Pulmonary Sequestration

The purpose of this study was to determine the prevalence of enlargement of the azygos system in the case of lung sequestration and its potential usefulness in the differential diagnosis of lower lobe opacities. Seven consecutive adult cases of pulmonary sequestrations were retrospectively enrolled; 4 sequestrations were proved surgically and all 7 angiographically. A group of 50 consecutive patients with a normal chest CT were used as controls. Another group consisted of 25 consecutive patients identified on the basis of an opacity in a posterobasal location on chest CT. For the 3 groups, the maximum diameter of the azygos and hemiazygos veins was measured, the level of measurement located between the upper poles of the kidneys and the confluence of inferior pulmonary veins into the left atrium. The diameter of the azygos veins (mean 10.4±5.1 mm) and of the hemiazygos veins (mean 7.1±3.0 mm) in the sequestration group was significantly larger than the diameter of the azygos and hemiazygos veins in the control group (mean 5.7±2.5 mm, and 3.4±2.4 mm, respectively), as well as in the study group (mean 5.9±2.6 mm and 3.3±2.6 mm, respectively). Our results suggest that enlargement of the azygos system in association with a posterobasal chest opacity, although nonspecific, may be a useful additional CT sign of sequestration.

Regenerative Nodules in Hepatic Cirrhosis

To evaluate the accuracy of surface coil gradient-echo (GRE) imaging in the detection of regenerative nodules of hepatic cirrhosis, 53 patients with diffuse liver disease, among whom 31 had cirrhosis, were prospectively investigated. Three GRE sequences acquired with a surface coil were used in the study: a T2*-weighted, a T1-weighted, and a gadopentetate-enhanced sequence. ROC analysis showed that two surface coil GRE sequences were superior to conventional T2-weighted spin-echo imaging acquired with a body coil for the detection of regenerative nodules. The detection of regenerative nodules was also more accurate for the diagnosis of cirrhosis than the measurement of the caudate-to-right lobe ratio. These results suggest that there could be a potential for surface coil GRE imaging in the assessment of the characteristic macroscopic alterations of cirrhosis.

Carcinoid tumor of the small intestine: MDCT findings with pathologic correlation

BACKGROUND

MDCT currently frequently represents the first choice modality for imaging in acute or subacute abdominal conditions implicating the small bowel. As a consequence, the MDCT features of intestinal carcinoid tumors and of their peculiar metastatic spread have to be known by abdominal radiologists.

PATIENTS AND METHODS

These features are described and illustrated in the retrospective review of seven proven cases of small intestine carcinoids diagnosed and treated in our institution. The findings are described and correlated with gross anatomy specimens.

RESULTS

The primary tumour clearly appeared as a contrast-enhancing intraluminal lesion in all cases except in one case in which the primary lesion remained unlocalized and in another in which the primary tumour finally appeared infracted at gross anatomy. The maximal tumoral enhancement was obtained in 3 patients imaged during the acute arterial phase. The diameter of the primary tumour ranged from 1 to 3 cm and all masses were ileal comprising one lesion in the proximal ileum, two in the medium ileum and three in the distal ileum. 6/7 patients had multiple prominent mesenteric nodal metastases, all also appearing as hypervascularised enhancing masses. In 4/7 patients the nodal metastases represented the major finding being much prominent and larger than the primary tumour. Signs of retractile mesenteritis with soft tissue stranding, retraction and stellate pattern of the mesentery were found around the mesenteric metastases in 5/7 patients and direct incarceration of vessels were found in 3 cases.

CONCLUSION

The analysis of the arterial phase of MDCT study appears primordial to detect the sometimes very small but intensively enhancing primary tumor and to delineate encasement or direct obstruction of mesenteric vessels frequently caused by enhancing nodal metastases which volume often exceeds that of the primary tumor. Secondary retractile mesenteritis, deformation or ischemia of bowel loops, and hypervascular hepatic metastases are typical associated findings.

The whirl sign in caecal volvulus: a decisive diagnostic clue

The case of a 35-year-old woman with acute right flank pain, right iliac fossa pain, nausea and vomiting for 6 hours is presented. Plain abdominal radiography and CT scan were performed to find the etiology. These exams showed no signs of colonic obstruction but thickened non-enhancing wall of caecum with ascites was suggestive for ischemia. The whirl sign depicted on CT was the decisive feature for the diagnosis of caecal volvulus.

[Pictorial essay. Infarction of the greater omentum: can US and CT findings help to avoid surgery?]

Infarction with or without torsion of the greater omentum is an uncommon but well recognised acute abdominal condition which was seldom diagnosed preoperatively before the widespread clinical use of US and CT. The aetiology is unknown and speculative. In most cases the pathology is right sided and clinical presentation consists of an acute or subacute flank pain with mild peritonism usually evoking appendicitis or cholecystitis. Recently, US and CT have proved to provide sufficiently typical, consistent and well-recognizable features to avoid unnecessary surgery. We report on six typical -five right sided and one left sided- cases investigated with CT and US. Two patients underwent surgical treatment, one because the usually spontaneous regression of the entity was ignored and the other because of extremely severe clinical symptoms. In the other four patients, conservative medical management was preferred and successful. Even though US may be efficient if performed by a well-trained echographist, CT appears to be the procedure of choice as it is operator independent and reliable for excluding mimicking surgical conditions or associated pathology.

