Dynamic contrast-enhanced MRI for monitoring bisphosphonate therapy in Paget's disease of bone.

PURPOSE: The purpose of this study was to evaluate changes in regional bone perfusion in Paget's disease (PD) following bisphosphonate therapy. We used dynamic contrast-enhanced MRI (DCE-MRI) for assessment of bone perfusion and compared MRI findings with alkaline phosphatase (AP) as a serum marker of bone turnover. MATERIALS AND METHODS: We examined 20 patients (8 women, 12 men, 66 ± 11 years) with symptomatic PD of the axial skeleton. Patients were selected for infusion therapy with the bisphosphonate pamidronate. The most affected bone of lumbar spine or pelvis was examined by DCE-MRI prior to therapy and after a 6-month follow-up. The contrast uptake was evaluated using a two-compartment model with the parameters amplitude A and exchange rate constant K(ep). Color-coded parametric images were generated to visualize bone vascularization. RESULTS: After a 6-month follow-up there was a significant decrease in alkaline phosphatase and in DCE-MRI parameters A and K(ep) (p < 0.0001). Patients without previous bisphosphonate treatment showed a significantly greater decrease in alkaline phosphatase and K(ep) (p < 0.001). CONCLUSION: DCE-MRI shows a significant reduction in regional bone perfusion in PD following parenteral bisphosphonate treatment. Reduction in bone perfusion is greater in bisphosphonate-naïve patients than in those who had been previously treated.

[Imaging in the emergency room]. / Bildgebung im Schockraum.

In order to reduce mortality in severely injured patients, a rapid radiologic diagnosis is essential. Sonography plays a role only as a focused assessment with sonography for trauma (FAST) to clarify free intraperitoneal fluid immediately on admittance. Today, whole-body multislice helical computed tomography (CT) has become increasingly important as a diagnostic tool. Based on the results of the CT scan, patients can be referred for laparotomy or safely classified for "wait and see" treatment. Although the reduction in injury-related mortality would outweigh the risk of radiation dose, the indiscriminate use of CT for patients with minor injuries is not justified and must be avoided.

[Extrapulmonary tuberculosis: radiological imaging of an almost forgotten transformation artist]. / Extrapulmonale Tuberkulose: Die radiologische Bildgebung eines fast vergessenen Verwandlungskünstlers.

Tuberculosis (TB) continues to be one of the infectious diseases with the world's highest rates of avoidable morbidity and mortality. A continuing downward trend has only been observed in highly industrialized countries, including Germany with 4,400 cases in the year 2009 representing an incidence of 5.5 per 100,000 persons. At the same time, the exposure to this patient group and the clinical experience are decreasing. Tuberculosis may affect any organ. The lung was the manifestation site in 80% of cases, and extrapulmonary manifestations were recorded in 20% of cases in Germany in the year 2008. Lymph node involvement is most common with a rate of approximately 50% of all extrapulmonary cases followed by the pleura in 18% of cases, genitourinary tract in 13% of cases, bones and joints in 6% of cases, gastrointestinal tract in 6% of cases, the central nervous system in 3% of cases and the spine in 3% of cases. Symptoms like fever, night sweats and weight loss are non-specific and may be absent. The aim of the review is to raise awareness of this disease, which is increasingly falling into oblivion, with its various radiological manifestations and to point out clinical-epidemiological and demographic factors that raise suspicion of tuberculosis.

Combined CT- and fluoroscopy-guided nephrostomy in patients with non-obstructive uropathy due to urine leaks in cases of failed ultrasound-guided procedures.

AIM: To report our experience of combined CT- and fluoroscopy-guided nephrostomy in patients with non-obstructive uropathy due to urine leaks in cases of failed ultrasound-guided procedures. PATIENTS AND METHODS: Eighteen patients (23 kidneys) with non-obstructive uropathy due to urine leaks underwent combined CT- and fluoroscopy-guided nephrostomy. All procedures were indicated as second-line interventions after failed ultrasound-guided nephrostomy. Thirteen males and five females with an age of 62.3±8.7 (40-84) years were treated. Urine leaks developed in majority after open surgery, e.g. postoperative insufficiency of ureteroneocystostomy (5 kidneys). The main reasons for failed ultrasound-guided nephrostomy included anatomic obstacles in the puncture tract (7 kidneys), and inability to identify pelvic structures (7 kidneys). CT-guided guidewire placement into the collecting system was followed by fluoroscopy-guided nephrostomy tube positioning. Procedural success rate, major and minor complication rates, CT-views and needle passes, duration of the procedure and radiation dose were analyzed. RESULTS: Procedural success was 91%. Major and minor complication rates were 9% (one septic shock and one perirenal abscess) and 9% (one perirenal haematoma and one urinoma), respectively. 30-day mortality rate was 6%. Number of CT-views and needle passes were 9.3±6.1 and 3.6±2.6, respectively. Duration of the complete procedure was 87±32 min. Dose-length product and dose-area product were 1.8±1.4 Gy cm and 3.9±4.3 Gy cm2, respectively. CONCLUSIONS: Combined CT- and fluoroscopy-guided nephrostomy in patients with non-obstructive uropathy due to urine leaks in cases of failed ultrasound-guided procedures was feasible with high technical success and a tolerable complication rate.

