[The methodology and accuracy of MRI-based orbital volume calculations]. / Zur Methodik und Genauigkeit der MR-Volumetrie der Orbita.

OBJECTIVE: The aim of the present work was to establish a method for orbital volume calculation based on MR scanning data for the sake of better radiation hygiene. MATERIALS AND METHODS: The orbital volumes of 35 ophthalmologically healthy children were calculated on the basis of MRI scans. After data transfer to a separate workstation, volumetric analysis was carried out by two independent radiologists using semi-automated software. The accuracy of the calculated values was compared with orbital volumes measured by anatomic preparations and given in studies by various authors. RESULTS: Volume calculation was possible in all patients using MRI data. There is an acceptable agreement with the presented anatomic facts and the measured values of Bentheley. In the Wilcoxon test there was not a big difference between the courses of the values (p = 0.507). CONCLUSION: Even though we can obtain a better image of the bizarre structure of the bony orbits with CT, MR-based volumetry of the orbit is a reliable method and is not burdened by radiation exposure. It can thus be an important condition for the planning and the controlling of modern therapeutic concepts in treating anophthalmos and microphthalmos.

Mycotic aneurysm rupture of the descending aorta.

A 69-year-old diabetic male with salmonella bacteremia developed hypovolemic shock and swelling of the neck. A CT examination revealed massive mediastinal hemorrhage extending into the neck soft tissues caused by false aneurysm rupture of the descending thoracic aorta. Aortography showed continuous extravasation from a large leak at the medial side of the descending thoracic aorta. Although surgical intervention was immediately performed, the patient died 3 weeks later from multiple-organ failure. In this report, CT and angiographic findings of mycotic aneurysm rupture are presented and a review is given.

Transjugular intrahepatic portosystemic shunt (TIPS). Thrombogenicity in stents and its effect on shunt patency.

PURPOSE: To compare the thrombogenicity and patency of the Palmaz stent and the Wallstent, and to evaluate the effect of periprocedural heparin therapy in cirrhotic patients with maintained coagulation capacity who receive a transjugular intrahepatic portosystemic shunt (TIPS). MATERIAL AND METHODS: Twenty-four patients were randomized into 4 groups of 6 patients. Each received a Palmaz-stent or Wallstent TIPS with or without periprocedural heparin therapy. The groups receiving periprocedural heparin were given 24 U/kg b.w. just before stent placement, followed by 24 h therapeutic i.v. heparin. After 24 hours, all patients received i.v. heparin for 1 week followed by subcutaneous treatment with low-molecular-weight heparin (0.3 ml/day) for another 4 weeks. Stent thrombogenicity was determined scintigraphically after i.v. injection of 120-290 mBq of 99mTc-labeled platelets at the time of stent placement and expressed as the stent/heart ratio. Shunt patency was assessed by duplex sonography and confirmed radiologically. RESULTS: The aggregation ratio was highest 90 min after stent implantation. Wallstents showed a significantly higher ratio than Palmaz stents. Heparin reduced the ratio in patients with a Wallstent (-41%) but had no effect on Palmaz stents. Patients with a Wallstent without heparin had a higher rate of early shunt insufficiency (66.6%) than the other patients (0-16.6%). Primary assisted long-term patency was similar in the 4 groups. CONCLUSION: Wallstents were more thrombogenic than Palmaz stents and gave a significantly higher risk of early shunt insufficiency in cirrhotic patients with maintained coagulation capacity. Periprocedural heparin was effective in the prevention of shunt insufficiency and is therefore indicated in such patients.

Randomised trial of transjugular-intrahepatic-portosystemic shunt versus endoscopy plus propranolol for prevention of variceal rebleeding.

BACKGROUND: The transjugular-intrahepatic-portosystemic shunt is a new interventional treatment for portal hypertension. The aim of our study was to compare the transjugular shunt with endoscopic treatment for the prophylaxis of recurrent variceal bleeding. METHODS: Between March, 1993, and March, 1996, 126 patients with variceal bleeding were randomly assigned either transjugular shunt (n = 61) or endoscopic treatment (n = 65). Patients were followed up for a median of 14 (IQR 8-25) months and 13 (8-25) months, respectively. In 31 (51%) of the shunted patients, simultaneous transjugular-variceal embolisation was done at the time of shunt placement. Endoscopic treatment consisted of sclerotherapy and/or banding ligation and was combined with propranolol medication. FINDINGS: Technical success was achieved in all patients assigned to the shunt group. During follow-up, the cumulative 1-year variceal rebleeding rates in the shunted and endoscopically treated patients were 15% and 41% and the 2-year rates were 21% and 52% (p = 0.001), respectively. In nine (12%) patients from the endoscopic group treatment failed and the patients received the transjugular-shunt treatment. A total of 19 bleeding episodes from any source occurred in 15 patients in the shunt group compared with 100 episodes in 33 patients in the endoscopic group. There was no difference in survival with estimated 1-year survival rates for shunted and endoscopically treated patients of 90% and 89%, and 2-year survival rates of 79% and 82%, respectively. The incidence of clinically significant hepatic encephalopathy after 1 year was higher in the shunt group (36% vs 18%, p = 0.011). INTERPRETATION: These results suggest, that the transjugular shunt is more effective than endoscopic treatment in prevention of variceal rebleeding but has a considerable risk of hepatic encephalopathy. Survival is similar in the two groups.