Epiploic appendagitis: color Doppler sonographic findings

The aim of this study was to analyze the color Doppler sonographic findings in primary epiploic appendagitis. Color Doppler sonographic findings of ten patients with primary epiploic appendagitis were reviewed. The following sonographic features were analyzed: identification of a mass adjacent to the colonic wall; identification of spotty color areas with arterial flow in this mass and detection of abnormalities of the colonic wall adjacent to the infiltrated fatty tissue. A well-delineated hyperechoic mass adjacent to the colonic wall was detected in each patient with sonography. No colonic wall abnormalities were observed nor color Doppler signal in and around the hyperechoic area. Absence of flow at color Doppler sonography is an additional feature of epiploic appendagitis.

Spontaneous haemoperitoneum from surreptitious ingestion of a rodenticide

Superwarfarins have progressively replaced warfarin as rodenticides as they are more potent and have a longer anticoagulant activity. Human exposure may be complicated by spontaneous haemorrhage in various sites. We report the case of a 51-year-old woman who was admitted with spontaneous haemoperitoneum and intramural haematoma along the small intestine. After the evidence of a deficit of vitamin K1-dependent clotting factors (II, VII, IX, X), the patient admitted that she was chronically ingesting difenacoum. She was successfully treated with fresh frozen plasma and vitamin K1. Follow-up was not accepted.

Prognosis of ischemic colitis: comparison of color doppler sonography with early clinical and laboratory findings

OBJECTIVE

The objective of this study was to compare the value of color Doppler sonography with early clinical and laboratory findings in determining the prognosis of patients with ischemic colitis.

SUBJECTS AND METHODS

We reviewed the early clinical, laboratory, and color Doppler sonographic data of 24 patients with ischemic colitis. The patients were divided into two groups on the basis of their outcome. The first group comprised the patients with transient ischemia who recovered uneventfully, and the second group included the patients who needed surgery because of symptomatic transmural colic gangrene or colic stricture. Clinical data and laboratory values were compared with color Doppler sonographic findings including colic wall thickness, presence of stratification, and arterial flow in the bowel wall.

RESULTS

At univariate analysis, increased age (p = 0.007), leukocyte count (p = 0.030), lactate dehydrogenase level (p = 0.030), blood lactate level (p = 0.041), and absence of vascular flow in the colic wall (p<0.001) were significantly related to complicated ischemic colitis. At multivariate analysis, absence of arterial flow was the only significant predictor of complicated ischemic colitis (p = 0.002), with a sensitivity of 82%, a specificity of 92%, a positive predictive value of 90%, and a negative predictive value of 86%.

CONCLUSION

Absence of arterial flow in the wall of the ischemic colon on initial color Doppler sonography is suggestive of an unfavorable outcome and is more closely associated with outcome than early clinical and laboratory findings.

Extrahepatic biliary obstruction: magnetic resonance imaging compared with endoscopic ultrasonography

BACKGROUND AND STUDY AIMS

The aim of this study was to compare prospectively the diagnostic efficacy of magnetic resonance (MR) imaging and endoscopic ultrasonography (EUS) in extrahepatic biliary obstruction.

PATIENTS AND METHODS

A total of 50 patients with suspected benign or malignant extrahepatic biliary obstruction underwent MR imaging, including MR cholangiopancreatography, and EUS, within a median time delay of 1 day. The final diagnosis was established by endoscopic retrograde cholangiopancreatography in 37 cases, intraoperative cholangiography in nine cases, and clinical and biochemical follow-up in four cases.

RESULTS

In total, 33 patients had extrahepatic biliary obstruction, of benign origin in 21 cases and of malignant origin in 12 cases, whereas 17 had no evidence of obstruction. The sensitivity and specificity of MR imaging were 91% and 94 %, respectively. There were one false-positive and three false-negative results, all related to choledochal sludge. The corresponding values for EUS were 97% and 88%. There were two false-positive results and one false-negative result. False-positive diagnoses were related to the presumed presence of biliary sludge and choledocholithiasis, whereas the false-negative diagnosis occurred in one patient with a final diagnosis of sludge. No significant difference in sensitivity and specificity was observed between the two imaging methods (P>0.05).

CONCLUSION

In our study MR imaging was as accurate as EUS in the diagnosis of extrahepatic biliary obstruction.

