CT enterography with polyethylene glycol solution vs CT enteroclysis in small bowel disease.

OBJECTIVE: The aim of the study is to compare CT enterography with polyethylene glycol solution (PEG-CT) with CT enteroclysis (CT-E) in patients with suspected small bowel disease. METHODS: 145 patients underwent abdominal contrast-enhanced 16-row multidetector CT after administration of 2000 ml of PEG by mouth (n = 75) or after administration of 2000 ml of methylcellulose by nasojejunal tube (n = 70). Small bowel distension, luminal and extraluminal findings were evaluated and compared with small bowel follow-through examination in 60 patients, double contrast enema in 50, surgery in 25 and endoscopy in 35. Statistical evaluation was carried out by χ² testing. For both techniques we have also calculated the effective dose and the equivalent dose in a standard patient. RESULTS: Crohn's disease was diagnosed in 64 patients, neoplasms in 16, adhesions in 6. Distension of the jejunum was better with CT-E than PEG-CT (p<0.05: statistically significant difference). No significant difference was present for others sites (p>0.05). Evaluation of pathological ileal loops was good with both techniques. The values of sensitivity, specificity and diagnostic accuracy were respectively 94%, 100% and 96% with CT-E, and 93%, 94% and 93% with PEG-CT. The effective dose for PEG-CT was less than the dose for the CT-E (34.7 mSv vs 39.91 mSv). CONCLUSION: PEG-CT shows findings of Crohn's disease as well as CT-E does, although CT-E gives better bowel distension, especially in the jejunum, and has higher specificity than PEG-CT.

CT enteroclysis: multidetector technique (MDCT) versus single-detector technique (SDCT) in patients with suspected small-bowel Crohn's disease.

PURPOSE: This study was done to evaluate the diagnostic role of enteroclysis with multidetector computed tomography (MDCT) and single-detector CT (SDCT) in patients affected by small-bowel Crohn's disease. MATERIALS AND METHODS: Forty-five patients underwent abdominal SDCT (n=20) or 16-row MDCT (n=25) after administration of methylcellulose by nasojejunal tube. Each examination was assessed for small-bowel distension and site and characteristics of the diseased loops. The two CT techniques were then compared. Results were compared with double-contrast enteroclysis performed in all patients and with ileoscopy performed in 28 patients. RESULTS: In comparison with double-contrast enteroclysis, sensitivity, specificity and diagnostic accuracy were 90%, 71% and 89% for SDCT and 92%, 83% and 90% for MDCT. Ileoscopy confirmed the absence of disease in five patients and the presence of Crohn's disease in 20. Compared with SDCT, MDCT reduced scanning time and respiratory artefacts and permitted better multiplanar reconstructions. CONCLUSIONS: MDCT is superior to SDCT because it allows a better spatial resolution and improves depiction of the pathological patterns of Crohn's disease.

Multidetector CT in small-bowel neoplasms.

PURPOSE: The aim of this study was to assess the diagnostic potential of multidetector computed tomography (MDCT) in the evaluation of small-bowel neoplasms. MATERIALS AND METHODS: We studied 120 patients with suspected small-bowel disease by 16-slice MDCT after oral administration of a polyethylene glycol solution (n=56) or methylcellulose via a nasojejunal tube (n=64). Unenhanced and contrast-enhanced CT was performed. Contrast-enhanced CT images were acquired 40 s after IV injection of 130 ml of iodinated contrast agent at a rate of 3 ml/s. Multiplanar reconstructions were performed at the end of the examinations. RESULTS: Fifteen patients were found to be affected by small-bowel neoplasm (six had non-Hodgkin's lymphoma, three had carcinoid tumour, two had Peutz-Jeghers syndrome, two had adenocarcinoma, two had melanoma metastases, one had lipoma). In the remaining patients, 58 cases of Crohn's disease and seven miscellaneous diseases were detected. All findings were confirmed by barium studies, surgery or endoscopy. CONCLUSIONS: MDCT performed after bowel-loop distension with low-density contrast material and IV administration of iodinated contrast agent is a reliable method for diagnosing and staging small-bowel neoplasms.

The value of the per oral pneumocolon in the study of the distal ileal loops.

