Diagnostic accuracy of high-resolution T2-weighted MRI vs contrast-enhanced T1-weighted MRI to screen for cerebellopontine angle lesions in symptomatic patients.

OBJECTIVE: To evaluate diagnostic accuracy of high-resolution T2-weighted MRI (T2w) for detecting cerebellopontine angle (CPA) lesions compared to a combined protocol including gadolinium enhanced T1-weighted MRI (GdT1w). SETTING: Department of Radiology & Nuclear Medicine, Radboud University Medical Centre, Nijmegen, The Netherlands. PARTICIPANTS: A random sample of MRIs from 350 patients (700 CPAs) with asymmetrical audiovestibular complaints was used, acquired between 2013 and 2016. MAIN OUTCOME MEASURES: Sensitivity, specificity, positive and negative predictive values of T2w results compared to GdT1w and, in patients with any suggestion of CPA pathology, to the complete examination (T1w, GdT1w and T2w). Inter-rater agreement between an experienced neuroradiologist and a less experienced observer was calculated. RESULTS: Results of 678 CPAs in 340 patients were analysed. On T2w, the neuroradiologist identified all 27 lesions >2 mm in size out of a total of 30 CPA lesions (sensitivity: 90% [95% CI: 73.5%-97.9%]). Negative predictive value reached 99.5% (95% CI: 98.7-99.9). One missed lesion of 2 mm would have been detected in clinical practice, as this was one of 14 patients for which additional GdT1w would have been ordered based on T2w alone, increasing sensitivity to 93% (95% CI: 77.9%-99.2%) and negative predictive value to 99.7% (95% CI: 98.9%-100%). Inter-rater agreement for T2w was 98% (95% CI: 96.4-98.8). CONCLUSION: T2w has a very high diagnostic accuracy for the presence of CPA lesions in patients with asymmetrical audiovestibular complaints. However, in a screening protocol with T2w only, smallest vestibular schwannomas as well as rare differential diagnoses that probably only would be detected on GdT1w may remain unnoticed.

Potential savings in the diagnosis of vestibular schwannoma.

INTRODUCTION: Magnetic resonance imaging (MRI) is used to screen patients at risk for vestibular schwannoma (VS). These MRIs are costly and have an extremely low yield; only 3% of patients in the screening population has an actual VS. It might be worthwhile to develop a test to predict VS and refer only a subset of all patients for MRI. OBJECTIVE: To examine the potential savings of such a hypothetical diagnostic test before MRI. DESIGN: We built a decision analytical model of the diagnostic strategy of VS. Input was derived from literature and key opinion leaders. The current strategy was compared to hypothetical new strategies, assigning MRI to the following: (i) all patients with pathology, (ii) all patients with important pathology and (iii) only patients with VS. This resulted in potential cost savings for each strategy. We conducted a budget impact analysis to predict nationwide savings for the Netherlands and the United Kingdom (UK), and a probabilistic sensitivity analysis to address uncertainty. RESULTS: Mean savings ranged from €256 (95%CI €250 - €262) or approximately US$284 (95%CI US$277 - US$291) per patient for strategy 1 to €293 (95%CI €290 - €296) or approximately US$325 (95%CI US$322 - US$328) per patient for strategy 3. Future diagnostic strategies can cost up to these amounts per patient and still be cost saving. Annually, for the Netherlands, €2.8 to €3.2 million could be saved and €10.8 to €12.3 million for the UK. CONCLUSIONS: The model shows that substantial savings could be generated if it is possible to further optimise the diagnosis of VS.

The diagnostic accuracy of non-imaging screening protocols for vestibular schwannoma in patients with asymmetrical hearing loss and/or unilateral audiovestibular dysfunction: a diagnostic review and meta-analysis.