[Recurrent bleeding from colonic varices in portal hypertension. The successful prevention of recurrence by the implantation of a transjugular intrahepatic stent-shunt (TIPS)]. / Rezidivierende Kolonvarizenblutung bei portaler Hypertonie. Erfolgreiche Rezidiv-Prophylaxe durch Implantation eines transjugulären intrahepatischen Stent-Shunts (TIPS).

HISTORY AND CLINICAL FINDINGS: Sclerotherapy was performed in a 52-year-old patient with alcoholic liver cirrhosis (Child-Pugh stage A) for recurrent bleeding from oesophageal varices. Half a year later he again was admitted to hospital because of recurrent passage of bloody stools. The cardiovascular status was stable; the liver was enlarged by 15 cm in the medioclavicular line. INVESTIGATIONS: Endoscopy revealed several varices in the colon near the right flexure. One of the varices had an ulcer of 5 mm size. Duplex sonography revealed portal hypertension with cirrhosis of the liver and partial thrombosis of the main trunk of the portal vein without any sign of cavernous transformation. TREATMENT AND COURSE: Because of the partial portal vein thrombosis it was decided to insert a transjugular intrahepatic portosystemic stent shunt. This obviated the thrombosis and lowered the portosystemic pressure gradient by 6.8%. With the shunt functioning well there were no further bleedings in the subsequent year. CONCLUSION: The only slightly invasive TIPS implantation is an effective therapeutic procedure for bleeding from colon varices caused by portal hypertension.

Budd-Chiari syndrome: technical, hemodynamic, and clinical results of treatment with transjugular intrahepatic portosystemic shunt.

PURPOSE: To evaluate use of the transjugular intrahepatic portosystemic shunt (TIPS) as a nonsurgical approach for the management of Budd-Chiari syndrome (BCS). MATERIALS AND METHODS: Twelve patients with fulminant (n = 2), subacute (n = 5), or chronic (n = 5) BCS underwent TIPS placement. Hepatic venous obstruction was demonstrated at computed tomography and color duplex sonography. BCS was confirmed histologically in all patients. Hemodynamic parameters and clinical characteristics were assessed. RESULTS: TIPS creation was successful in all patients. Treatment reduced the portal venous pressure gradient by 75% and resulted in a mean shunt flow of 2,300 mL/min +/- 650 (standard deviation). No serious procedure-related complications were observed. The two patients with fulminant BCS died of septicemia or progressive liver failure despite intervention. The other 10 patients showed clinical improvement with reduction or disappearance of ascites. During follow-up, shunt dysfunction occurred in five of 10 patients with recurrence of ascites requiring repeat intervention. CONCLUSION: TIPS placement is safe and effective in patients with portal hypertension caused by subacute or chronic BCS.

[Septic portal vein thrombosis. Its successful therapy by local fibrinolysis and a transjugular portasystemic stent-shunt (TIPS)]. / Septische Pfortaderthrombose. Erfolgreiche Therapie durch lokale Fibrinolyse und transjugulären portosystemischen Stent-Shunt (TIPS).

HISTORY AND FINDINGS: A 68-year-old man, without any preceding hepatic or abdominal disease, suddenly developed a severe septic illness with consumptive coagulopathy and upper abdominal pain. B-mode and duplex ultrasonography revealed fresh portal vein thrombosis. Despite extensive conservative measures there was no significant improvement after one week and further thrombus extension with threatened acute mesenteric vein occlusion. TREATMENT AND COURSE: Local fibrinolysis with recombinant plasminogen activator and urokinase via percutaneous transjugular intrahepatic catheterization of the portal vein achieved almost complete dissolution of the thrombus within 3 days. Subsequently the portal vein catheter was changed into a transjugular portosystemic stent shunt (TIPS). CONCLUSIONS: While local or systemic fibrinolysis has been practised in previously reported cases of acute portal vein thrombosis, the described use of TIPS introduces a new element. The shunt between hepatic and portal veins assures therapeutic access to the portal venous bed. It lowers portal vein pressure and can diminish the danger of recurrent thrombosis by raising portal flow. This minimally invasive procedure may be a nearly ideal treatment even in the course of portal vein thrombosis which has a high complication rate.