MR imaging of hypervascular liver tumors: timing optimization during the arterial phase

To analyze the optimal timing strategy for the detection of hypervascular liver tumors during the arterial phase of magnetic resonance (MR) imaging, a test examination after injection of 2 mL of gadopentetate dimeglumine was performed in 47 patients. The time course of the tumor-to-liver contrast-to-noise ratio (CNR) for all studies together was determined relative to the start of injection, the time of peak aortic enhancement, and the time of peak enhancement in the tumor. All studies were grouped together and the highest CNR was transiently observed at the time of peak tumor enhancement. This CNR was significantly higher than those observed at fixed delays after peak aortic enhancement. However, the CNRs at peak tumor enhancement+/-1.5 seconds did not differ significantly from those obtained after peak aortic enhancement. Finally, the CNRs obtained at fixed delays after the start of injection remained significantly lower. In hypervascular liver tumors, a higher CNR can be obtained during the arterial phase when the MR imaging delay is determined relative to the time of peak enhancement in the tumor or the aorta rather than being fixed after the start of contrast material injection. Timing based on the enhancement profile in the tumor rather than in the aorta should be performed only if rapid MR imaging is available with a time resolution of about 1.5 seconds to image the whole liver.

Living-related liver transplantation: is Doppler sonography sufficient to define the hepatic artery anatomy before surgery?

OBJECTIVE

to evaluate the accuracy of colour Doppler sonography (CDS) in the assessment of the left hepatic arterial supply in living donors before hepatic transplantation.

MATERIAL AND METHODS

Pre-operative sonographic Doppler data of the left hepatic artery (LHA) were compared retrospectively with the selective hepatic angiographic data and the intra-operative observations in 60 living donors.

RESULTS

Pre-operative Doppler data of the LHA were available in 53 cases and incomplete or absent in seven cases. In 51 cases (96%) the origin of the LHA or an accessory LHA were correctly described at Doppler sonography (44 classical LHA in anatomic position, seven accessory LHA). In 11 cases (21%), Doppler data were insufficient or incorrect to define the arterial supply of the hepatic segments II, III and IV. Doppler studies were unable to determine the length or the diameter of the LHA.

CONCLUSION

Doppler sonography seems to be able to define the main left hepatic artery anatomy. Selective hepatic angiography is still indicated to determine the length, diameter and intra-hepatic segmental supply.

MR imaging of hypervascular liver tumors: timing optimization during the arterial phase

To analyze the optimal timing strategy for the detection of hypervascular liver tumors during the arterial phase of magnetic resonance (MR) imaging, a test examination after injection of 2 mL of gadopentetate dimeglumine was performed in 47 patients. The time course of the tumor-to-liver contrast-to-noise ratio (CNR) for all studies together was determined relative to the start of injection, the time of peak aortic enhancement, and the time of peak enhancement in the tumor. All studies were grouped together and the highest CNR was transiently observed at the time of peak tumor enhancement. This CNR was significantly higher than those observed at fixed delays after peak aortic enhancement. However, the CNRs at peak tumor enhancement+/-1.5 seconds did not differ significantly from those obtained after peak aortic enhancement. Finally, the CNRs obtained at fixed delays after the start of injection remained significantly lower. In hypervascular liver tumors, a higher CNR can be obtained during the arterial phase when the MR imaging delay is determined relative to the time of peak enhancement in the tumor or the aorta rather than being fixed after the start of contrast material injection. Timing based on the enhancement profile in the tumor rather than in the aorta should be performed only if rapid MR imaging is available with a time resolution of about 1.5 seconds to image the whole liver.

[Radiology and emergency medicine: state of the art]

Emergency medicine has emerged as a specific medical specialty for 30 years. To be efficient, the emergency clinician frequently needs the contribution of radiological examinations. This is the reason why emergency radiology has emerged as a new radiologic subspecialty. The aim of this paper is to review the recent history of emergency medicine and to summarize the present state of the radiological organisation for emergency care in the Western countries.

Familial adenomatous polyposis associated with multiple adrenal adenomas in a patient with a rare 3' APC mutation

Familial adenomatous polyposis (FAP) is characterised by hundreds of colorectal adenomas. Endocrine neoplasms have occasionally been reported, as have gastric polyps, which are usually hamartomatous in the fundus of the stomach and adenomatous in the antrum. A 57 year old man with colorectal, gastric, and periampullary adenomatous polyposis, in association with three bilateral adrenocortical adenomas, is presented. Mutation screening showed a 5960delA germline mutation in the adenomatous polyposis coli (APC) gene predicted to lead to a premature stop codon. This mutation was found in three of the four children of the patient. Western blot analysis of a lymphoblastoid cell line derived from the patient failed to detect any truncated APC polypeptide. This rare 3' mutation is responsible for an unusually complex and late onset phenotype of FAP.

[Spiral CT in pulmonary embolism]

Pulmonary embolism is a leading cause of morbidity and mortality that can occur in many clinical situations. For several years, spiral CT has represented a relatively non invasive modality for diagnosing this common disease. The present article is reviewing the CT features of acute and chronic pulmonary embolism, the technical aspects of spiral CT acquisition, the diagnostic accuracy and major limitations and pitfalls of the technique.