AIM: To verify the diagnostic accuracy of per oral pneumocolon in the identification of both normal and pathological patterns in patients with suspected or proven small bowel disease. MATERIALS AND METHODS: Per oral pneumocolon was performed after small bowel follow-through examinations in a series of 42 selected patients. The terminal ileum visibility, the loop location and possible pathological patterns were evaluated separately before and after insufflation. In post-insufflation images the presence/absence of reflux and grade of reflux were evaluated. RESULTS: The diagnostic quality of per oral pneumocolon as compared with per oral small bowel examination was superior in 23 of the 42 patients (54.8%; group 1), similar in nine of the 42 (21.4%; group 2), and inferior in 10 of the 42 (23.8%; group 3). Transvalvular reflux was present in 22 of 23 (95.6%) patients from group 1 and only in one of 10 patients (10%) from group 3 (p<0.001: statistically significant difference). Among the 24 of 42 (57.1%) patients with suspected or proven Crohn's disease, per oral pneumocolon increased the confidence with which the ileum was considered normal in 12 patients and it allowed a better evaluation of the disease extent and the differentiation between prolonged spasms and stenosis in five patients. CONCLUSION: In conclusion per oral pneumocolon should be performed after a small bowel follow-through examination in selected patients.

Crohn disease of the small bowel: MR enteroclysis versus conventional enteroclysis.

Enteroclysis has been suggested as the technique of choice for the evaluation of Crohn disease of the small intestine. Adequate distention of the entire small bowel with barium suspension allows the radiologic demonstration of mucosal abnormalities and provides functional information by defining distensibility or fixation of the small bowel loops. The principal disadvantage of conventional enteroclysis is the limited indirect information on the state of the bowel wall and extramural extension of Crohn disease, and its effectiveness may be hindered owing to overlapping bowel loops. Moreover, the radiation dose administered to patients, mostly at a young age, should be considered. Magnetic resonance (MR) enteroclysis is an emerging technique for small bowel imaging and was introduced to overcome the limitations of conventional enteroclysis and MR cross-sectional imaging by combining the advantages of both into one technique. MR enteroclysis has the potential to change how the small bowel is assessed because of the functional information, soft tissue contrast, direct multiplanar imaging capabilities, and lack of ionizing radiation.

Clinical correlations of small bowel CT and contrast radiology findings in Crohn's disease.

BACKGROUNDS AND OBJECTIVE: Aim of the present study was to evaluate the clinical correlates of small bowel CT patterns in patients with Crohn's disease (CD), as compared to barium studies and endoscopic findings, as far as parameters of disease activity are concerned. MATERIAL AND METHODS: Thirty five patients with pathologically proven CD were studied by means of helical single detector CT (13) or multidetector CT (22), after administration of low density contrast by mouth (13) or by nasojeunal tube (22). Eight hours later, all patients were studied with barium administered by mouth (13) or with barium and methilcellulose administered by nasojeunal tube (22). Clinical activity was assessed by CDAI score, ESR, CRP, alpha1 glycoprotein and fibrinogen levels. In twenty one patients, colonoscopy was also performed. RESULTS: Sensitivity of small bowel CT versus endoscopy was of 88% while sensitivity of barium studies was of 77% versus endoscopic findings, and it reached 100% for the combination of both exams. We found positive correlations between the detection at CT of "target sign" and a CDAI score > 150 or abnormal values of CRP, ESR, alpha1 glycoprotein. Abnormal ESR or fibrinogen levels were correlated with the detection of fistulas at CT scans. The diameter of enlarged mesenteric lymph nodes was correlated with alpha1 glycoprotein values. No similar correlations were detected for contrast radiology findings. DISCUSSION: This study underscores the clinical usefulness of performing small bowel CT in adjunct to conventional diagnostic studies in Crohn's disease patients. CT findings (either by oral route or nasojeunal tube) correlate with parameters of disease activity.

[Malignant biliary hilar stenosis: MR cholangiography compared with direct cholangiography]. / Stenosi maligne ilari delle vie biliari: correlazione tra la colangiografia con risonanza magnetica e le colangiografie dirette.

