[Pheochromocytoma and paraganglioma : Importance of diagnostic imaging]. / Phäochromozytom und Paragangliom : Stellenwert der bildgebenden Diagnostik.

CLINICAL BACKGROUND: If pheochromocytoma (PC) or paraganglioma (PGL) is diagnosed based on serologic studies, imaging is required to locate the adrenal mass for further management. Besides pathognomonic hormonal findings, PC/PGL can exhibit typical imaging features. However, PC/PGL can also show morphological overlap with other pathologies. STANDARD RADIOLOGICAL METHODS: The modality of choice for evaluation of PC is CT. In case of extra-adrenal location, MRI is superior to CT. Imaging with PET-CT provides complementary information in the differentiation of PC/PGL and is recommended as the imaging modality of choice for malignant PC/PGL. 68Ga-DOTATATE (or 68Ga-DOTATOC/ 68Ga-DOTANOC) PET-CT has high sensitivity for SDHx-mutated PC/PGL and serves for planning of radioreceptor therapy with somatostatin analogues. In contrast, 123I-metaiodobenzylguanidine (MIBG) scintigraphy is important in assessing the potential efficacy of radioreceptor therapy with MIBG. METHODICAL DETAILS: The CT protocol for PC evaluation should include non-enhanced, arterial, portal-venous and late phases; the latter for the evaluation of wash-out. Recent studies indicate non-enhanced CT alone may be sufficient to rule out PC. For MRI, in- and opposed-phase sequences should be additionally acquired. PRACTICAL RECOMMENDATIONS: A relevant proportion of PC is diagnosed incidentally. Therefore, imaging of PC will gain further importance. Recent studies show better response rates of PC/PGL after radioreceptor therapy with somatostatin analogues (177Lu-DOTATATE) than with MIBG. Therefore, 68Ga-DOTATATE PET-CT gains further importance-for diagnostic imaging and therapy planning.

Inflammatory pseudotumor (IPT)-surgical cure of an inflammatory syndrome.

UNLABELLED: We report on four female adolescents, who presented with inflammatory symptoms. Extensive diagnostic workup revealed tumors on different locations. After surgical removal, clinical and laboratory signs of inflammation disappeared rapidly. On histology, the tumors showed a mixture of inflammatory cells characteristic of inflammatory pseudotumors in three of the patients. CONCLUSION: In patients with unclear inflammatory symptoms, inflammatory pseudotumor should be added to the differential diagnosis. WHAT IS KNOWN: • The inflammatory pseudotumor (IPT) is a mostly benign myofibroblastic tumor of the soft tissue and causes inflammatory symptoms. What is new: • IPTs have may wider than hitherto defined histologic features. Removal of IPT is curative.

Biodegradation of polyethylene by the marine fungus Parengyodontium album.

Plastic pollution in the marine realm is a severe environmental problem. Nevertheless, plastic may also serve as a potential carbon and energy source for microbes, yet the contribution of marine microbes, especially marine fungi to plastic degradation is not well constrained. We isolated the fungus Parengyodontium album from floating plastic debris in the North Pacific Subtropical Gyre and measured fungal-mediated mineralization rates (conversion to CO2) of polyethylene (PE) by applying stable isotope probing assays with 13C-PE over 9 days of incubation. When the PE was pretreated with UV light, the biodegradation rate of the initially added PE was 0.044 %/day. Furthermore, we traced the incorporation of PE-derived 13C carbon into P. album biomass using nanoSIMS and fatty acid analysis. Despite the high mineralization rate of the UV-treated 13C-PE, incorporation of PE-derived 13C into fungal cells was minor, and 13C incorporation was not detectable for the non-treated PE. Together, our results reveal the potential of P. album to degrade PE in the marine environment and to mineralize it to CO2. However, the initial photodegradation of PE is crucial for P. album to metabolize the PE-derived carbon.