[The contribution of ultrasonography to the diagnosis of acute intestinal diseases in adults]

Various acute intestinal diseases can be imaged with ultrasound and in particular intestinal occlusion, acute ischemia and inflammatory diseases such as appendicitis and diverticulitis. We review the contribution and limitations of ultrasound to these diagnoses.

Comparison of unenhanced and gadoxetate disodium-enhanced spin-echo magnetic resonance imaging for the detection of experimental hepatocellular carcinoma in the rat

RATIONALE AND OBJECTIVES

The authors compare the potential value of unenhanced and gadoxetate disodium-enhanced spin-echo images for the detection of hepatocellular carcinoma in a rat model.

METHODS

Eleven rats with chemically induced hepatocellular carcinoma underwent unenhanced T2-weighted fast spin-echo imaging followed by T1-weighted spin-echo imaging before and at 5 minutes, 30 minutes, 3 hours, 1 day, and 3 days after intravenous administration of 60 micromol/kg gadoxetate disodium at 4.7 tesla. Tumor and liver enhancement, and tumor-to-liver contrast-to-noise (C/N) ratio were calculated.

RESULTS

After gadoxetate disodium administration, the tumors showed less enhancement than the liver. Tumor-to-liver C/N ratio increased from 5.5 +/- 0.8% on unenhanced T1-weighted images to 12.9 +/- 2.4% on gadoxetate-enhanced T1-weighted images (P = 0.02). However, the C/N ratio on unenhanced T2-weighted images (23.5 +/- 3.6%) remained higher than that on gadoxetate-enhanced T1-weighted images, a difference that is statistically significant (P < 0.01).

CONCLUSIONS

In the experimental setting of our study, the higher tumor-to-liver C/N ratio on unenhanced T2-weighted spin-echo images suggests that unenhanced T2-weighted spin-echo images are superior to gadoxetate disodium-enhanced T1-weighted spin-echo images for the detection of hepatocellular carcinoma.

Inadequate detection of accessory spleens and splenosis with laparoscopic splenectomy. A shortcoming of the laparoscopic approach in hematologic diseases

BACKGROUND

The ultimate goal of surgery for hematological disorders is the complete removal of both the spleen and accessory spleens in order to avoid recurrence of the disease. Whereas splenectomy by open surgery provides excellent results, the validity of laparoscopic splenectomy in this regard remains unknown.

OBJECTIVE

The purpose of this study was to evaluate the detection of accessory spleens during laparoscopic splenectomy for hematologic diseases.

METHODS

We therefore evaluated the pre-, intra-, and postoperative detection of accessory spleens in a consecutive series of 18 patients treated by elective laparoscopic splenectomy for hematological diseases by using computed tomography (CT) and denatured red blood cell scintigraphy (DRBCS).

RESULTS

Preoperative CT, DRBCS, and laparoscopic exploration detected 25%, 25%, and 75% of accessory spleens, respectively. At time of laparoscopy, 16 accessory spleens were detected in seven of the 18 patients (41%). In two patients (11%), laparoscopic exploration failed to detect accessory spleens, whereas preoperative CT (one case) and DRBCS (one case) did reveal them. Postoperatively, during a mean follow-up of 28 months (median, 24; range, 12-44 months), nine patients (50%) showed persistence of splenic tissue by DRBCS, and three of them had signs of disease recurrence.

CONCLUSIONS

This prospective clinical study suggests that elective laparoscopic surgery for hematological diseases does not allow complete detection of accessory spleens. Moreover, after such a laparoscopic approach, residual splenic tissue is detectable in half of the patients during the follow-up.

Inflammatory pseudotumor of the liver: MRI with mangafodipir trisodium

Inflammatory pseudotumor of the liver is a rare benign mass that is often misdiagnosed as hepatocellular carcinoma at preoperative imaging. We report a case of inflammatory pseudotumor of the liver with special emphasis on the appearance at MRI after administration of mangafodipir trisodium. On T1-weighted images the lesion was slightly hypointense relative to the liver, and on T2-weighted images it was isointense with a hyperintense capsule. No tumor enhancement was seen on T1-weighted images after administration of mangafodipir trisodium. MRI with mangafodipir trisodium might help to distinguish inflammatory pseudotumor of the liver from hepatocellular carcinoma.

Post-traumatic intrahepatic pseudoaneurysm: diagnosis with helical CT angiography and management with embolization

The authors report a case of liver trauma with hematoma complicated with a pseudoaneurysm. The latter was suspected on day 7, with a monophasic helical CT and was demonstrated with helical CT angiography. Arteriography confirmed the lesion and showed an associated arteriovenous fistula, unsuspected on helical CT. The pseudoaneurysm was managed with transcatheter embolization, completed with percutaneous embolization because of vascular spasm.

