Inflammatory pseudotumor of the liver in a patient with congenital granulocytopenia and HCV infection.

Inflammatory pseudotumor (IPT) of the liver is a rare pathologic lesion. Although IPTs within the liver shows spontaneous regression, these lesions are frequently misdiagnosed as malignant on the basis of the clinical manifestation and the results of diagnostic imaging. With special regard to magnetic resonance imaging (MRI), differential diagnosis such as hepatocellular or cholangiocellular carcinoma (HCC/CCC) as well as regenerative liver lesions are discussed in a case of IPT with concomitant hepatitis C virus (HCV) infection and congenital granulocytopenia.

[Left ventricular mass in endurance-athletes with athlete's heart and untrained subjects--comparison between different echocardiographic methods and MRI]. / Vergleich echokardiographischer Methoden zur linksventrikulären Muskelmassenbestimmung mit der MRT bei Ausdauerathleten mit Sportherz und Untrainierten.

UNLABELLED: The echocardiographic determination of left ventricular mass (LVM) and volume is of importance for the interpretation of cardiac adaptations and risk-stratification. In pathologically hypertrophied hearts, conventional one- and two-dimensional echocardiographic methods tend to overestimate LVM. For the athlete's heart, a comparison between different echocardiographic methods and magnetic resonance imaging (MRI) has not been performed so far. 23 healthy male endurance-athletes (28+/-4 yr) with athlete's heart (A) and 26 healthy untrained males (U; 26+/-4 yr) were examined by MRI and the following echocardiographic methods: ASE-Cube (ASE), Devereux (DEV), Troy (TRO), Teichholz (TEI), Reichek (REI) and Dickhuth (DIC). Indexed LVM were: MRI: 107+/-6 g/m(2) (A), 79+/-7 g/m(2) (U); ASE: 170+/-20 g/m(2) (A), 119+/-14 g/m(2) (U); DEV: 134+/-16 g/m(2) (A), 95+/-11 g/m(2) (U); TRO: 134+/-16 g/m(2) (A), 92+/-12 g/m(2) (U); TEI: 115+/-10 g/m(2) (A), 91+/-8 g/m(2) (U); REI: 114+/-14 g/m(2) (A), 89+/-11 g/m(2) (U); DIC: 110+/-14 g/m(2) (A); 80+/-9 g/m(2) (U). In A and U, LVM is significantly overestimated by ASE, DEV, TRO, TEI, and REI compared to MRI (p<0.05), but not by DIC. Although coefficients of correlation were similar, only DIC revealed acceptable limits of agreement (ASE: +20 to +172 g; DEV: -13 to +93 g; TRO: -18 to +92 g; TEI: -17 to +53 g; REI: -25 to +57 g; DIC: -37 to +45 g). Depending on the used method, LVM upper limits range between 93 (MRT) and 146 g/m(2) (ASE) in U, and 119 (MRT) and 209 g/m(2) (ASE) in A. CONCLUSION: Compared to MRI, DIC is the most accurate conventional echocardiographic method to determine LVM in U and A. For a correct interpretation of LVM, differences of the echocardiographic methods have to be considered.

Pathophysiological changes after traumatic brain injury: comparison of two experimental animal models by means of MRI.

In an experimental study MRI was used to compare the pathophysiological changes of brain tissue after lateral fluid percussion injury (FPI) versus cold injury (CI) as models of traumatic brain injury (TBI). Two groups of Sprague-Dawley rats (n=23) were subjected to mild FPI, respectively, CI localized over the right parietal cortex. MRI was performed at different time points including T1w, T2w and T1w-CE (Gd-DTPA 0.2 mmol/kg BW) sequences as well as perfusion-weighted imaging with calculation of regional cerebral blood volume (rCBV) and regional cerebral blood flow (rCBF). T2w and T1w-CE images showed hyperintense areas in the traumatised cortex demonstrating brain edema and blood-brain barrier (BBB)-breakdown increasing up to 12 h. Perfusion-weighted imaging demonstrated a significant decrease of rCBV and rCBF in the ipsilateral cortex of CI animals compared with the contralateral hemisphere. In contrast, rats of the FPI group showed only slight differences in rCBF and rCBV comparing the left and right cortex. The results of our study confirm that both mild FPI and CI produced focal brain edema with concomitant breakdown of the BBB as a model of TBI. Since differences regarding perfusion are much more pronounced in CI our results suggest that, this model more likely seems to reflect pathophysiological changes of brain ischemia, whereas FPI seems to be better suited to model the pathophysiological characteristics of TBI.

cAMP and cGMP do not mediate the vasorelaxation induced by iodinated radiographic contrast media in isolated swine renal arteries.