The transjugular intrahepatic portosystemic stent-shunt procedure for refractory ascites.

BACKGROUND: Previous studies have suggested that the transjugular placement of an intrahepatic stent to establish a portosystemic shunt is an effective treatment of uncomplicated ascites accompanying variceal bleeding. We studied the stent shunt for use in patients with liver cirrhosis and ascites refractory to medical treatment. METHODS: Fifty of 62 consecutive patients with cirrhosis and refractory ascites (18 with Child-Pugh class B liver disease and 32 with class C) were treated with the stent shunt--an expandable stent of metallic mesh placed between a major branch of the portal vein and one of the hepatic veins. Patients were followed for a mean (+/- SD) of 426 +/- 333 days. Those with advanced cancer, severe heart failure, or severe liver failure were excluded. RESULTS: The stent shunt was successfully placed in all patients and reduced the pressure gradient between the portal vein and the inferior vena cava by an average of 63 percent. Thirty-seven patients (74 percent) had complete responses (total remission of ascites within three months), and nine patients (18 percent) had partial responses (ascites detected by ultrasound but with no need for paracentesis). Four patients did not respond, including two who died within two weeks of shunt placement. After the procedure, 25 patients had hepatic encephalopathy, as compared with 20 patients before the procedure; although encephalopathy improved in 3 patients, new encephalopathy developed in 8 patients. In the 28 of the 33 patients followed for more than six months who were evaluated, the mean serum creatinine concentration was 1.5 +/- 0.09 mg per deciliter (133 +/- 8 mumol per liter) before placement of the stent shunt, 1.5 +/- 1.6 mg per deciliter (133 +/- 141 mumol per liter) one week after the procedure, and 0.9 +/- 0.3 mg per deciliter (80 +/- 27 mumol per liter) after six months (P = 0.008 for the comparison of concentrations before and six months after the procedure). Renal function did not improve in the six patients with organic kidney disease. Procedure-related complications developed in 16 patients, including intraabdominal bleeding requiring blood transfusions in 2 patients. Thrombotic occlusion of the stent shunt occurred within two weeks in 5 patients, and later insufficiency of the shunt occurred in 16 patients, including 12 with recurrence of ascites after complete remission. During followup, an additional 29 patients died--10 of progressive liver disease and 19 of other causes. Survival for at least one year was associated with a patient's being under 60 years of age, having a serum bilirubin level before placement of the stent shunt of less than 1.3 mg per deciliter (22 mumol per liter), and having a complete response. CONCLUSIONS: Our findings in an uncontrolled prospective study suggest that the transjugular intrahepatic porto-systemic stent-shunt procedure was an effective treatment for many patients with liver cirrhosis and refractory ascites, but mortality from underlying diseases was substantial.

[Percutaneous needle biopsy in skeletal metastases. Indications, technique, value and results]. / Perkutane Nadelbiopsie bei Skelettmetastasen. Indikationen, Technik, Stellenwert und Ergebnisse.

Although modern imaging techniques have improved diagnostic specificity in osteolytic and osteoplastic lesions, histological examination is often still mandatory when primary bone tumors or skeletal metastases are concerned. We have developed a percutaneous puncture set, including sufficiently steady, but still fine biopsy needles (1.4-2 mm) and a slow rotating drill accessory. With this set, histological material can be obtained from almost anywhere in the skeleton with local anesthesia low complication risk, and low patient stress and discomfort. Together with the high accuracy of CT- or fluoroscopy-guided puncture (near 95%), this allows biopsies to be taken on an outpatient basis, with broad indications. Biopsy can be used early when making a diagnosis. Tedious searching for the primary tumor can thus be avoided with subsequent economic benefits.

The reducing stent: treatment for transjugular intrahepatic portosystemic shunt-induced refractory hepatic encephalopathy and liver failure.