Early diagnosis of acute intestinal ischaemia: contribution of colour Doppler sonography

The aim of this study was to evaluate the contribution of colour Doppler sonography in the diagnosis of acute intestinal ischaemia. In a two years experience, all patients admitted for acute abdominal pain in our emergency department were evaluated with colour Doppler sonography of the abdomen. The final diagnosis based on clinical evolution, endoscopic or surgical findings and further radiological investigations was compared to the sonographic results. Therapy and final outcome of the patients with acute intestinal ischaemia were also evaluated. In twenty-one patients a final diagnosis of acute intestinal ischaemia (mesenteric ischaemia (n = 13) and ischaemic colitis (n = 8)) was made. Intestinal ischaemia was correctly diagnosed by initial clinical and biological data and further confirmed by sonography in eight cases (mesenteric ischaemia (n = 2) and ischaemic colitis (n = 6)). Eleven other cases were detected by suggestive colour Doppler sonography features (mesenteric ischaemic (n = 10) and ischaemic colitis (n = 1)). Sixteen of the 21 patients had a final favourable outcome (mesenteric ischaemia (10/ 13) and ischaemic colitis (6/8)). We conclude that sonography has a place in the diagnosis of acute intestinal ischaemia and has to be integrated in the diagnostic algorithm of this acute condition. By this way, this diagnosis may be suspected earlier and may allow a prompt and adapted treatment with possible improvement in survival rate.

Detection and segmental location of malignant hepatic tumors: comparison of ferumoxides-enhanced gradient-echo and T2-weighted spin-echo MR imaging

OBJECTIVE

The aim of our prospective study was to compare the values of ferumoxides-enhanced gradient-echo and T2-weighted spin-echo MR imaging for the detection and segmental location of malignant hepatic tumors.

SUBJECTS AND METHODS

Eighteen patients underwent ferumoxides-enhanced T2 weighted spin-echo and steady-state gradient-echo imaging before surgery. Intraoperative sonography was used as the reference examination and showed 28 malignant tumors involving 39 of the 144 hepatic segments. The MR images were reviewed independently by two observers who recorded the number of tumors and their segmental location. The results of the segmental location were subjected to receiver-operating-characteristic analysis. Tumor-liver, vessel-liver, and tumor-vessel contrast-to-noise ratios were calculated.

RESULTS

Detection on the gradient-echo images did not differ significantly from that on the T2-weighted spin-echo MR images (observers A and B detected 23 and 24 tumors, respectively, on the gradient-echo images; the two observers each detected 22 tumors on the T2-weighted spin-echo images). Segmental localization was significantly better on the gradient-echo images than on the T2-weighted spin-echo images (mean area under the receiver-operating-characteristic curve: 0.974 versus 0.895 for observer A and 0.962 versus 0.906 for observer B, p = .024). The highest contrast-to-noise ratios for vessel to liver and tumor to vessel were obtained on the gradient-echo images and the highest tumor-liver contrast-to-noise ratio was obtained on the T2-weighted spin-echo images.

CONCLUSION

In our study, ferumoxides-enhanced gradient-echo imaging was as accurate as T2-weighted spin-echo imaging for revealing malignant hepatic tumors and was superior for showing their segmental location.

Adult polycystic liver disease: is fenestration the most adequate operation for long-term management?

OBJECTIVE

The aim of this study was to evaluate the immediate and long-term results in a retrospective series of patients with highly symptomatic adult polycystic liver disease (APLD) treated by extensive fenestration techniques. A classification of APLD was developed as a stratification scheme to help surgeons conceptualize which operation to offer to patients with APLD.

SUMMARY BACKGROUND DATA

Treatment options for APLD remain controversial, with partisans of fenestration techniques or combined liver resection-fenestration.

METHODS

Clinical symptoms, performance status, liver volume measurement by computed tomography (CT), and morbidity were recorded before surgery and after surgery. Adult polycystic liver disease was classified according to the number, size, and location of liver cysts and the amount of remaining liver parenchyma. Follow-up was obtained by clinical and CT examinations in all patients.

RESULTS

Ten patients with highly symptomatic APLD were operated on using an extensive fenestration technique (by laparotomy in 8 patients and by laparoscopy in 2 patients, 1 of whom conversion to laparotomy was required). The mean preoperative liver volume was 7761 cm3. There was no mortality. Postoperative morbidity occurred in 50%, mainly from biliary complications, requiring reintervention in two cases. Massive intraoperative hemorrhage occurred in one patient. During a mean follow-up time of 71 months (range, 17 to 239 months), all patients were improved clinically according to their estimated performance status. The mean postoperative liver volume was 4596 cm3, which represents a mean liver volume reduction rate of 43%. However, in type III APLD, despite absence of clinical symptoms, a significant increase in liver volume was observed in 40% of the patients.

CONCLUSIONS

Extensive fenestration is effective in relieving symptoms in patients with APLD. Hemorrhage and biliary complications are possible consequences of such an aggressive attempt to reduce liver volume. The procedure can be performed laparoscopically in type I APLD. A longer follow-up period is mandatory in type II APLD, to confirm the usefulness of the fenestration procedure. In type III APLD, significant disease progression was observed in 40% of the patients during long-term follow-up. Fenestration may not be the most appropriate operation for long-term management of all types of APLD.