BACKGROUND: Currently, all patients presenting with asymmetrical sensorineural hearing loss and/or unilateral audiovestibular dysfunction (i.e. tinnitus, dizziness) undergo MRI, leading to a substantial amount of MRIs with negative findings as the incidence of vestibular schwannoma (VS) in this screening population varies between 1% and 4.7% (i.e. more than 95% of MRIs are negative for VS). OBJECTIVE OF REVIEW: The aim was to assess the diagnostic accuracy of different non-imaging screening protocols that can be used prior to MRI to select patients at high risk of VS. TYPE OF REVIEW: Diagnostic review and meta-analysis. SEARCH STRATEGY: We systematically searched MEDLINE, Embase and The Cochrane Library as from inception up to 28 July 2016. We included studies that compared non-imaging screening protocols to MRI as gold reference standard. EVALUATION METHOD: Methodological quality was assessed by two independent reviewers using the Quality Assessment of Diagnostic Accuracy Studies tool. Data necessary to complete 2 × 2 tables were obtained, and patient, study, screening and imaging characteristics were extracted. We calculated sensitivity and specificity of all tests and obtained pooled estimates using a bivariate random effects model. RESULTS: We analysed 12 studies (4969 patients) of poor to moderate quality according to the quality assessment. Most studies tested diagnostic accuracy of multiple screening protocols. Five pure-tone audiometry (PTA) protocols were studied by multiple authors; pooled estimates for sensitivity ranged from 88% [95% CI: 84-91] to 91% [95% CI: 52-99] and specificity from 31% [95% CI: 10-66] to 58% [95% CI: 49-65]. Due to heterogeneity, we were unable to pool other tests. In five studies testing auditory brainstem response, sensitivity values ranged from 37% [95% CI: 23-52] to 100% [95% CI: 40-100] and specificity from 57% to 96% [95% CI: 87-100]. Two authors studied PTA shape as a screening test. Presenting symptoms, electronystagmography, caloric irrigation and hyperventilation test were assessed by one study each. All reported low diagnostic accuracy. CONCLUSIONS: All identified studies had a moderate-to-high risk of bias, and none of the currently available non-imaging screening protocols appear to be accurate in detecting VSs.

X-ray pulses approaching the attosecond frontier.

Single soft-x-ray pulses of approximately 90-electron volt (eV) photon energy are produced by high-order harmonic generation with 7-femtosecond (fs), 770-nanometer (1.6 eV) laser pulses and are characterized by photoionizing krypton in the presence of the driver laser pulse. By detecting photoelectrons ejected perpendicularly to the laser polarization, broadening of the photoelectron spectrum due to absorption and emission of laser photons is suppressed, permitting the observation of a laser-induced downshift of the energy spectrum with sub-laser-cycle resolution in a cross correlation measurement. We measure isolated x-ray pulses of 1.8 (+0.7/-1.2) fs in duration, which are shorter than the oscillation cycle of the driving laser light (2.6 fs). Our techniques for generation and measurement offer sub-femtosecond resolution over a wide range of x-ray wavelengths, paving the way to experimental attosecond science. Tracing atomic processes evolving faster than the exciting light field is within reach.

Positron emission mammography in the diagnosis of breast cancer. Is maximum PEM uptake value a valuable threshold for malignant breast cancer detection?

AIM: To evaluate the diagnostic value (sensitivity, specificity) of positron emission mammography (PEM) in a single site non-interventional study using the maximum PEM uptake value (PUVmax). PATIENTS, METHODS: In a singlesite, non-interventional study, 108 patients (107 women, 1 man) with a total of 151 suspected lesions were scanned with a PEM Flex Solo II (Naviscan) at 90 min p.i. with 3.5 MBq 18F-FDG per kg of body weight. In this ROI(region of interest)-based analysis, maximum PEM uptake value (PUV) was determined in lesions, tumours (PUVmaxtumour), benign lesions (PUVmaxnormal breast) and also in healthy tissues on the contralateral side (PUVmaxcontralateral breast). These values were compared and contrasted. In addition, the ratios of PUVmaxtumour / PUVmaxcontralateral breast and PUVmaxnormal breast / PUVmaxcontralateral breast were compared. The image data were interpreted independently by two experienced nuclear medicine physicians and compared with histology in cases of suspected carcinoma. RESULTS: Based on a criteria of PUV>1.9, 31 out of 151 lesions in the patient cohort were found to be malignant (21%). A mean PUVmaxtumour of 3.78 ± 2.47 was identified in malignant tumours, while a mean PUVmaxnormal breast of 1.17 ± 0.37 was reported in the glandular tissue of the healthy breast, with the difference being statistically significant (p < 0.001). Similarly, the mean ratio between tumour and healthy glandular tissue in breast cancer patients (3.15 ± 1.58) was found to be significantly higher than the ratio for benign lesions (1.17 ± 0.41, p < 0.001). CONCLUSION: PEM is capable of differentiating breast tumours from benign lesions with 100% sensitivity along with a high specificity of 96%, when a threshold of PUVmax >1.9 is applied.

Spin-orbit coupling of light in asymmetric microcavities.