Strong molecular alignment dependence of H2 electron impact ionization dynamics.

Low-energy (E(0) = 54 eV) electron impact single ionization of molecular hydrogen (H(2)) has been investigated as a function of molecular alignment in order to benchmark recent theoretical predictions [Colgan et al., Phys. Rev. Lett. 101, 233201 (2008) and Al-Hagan et al., Nature Phys. 5, 59 (2009)]. In contrast to any previous work, we observe distinct alignment dependence of the (e,2e) cross sections in the perpendicular plane in good overall agreement with results from time-dependent close-coupling calculations. The cross section behavior can be consistently explained by a rescattering of the ejected electron in the molecular potential resulting in an effective focusing along the molecular axis.

Identification and long-term observation of early joint damage by magnetic resonance imaging in clinically asymptomatic joints in patients with haemophilia A or B despite prophylaxis.

Severe haemophilia is associated with recurrent joint bleeds, which can lead to haemophilic arthropathy. Subclinical joint bleeds have also been associated with joint damage detected using magnetic resonance imaging (MRI). We investigated the development of early changes in clinically asymptomatic joints using MRI in haemophilia A or B patients receiving prophylactic therapy. In this single-centre retrospective cohort study, patients with clinical evidence of joint damage in one ankle and one clinically asymptomatic ankle, in which we performed an MRI scan of both ankles in one session, were enrolled. MRI findings were graded using a 4-point scoring system (0 = normal findings and III = severe joint damage). Since 2000, 38 MRIs in 26 patients have been performed. Starting at a median age of 4 years, 23 patients received prophylaxis 2-3 times weekly. On-demand treatment was performed in three patients. Eight patients (31%) presented with an MRI score of 0, 12 (46%) had a score of I, four (15%) had a score of II, and two (8%) had a score of III in the clinically unaffected ankle. The six patients with MRI scores of II and III had started regular prophylaxis between the ages of 2 years and 15 years; none had developed an inhibitor or experienced a clinically evident bleed in the asymptomatic ankle. During our study, five of 26 patients had a worsening of MRI findings without experiencing a joint bleed. Early morphological changes in clinically asymptomatic ankles can be detected using MRI, despite adequate prophylaxis.

Wavelength dependence of the suppressed ionization of molecules in strong laser fields.

We study ionization of molecules by an intense laser field over a broad wavelength regime, ranging from 0.8 to 1.5 µm experimentally and from 0.6 to 10 µm theoretically. A reaction microscope is combined with an optical parametric amplifier to achieve ionization yields in the near-infrared wavelength regime. Calculations are done using the strong-field S-matrix theory and agreement is found between experiment and theory, showing that ionization of many molecules is suppressed compared to the ionization of atoms with identical ionization potentials at near-infrared wavelengths at around 0.8 µm, but not at longest wavelengths (10 µm). This is due to interference effects in the electron emission that are effective at low photoelectron energies but tend to average out at higher energies. We observe the transition between suppression and nonsuppression of molecular ionization in the near-infrared wavelength regime (1-5 µm).

Low energy (e, 2e) study from the 1t(2) orbital of CH4.

Single ionization of the methane (CH(4)) 1t(2) orbital by 54 eV electron impact has been studied experimentally and theoretically. The measured triple differential cross sections cover nearly a 4π solid angle for the emission of low energy electrons and a range of projectile scattering angles. Experimental data are compared with theoretical calculations from the distorted wave Born approximation and the molecular three-body distorted wave models. It is found that theory can give a proper description of the main features of experimental cross section only at smaller scattering angles. For larger scattering angles, significant discrepancies between experiment and theory are observed. The importance of the strength of nuclear scattering from the H-nuclei was theoretically tested by reducing the distance between the carbon nuclei and the hydrogen nuclei and improved agreement with experiment was found for both the scattering plane and the perpendicular plane.