Detection of reperfused ischemia of the rat intestine: value of magnetic resonance imaging with small-molecular-weight dysprosium and gadolinium chelates

RATIONALE AND OBJECTIVES

The authors assessed whether the small-molecular-weight magnetic resonance (MR) imaging contrast agents dysprosium diethylenetriamepentaacetic acid bismethylamide (sprodiamide injection), which enhances T2*, and gadolinium diethylenetriamepentaacetic acid bismethylamide (gadodiamide injection), which enhances T1, could improve the detection of reperfused ischemia of the rat intestine.

METHODS

Eighteen rats were subjected to vascular occlusion of the distal ileum for 30 minutes, followed by reperfusion. Ten minutes after reperfusion, T1- and T2-weighted spin-echo (SE) images were obtained before and after administration of sprodiamide, gadodiamide, or both. The same imaging protocol was applied in another group of 18 rats subjected to 10 minutes of occlusion and reperfusion. Histologic examination of the intestine was performed after MR imaging.

RESULTS

Villous injury (ie, denudation) was observed in most cases after 30 minutes of occlusion, but not after 10 minutes of occlusion. After 30 minutes of occlusion, the superficial part of the ischemic intestine was hyperintense to the normal intestine on unenhanced T2-weighted images. Administration of sprodiamide improved the contrast between the normal and ischemic intestine on T2-weighted images, and administration of both gadodiamide and sprodiamide improved the contrast on T1- and T2-weighted images. After 10 minutes of occlusion, no contrast was discernible before or after contrast material administration.

CONCLUSION

These results suggest that the detection of reperfused intestinal ischemia of sufficient duration to cause villous injury can be improved by using sprodiamide injection alone or in combination with gadodiamide.

Ferumoxides and Tc-99m sulfur colloid: comparison of the tumor-to-liver uptake in focal nodular hyperplasia

The tumor-to-liver uptake of two reticuloendothelial agents, namely ferumoxides and technetium-99m (Tc-99m) sulfur colloid, was compared in focal nodular hyperplasia (FNH). Twelve patients with FNH who had undergone ferumoxides-enhanced MR imaging and planar Tc-99m sulfur colloid scintigraphy within 1 year were included from the study. Fourteen patients with FNH with a diameter larger than 3 cm were selected for the comparison. The tumor-to-liver ferumoxides uptake was calculated and the Tc-99m sulfur colloid uptake was assessed visually. Fermuoxides uptake was observed in all but one patient with FNH (mean tumor-to-liver ratio = .36). The six tumors showing normal (n = 5) or increased (n = 1) radiocolloid uptake when compared to the liver accumulated more ferumoxides than the eight tumors showing decreased radiocolloid uptake (P < .01). However, in some tumors, no direct relation was observed between ferumoxides and Tc-99m sulfur colloid uptake. Our observations suggest that ferumoxides uptake might not exactly mimic Tc-99m sulfur colloid uptake in FNH.

[Value of echography in the diagnosis of acute intestinal occlusion]

OBJECTIVE

The aim of our study was to assess the value of sonography in the diagnosis of acute intestinal occlusion.

MATERIAL AND METHODS

Sonographic findings were reviewed in 50 cases of intestinal occlusion (39 small bowel and 11 colonic occlusions). The final diagnosis was based on surgical findings (n = 40) or clinical course and further imaging findings (n = 10).

RESULTS

Occlusion was correctly detected with sonography in 48 cases (96%). The location was correctly established with sonography in 43 cases (86%). The precise cause was suggested with sonography in 21 cases (42%).

COMMENTARY

These results confirm the value of sonography for the diagnosis of intestinal occlusion and the identification of its level and its cause.

[Follow-up of TIPS: evaluation of signs of dysfunction with Doppler ultrasonography]

PURPOSE

to assess the signs of TIPS dysfunction at Doppler sonography.

MATERIALS AND METHODS

retrospective study of signs observed in 106 TIPS including 31 TIPS with dysfunction (portoauricular pressure gradient > 12 mmHg).

RESULTS

the signs of TIPS dysfunction were a decrease in the mean velocity in the TIPS (for a velocity < 40 cm/sec, 90% sensitivity, 96%), a hepatopetal intrahepatic portal flow (on the right 90% sensitivity, 100% specificity, on the left 95% sensitivity, 92% specificity), a lack of cardiac modulation of the signal in the TIPS (93% sensitivity, 65% specificity), a hepatic vein flow reversal (30% sensitivity, 100% specificity), and, the only direct sign of stenosis, an increase of the mean velocity in the stenosis (42% sensitivity, 95% specificity for a velocity > or = 1 m/sec).

CONCLUSION

the most sensitive Doppler signs of tips dysfunction are the indirect signs of stenosis.