When spinning particles, such as electrons and photons, undergo spin-orbit coupling, they can acquire an extra phase in addition to the well-known dynamical phase. This extra phase is called the geometric phase (also known as the Berry phase), which plays an important role in a startling variety of physical contexts such as in photonics, condensed matter, high-energy and space physics. The geometric phase was originally discussed for a cyclically evolving physical system with an Abelian evolution, and was later generalized to non-cyclic and non-Abelian cases, which are the most interesting fundamental subjects in this area and indicate promising applications in various fields. Here, we enable optical spin-orbit coupling in asymmetric microcavities and experimentally observe a non-cyclic optical geometric phase acquired in a non-Abelian evolution. Our work is relevant to fundamental studies and implies promising applications by manipulating photons in on-chip quantum devices.

The phase diagram of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine/sucrose in the dry state. Sucrose substitution for water in lamellar mesophases.

The phase diagram of the binary system, 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC)/sucrose, was determined by DSC. In contrast to dry DPPC, which exhibits chain melting at 342.5 K, the main feature of the DPPC/sucrose system is eutectic melting at 320 K. This was supported earlier by Crowe, J.H., Crowe, L.M. and Chapman, D. (Science 223 (1984) 701-703), who reported a drastic decrease in the chain-melting temperature of the dry lipid in the presence of some mono- and disaccharides. Electron microscopy suggests that the phase structures on either side of the phase transition are of the lamellar type. Definite sugar saturation concentrations can be derived from this phase diagram. Up to about 17 mol% sucrose, i.e., 1 mol of sucrose per 5 mol of lipid is adopted by DPPC in the low-temperature phase Lc. In the high-temperature phase Lm the saturation concentration is well above 90 mol% sucrose at 320 K (eutectic point) but decreases with increasing temperature. The lower limit of 50 mol% sucrose is reached at 455 K. At this temperature, peritectic melting of sucrose occurs. Because of some similarities in the phase diagrams of DPPC/sucrose and DPPC/water, it is possible to understand the sucrose substitution for water in dry lamellar mesophases.

A dedicated compression device for high resolution X-ray tomography of compressed gas diffusion layers.

We present an experimental approach to study the three-dimensional microstructure of gas diffusion layer (GDL) materials under realistic compression conditions. A dedicated compression device was designed that allows for synchrotron-tomographic investigation of circular samples under well-defined compression conditions. The tomographic data provide the experimental basis for stochastic modeling of nonwoven GDL materials. A plain compression tool is used to study the fiber courses in the material at different compression stages. Transport relevant geometrical parameters, such as porosity, pore size, and tortuosity distributions, are exemplarily evaluated for a GDL sample in the uncompressed state and for a compression of 30 vol.%. To mimic the geometry of the flow-field, we employed a compression punch with an integrated channel-rib-profile. It turned out that the GDL material is homogeneously compressed under the ribs, however, much less compressed underneath the channel. GDL fibers extend far into the channel volume where they might interfere with the convective gas transport and the removal of liquid water from the cell.

Demonstration of CD13/aminopeptidase N on synovial fluid T cells from patients with different forms of joint effusions.

Cytofluorometric analysis was performed to characterize the immunophenotype of lymphocytes of the synovial fluid (SF) and the peripheral blood (PB) from patients suffering from juvenile chronic arthritis (JCA) or rheumatoid arthritis (RA). The most obvious difference could be found in expression of the surface protease aminopeptidase N (AP N/CD13). Whereas monoclonal antibodies specific to CD13 failed to reveal surface expression on lymphocytes of the PB; 63 +/- 15% of SF T cells gave positive staining for CD13 using Leu-M7. No correlation between CD13 expression and joint disease could be found in patients who had different types of inflammatory joint effusions. CD13 expression of T cells was also found in synovial tissue and inflammatory serous cavity effusions. Fixation of T cells revealed the presence of intracellular CD13 antigen already located in the PB T cells of healthy individuals. Induction of CD13 expression on PB T cells could be demonstrated after incubation with Con A/IL-2 or SF from patients with RA. Our findings suggest a role for AP N as a new activation-associated molecule of T lymphocytes.

Femtosecond X-Ray fluorescence

Using few-cycle-driven coherent laser harmonics, K-shell vacancies have been created in light elements, such as boron (E(B) = 188 eV) and carbon (E(B) = 284 eV), on a time scale of a few femtoseconds for the first time. The capability of detecting x-ray fluorescence excited by few-femtosecond radiation with an accuracy of the order of 1 eV paves the way for probing the evolution of the microscopic environment of selected atoms in chemical and biochemical reactions on previously inaccessible time scales (<100 fs) by tracing the temporal evolution of the "chemical shift" of peaks associated with inner-shell electronic transitions in time-resolved x-ray fluorescence and photoelectron spectra.