AIM: To assess the diagnostic value of three-dimensional (3D) magnetic resonance cholangiography (MRC) versus direct cholangiography such as endoscopic retrograde cholangiography (ERC) and percutaneous transhepatic cholangiography (PTC) in malignant biliary stenosis. MATERIAL AND METHODS: Twenty-nine patients (15 female and 14 male) (mean age 62 years) with malignant biliary strictures underwent MRC and ERC. Breath-hold 3D steady state free precession MR cholangiography was performed on a 1.5-T imager in the patients before ERC. In 25 patients findings at ERC/PTC were considered the standard of reference: 19 patients underwent ERC, 5 PCT and 1 both ERC and PTC due to unsuccessful papilla cannulation during the endoscopic examination. In the 4 remaining patients the surgical specimen was considered the standard of reference. In the 29 patients studied, histology performed during direct cholangiography and the examination of the surgical specimens demonstrated that the malignant hilar stenoses were caused by hilar cholangiocarcinoma (n=7), cholangiocarcinoma of the distal VBP (n=1), gallbladder cancers (n=6), endometrial metastasis (n=2), ovary metastasis (n=1), colon metastasis (n=1), breast metastasis (n=1). The correct identification of biliary stenosis and extension of the tumor (according to the Bismuth classification) by MR cholangiography and ERC were independently assessed by two readers blinded to each other's report. The results were compared. RESULTS: Identification of biliary stenosis and neoplastic extension were accurate in respectively 29/29 (100%) and 26/29 (89%) cases with MR cholangiography. The comparison of ERC/PTC and MRC images yielded the following results: Bismuth Type I (6 vs 6), Type II (5 vs 8), Type III (13 vs 10), Type IV (5 vs 5). Our results indicate that MR is less capable of identifying the extension of small lesions at the primary confluence of bile ducts than are ERC/PCT. DISCUSSION AND CONCLUSIONS: MR cholangiography is a non-invasive technique for biliary tract imaging. It does not require administration of contrast medium and allows complete visualisation of the biliary ducts. MR cholangiography allowed accurate diagnosis of malignant hilar stenosis providing equal information as direct cholangiography and may therefore obviate the need for ERC/PTC.

Magnetic resonance pancreatography (MRP): morphology and function.

MRCP is able to non-invasively assess the pancreatic ducts, with moderate/high agreement with ERCP: There is however a high number of false negative results, mainly due to the small size of the main pancreatic duct, especially in the tail, and side branches. Secretin stimulates the exocrine pancreas with accumulation of fluid and bicarbonates in the ductal system, and subsequent enlargement. This increase in caliber improves the assessment of the morphology of pancreatic ducts and their abnormalities. MRCP accuracy in assessing ductal abnormalities, improves after secretin administration. Furthermore, dynamic MRCP during secretin administration is also able to afford the functional evaluation of the pancreatic flow dynamics. Papillary stenosis, either idiopathic or due to Santorinicele, is easily diagnosed by means of S-MRCP. Furthermore a noninvasive assessment of the pancreatic exocrine reserve can be performed with dynamic MRCP during secretin administration.

Imaging of chronic pancreatitis.

Chronic pancreatitis is characterized by progressive, irreversible morphologic changes whose most common cause is excessive alcohol intake. Radiologic imaging plays a major role in the diagnosis, staging of disease severity, detection of complications and selection of treatment options. The sensitivity of US ranges from 60% to 70% while its specificity is higher reaching 80%-90% in the detection of abnormalities of main pancreatic duct. As for CT, its sensitivity and specificity in the diagnosis of chronic pancreatitis, in recent studies is 74% and 85% respectively. The performance of Magnetic Resonance cholangiopancreatography was shown to be enhanced by secretin stimulation with better visualization of ductal and parenchymal changes. However, endoscopic retrograde cholangiopancreatography is the most sensitive indicator of the presence and extent of the disease. Ductal abnormalities can be used to classify chronic pancreatitis.

Imaging of acute pancreatitis.

Pancreatitis is one of the most complex and clinically challenging of all abdominal disorders. It is classified according to clinical, morphologic and histologic criteria. The primary role of radiologic imaging in patients with suspected pancreatitis is to confirm or exclude the clinical diagnosis of pancreatitis. Second, if possible, the cause of the disease is established with the assessment of disease severity and detection of complications. Imaging can also provide guidance for percutaneous therapy. Sonography in acute pancreatitis is a good screening test in patients with suspected biliary pancreatitis and a mild clinical course. Contrast-enhanced CT is preferred for patients with acute pancreatitis because it can accurately diagnose and stage the disease and the necessary information for percutaneous management is provided. The diagnosis of acute pancreatitis on MRI relies on the presence of morphologic and peripancreatic changes. Pancreatic necrosis and complications of acute pancreatitis such as hemorrhage, pseudocysts or abscesses are well-examined by MRI.

High resolution spiral computed tomography of the pancreas.