PURPOSE: To examine the efficacy of a stent device in reducing the diameter of transjugular intrahepatic portosystemic shunts (TIPS) in patients with progressive liver failure or with shunt-induced hepatic encephalopathy. MATERIALS AND METHODS: Seven patients with TIPS (four with severe hepatic encephalopathy, three with progressive liver failure) underwent transjugular implantation of a stent designed to reduce the flow through the original TIPS channel. RESULTS: Implantation of the reducing stent proceeded without complication. Duplex sonography showed that stent flow decreased by 41% +/- 18 (mean +/- standard deviation). The four patients with hepatic encephalopathy showed substantial improvement. Concentrations of plasma ammonium and serum bilirubin improved considerably. In contrast, functional impairment progressed in the three patients treated for liver failure. The patients soon died. CONCLUSION: With the limited experience of treating these seven patients, the authors suggest that shunt-induced hepatic encephalopathy can be effectively treated with implantation of a reducing stent. Hepatic failure, however, is a deleterious complication that seems to be irreversible.

CT and MRI of Gorham syndrome.

Gorham syndrome, also known as massive osteolysis or vanishing bone, is a rare disorder (135 cases reported) leading to extensive loss of bony matrix, replaced by proliferating thin-walled vascular channels. Three histologically proven cases of the disease are reported, including the clinical presentation and modern imaging features with CT (with 3D reconstruction) as well as T1- and T2-weighted MRI. Two cases in young women were located in the pelvis with extensive osteolysis reaching to the acetabulum. The third case in a 2-month-old boy is the youngest case ever reported and involved the humerus. The radiological appearance of the disease is discussed and the importance of the modern imaging methods debated.

Experimental use of a modified fibrin glue to induce site-directed angiogenesis from the aorta to the heart.

From 10 cultures of manipulated Escherichia coli bacteria expressing the class I heparin-binding growth factor polypeptide alpha-endothelial cell growth factor, 11.2 +/- 0.7 mg alpha-endothelial cell growth factor was eluted by heparin-sepharose affinity chromatography. Analysis of molecular weight (17,000 kD) was done by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and purification of the growth factor was done by high-performance liquid chromatography. The harvested alpha-endothelial cell growth factor was proved by protein blotting. To assess the growth-promoting activity, we did an endothelial cell growth assay by comparing adult human endothelial cell control cultures, without adding growth factor to the culture medium, with adult human endothelial cell cultures with 0.02 to 20.0 ng/ml alpha-endothelial cell growth factor and 1.0 ng/ml heparin and with adult human endothelial cell cultures with alpha-endothelial cell growth factor but without heparin. Tritiated thymidine counts proved the significant growth-promoting activity of alpha-endothelial cell growth factor. In 10 experimental animals modified fibrin glue containing 1 microgram alpha-endothelial cell growth factor was implanted between the aorta and the myocardium of the left ventricle and results were compared with those in five control animals that received normal fibrin glue without growth factor. After 9 weeks of implantation, angiography and histologic investigation showed newly grown vascular structures between the aorta and the myocardium in all experimental animals, but none in the control animals. Our study proved the feasibility of initiating site-directed formation of new blood vessel structures to the heart by a modified fibrin glue implant containing angiogenic growth factor alpha-endothelial cell growth factor.

[Hemodynamics, liver function and clinical follow-up after TIPS]. / Hämodynamik, Leberfunktion und klinischer Verlauf nach TIPS.

In 126 patients with liver cirrhosis treated electively with transjugular intrahepatic portosystemic stent shunt (TIPS) to prevent variceal rebleeding, the portosystemic pressure gradient decreased by 60%. In spite of this incomplete effect the risk for variceal rebleeding was still under 20% after 2 years. Only 1 patient died of variceal rebleeding. Shunt insufficiency occurred in 50%, mainly during the first year, but shunt function was restored in nearly all cases by radiologic intervention, i.e., redilatation or implantation of an additional stent. During the follow-up of 16 +/- 9 months, 21 patients (17%) died, one-third of them from progressive liver failure aggravated in 4 cases by severe drinking. De novo hepatic encephalopathy was observed in 10%, especially in older patients and patients with impaired liver function before TIPS. In such patients it is recommended that the shunt be dilated to 0.8 cm at most, and the TIPS procedure can be combined with transjugular embolization of the varices. The advantages of TIPS over both endoscopic sclerotherapy and drug treatment must be clarified in randomized studies, which have already been initiated in several centers.

[The value of CEA immunoscintigraphy for diagnosis of colorectal cancer and its metastases: results of a prospective study]. / Die Bedeutung der CEA-Immunszintigraphie für die Diagnostik kolorektaler Karzinome und ihrer Metastasen: Ergebnisse einer prospektiven Studie.