Effects of neoadjuvant radio-chemotherapy on 18F-FDG-PET in esophageal carcinoma.

AIM: To investigate whether results of [F-18]-fluorodeoxy-d-glucose (FDG) positron emission tomography (PET) of esophageal cancer (EC) before and after neoadjuvant radio-chemotherapy correlate with histopathology after esophageal resection. METHODS: Twenty consecutive patients with EC without distant metastases were examined twice with 18F-FDG-PET during primary staging and after neoadjuvant radio-chemotherapy. FDG standardised uptake values (SUV) were correlated with the histopathological findings (percentage of viable tumour cells, tumour regression grade 1-5). RESULTS: Regression analysis revealed a slight (not significant) positive correlation between SUV(pre) (R=0.41, p=0.08) and SUV(post) (R=0.37, p=0.11) and the percentage of viable tumour cells in the resectate. Although all patients showed a significant decrease in SUV after radio-chemotherapy (p < 0.01) the percentual decrease of the SUV after therapy (DeltaSUV%) did not significantly differ between the TRG-groups. In 12 of 20 patients (60%), therapy-induced esophagitis was detected in post-therapeutic PET images. CONCLUSION: In EC, a higher pre-therapeutic SUV might be correlated with a higher fraction of vital tumour cells remaining after radio-chemotherapy. Applying the neoadjuvant therapy protocol and the study design used in this examination, there is no correlation between decrease in SUV and histopathology.

Characterization of four drug-resistant P388 sublines: resistance/sensitivity in vivo, resistance-and proliferation-markers, immunogenicity.

It was the aim of this study to compare drug-resistant sublines of the murine P388 in relation to resistance markers, the resistant phenotype and immunogenicity. Resistance to drugs either belonging to the MDR type (Doxorubicin, Vincristine, Mitoxantrone) or to the non-MDR type (Methotrexate) was generated in vivo in order to mimic the clinical situation. All resistant sublines expressed the mdr1 gene and the p-glycoprotein determined on m-RNA level or immunohistochemically, while no expression was registered in the parent P388. The rhodamine 123 fluorescence as marker for the energy dependent drug efflux pump was decreased only in the MDR-sublines, while the parent P388 and the Methotrexate-resistant line retained 100% or 90% of the dye, respectively. This indicates that the rhodamine efflux is a more function-related marker for MDR than the mdr1 gene and the pgp. The in vivo characterization of the sublines as regards their sensitivity to cytostatics revealed a clear-cut cross-resistance to MDR drugs in the MDR-lines, while the Methotrexate resistant subline was only cross-resistant to Cytarabine. In each resistant subline collateral sensitivity to certain but different cytostatics was observed. Experiments to overcome resistance by concomitant treatment with the modulators Nifedipine, Verapamil, Cyclosporin A and Chloroquin led to only limited success. The sublines P388/Mitox, P388/Vinc and P388/MTX developed immunogenicity which was never registered in the original P388. Vaccination with lethally irradiated drug-resistant cells resulted in a substantial rejection of viable tumor cells of the same line. With the P388/Mitox and P388/Vinc also an over-cross immunization was possible. This generation of immunogenicity as a concomitant characteristic of resistance should be considered as therapeutic potential also in the treatment of clinical cancer.

Multidrug resistance of murine leukemia cells characterization and correlation with cytochrome P-450 dependent activities, cytosolic calcium and cell cycle state.

This paper reports studies on P388 leukemic cells sensitive and resistant to ADR and VCR. The P450 dependent enzyme system and the cytosolic calcium were estimated and are discussed in relation to MDR. It could be shown, in comparison to sensitive P388 cells, that the plasma membrane permeability for fluorescent dyes like rhodamine 123 and fura-2 and the biotransformation of xenobiotics are changed in resistant cells. Whereas the transport behaviour for the dyes is similarly induced in resistant cells independent of the drug which made the MDR, the P450 dependent enzyme activities are strongly increased in P388/ADR in comparison to the P388 and P388/VCR. The cell cycle analysis shows the same effect. Many more cells of P388/ADR are in the S-phase in comparison to P388 or P388/VCR. The LI is also increased in this direction. Therefore, it can be concluded that, depending on the kind of drug which made the MDR, different biochemical mechanisms are activated.

Comparison of four magnetic resonance methods for mapping small temperature changes.