[60-year old woman with round lesion of the right upper lobe of the lung after heart transplantation]. / 60-jährige Patientin mit Raumforderung im rechten Lungenoberlappen nach Herztransplantation.

We report on a woman presenting with fever and novel round lesion in the lung four months after heart transplantation. Microbiologic assessment of bronchial lavage and operative specimen revealed pulmonary nocardiosis. Furthermore, cerebral involvement has been observed. Antibiotic treatment according to the microbiological sensitivity test for eleven months resulted in complete remission of pulmonary and cerebral nocardiosis. Immunosuppressive treatment increases the risk for opportunistic infections early after transplantation as well as malignancies during the late course.

[MR imaging in cardiac amyloidosis--morphology, function and late enhancement]. / Magnetresonanztomografie bei kardialer Amyloidose--Morphologie, Funktion und late enhancement.

PURPOSE: Since limited data is available using MR imaging in cardiac amyloidosis, the purpose of our study was to evaluate morphological and functional differences of the heart using cardiac MRI. MATERIALS AND METHODS: 19 consecutive patients (14 males, 5 females, mean age 59 +/- 6 years) with histologically proven cardiac amyloidosis were evaluated with MRI at 1.5 T. Results were compared with data of 10 healthy, age-matched control subjects (5 males, 5 females, mean age 60 +/- 6 years). Functional and morphological data including late enhancement (LE) was acquired. RESULTS: Compared to the control group, patients with cardiac amyloidosis had thickened atrial walls and dilated atriums. Both ventricles and the interventricular septum were thickened. The LV hypertrophy was focal in 11 / 19 (58 %) and global in 4 / 19 (21 %) of patients. A myocardial edema occurred in 2 / 19 patients with cardiac amyloidosis (11 %). An edema of the myocardium was visible in 2 / 19 (11 %) of patients. The LV ejection fraction was statistically significantly decreased. The prevalence of LE was 74 % (14 / 19 of patients). LE was detected predominantly in the LV anterior wall and in the interventricular septum. Within the segments LE was located predominantly in a subendocardial location. Between patients with and without LE no statistically significant differences of functional and morphological results were able to be established. CONCLUSION: There are three major outcomes of our assessment: 1. The LV hypertrophy is focal in the majority of patients with cardiac amyloidosis. 2. No statistically significant differences can be established in regard to the functional and morphological features between patients with and without LE. 3. Myocardial edema is a possible feature in cardiac amyloidosis.

Dynamic contrast-enhanced MRI in Paget's disease of bone--correlation of regional microcirculation and bone turnover.

The purpose of this study was to evaluate regional microcirculation in Paget's disease of bone (PD) with dynamic contrast-enhanced MR imaging (DCE-MRI). Additionally, we correlated regional bone perfusion with alkaline phosphatase as serum marker of bone turnover. We examined 71 patients with PD (27 men, 44 women, 67+/-10 years) localized at the axial and appendicular skeleton. Contrast uptake was analyzed using a two-compartment model with the output variables amplitude A and exchange rate constant k(ep). Color-coded parametric images were generated to visualize microcirculation. Serum levels of alkaline phosphatase (AP) were compared with DCE-MRI parameters. Amplitude A and exchange rate constant k(ep) were significantly increased in PD compared to unaffected bone (A(PD) 0.81+/-0.24 vs. A(control) 0.34+/-0.1 and k(ep PD) 4.0+/-2.86 vs. k(ep control) 1.73+/-0.88, p<0.001). There was a significant correlation (r(s)=0.5-0.7) of DCE-MRI parameters and AP at the axial (pelvis, spine) and appendicular skeleton (femur, tibia). The long bones showed increased circulation of the advancing peripheral zones and no vascularization of the central part, which had been replaced by fatty tissue. Regional microcirculation in PD is inhomogeneous with focal areas of excessive hypervascularity, especially in the advancing peripheral zone. There is a significant correlation of bone circulation and bone turnover in PD. DCE-MRI might therefore be a diagnostic tool for monitoring therapeutic effects of bisphosphonates in Paget's disease of bone.