[Procedure guidelines for whole-body 18F-FDG PET and PET/CT in children with malignant diseases]. / Empfehlungen zur Durchführung der Ganzkörper-18F-FDG-PET und -PET/CT bei Kindern mit onkologischen Erkrankungen. Anpassung der EANM-Guideline an aktuelle Gegebenheiten in Deutschland.

The purpose of these guidelines is to offer the nuclear medicine and the appropriate interdisciplinary team a framework for performing and reporting positron emission tomography (PET) and the combination with computed tomography (PET/CT) in children with malignant diseases mainly using the radiopharmaceutical 18F-fluorodeoxy-glucose (FDG). These guidelines are based on the recent guidelines of the Paediatric Committee of the European Association of Nuclear Medicine (EANM) (57) and have been translated and adapted to the current conditions in Germany. The adaptation of CT-parameters using PET/CT in children is covered in a more detailed way than in the EANM guideline taking into account that in Germany already a good portion of PET examinations is performed using an integrated PET/CT-scanner. Furthermore, a CT-scan without adoption of the CT acquisition parameters would result in a not tolerably high radiation exposition of the child. There are excellent guidelines for FDG PET and PET/CT in oncology published by the German Society of Nuclear Medicine (Deutsche Gesellschaft für Nuklearmedizin, DGN) (42) and EANM (4). These guidelines aim at providing additional information on issues particularly relevant to PET and PET/CT imaging in children. These guidelines should be taken in the context of local and national current standards of quality and rules.

[Procedure guidelines for MIBG-scintigraphy in children].

The German translation of the EANM guideline for MIBG scintigraphy in children (Olivier P et al. EJNM MI 2003; 30: B45-B50; Hahn K. Der Nuklearmediziner 2002; 25: 101-105) was reviewed and actualized according to current publications, legal requirements and conditions in Germany. For the first time this guideline was generated in consensus with the neuroblastoma study group of the Association of Paediatric Haematologie and Oncology (GPOH) with the result of an interdisciplinary recommendation. Further main alterations are related to the recommended (123)I activities with respect to the new EANM Paediatric Dosage Card and the explicit recommendation of SPECT.

Restaging of patients with lymphoma. Comparison of low dose CT (20 mAs) with contrast enhanced diagnostic CT in combined [18F]-FDG PET/CT.

AIM: Assessment of the clinical benefit of i.v. contrast enhanced diagnostic CT (CE-CT) compared to low dose CT with 20 mAs (LD-CT) without contrast medium in combined [(18)F]-FDG PET/CT examinations in restaging of patients with lymphoma. PATIENTS, METHODS: 45 patients with non-Hodgkin lymphoma (n=35) and Hodgkin's disease (n=10) were included into this study. PET, LD-CT and CE-CT were analyzed separately as well as side-by-side. Lymphoma involvement was evaluated separately for seven regions. Indeterminate diagnoses were accepted whenever there was a discrepancy between PET and CT findings. Results for combined reading were calculated by rating indeterminate diagnoses according the suggestions of either CT or PET. Each patient had a clinical follow-up evaluation for >6 months. RESULTS: Region-based evaluation suggested a sensitivity/specificity of 66/93% for LD-CT, 87%/91% for CE-CT, 95%/96% for PET, 94%/99% for PET/LD-CT and 96%/99% for PET/CE-CT. The data for PET/CT were obtained by rating indeterminate results according to the suggestions of PET, which turned out to be superior to CT. Lymphoma staging was changed in two patients using PET/CE-CT as compared to PET/LD-CT. CONCLUSION: Overall, there was no significant difference between PET/LD-CT and PET/CE-CT. However, PET/CE-CT yielded a more precise lesion delineation than PET/LD-CT. This was due to the improved image quality of CE-CT and might lead to a more accurate investigation of lymphoma.

Therapy of focal viral encephalitis in children with aciclovir and recombinant beta-interferon - results of a placebo-controlled multicenter study.