The importance of the CEA-immunoscintigraphy (IS; BW 431/26 Fa Behring) for the diagnosis of colorectal carcinoma and its metastases was determined in a prospective trial including 60 patients. The results were compared with results of the ultrasound, the CT-Scan and the Angio-CT. Patients suffered from a colorectal carcinoma (15), from a local tumor recurrence after bowel resection (10), from hepatic (39) and/or extrahepatic metastases (16). In 40 patients the diagnosis was confirmed by laparotomy. Regarding the detection of hepatic metastases the sensitivity and specificity of the Angio-CT were superior to the IS (0.86 and 0.63 vs. 0.78 and 0.45). Ultrasound and Angio-CT together revealed true positive results in 89.2%. The IS did not improve this rate. Regarding the detection of extrahepatic metastases the sensitivity and the specificity of the CT were slightly superior to the IS (0.59 and 0.87 vs. 0.47 and 0.28). However, the IS increased the rate of true positive results by 18.8% (US + CT 43.7%; +IS 62.5% true positive results). Due to these results the IS is not recommended as the method of choice to detect liver metastases. But in patients unfit for diagnostic laparotomy the IS may give additional information of the extrahepatic tumor stage.

MR detection of quantitative and structural changes in human aortic aneurysms.

Collagen is a major component of the extracellular matrix and a determinant of the elastic behavior of the human aorta. To investigate the changes found in aneurysmal degeneration, the authors studied the solid-state hydrogen-1 nuclear magnetic resonance line shape of collagen in aneurysms and normal human aortas. A three-component decomposition of the free induction decay was performed, with collagen characterized by a T2 of about 18 microseconds. The second moment of the collagen line shape was found to be increased in aneurysms (5.3 vs 4.8 G2), while, correspondingly, the T2 of collagen was lower in aneurysms (16.3 vs 17.7 microseconds). This corresponds to a modification of collagen structure and molecular motion. Collagen concentration was lower in nondiseased aortic walls (9.4% vs 7.3%). These results are discussed in reference to the contradictory conclusions in the current literature. The increase in collagen and the modification of its structure and molecular motion are explained by the need to resist an increasing tangential tension due to increased aortic diameter and diminished wall thickness in aneurysms and by intercalation or site binding in the helices or electric dipolar interactions in the less mobile side groups.

In vitro proton NMR study of collagen in human aortic wall.

The authors relate the findings in the 1H solid state line shape (at 60 MHz) of human aortic walls (n = 12) in native state and after histologically controlled selective lysis of collagen and elastin. An analysis of the line shape shows a composite free induction decay (FID) consisting of a low amplitude (3-7%) fast decaying component (T2 approximately 20 microseconds) and a slow decaying one (T2 > 1 ms). The fast component is identified as the protons of the collagen macromolecules. The second moment computed from the experimental fast component of the FID is in agreement with published studies examining the motional characteristics of collagen by multinuclear NMR employing spin labeling. A theoretical second moment is computed for the collagen macromolecular backbone from the atomic positions in the superhelix. Comparison with the observed experimental values allows determination of the step angle (29 degrees) of the fast rotational motion of the collagen strands along their long axis.

Characterization of human aortic collagen's elasticity by nuclear magnetic resonance.

The elasticity of the human aortic wall in longitudinal uniaxial elongation at high strain, known to be determined mostly from tissular collagen's behaviour, is studied and compared to the second moment of the 1H nuclear magnetic resonance (NMR) solid state line-shape, a proton nuclear magnetic resonance (at 60 MHz) characteristic for the molecular motion and the rigidity of the collagen macromolecular backbone. The 1H NMR signal of collagen is identified after selective histologically controlled chemical lysis. The computed second moment of the line-shape shows statistically significant correlation with the slope of the strain-stress curve of the aorta at high strain, thus proving the relationship between a macroscopic tissular elasticity parameter and a macromolecular rigidity characteristic of collagen, a major tissular component. In vivo extension of this technique (e.g., MRI) would allow us to gain information on the biomechanical state of the aorta, a naturally highly stressed and strained tissue.

["Rare" urography by MRI: an alternative to IVU?]. / L'urographie "RARE" par IRM: une alternative à l'UIV?

The authors describe the technique of RARE sequences (Hennig, 1986) and their hydrographic application to urinary imaging, RARE urography. Heavily T2-weighted non-tomographic images of the urinary tract are obtained in less than 30 seconds, without contrast medium or ionizing radiation. The whole urinary tract is visualised on one image with a spatial resolution superior to that of sonography. The semiology of RARE urography is similar to that of the intravenous pyelogram. Silent kidneys are also visualised.