Non-invasive detection of small temperature changes (< 1 degree C) is pivotal to the further advance of regional hyperthermia as a treatment modality for deep-seated tumours. Magnetic resonance (MR) thermography methods are considered to be a promising approach. Four methods exploiting temperature-dependent parameters were evaluated in phantom experiments. The investigated temperature indicators were spin-lattice relaxation time T1, diffusion coefficient D, shift of water proton resonance frequency (water PRF) and resonance frequency shift of the methoxy group of the praseodymium complex (Pr probe). The respective pulse sequences employed to detect temperature-dependent signal changes were the multiple readout single inversion recovery (T One by Multiple Read Out Pulses; TOMROP), the pulsed gradient spin echo (PGSE), the fast low-angle shot (FLASH) with phase difference reconstruction, and the classical chemical shift imaging (CSI). Applying these sequences, experiments were performed in two separate and consecutive steps. In the first step, calibration curves were recorded for all four methods. In the second step, applying these calibration data, maps of temperature changes were generated and verified. With the equal total acquisition time of approximately 4 min for all four methods, the uncertainties of temperature changes derived from the calibration curves were less than 1 degree C (Pr probe 0.11 degrees C, water PRF 0.22 degrees C, D 0.48 degrees C and T1 0.93 degrees C). The corresponding maps of temperature changes exhibited slightly higher errors but still in the range or less than 1 degree C (0.97 degrees C, 0.41 degrees C, 0.70 degrees C, 1.06 degrees C respectively). The calibration results indicate the Pr probe method to be most sensitive and accurate. However, this advantage could only be partially transferred to the thermographic maps because of the coarse 16 x 16 matrix of the classical CSI sequence. Therefore, at present the water PRF method appears to be most suitable for MR monitoring of small temperature changes during hyperthermia treatment.

Fast spectroscopic imaging for non-invasive thermometry using the Pr[MOE-DO3A] complex.

The praseodymium complex of 10-(2-methoxyethyl)-1,4,7,10-tetraaza-cyclododecane-1,4,7-tr iacetate) was evaluated as a temperature-sensitive contrast agent using the temperature dependence (approximately 0.12 ppm degrees C(-1)) of the chemical shift of its methoxy side group signal. Pr[MOE-DO3A] was employed in combination with spectroscopic imaging (SI) methods for the determination of spatially resolved 2D and 3D temperature distributions in phantoms. Conventional SI and fast echo planar SI sequences (EPSI) were implemented on a 4.7 T MR imaging system fulfilling the demands for non-invasive thermometry (NIT) with respect to thermal and temporal resolution, being <1 degree C and <20 s total measuring time, respectively. The sequences are based on a fast spin echo SI method taking into account the very short relaxation times of the Pr complex methoxy group (T1 = 28 ms, T2 = 13 ms) and its chemical shift difference (-24 ppm) from water. Calibration curves were measured in a uniformly heated water phantom and 2D SI methods were applied to dynamic heating experiments. The average differences between the temperatures measured via fibreoptic thermometer and those derived from the spectroscopic methods were < or =0.2 degrees C. Furthermore, 3D EPSI experiments with a 16 x 16 x 16 matrix size yielded temperature measurements within 17 s from voxels of size 3 x 3 x 3 mm3.

Endothelin (ET-1) is involved in the contrast media induced nephrotoxicity in children with congenital heart disease.

In 77 children with congenital heart disease urinary endothelin-1 (ET-1), an indicator of intrarenal endothelin release, was compared to urinary excretion of total protein, albumin, immunoglobuline G (IgG), alpha 1-microglobuline (alpha 1-MG), N-acetyl-beta-D-glucosaminidase (NAG) and villin. Urine samples were collected the day before and immediately after cardiac angiography with high (Conray 70; n = 56; CON) or low osmolality contrast media (Solutrast 300; n = 21; SOL) to assess the relationship between urinary endothelin and glomerular and tubular nephrotoxicity of contrast media. The children were further subdivided according to age: less than 1 year-CON 1 (n = 20); SOL 1 (n = 12) and 1-18 years CON 2 (n = 36); SOL 2 (n = 9). Results (median): 1. There are no significant changes in total protein-, albumin- and IgG-excretion as parameters of glomerular toxicity. 2. Tubular toxicity of contrast media is shown by significant increase of alpha 1-MG-(10.0 to 23.2 mg/g Crea; p < 0.001), NAG-(5.9 to 9.6 mg/g Crea; p < 0.001) and Villin-excretion (1.0 to 2.0 STS, p < 0.001) in all children. 3. Endothelin excretion (101.0 to 163.0 ng/g Crea, p < 0.001) and concentration (42.5 to 56.0 pg/ml; p < 0.001) were elevated after angiography in all children. 4. The changes in endothelin excretion are correlated to the changes in alpha 1-MG (r = 0.65; p < 0.001) and NAG (r = 0.43, p < 0.001) in all children.(ABSTRACT TRUNCATED AT 250 WORDS)