PURPOSE: Vasodilatation is a frequent side effect of radiographic contrast media, partially due to a direct effect on vascular smooth muscles. Our purpose was therefore to examine any possible implication of the cyclic adenosine monophospate (cAMP) and cyclic guanosine monophosphate (cGMP) pathways in contrast media induced vasorelaxation. MATERIAL AND METHODS: Isolated segments of swine renal arteries were precontracted with 10 microM phenylephrine and relaxed with iomeprol before and after blockade of the cAMP and cGMP pathways. RESULTS: 80 mM and 160 mM of iomeprol significantly relaxed about 52% and 68% of the precontracted arterial rings, respectively. 10 microM of IBMX, a phosphodiesterase inhibitor, did not increase the relaxant effect of 80 mM iomeprol but increased the relaxations induced by 400 nM forskolin by about 1.9 times (which stimulates the production of cAMP), and by 1 microM sodium nitroprusside (which stimulates the production of cGMP). 1 microM of H89 (an inhibitor of the cAMP-dependent protein kinase), was able to reduce the relaxation induced by 4 microM forskolin by about 2.5 times but had no significant effect on the relaxation induced by 160 mM iomeprol. 10 microM of ODQ (an inhibitor of the soluble guanylate cyclase), could reduce the relaxation induced by 10 microM of SNP but not the one induced by 160 mM iomeprol. Moreover, the absence of endothelial cells did not alter the relaxation induced by iomeprol. CONCLUSION: The activation of the cAMP and cGMP pathways are not involved in the in vitro relaxation induced by iomeprol in swine renal arteries.

Iodinated radiographic contrast media inhibit the capacitative calcium entry into smooth muscle cells of the swine renal artery.

RATIONALE AND OBJECTIVES: To investigate whether nonionic, iodinated, radiographic contrast media (RCM) could modulate calcium release from or calcium entry into smooth muscle cells of the swine renal artery. METHODS: Intracellular calcium concentrations of isolated myocytes loaded with the calcium-sensitive dye fluo-3 were analyzed using a fluorescence imaging system. Calcium signals were compared with isometric contractions of vascular segments in an organ bath. The effects of the triiodinated monomer iomeprol were compared with those of a mannitol solution. RESULTS: Stimulation of alpha-receptors by phenylephrine caused a biphasic calcium signal. Transient liberation of calcium from intracellular stores triggered the sustained entry of extracellular calcium (capacitative entry). Iomeprol and mannitol slightly inhibited the initial transient spike to the same extent. The calcium influx was reversibly inhibited by RCM by about 50%. Up to a concentration of 40 mmol/L, the inhibition induced by iomeprol was significantly higher than that induced by mannitol (P < 0.05-0.01). In isolated arterial segments, relaxation of the contraction phase depending on the calcium influx was significantly higher with the RCM than with mannitol (P < 0.01). CONCLUSIONS: Vasodilatation by CM is associated with a reduction in the capacitative entry of calcium. The mechanism of this effect is not clear, but it can be ruled out that it is mainly due to the high osmolarity of these compounds.

Lymphangioma of the pancreas and the duodenal wall: MR imaging findings.

Pancreatic lymphangiomas are rare benign tumours with a histogenesis not yet completely understood. Predominantly the cystic aspect of this lesion can complicate the differentiation from other neoplastic and non-neoplastic cystic tumours of the pancreas. We present a case of a middle-aged woman with a lymphangioma involving the duodenal wall and the pancreatic head. With special regard to MR imaging findings differential diagnosis is discussed.

Intra-abdominal tuberculous peritonitis.

We report the case of a 15-year-old boy suffering from progressive dyspnea on exertion and painful abdominal protrusion. Final diagnosis of intra-abdominal tuberculosis (TB), including lymphadenopathy and abdominal abscess formation, was made following elective laparotomy. This type of disease is a rare manifestation of extrapulmonary tuberculosis. The imaging findings in unenhanced and contrast-enhanced MRI and laparoscopic images are presented. Differential diagnosis of abdominal abscess formation and other fungal or bacteriological infections, as well as the imaging findings of this type of lesion, are discussed. This case demonstrates that atypical manifestation of TB may remain unrecognized; thus, awareness of this kind of manifestation of tuberculosis may prevent patients from being subjected to inappropriate therapies.

Rare pseudotumors of the urinary bladder in childhood.