Comparison of CT during arterial portography and MR during arterial portography in the detection of liver metastases.

OBJECTIVE: This study compared MR during arterial portography (MRAP) with CT during arterial portography (CTAP) with regard to the detection and differentiation of liver metastases before surgery. MATERIALS AND METHODS: Fifteen patients with liver metastases were enrolled before surgery according to the guidelines of our institutional review board and good clinical practice. After mesentericography, unenhanced scans (Volume Zoom) were performed initially. For CTAP, the contrast medium was injected through the superior mesenteric artery. Images were acquired in portal and delayed enhancement. The MR protocol (1.5 T; Magnetom Symphony) started with T1-weighted fast low-angle shot (FLASH) T2-weighted turbo spin echo (TSE). MRAP followed with gadolinium-enhanced dynamic T1-weighted 3D FLASH. Delayed-phase T1-weighted 2D FLASH axial images were performed 2 min after IV injection of the contrast medium. Qualitative and quantitative evaluation of CTAP and MRAP was performed by three blinded radiologists regarding the number of lesions and their size, localization, and differential diagnosis. RESULTS: The overall sensitivity in detecting liver metastases was 97% with MRAP and 93% with CTAP (p > 0.05, not significant [n.s.]). The specificity was calculated to be 97% for MRAP and 82% for CTAP (p < 0.0001, statistically significant [s.s.]). The differences in sensitivity were more accentuated if only lesions 10 mm or smaller were considered (95% vs 88%, p > 0.05, n.s.), for which the respective specificities were 95% and 80% (p < 0.0014, s.s.). Improvements in sensitivity and specificity were associated with a higher lesion-to-liver contrast-to-noise ratio (59.4 +/- 51.0 for MRAP vs 10.4 +/- 7.3 for CTAP) and resulted in higher diagnostic confidence in the differential diagnosis of liver lesions (p < 0.001, s.s.) and better interobserver agreement (median kappa value, 0.88 vs 0.63). CONCLUSION: MRAP proved to be a reliable method in the preoperative detection of small liver metastases in particular, with a higher sensitivity and specificity than CTAP. If organizational difficulties of MRAP can be overcome, MRAP could be considered instead of CTAP in the preoperative invasive evaluation of metastatic liver disease.

[Imaging methods in the diagnosis and therapy of cystic echinococcosis]. / Bildgebende Verfahren in Diagnostik und Therapie der zystischen Echinokokkose.

Imaging studies, ultrasonography, play a central role for the diagnosis and follow-up of cystic echinococcosis (hydatid disease) due to the non-specific clinical symptoms and still inadequate sensitivity and specificity of currently available serological tests. Due to the increasing number of people immigrating to central Europe from countries with a high incidence of cystic echinococcosis, cystic echinococcosis has become an important differential diagnosis of cystic lesions. The imaging modality to localize and stage the disease depends on the organs affected. Ultrasonography is the most important imaging technique to screen for abdominal lesions (more than 75 % of the cases). Therefore, an expert committee of the WHO Working Group on echinococcosis has recently suggested a standardized ultrasonographic classification of hepatic cystic echinococcosis. This classification proofs to be very useful for staging echinococcal cysts with respect to parasite activity. Ultrasonography is not only an excellent tool for the primary diagnosis and therapeutic decision but also for follow-up of patients treated for cystic echinococcosis. Indications for computed tomography or magnetic resonance tomography are restricted to extra abdominal disease, patients not suited for ultrasonography because of obesity or meteorism, complicated cysts and planning of surgery or interventional therapy. Apart from surgery three other treatment options are well established: (1) chemotherapy with albendazole or mebendazole, (2) percutaneous drainage and sterilization (PAIR) and (3) observation of inactive echinococcal stages ("watch and wait" approach).

Preoperative evaluation of living renal donors: value of contrast-enhanced 3D magnetic resonance angiography and comparison of three rendering algorithms.