Detection of hepatic metastases: ferumoxides-enhanced MR imaging versus unenhanced MR imaging and CT during arterial portography

PURPOSE

To prospectively compare the diagnostic accuracy of computed tomography (CT) during arterial portography (CTAP) with that of unenhanced and ferumoxides-enhanced magnetic resonance (MR) imaging at 0.5 T in the detection of hepatic metastases.

MATERIALS AND METHODS

Four pairs of radiologists independently assessed the metastatic involvement of 134 hepatic segments (31 with and 103 without metastasis) in 17 patients at unenhanced and ferumoxides-enhanced spin-echo and gradient-echo MR imaging (alone and in combination) and at CTAP. The diagnostic performance of the various imaging modalities was assessed by means of receiver operating characteristic analysis.

RESULTS

The accuracy of CTAP, unenhanced MR imaging (combined unenhanced sequences), and ferumoxides-enhanced MR imaging (combined contrast material-enhanced sequences) was 0.925, 0.908, and 0.951, respectively. Ferumoxides-enhanced MR imaging was significantly more accurate (P < .05) than unenhanced MR imaging and CTAP. When 14 segments containing cysts were excluded, the difference between ferumoxides-enhanced MR imaging and CTAP was no longer statistically significant (P = .1).

CONCLUSION

Ferumoxides-enhanced MR imaging is more accurate than unenhanced MR imaging and at least as accurate as CTAP for the detection of hepatic metastases.

Ferristene as intestinal MR contrast agent. Distribution and safety of a fast ingestion procedure with oral metoclopramide

PURPOSE

To compare the small bowel distribution and safety of a fast ingestion procedure of ferristene to those of the standard ingestion procedure.

MATERIAL AND METHODS

Sixty-four patients received 0.5 g/l ferristene in 800 ml water. Thirty-four patients of the fast ingestion group ingested ferristene with 20 mg of oral metoclopramide during the course of 30 min before MR imaging and received an i.v. injection of an antiperistaltic agent during the MR study. Thirty patients of the standard group ingested ferristene during the course of 2 h, without additional drugs. Ferristene distribution was assessed by 2 reviewers and adverse events were recorded.

RESULTS

More than 50% of the small bowel segments analyzed were filled with ferristene in 30 patients in the fast ingestion group and in 28 patients in the standard ingestion group. One patient in each group experienced nausea and/or vomiting. Some bloating or sensation of fullness was reported by 2 patients in the fast ingestion group and by 3 patients in the standard ingestion group.

CONCLUSION

The distribution of ferristene in the small bowel and the safety of the procedure were thus similar in the 2 groups using either a fast ingestion procedure with oral metoclopramide or the more time-consuming standard ingestion procedure.

[Unilateral peripheral pulmonary nodules: initial symptoms of a limited form of Wegener's disease]

The X-ray and CT follow-up features of unilateral peripheral pulmonary masses spontaneously varying in size and amount in a patient with limited Wegener disease are reported. Diagnosis was established by nasal biopsy and dosage of the neutrophils anti-cytoplasmic autoantibodies. The current literature over the condition is reviewed.

Intraductal papillary-mucinous tumours of the pancreas. Clinical and radiological aspects

Intraductal papillary-mucinous tumours are rare epithelial tumours with all intermediate types occurring from papillary to mucin-hypersecreting forms. They affects generally old men and recurring pancreatitis is the main clinical feature. Endoscopic Retrograde Pancreatography is the best diagnostic method, showing large dilatation of the ducts and filling defects due to mucin's plugs or papillary tumour. IPMT are slow-growing and have low malignant potential; as to far, surgical resection is considered mandatory, however, better distinction between benign and malignant evolution will probably select cases in which conservative follow-up may be proposed.

Laparoscopic splenectomy in adults and children: experience with 31 patients

BACKGROUND

Open surgery is the standard approach for splenectomy in hematologic disorders, but a few cases of successful laparoscopic splenectomy have been reported.

METHODS

Thirty-one patients (18 adults, group 1; and 13 children, group 2) underwent laparoscopic splenectomy. Indications for surgery included idiopathic thrombocytopenic purpura (25 patients), congenital spherocytosis (4 patients), and hemolytic anemia (2 patients). In 97% of the patients the diameter of the spleen was less than 15 cm.

RESULTS

Laparoscopic splenectomy was successful in 94% of the patients; conversion to open surgery was mainly related to hemorrhage. Accessory spleen was found in 39% in group 1 and 8% in group 2. Two adults received intraoperative autotransfusion. Postoperative morbidity was minimal. The median postoperative stay was 3 days (range, 2 to 12 days) in group 1 and 2 days (range, 2 to 5 days) in group 2.

CONCLUSIONS

Laparoscopic splenectomy is safe in both adults and children. Adequate selection of patients (small-size spleen, splenic destruction on preoperative scanning of platelets), appropriate preparation in patients with idiopathic thrombocytopenic purpura (immunoglobulin G), and meticulous surgical technique (with routine opening of the gastrocolic ligament to search for accessory spleen) are key factors in obtaining the same long-term results as with open surgery.