We report two cases of inflammatory pseudotumors of the urinary bladder, one case of a chronic granulomatous pseudotumor (CGT) and one case of a pseudosarcomatous myofibroblastic (fibromyxoid) tumor (PMT). Both tumors resembled malignancies such as rhabdomyosarcomas regarding clinical appearance and imaging findings and represent rare urinary bladder tumors. The imaging findings on unenhanced and contrast-enhanced MRI as well as histological specimen are presented. Final diagnosis was made following elective surgery. Differential diagnosis of urinary bladder tumors as well as the imaging findings of these clinically comparable cases are discussed. Awareness of these benign lesions may prevent patients from inappropriate therapies such as chemotherapy or radiation therapy.

In vivo microscopic evaluation of the microvascular behavior of FITC-labeled macromolecular MR contrast agents in the hamster skinfold chamber.

RATIONALE AND OBJECTIVES: The extravasation properties of two macromolecular MR imaging contrast media (CM) in relation to structural differences of the terminal vascular bed were investigated to determine whether differentiation between normal (physiological) and tumor (pathological) tissue can be achieved by means of extravasation characteristics. METHODS: Gd-DTPA-polylysine (50 kD, CM1) and Gd-DOTA cascade polymer (Gadomer 17; 20 kD, CM2) were labeled with fluorescein isothiocyanate (FITC) to enable in vivo fluorescence microscopy of the microcirculation. After implantation of a dorsal skinfold chamber and 7 days (range, 6-8) after induction of an amelanotic melanoma (A-Mel-3), 14 male hamsters weighing 85 g (range, 70-95 g) received 200 micromol/kg of CM1 by intravenous injection into the jugular vein. CM2 was similarly investigated after an interval of 24 hours. Fluorescence microscopy was performed in areas of subcutaneous tissue, striated muscle, and tumor tissue. Microscopic images were registered by a charge-coupled-device video camera and transferred to a video system. Distribution intensities of CM were evaluated on a digitally based measurement system. A control investigation was performed with FITC-dextran (150 kD). RESULTS: Gd-DTPA-polylysine showed no extravasation into physiological tissue for the first 10 minutes after injection. After this period, however, the first signs of leakage became apparent. Gd-DOTA cascade polymer was extravasated after 5 minutes into the tumor-free tissue. In tumor capillaries, Gd-DTPA-polylysine could be detected in the extravasal space as well as in physiological tissue after 15 minutes. After injection of Gd-DOTA cascade polymer, direct leakage from tumor capillaries was observed, with a contrast maximum between tumor and surrounding tissue occurring 3 to 5 minutes after CM injection. Good delineation of tumor vascularization from striated muscle and subcutaneous tissue was achieved. CONCLUSIONS: The CM studied showed different microvascular permeation properties. Faster leakage of Gd-DOTA cascade polymer was observed in areas with neoplastic tumor vessels, whereas extravasation in physiological tissue was detected after a period of 5 minutes. Gd-DTPA-polylysine demonstrated nonspecific leakage at later time points.

Littoral cell angioma of the spleen: CT and MR imaging appearance.

We report a case of littoral cell angioma (LCA) of the spleen, a recently described splenic pathology, which imaging characteristics and pathologic morphology have been discussed only by a few authors. The imaging findings in unenhanced and contrast-enhanced MRI and CT as well as histologic specimen are presented. Diagnosis was made after elective splenectomy. Differential diagnosis of splenic tumors as well as the imaging findings in this particular case are discussed.

[Interferon alpha-2a in the treatment of diffuse thoracic angiomatosis in adulthood--a ase report]. / Interferon alpha-2a zur Therapie einer diffusen thorakalen Angiomatose im Erwachsenenalter--Ein Fallbericht.

A diffuse angiomatosis affecting thoracal organs is a rare, frequently fatal disorder occurring mainly in childhood. The definite diagnosis is usually made by autopsy. A specific treatment does not exist. In the case report presented here we describe the course of an 37-year old patient presenting initially with dyspnea and hemoptysis. Radiological investigations showed a mass lesion in the anterior superior mediastinum, bihilar masses and a periesophageal mass with soft tissue density and a pericardial effusion. Bilateral interstitial infiltrations were also present. CT-guided mediastinal biopsies and bronchial mucosal biopsies were nonspecific. Open-lung biopsy revealed the diagnosis of an extensive diffuse angiomatosis affecting mediastinum, pericardium and pleura. During the 18-month monotherapy with interferon-alpha 2a the patient showed significant improvements of clinical as well as laboratory and radiological parameters. The presented case confirms the experience of several authors, that the diagnosis of a diffuse thoracal authors can only be made by open lung biopsy or autopsy. The presented case also underlines the possibility of a palliative therapy of aggressive angiomatous diseases with interferon-alpha 2a.