The aim of this study was to assess the value of contrast-enhanced three-dimensional MR angiography (CE 3D MRA) in the preoperative assessment of potential living renal donors, and to compare the accuracy for the depiction of the vascular anatomy using three different rendering algorithms. Twenty-three potential living renal donors were examined with CE 3D MRA (TE/TR=1.3 ms/3.7 ms, field of view 260-320x350 mm, 384-448x512 matrix, slab thickness 9.4 cm, 72 partitions, section thickness 1.3 mm, scan time 24 s, 0.1 mmol/kg body weight gadobenate dimeglumine). Magnetic resonance angiography data sets were processed with maximum intensity projection (MIP), volume rendering (VR), and shaded-surface display (SSD) algorithms. The image analysis was performed independently by three MR-experienced radiologists recording the number of renal arteries, the presence of early branching or vascular pathology. The combination of digital subtraction angiography (DSA) and intraoperative findings served as the gold standard for the image analysis. In total, 52 renal arteries were correspondingly observed in 23 patients at DSA and surgery. Other findings were 3 cases of early branching of the renal arteries, 4 cases of arterial stenosis and 1 case of bilateral fibromuscular dysplasia. With MRA source data all 52 renal arteries were correctly identified by all readers, compared with 51 (98.1%), 51-52 (98.1-100%) and 49-50 renal arteries (94.2-96.2%) with the MIP, VR and SSD projections, respectively. Similarly, the sensitivity, specificity and accuracy was highest with the MRA source data followed by MIP, VR and SSD. Time requirements were lowest for the MIP reconstructions and highest for the VR reconstructions. Contrast-enhanced 3D MRA is a reliable, non-invasive tool for the preoperative evaluation of potential living renal donors. Maximum intensity projection is favourable for the processing of 3D MRA data, as it has minimal time and computational requirements, while having similar or superior accuracy for the depiction of vessel anomalies or pathology compared with VR and SSD, respectively.

Radiation dose reduction in chest radiography using a flat-panel amorphous silicon detector.

AIM: The aim of this study was to evaluate the image quality and the potential for radiation dose reduction with a digital flat-panel amorphous silicon detector radiography system. MATERIAL AND METHODS: Using flat-panel technology, radiographs of an anthropomorphic thorax phantom were taken with a range of technical parameters (125kV, 200mA and 5, 4, 3.2, 2, 1, 0.5, and 0.25mAs) which were equivalent to a radiation dose of 332, 263, 209, 127, 58.7, 29, and 14 microGy, respectively. These images were compared to radiographs obtained by a conventional film-screen radiography system at 125kV, 200mA and 5mAs (equivalent to 252 microGy) which served as reference. Three observers evaluated independently the visibility of simulated rounded lesions and anatomical structures, comparing printed films from the flat-panel amorphous silicon detector and conventional x-ray system films. RESULTS: With flat-panel technology, the visibility of rounded lesions and normal anatomical structures at 5, 4, and 3.2mAs was superior compared to the conventional film-screen radiography system. (P< or =0.0001). At 2mAs, improvement was only marginal (P=0.19). At 1.0, 0.5 and 0.25mAs, the visibility of simulated rounded lesions was worse (P< or =0.004). Comparing fine lung parenchymal structures, the flat-panel amorphous silicon detector showed improvement for all exposure levels down to 2mAs and equality at 1mAs. CONCLUSION: Compared to a conventional x-ray film system, the flat-panel amorphous silicon detector demonstrated improved image quality and the possibility for a reduction of the radiation dose by 50% without loss in image quality.

[Recurrence of cystic adventitial degeneration of the popliteal artery--magnetic resonance tomography and MR angiography]. / Rezidiv einer zystischen Adventitiadegeneration der A. poplitea--Magnetresonanztomographie und MR-Angiographie.

Adventitial cystic disease is a rare disorder characterized by mucin-containing cysts of the adventitial tissue. The condition has a predilection for the popliteal artery. Men are predominantly affected, usually around the fourth decade. We report of a case of recurrent adventitial cystic disease and the possibilities of modern cross-sectional imaging. In particular we discuss the advantages of magnetic resonance imaging and magnetic resonance angiography for the diagnosis of this condition. Furthermore, the etiology and the possibilities of surgical treatment are illustrated.

Therapy of pseudomyxoma peritonei of appendiceal origin--surgical resection and intraperitoneal chemotherapy.

Pseudomyxoma peritonei (PMP) is rare clinical entity presenting with mucus-producing lesions on the peritoneal surface. PMP is found in middle-aged or older patients in approximately two out of 10,000 laparotomies. Most of the reported cases are due to a primary process located in either appendix or the ovaries. PMP presents with an insidious onset of symptoms, and is characterized by long-term survival with good general health and absence of visceral invasion or distant metastasis. The treatment of choice for PMP is surgical resection and the removal of free mucus. Despite a high rate of disease recurrence, adjuvant or palliative chemotherapy has not yet been clearly established. In our opinion, intraperitoneal application may be more effective than a systemic regimen because only local treatment can provide sufficient concentrations of chemotherapeutic agents. In view of the lack of standardized treatment regimens and based on our experience, we recommend intraperitoneal chemotherapy with 5-FU and mitomycin C or cisplatin. We report ten cases of PMP of appendiceal origin and present a review of the literature on this disease and its treatment.