Focal viral encephalitis in childhood is a rare but life-threatening disease. Animal experiments and case reports suggest a positive effect of an additional therapy with interferon-beta on the course of the disease. Therefore, we initiated a prospective, double-blind placebo-controlled study to investigate the benefit of a combination therapy of Aciclovir (ACV) and recombinant interferon-beta (rIFN-beta) in juvenile focal viral encephalitis. - Initial inclusion criterium was suspicion of focal viral encephalitis. Diagnosis was proven by demonstration of characteristic focal lesions in cerebral imaging or virological evidence of HSV in cerebrospinal fluid. Patients were treated with ACV plus rIFN-beta or ACV plus placebo. Neurological outcome was determined 21 days and 3 months after onset of the disease. - Initially 59 patients were enrolled in the study. Encephalitis was proven in 14 patients (7 ACV + rIFN-beta, 7 ACV + placebo). The study groups were balanced in terms of important prognostic criteria. 10 patients (5 ACV + rIFN-beta, 5 ACV + placebo) were cured or had slight defects, 4 patients (2 ACV + rIFN-beta, 2 ACV + placebo) showed moderate to severe defects. There was no significant difference in favour of the additive therapy with rIFN-beta.

The combination of hypointense and hyperintense signal changes on T2-weighted magnetic resonance imaging sequences: a specific marker of multiple system atrophy?

OBJECTIVE: To compare the frequency and specificity of hypointense magnetic resonance imaging (MRI) signal changes alone with the frequency and specificity of a pathological MRI pattern consisting of a hyperintense lateral rim and a dorsolateral signal attenuation on T2-weighted MRIs in patients with parkinsonism of various origins. PATIENTS: Ninety patients with Parkinson disease (PD) (n = 65), progressive supranuclear palsy (PSP) (n = 10), and multiple system atrophy (MSA) of the striatonigral degeneration type (n = 15) underwent MRI. SETTING: University medical center. RESULTS: Nine of the 15 patients with MSA showed the pattern with hyperintense lateral rim and a dorsolateral hypointense signal attenuation on T2-weighted images within the putamen. This pattern was not found in the 65 patients with PD, nor in the 10 patients with PSP. Only hypointense changes in the putamen were found in 6 patients (9%) with PD, 4 patients (40%) with PSP, and 5 patients (36%) with MSA. CONCLUSIONS: Our data suggest that the pattern consisting of hypointense and hyperintense T2 changes within the putamen is a highly specific MRI sign of MSA, while hypointensity alone remains a sensitive, but nonspecific MRI sign of MSA. In clinically doubtful cases, the appearance of a hypointense and hyperintense signal pattern on MRI makes the diagnosis of PD very unlikely, while hypointense signal changes alone do not exclude idiopathic PD.

Comparison of technetium-99m-sestamibi scintimammography with contrast-enhanced MRI for diagnosis of breast lesions.

UNLABELLED: Scintimammography using 99mTc-sestamibi and contrast-enhanced MRI were performed to determine the diagnostic accuracy of either method in the diagnostic workup of patients suspicious for breast tumors. METHODS: Fifty-six patients (42 with indeterminate mammograms) underwent preoperative prone planar scintimammography and pre- and postcontrast-enhanced MRI. Visually determined signal increase after application of Gd-DTPA was compared with visually scored sestamibi uptake, and the diagnoses of both methods were correlated with the final histopathologic results. RESULTS: Overall, sensitivity and specificity of scintimammography for diagnosing breast cancer were 88% and 83%, respectively. In the subgroup of patients with indeterminate mammograms, sensitivity was 79% and specificity was 83%. MRI readings provided a higher sensitivity (91% with respect to all patients and 89% with respect to patients with indeterminate mammograms), but a considerably lower specificity (52% in both groups) due to contrast-enhancement in different benign lesions. CONCLUSION: Due to its considerably higher specificity, scintimammography rather than MRI may be suitable to reduce the number of breast biopsies which yield benign results. Thus, this method may be suggested as the preferable tool in the diagnostic workup of patients with indeterminate mammographic findings.

