adhesive bands, SBO results from compression of the intestine caused by the band itself. Recent advances in spatial resolution using multidetector CT (MDCT) have enabled detailed assessment of the configuration of the SBO site. Presented in this pictorial essay are characteristic MDCT findings regarding the mechanism of the obstruction process of adhesive SBO.     

Prevalence of cystic fibrosis in fetuses with dilated bowel.

The authors reviewed the ultrasonographic images and medical records of 15 consecutive fetuses with dilated loops of bowel distal to the duodenum and determined the prevalence of cystic fibrosis among them. The criteria for dilated bowel loops included both subjective criteria and luminal measurements. Five of the fetuses (33%) had cystic fibrosis. Eleven had bowel obstruction at birth, and four of those 11 (36%) also had cystic fibrosis. One of the four fetuses without bowel obstruction at birth had cystic fibrosis. There were no differences in sonographic findings between fetuses with and without cystic fibrosis, except that one third-trimester fetus with cystic fibrosis had echogenic small bowel with shadowing. All of the fetuses with dilated bowel loops persisting at birth required surgery. Further studies are indicated to determine the exact risk of cystic fibrosis in this population.     

Ct evaluation of small bowel obstruction.

Although small bowel obstruction is a common occurrence, it is essential that this clinical condition be treated properly, that the site, level, and cause of obstruction be determined accurately, and that a tentative prognosis be formulated prior to surgery. The diagnosis of small bowel obstruction is based on a comprehensive approach that includes clinical background, patient history, and results of physical examination and laboratory tests. A variety of radiologic procedures are available to aid in the diagnosis of small bowel obstruction. Recent studies have demonstrated the superiority of CT in revealing the site, level, and cause of obstruction and in demonstrating threatening signs of bowel inviability. CT has proved useful in characterizing small bowel obstruction from extrinsic causes (adhesions, closed loop, strangulation, hernia, extrinsic masses), intrinsic causes (adenocarcinoma, Crohn disease, tuberculosis, radiation enteropathy, intramural hemorrhage, intussusception), intraluminal causes (eg, bezoars), or intestinal malrotation. Conventional radiography was the modality of choice for many years and should remain the initial imaging method in patients with suspected small bowel obstruction. However, the unique capabilities of CT in this setting make this modality an important additional diagnostic tool when specific disease management issues must be addressed.     

Magnetic resonance enterography/enteroclysis in acquired small bowel diverticulitis and small bowel diverticulosis

Purpose

Small bowel (SB) diverticulosis is a rare disorder that may entail serious complications, including SB diverticulitis. Both are often missed in imaging. Magnetic resonance enterography/enteroclysis (MRE) is increasingly used to assess SB disease; awareness of the appearance of SB diverticulitis is essential to ensure appropriate management. Our aim was to systematically describe imaging characteristics of SB diverticulosis and diverticulitis in MRE.

Methods

This retrospective, HIPAA-compliant study identified 186 patients with suspected SB diverticulosis/diverticulitis in medical databases of two tertiary medical centres between 2005 and 2011. Patients with surgically confirmed diagnoses of SB diverticulosis/diverticulitis were included. Two observers analyzed MR images for the presence, location, number, and size of diverticula, wall thickness, and mural and extramural patterns of inflammation.

Results

Seven patients were recruited. MRI analysis showed multiple diverticula in all (100 %). Diverticular size ranged from 0.5 to 6 cm. Prevalence of diverticula was higher in the proximal than the distal SB (jejunum 86 %, ileum 57 %, distal ileum43%). Diverticulitis occurred in 3/7 patients (43 %) showing asymmetric bowel wall thickening and focal mesenteric inflammation.

Conclusion

SB diverticulitis demonstrates characteristic MRE imaging features to distinguish this rare disorder from more common diseases. Asymmetric, focal mesenteric and mural inflammation and presence of multiple diverticula are keys to diagnosis.

Key points

? Small bowel diverticulosis and diverticulitis is rare and often missed in imaging ? Acquired small bowel diverticula are variable in size and number ? Small bowel diverticulitis demonstrates characteristic features on MR enterography/enteroclysis ? A focal or segmental asymmetric small bowel inflammation should prompt the search for diverticula

     

Angiography of intussusception of the small bowel.

Angiography demonstrated intussusception in a patient with recurrent unexplained gastrointestinal hemorrhage after outside barium studies had been interpreted as normal. Magnification arteriography provided an unusually clear depiction of the anatomic derangement of intussusception.