Endocrine mechanisms of stress-induced DHEA-secretion.

Acute psychological stress of a first time parachute jump stimulated DHEA and cortisol secretion in healthy volunteers. A significant shift from cortisol to DHEA occurred during this stress exposure. This effect was more pronounced in subjects receiving the beta-adrenoceptor antagonist propranolol prior to the jump. In contrast, infusion of epinephrine (0.10 microgram/kg/min) or norepinephrine (0.15 microgram/kg/min) for 20 min neither affected DHEA plasma levels nor the DHEA/cortisol ratio. However, pretreatment with propranolol resulted in a significant increase of the DHEA/cortisol ratio upon infusion of the beta-adrenoceptor agonist epinephrine. These data demonstrate that during acute psychological stress stimulation of adrenal steroid release is accompanied by a shift towards DHEA. Augmentation of this effect by beta-adrenoceptor blockade indicates a beta-adrenoceptor-dependent mechanism affecting DHEA release.

Epinephrine or norepinephrine fail to influence pituitary-adrenal secretion in man.

It is unknown whether plasma catecholamines have direct physiologic effects on pituitary-adrenocortical secretion in man. Therefore we investigated the effects of epinephrine and norepinephrine on plasma concentrations of adrenocorticotropin (ACTH), beta-endorphin and cortisol. Nineteen healthy male volunteers received infusions of either NaCl, epinephrine (0.10 micrograms/kg/min) or norepinephrine (0.15 micrograms/kg/min) for 20 minutes. 30 min before to 120 min after the infusion blood was continuously drawn to determine plasma levels of epinephrine, norepinephrine, and cortisol. In addition, ACTH and beta-endorphin plasma concentrations were analyzed at 6 time points before, during and after infusion. Infusion of catecholamines increased epinephrine and norepinephrine concentrations in physiological ranges as observed during intense psychological stress or exhausting physical exercise. However, these increases in catecholamine plasma levels neither affected concentrations of POMC-derived hormones nor plasma levels of cortisol. We conclude that in man, physiologic increases in circulating catecholamines have no influence on pituitary-adrenal hormone concentrations.

Catecholamines modulate human NK cell circulation and function via spleen-independent beta 2-adrenergic mechanisms.

Increases in catecholamines have been shown to induce changes in migration of lymphocytes, in particular NK cells. To analyze the mechanisms of catecholamine-induced NK cell trafficking, normal healthy male human subjects and splenectomized individuals were infused with either adrenaline (0.10 microgram/kg/min), noradrenaline (0.15 microgram/kg/min), or NaCl i.v. for 20 min. Lymphocyte subsets (CD3+, CD4+, CD8+) transiently increased after administration of both catecholamines, with most pronounced increases (up to 600%) in NK cell numbers (CD16+ or CD56+) after infusion of adrenaline. These changes in NK cell numbers and function were accompanied neither by alterations in expression of adhesion molecules (CD11a), CD11b, CD31, CD43, CD44, CD62L) on NK cells nor by changes in plasma concentrations of soluble (s) adhesion molecules (sVCAM-1, sICAM-1, sE-selectin). Comparable increases in lymphocyte subsets were observed in splenectomized subjects, suggesting lymphocyte recruitment from other sources than the spleen. Furthermore, catecholamine-induced increases in lymphocyte subsets could be inhibited by pretreatment with the nonselective beta-adrenoceptor antagonist propranolol, but not by the beta1-selective antagonist bisoprolol. These data demonstrate that adrenaline and noradrenaline modulate the migratory capacity of human NK cells via spleen-independent beta 2-adrenoceptor mechanism.

[Results of a combined glaucoma- and cataract-operation (author's transl)]. / Resultate bei kombinierter Glaukom- und Katarakt-operation.

106 eyes with glaucoma and cataract have been operated simultaneously with a combined cataract-extraction (cryoextraction) and trephining with scleral flap (Elliot-Fronimopoulos). In 95 eyes intraocular pressure was compensated without local therapy (about 90%).

[Trepanation with scleral flap (Elliot-Fronimopoulos) in acute narrow-angle glaucoma (author's transl)]. / Trepanation mit Skleradeckel (Elliot-Fronimopoulos) bei akutem Engwinkelglaukom

120 eyes with acute closed angle glaucoma were operated by goniotrepanation (Elliot-Fronimopoulos). The follow-up controls showed excellent results. Especially the quick restoration of the anterior chamber and the increase in its depth must be emphasized. There are very rare complications and the resulting eye pressure is normal.