Computed tomography (CT) is a very useful tool in the assessment of pancreatic disease. Searching for subtle signs, as in chronic pancreatitis or staging of adenocarcinoma, high spatial and contrast resolution is needed. The high resolution computed tomography (HRCT) technique for pancreatic scans, and its evolution from dynamic CT to multislice spiral CT, is described. 2D and 3D dimensional reconstructions are depicted and their role in diagnosis is focused. Together with spatial resolution, contrast enhancement protocols are discussed, aimed to achieve optimal contrast between the lesion and normal parenchyma.

Staging of pancreatic ductal adenocarcinoma with spiral CT and MRI.

Detection of pancreatic adenocarcinoma is crucial for accurate staging both with spiral CT and dynamic MRI; consequently an accurate technique is required and so-called pancreatic phase is recognized as the best one for tumor conspicuity. For vascular involvement optimal results have been achieved in assessing unresectability; vein involvement seems more difficult to be defined as it is sustained by a different spread compared to arterial involvement. Grading of vessel circumference contact represents the best tool in "venous" staging, but shape deformation and collateral veins dilation are also important signs. Lymph node staging is less accurate, lacking in specificity, but spiral CT demonstrated better results if compared with dynamic MRI. Assessment of liver metastases has been improved by the advent of spiral CT and dynamic contrast enhanced MRI, while peritoneal staging seems to be unaffected. In conclusion, both spiral CT and dynamic contrast enhanced MRI are accurate in pancreatic adenocarcinoma staging, mainly for vessels and liver involvement; no definite differences have been established, because only a few studies have compared them both with state-of-art techniques. Therefore standardized multicentric trials are desirable. Up to now, the choice of which technique to employ should be based on local expertise; moreover, the aggressive approach of surgical equipes should be kept in mind.

Pancreas divisum and "santorinicele": diagnosis with dynamic MR cholangiopancreatography with secretin stimulation.

PURPOSE: To evaluate the usefulness of magnetic resonance (MR) cholangiopancreatography (MRCP) before and after secretin administration in diagnosing santorinicele in patients with pancreas divisum. MATERIALS AND METHODS: One hundred seven patients suspected of having pancreatic disease underwent MRCP before and after secretin administration (S-MRCP). S-MRCP images were evaluated for pancreas divisum and santorinicele and for size of the main pancreatic duct and santorinicele. The onset of duodenal filling was calculated on dynamic S-MRCP images. RESULTS: Pancreas divisum was detected in five (5%) of 107 patients at MRCP and in 10 (9%) of 107 patients at S-MRCP. Santorinicele was detected in three (21%) of 14 patients at MRCP and in an additional four (seven [50%] of 14) patients at S-MRCP in patients with pancreas divisum. Santorinicele was confirmed in six of seven patients at endoscopic retrograde cholangiopancreatography (ERCP); in one of seven patients, ERCP was unsuccessful. The duct of Santorini was significantly (P: <.05) larger in the pancreatic head in patients with pancreas divisum and santorinicele (3.6 mm) compared with those with only pancreas divisum (2.2 mm). A noteworthy reduction in size of the pancreatic duct (26%) and of the santorinicele (63%) was observed after sphincterotomy. The onset of duodenal filling was delayed significantly in patients with santorinicele (2.1 vs 1.3 minutes; P: <.05). CONCLUSION: S-MRCP helps in identifying pancreas divisum and santorinicele, which may be the cause of impeded pancreatic outflow.

Severe chronic pancreatitis versus suspected pancreatic disease: dynamic MR cholangiopancreatography after secretin stimulation.

PURPOSE: To assess whether secretin stimulation improves visualization of the pancreatic ducts at magnetic resonance (MR) cholangiopancreatography (MRCP) in patients with severe chronic pancreatitis or suspected pancreatic disease. MATERIALS AND METHODS: Thirty-one patients (group 1) with chronic pancreatitis and 84 patients (group 2) with clinical and/or laboratory findings suggestive of pancreatic disease who did not have ductal alterations at ultrasonography (US) and/or computed tomography (CT) underwent MRCP before and up to 10 minutes after secretin stimulation. Size of the main pancreatic duct (head, body, tail) and duodenal filling before and after secretin stimulation were measured quantitatively. Image quality, number of main pancreatic ductal segments visualized, visualization of side branches, ductal narrowing, endoluminal filling defects, and presence of pancreas divisum were analyzed qualitatively. RESULTS: In both groups, the size of the main pancreatic duct increased significantly 3 minutes after secretin stimulation. Reduced duodenal filling was detected in patients with severe chronic pancreatitis (P < .001). The number of segments of the main pancreatic duct visualized improved from 85 (91%) to 93 (100%) of 93 in group 1 and from 164 (65%) to 245 (97%) of 252 (P < .001) in group 2. Visualization of side branches improved from 22 (71%) to 31 (100%) of 31 in group 1 and from three (4%) to 53 (63%) of 84 (P < .001) in group 2. Pancreas divisum was visualized in one additional patient in group 1 and in six additional patients in group 2. CONCLUSION: The administration of secretin improves visualization of the pancreatic ducts and helps in the evaluation of exocrine reserve.