Quantitative comparison of automatic and interactive methods for MRI-SPECT image registration of the brain based on 3-dimensional calculation of error.

UNLABELLED: A wide range of techniques for registration of medical images has been devised in recent years. The aim of this study is to quantify the overall spatial registration error of 3 different methods for image registration: interactive matching, surface matching, and uniformity index matching as described by Woods. METHODS: MRI and ethylcysteinate dimer-SPECT images of the brain were registered for 15 patients. The matching error was assessed by determining intra- and interobserver variability of registrations. Quantification of the registration error was based on the mean spatial distance of 5000 voxels between 2 image positions. The mean position after repeated registrations in each patient was used as the gold standard. To evaluate the coherence of the 3 different registration methods, intermethod variability was determined. RESULTS: Interactive matching showed an intraobserver/interobserver variability of 1.5+/-0.3 mm/1.6+/-0.3 mm (mean +/- SD). The time demand for this method was 11+/-5 min. Surface matching revealed a variability of 2.6+/-1.1 mm/3.8+/-1.0 mm and a time demand of 26+/-12 min. Reproducibility of Woods' algorithm was 2.2+/-0.8 mm with a time demand of 9+/-3 min. In 4 of the 15 cases, Woods' method failed. The mean deviation between all 3 methods was 2.3+/-0.8 mm. CONCLUSION: With a suitable user interface, interactive matching had the lowest registration error. The influence of subjectivity was shown to be negligible. Therefore, interactive matching is our preferred technique for image fusion of the brain.

MR and MR angiography of Sturge-Weber syndrome.

PURPOSE: To assess the potential of magnetic resonance angiography (MRA) as an adjunct to spin-echo sequences in evaluating the cerebral vascular anomalies seen in Sturge-Weber syndrome. METHODS: Four pediatric patients with Sturge-Weber syndrome were evaluated with conventional MR imaging and with arterial and venous MRA. Resultant images were evaluated for evidence of volume loss, cortical enhancement, vascular anomalies, and enlarged choroid plexus. RESULTS: Venous MRA revealed reduced flow of the transverse sinuses and jugular veins, prominent deep collateral venous system, and a lack of superficial cortical veins. Arterial MRA, performed in all cases, revealed a reduced flow signal from the left middle cerebral artery in one hemiparetic patient and angiomatous changes of high branches of a middle cerebral artery in two patients. CONCLUSION: Arterial and, in particular, venous MRA can be useful adjuncts to standard spin-echo sequences in diagnosing Sturge-Weber syndrome.

Usefulness of 3-D reconstructed images of the human cerebral cortex for localization of subdural electrodes in epilepsy surgery.

Three-dimensional (3-D) images of 14 patients, in whom subdural electrodes were implanted for epilepsy surgery evaluation, were produced by fusing computerized tomography (CT) scans and magnetic resonance images (MRI) to determine the exact location of the electrodes. In 25% (198 of 806) of the subdural electrodes an exact location for resection strategy was not evident from the X-rays. The location of these electrodes ('doubtful location', DL) was compared to the 3-D images. Intraoperative inspection served as the gold standard. Concordance score was defined as good for 75-100% concordance, moderate for 50-75%, and poor for less than 50% concordance of the DL electrodes to the intraoperatively determined location. A comparative analysis of the 3-D images and X-ray films showed a highly significant difference (P < 0.0002) in favor of 3-D images. The concordance score for the DL electrodes in the 3-D images was good in 93% of the patients and moderate in 7%. In contrast, the concordance score was good in only 7% of the patients for the two-dimensional (2-D) skull films, moderate in 57%, and poor in 36%. Interobserver reliability was better for 3-D images (93%) than for the 2-D X-rays (43%). These findings suggest that 3-D images aid preoperative planning for resective epilepsy surgery.