[Appropriate uptake period for myocardial PET imaging with 18F-FDG after oral glucose loading]. / Optimaler Akquisitionszeitpunkt für die Herz-PET mit 18F-FDG nach oraler Glukosebelastung.

AIM: Identification of a rationale for the appropriate uptake period for myocardial (18)F-FDG-PET imaging of patients with and without diabetes mellitus. METHODS: In a subset of 27 patients, static 2D-PET examination was performed of patients with chronic coronary artery disease and known myocardial infarction. The patients fasted (at least 4 h) before examination. (18)F-FDG (330 +/- 20 MBq) was injected intravenously. The image quality was semiquantitativly determined by ROI-analysis and the myocardium-to-blood pool activity ratio (M/B) was calculated. I.) Scans 30, 60, and 90 min p. i. of 10 non-diabetic patients (60 g oral glucose loading one hour before FDG-injection, low-dose intravenous insulin bolus if necessary). II.) Scans 30, 60, and 90 min p. i. of 10 patients with known non-insulin dependent diabetes (20 g glucose, insulin bolus). III.) Scans 90 min p. i. of 7 patients with known non-insulin dependent diabetes and elevated fasting serum glucose level (140-200 mg/dl; insulin bolus, no glucose). RESULTS: I.) The M/B ratio significantly increases in nondiabetic patients with the uptake time (30 min 1.95 +/- 0.20; 60 min 2.96 +/- 0.36; 90 min 3.78 +/- 0.43). II.) In patients with non-insulin dependent diabetes the M/B ratio also significantly increases with uptake time. Compared to non-diabetic patients group II reached smaller M/B values (30 min 1.56 +/- 0.10; 60 min 2.15 +/- 0.14; 90 min 2.71 +/- 0.19). III.) In the group of patients with elevated fasting serum glucose level (who only got insulin but no glucose loading) the M/B activity ratio 90 min p. i. was clearly inferior compared with diabetic patients after oral glucose loading and insulin administration (M/B 2.71 +/- 0.19 versus 2.16 +/- 0.07). CONCLUSIONS: In static myocardial viability PET studies with (18)F-FDG an uptake time of 90 min yields image quality superior to that obtained after shorter uptake time.

Pharmacokinetics of isometronidazole. Basic model and estimation of the kinetic parameters from experimental data.

For the optimal timing of application of radiosensitizers in a course of radiotherapy it is important to know the sensitizer concentration at the time of irradiation. We have studied the pharmacokinetics of the hypoxic cell sensitizer isometronidazole in man and mouse and analyzed the data on the basis of an open two-compartment model after extravasal application. The parameter estimation is performed directly to avoid estimation biasing and data points from blood and tissue compartments are approximated simultaneously. The values obtained differ significantly from the estimations calculated by other authors for the same data.

1H and 31P NMR characterisation of a double breast coil for spectroscopic measurements and imaging.

For the first time a double turn breast coil has been described which can be used for 1H imaging, 1H spectroscopy and 31P spectroscopy. The paper describes basic technical features of the coil, coil design, B1 field/excitation field distribution for 1H and 31P, sensitivity, and feasibility for 31P spectroscopic in vivo studies. The main advantage of the double frequency tuneable coil is that 1H imaging for tumor localization and 31P spectroscopy for response control can be done without an additional repositioning of the patient.

False-positive radio-iodinated metaiodobenzylguanidine (123I-MIBG) accumulation in a mast cell-infiltrated infantile haemangioma.

Radio-iodinated metaiodobenzylguanidine ((123)I-MIBG) is used for the detection and staging of neuroblastoma, pheochromcytoma and other neuroendocrine tumours in diagnostic nuclear medicine. A specific uptake and storage mechanism provides the basis for imaging with (123)I-MIBG. Nevertheless, cases of false-positive (123)I-MIBG scintigraphy with accumulation in non-chromaffin tumours have been described. Here, we present a case of a false-positive (123)I-MIBG scan in a case of a mast-cell infiltrated infantile haemangioma and discuss the possible uptake mechanism.