Role of diagnostic imaging in abdominal lymphadenopathy.

Abdominal lymph node chains and route of lymph drainage of various organs (stomach, duodenum, liver, gallbladder, pancreas, small intestine, appendix, blind intestine, colon rectum) are analyzed according to their location. The role of conventional radiology and diagnostic imaging is evaluated in the study of abdominal lymphatic system with particular reference to lymphangiography and the new procedures of sonography, CT and MRI. Present methods used in inflammatory abdominal lymphadenopathy with special attention to tuberculous lymphadenitis, liver cirrhosis, neoplastic abdominal lymphadenopathy, colorectal and pancreatic cancer, are illustrated. Combined modality imaging is considered in gastric cancer based on the evolution of the classification of gastric lymph nodes. The role of sonography, endoscopic ultrasonography, spiral CT and MRI is assessed in gastric cancer N staging. A retrospective study is analyzed and perspectives for the application of a new CT protocol are proposed. PET potentialities in the study of abdominal lymph nodes are examined.

[Dynamic pancreatography with magnetic resonance after functional stimulus with secretin in chronic pancreatitis]. / Pancreatografia dinamica con Risonanza Magnetica dopo stimolo funzionale con secretina nella pancreatite cronica.

AIM OF THE STUDY: Magnetic Resonance pancreatography (MRP) was performed before and after the intravenous injection of secretin to assess the improvement in pancreatic duct visualization and to perform a dynamic study of the pancreatic exocrine function. MATERIAL AND METHODS: 20 MRP examinations were performed in 18 patients with suspected or known chronic pancreatitis. Coronal T2-weighted half-Fourier SSFSE images were obtained with a phased array surface coil. Images were obtained before and up to 10 minutes after the injection of 1 cu/kg b.w. secretin. Quantitative image analysis included main pancreatic duct enlargement over time after secretin injection and the amount of duodenal filling. Qualitative image analysis included: overall image quality improvement, number of pancreatic duct segments visualized, secondary ducts dilation, intraductal filling defects, the presence of pancreas divisum. RESULTS: After secretin injection the overall image quality was judged sufficient in 2 patients and satisfactory in 18 patients. The number of pancreatic duct segments visualized increased from 40/57 (79%) to 57/57 (100%); secondary ducts were visualized in 4 patients before secretin compared to 18 after secretin. The number of stenosis visualized increased from 6 to 9, while intraluminal filling defects increased from 2 to 6. Pancreas divisum was detected in 2 patients after secretin versus 0 before secretin. The main pancreatic duct enlargement was statistically significant in the head of the pancreas (p < .05). Duodenal filling was normal in 13 patients and decreased in 7. DISCUSSION AND CONCLUSIONS: Secretin injection extends the capabilities of MRP in visualizing the morphologic features of pancreatic ducts. The depiction of pancreatic ducts, stenosis, filling defects and pancreas divisum was improved after secretin injection. The exocrine function of the pancreas can be evaluated analyzing the entity and the timing of the duodenal filling.

The use of cyanoacrylate tissue adhesive in high-risk intestinal anastomoses.

The success of every intestinal surgical procedure primarily depends on correct technical execution of the intestinal sutures. Despite the continuing improvements in intestinal synthesis techniques and the introduction of mechanical staplers, the risk of anastomotic dehiscence remains a major concern. For high-risk anastomoses, defined as those performed under critical conditions, n-butyl-2-cyanoacrylate tissue adhesive allows for quick sealing of the two stumps and supports the physiological wound-healing process. Furthermore, no experimental or clinical studies have shown that this glue has any carcinogenic or mutagenic properties. Thus, we believe that n-butyl-2-cyanoacrylate will be extremely useful for intestinal anastomoses with a high risk of dehiscence.