Laparoscopic resection of a congenital liver cyst and simultaneous closure of a diaphragmatic defect in a 5-month-old infant.

Congenital liver cysts are an unusual finding and present a difficult diagnostic challenge. In a 5-month-old infant, routine echocardiography detected a cystic lesion (3 cm in diameter) just below the diaphragm. All conventional diagnostics, including magnetic resonance imaging (MRI), failed to clarify its etiology definitively. Moreover, a phrenic irregularity was suspected at the site of Morgagni. Finally, laparoscopy (5-mm scope and instruments) confirmed the diagnosis of a solitary liver cyst and a diaphragmatic defect. Using a Harmonic scalpel, the cyst was resected and the diaphragmatic defect was closed with interrupted nonabsorbable sutures. The patient's postoperative course was uneventful. Pathological analysis showed a true liver cyst with mesothelial lining and hepatic residues. Retrospective speculation suggests a common embryologic origin for both malformations. In conclusion, laparoscopy allowed final diagnosis and simultaneous treatment of an infant with the rare combination of a liver cyst and a diaphragmatic defect. To our knowledge, this case represents the first endosurgical experience of such a simultaneous procedure.

[Simpson's atherectomy of the peripheral arteries: early results and follow-up]. / Simpson-Atherektomie peripherer Arterien--Frühergebnisse und Nachkontrollen.

Over a seventeen-month period, a percutaneous transluminal removal of stenosing plaque material from leg and pelvic arteries was performed successfully and without complication in 43 patients. A complete atherectomy in the femoropopliteal vessels succeeded in 99% of cases. In the pelvic region, the primary results were much lower (58%). After six months, the angiographically checked restenosis rate was 17% for femoropopliteal vessels and 11% for iliac arteries, and the corresponding Kaplan-Meier cumulative patency rates were 73.8 and 78.7% respectively. Simpson's atherectomy is the only method of its kind that is therapeutically effective and diagnostically significant, since the removed plaque can be used for further tests.

[A combined PACS and Internet information system in a university medical center]. / Kombiniertes PACS und Intranet-Informationssystem an einem Universitätsklinikum.

PURPOSE: The Department of Radiology at the University Hospital Innenstadt Munich provides all clinical departments of a large university hospital with several radiology units at different locations. During the last four years all units have been fully digitalized with a stepwise installation of a PACS. The PACS also processes images from the Nuclear Medicine Department. METHODS: As image modalities, archive systems and review workstations, we use devices from multiple vendors, which are integrated into a consistent system using the DICOM standard. The hospital has developed its own RIS and an Internet information system, which provides access to all reports and images from radiology for all clinical departments inside the hospital. Additionally, other clinical information such as laboratory results or ECG examinations are available through the system. RESULTS: After one year of operation, the system succeeded in the clinical routine work as the primary source for radiological reports and images as well as for laboratory values. CONCLUSION: The advantages of digitalization were, besides reduction of film cost, especially optimizations of work flow with access to digital images from everywhere at any time.

[Magnetic resonance tomography and magnetic resonance angiography in lymphangiomatosis]. / Magnetresonanztomographie und Magnetresonanzangiographie der Lymphangiomatose.

Generalised lymphangiomatosis is a rare benign congenital abnormality of the lymphatic vessels with a complex pattern. 3 patients with different types of lymphangiomatosis were studied by MRT and MRA and histopathologically. All patients had multiple organ involvement in the abdomen, the skeleton and the skull. The basis in each case was lymphangiomatosis of capillary-cavernous, cystic or cavernous type. The results of MRT and MRA in diagnosing splenic, vascular and skeletal changes correlated accurately with operative findings and with the histopathological classification. In summary, MRT combined with MRA and using paramagnetic contrast media are the diagnostic methods of choice for the investigation of generalised lymphangiomatosis with multiple organ involvement.