Acute intestinal ischemia due to occlusion of the superior mesenteric artery: detection with Doppler sonography

The aim of our study was to assess the feasibility of using Doppler sonography for the detection of acute intestinal ischemia due to occlusion of the superior mesenteric artery. Between September 1993 and March 1995, abdominal sonography with Doppler imaging of the mesenteric vessels was performed in 770 patients with emergency admissions for acute abdominal pain. In six cases, the diagnosis, based on surgery or arteriography and computed tomography, was acute intestinal ischemia due to complete or localized occlusion of the superior mesenteric artery. Five cases of occlusion of the superior mesenteric artery were correctly detected by Doppler sonography. These results suggest that Doppler sonography may be a feasible method for detecting acute intestinal ischemia due to proximal superior mesenteric artery occlusion.

Diagnosis of acute intestinal ischemia by color Doppler sonography. Color Doppler sonography and acute intestinal ischemia

Detection of acute intestinal ischemia is a diagnostic challenge. Color Doppler sonography of the abdomen may contribute to its diagnosis by showing lesions of the gut wall associated with occlusion or stenosis of the mesenteric vessels. Our overview of the sonographic findings of acute intestinal ischemia is presented as well as a proposition of algorithm for the working up to the diagnosis based on recent clinical experience.

MRI of the anal canal: correlation with histologic examination

The purpose of this study was to correlate the MRI features of the anal canal with histologic findings. T1- and T2-weighted MR images of nine anal canals were obtained after fixation in 10% formalin. In three specimens, imaging was repeated after removal of histologic layers with a dissecting microscope. Corresponding histologic slices were stained with hematoxylin-eosin, Masson trichrome, and periodic acid-Schiff. Four layers were visualized on T2-weighted images. An inner layer of high signal intensity and a second layer of low signal intensity corresponded to the mucosa as well as mucous secretions and to the submucosa. The high signal intensity layer vanished at the distal part of the anal canal in accordance with the lack of mucus-secreting epithelium below the level of the dentate line. A third layer of intermediate signal intensity corresponded to the internal sphincter. A fourth layer of low signal intensity corresponded to the longitudinal muscle and external sphincter. T2-weighted MRI is capable of showing the internal architecture of the wall of the anal canal. In particular, the internal sphincter can be differentiated from the external sphincter and longitudinal muscle.

Reperfused ischemia of the rat intestine: detection by MR imaging with polylysine-Gd-DTPA enhancement

To detect reperfused ischemia of the rat intestine, T2-weighted spin-echo images were acquired, followed by T1-weighted images before and after administration of polylysine-Gd-DTPA or Gd-DTPA. Before administration of the contrast agent, the reperfused intestine was hyperintense on T2-weighted images, and to a lesser extent on T1-weighted images. After administration of polylysine-Gd-DTPA, the reperfused intestine enhanced more than the normal one, giving a significantly better contrast-to-noise (CNR) ratio than on unenhanced images. Gd-DTPA induced the same enhancement of the reperfused and the normal intestine and the CNR was lower than on unenhanced T2-weighted images. Reperfused intestinal ischemia could thus be better detected on polylysine-Gd-DTPA-enhanced MR images than on unenhanced images or on Gd-DTPA-enhanced images.

[Iron oxides as contrast agents for MRI of the liver]

Iron oxide particles are a potent class of MR contrast agents. Depending on their size and formulation, iron oxides are selectively taken up by the reticuloendothelial system or the hepatocytes. Experimental and clinical studies have shown that iron oxides can improve the detection and the characterization of liver tumors and can contribute to the detection of diffuse liver lesions. These tissue-specific MR contrast agents combine anatomic and functional information about liver lesions.

Comparison of gadolinium-DTPA and polylysine-gadolinium-DTPA--enhanced magnetic resonance imaging of hepatocarcinoma in the rat

RATIONALE AND OBJECTIVES

To compare the magnetic resonance (MR) imaging characteristics of gadolinium-DTPA (Gd-DTPA), a low-molecular-weight contrast agent, and polylysine-Gd-DTPA, a macromolecular contrast agent, in two types of hepatocarcinomas (HCC) in the rat.

METHODS

T1-weighted spin-echo images were obtained in 13 rats with chemically induced HCC and 26 rats with Novikoff HCC before and 3 minutes to 60 hours after administration of either Gd-DTPA or polylysine-Gd-DTPA.

RESULTS

Three minutes after polylysine-Gd-DTPA administration, the tumor-to-liver contrast of the two types of HCC increased significantly (positive contrast for chemically induced HCC and negative contrast for Novikoff HCC). At 30 minutes and 60 hours, the tumor-to-liver contrast remained above baseline values in chemically induced HCC and returned progressively to baseline values in Novikoff HCC. No significant increase in tumor-to-liver contrast was observed after Gd-DTPA administration.

CONCLUSIONS

These results suggest that polylysine-Gd-DTPA provides a higher and more prolonged increase in tumor-to-liver contrast than Gd-DTPA.