[Reduction of the radiation exposure of patients caused by selected interventional and angiographic procedures]. / Reduzierung der Strahlenexposition von Patienten bei ausgewählten interventionellen und angiographischen Massnahmen.

PURPOSE: To reduce patient doses caused by selected interventional and angiographic procedures using the digital C-arm unit "Multiskop". MATERIALS AND METHODS: After a patient study done previously, physical measurements with test phantoms were carried out, and physical-technical parameters such as distance between focus and image intensifier, additional filtration, and radiation dose per image were optimised. Then, the dose-area product (DAP) and the fluoroscopic time were measured for 130 percutaneous transluminal angioplasties (PTA), 40 PTA with stent implantation, 61 embolisations, and 302 digital subtraction angiographies (DSA). In the case of 16 PTA, 9 embolisations, and 38 DSA the number of radiographs was determined, and the DAP was divided into two parts, fluoroscopy and radiography. The measuring values were compared with data of the patient study done previously. RESULTS: The median values of the DAP and the fluoroscopic time amounted to 25 Gy cm2 and 9.7 min for PTA, 97 Gy cm2 and 8.5 min for PTA with stent implantation, 88 Gy cm2 and 17.2 min for embolisation as well as 54 Gy cm2 and 2.8 min for DSA. For the relation between DAP caused by fluoroscopy and radiography, and the number of radiographs, median values of 0.76 and 63 for PTA, 0.81 and 123 for embolisation as well as 1.85 and 134 for DSA were determined. In comparison to the patient study done previously the median values of the DAP were reduced by 31% for PTA, 26% for PTA with stent implantation, 55% for embolisation, and 38% for DSA. CONCLUSIONS: The comparison between the patient studies done previously and recently indicates the great potential of dose reduction for interventional and angiographic procedures. Although the X-ray equipment is ten years old the patient dose can be reduced by organizational and physical-technical modifications to such an extent that preliminary national reference dose values will not be exceeded. For further significant dose reductions while maintaining adequate image quality it will be necessary to purchase a modern X-ray equipment with pulsed fluoroscopy and automatic filter selection.

[Urologic importance of interventional radiology techniques]. / Importance des techniques radiologiques interventionnelles d'un point de vue urologique.

In radiology several therapeutical methods were developed and introduced into clinical routine in the last 10 to 15 years. In part these techniques are in competition with established surgical procedures although their main advantage is significantly less invasion. For the urologist diagnostic radiological procedures like selective blood sampling from renal or suprarenal vessels for hormone determination or CT-guided biopsy of retroperitoneal tumors are of special interest as well as procedures with therapeutic aims such as placement of drainage-tubes, percutaneous therapy of varicoceles and arterial endovascular interventions for hemorrhage or vascular wall stenosis. The role of these interventional techniques relevant for urology is described and critically discussed.

[Comparison of radiation exposure of patients caused by selected interventional and angiography procedures--initial results]. / Vergleich der Strahlenexposition von Patienten bei ausgewählten interventionellen und angiographischen Massnahmen--erste Ergebnisse.

PURPOSE: To determine and judge patient doses caused by selected interventional and angiographic procedures using the "Multiskip" digital C-arm unit. MATERIALS AND METHODS: The dose-area product and the fluoroscopic time were measured for 71 percutaneous transluminal angioplasties (PTA), 33 PTA with stent implantation, and 37 embolizations; in addition, they were also measured for 285 digital subtraction angiographies (DSA). In the case of 13 PTA, 10 embolizations, and 33 DSA the number of radiographs was determined, and the dose-area product was divided into two parts, fluoroscopy and radiography, applying a computer programme. RESULTS: The median values of the dose-area product and the fluoroscopic time amounted to 36 Gy cm2 and 11.5 min for PTA, 131 Gy cm2 and 14.4 min for PTA with stent implantation, 197 Gy cm2 and 24.5 min for embolisation as well as 87 Gy cm2 and 3.7 min for DSA. For the relation between dose-area products caused by fluoroscopy and radiography and the number of radiographs, median values of 0.67 and 70 for PTA, 0.58 and 153 for embolisation as well as 1.35 and 135 for DSA were determined. CONCLUSIONS: To reduce the relatively high patient doses the modification of the C-arm unit is aspired to realize pulsed fluoroscopy and automatic filter selection. Also experimental investigations will be done related to additional filtration and reduction of the image intensifier input dose rate and dose per frame, respectively. Then, the effect of dose reduction caused by these measures will be confirmed in a comparable patient study.