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Aim High resolution scintigraphy ( HRS) can be useful in radio-guided surgery (RGS) and small animal imaging. Devices are generally based on arrays of sensible elements: room temperature semiconductor arrays or scintillating crystals arrays that can be coupled with position sensitive photomultipliers (PSPMT). Here we describe a small Field Of View (FOV) portable cameras based on 1 and 4 inches2 PSPMT. Materials & Methods These cameras show a peculiar crystal- collimator- PSPMT matching that allows the exact positioning of all the scintillating elements inserted in the square holes of a parallel Tungsten collimator. This arrangement ensures no crosstalk of ? rays or light among crystals. The scintillation light emerging from each crystal is revealed by a PSPMT (H8500 or R8520-00-C12). The anodes allow event positioning through the reconstruction of the maximum of the multiplied charge distribution by the centroid algorithm. Data are then selected with an appropriate energy window and transferred to a workstation. We studied the spatial resolution and the homogeneity of two cameras both equipped with 2.4x2.4x5 mm3 CsI (Tl) crystals and a 25 mm long collimator. A thin Plexiglas container filled with 99mTc was used to check homogeneity and pixel identification. A Derenzo phantoms with the diameter of the holes ranging from 2 to 4 mm was positioned at contact, at 1, 2, 3 cm distance from the collimator and filled with 99mTc to assess the camera spatial resolution. Results The energy resolution was 19.1 % FWHM of the 99mTc peak over the whole FOV area. Both cameras showed homogeneity within ± 5% between max and min pixel counts. Pixel identification showed average peak to valley ratio of 20:1. Spatial resolution was 3.3 mm at 1 cm, 4.9 mm at 3 cm, 6.0 mm at 5 cm and 10.9 mm at 10 cm distance. Conclusion Measurement of resolution were performed to foresee the working conditions of HR cameras. Actually when nuclear physicians show to surgeons sentinel nodes or parathyroid glands, they are on contact with the source or at few cm distance. Both detectors were used for RGS and showed hot nodes less than 2 mm large and distant 2.5 mm each other. In several instances a spot detected as single node by Anger camera showed the presence of two near nodes.

Sentinel node (SN) biopsy is an established method for breast cancer staging. Many authors suggested lymphoscintigraphy (LS) in order to indicate the sentinel node; others adopted the vital dye method together with radiocolloids, but only with γ-probe detection during operation without preliminary Anger camera LS. The second method is more simple and fast when compared with LS plus radioguided surgery. The Imaging Probe (IP) is a portable, hand held, high-resolution mini γ-camera studied by our group since 1998. Initial studies on sentinel node biopsy were carried out by us with IP on small series of patients to validate and to demonstrate the effectiveness and usefulness of IP against conventional probes. The aim of the present study is to show that surgeon removes the mammary sentinel node quicker and safer when using IP and conventional γ-probe together than conventional probe only. The results of our study not only show that our device makes quicker and safer SN biopsy, but also that the number of detected nodes is larger with our method than with conventional diagnostic and surgical techniques.

High-resolution (HR) gamma-ray detector 99m Tc Bombesin (99m TcBN) and 99m Tc sestamibi (99m TcSM), have been used to drive Mammotome biopsy after fusion of scintigraphic with digital X-ray images. We studied eight patients with class V microcalcifications. An HR detector with spatial resolution of 3 mm was matched with Mammotome biopsy system provided with Fisher digital X-ray device: images were fused to use the pointer indifferently on X-ray, scintigraphic and fused images. Fusion between X-ray and HR image has previously been reported. The 12 Mammotome samples/patient were weighted and counted in a well counter. Tumour/bkg (T/B) ratio was measured on HR images as well as on biopsy samples. Axilla was also explored with the portable HR device in order to diagnose node invasion. Conventional histology assessment and immunohystochemical study with anti BN receptor antibody was blindly performed on samples. All the patients studied with 99m TcSM showed T1b cancer, 99m TcBN detected one T1a and two T1b cancers. HR scan of axilla detected node metastases in two patients, both studied with 99m TcBN. All the biopsies showed cancer on at least one of the 12 samples. Histology found node metastases in three patients: the two 99m TcBN positive and one studied with 99m TcSM whose axilla was negative at HR scan. Samples showed T/B ratio of 6.6±0.4 for 99m TcSM and 11.3±0.9 for 99m TcBN (p

Aim: Osteomyelitis is a heavy complication of diabetic foot and its diagnosis requires an integrate approach, both for the clinicians and for the specialist imaging. Leukocytes scan (WBCS) plays a key role in the diagnosis of osteomyelitis. It is performed to reduce the number of amputation, to improve wound healing and to reduce the mortality of patients. The suboptimal spatial resolution of Anger cameras (AC) represents a limitation to achieve these goals. Some studies suggested the role of High Resolution Scintigraphy (HRS) in the diagnosis, radioguided surgery and biopsy of different diseases. Aim of present study is to verify if WBCS is able to improve the diagnosis of osteomyelitis and to help surgery with the use of an hand held High Resolution Detector (HRD),.Materials and Methods: 10 patients, mean age 64 yrs, with forefoot ulcers, were enrolled. In all patients planar X-ray, MRI and conventional 99mTc-HMPAO-WBCs were performed. 24h after administration of radiolabelled WBC, each patient was studied by HRS with HRD. The hand held HRD showed four inch2 FOV, 2 mm spatial resolution, 18% energy resolution. The patients underwent surgery or bone biopsy using HRS.Results: Three patients showed negative scan with both devices. They showed an ulcer without infection, debridement of lesion was sufficient to obtain healing (Table). Seven patients showed positive scan at AC without bone infection. HRD showed hot spots of radioactivity in the same patients. In four of them, the hot spot was bar-shaped. This bar-shaped radioactivity was considered as sign of osteomyelitis. One patient, with positive WBCs, refused surgery. Two patients, with positive scan and no sign of osteomyelitis at AC as well as at HRD underwent complete curettage of purulent inflammation using HRD during the surgical treatment. Two of the 4 patients showing infection at HRD were treated by amputation of the two distal phalanges of the toe because of osteomyelitis. The other patients underwent to radio-guided bone biopsy. Bone infection was confirmed by culture exam.Conclusions: HRD seems to be able to guide surgical treatment opening a new way in the therapy of infected foot. It is possible to assess if surgical removal of purulent inflammation is complete and to precisely guide biopsy or removal of the bone with osteomyelitis.

Bombesin (BN) like peptides modulate some functions of central nervous system (CNS) such as feeding and sleep awake cycle. Other roles, including modulation of psychiatric disorders, have been hypothesised by some researchers. A CNS map of bombesin receptors ( BNR) would help understanding the complex cerebral functions of BN like peptides, but this is not available. 99mTc labelled BN-like peptide scan of CNS is the ideal method to obtain the above map. Our group previously reported synthesis, 99mTc labelling and usefulness for cancer diagnosis of BN-like peptides. We have also developed High Resolution (HR) gamma cameras: HR imaging is mandatory to study CNS of small animals. Methods: We performed HR Planar and SPECT images of rat brain with A) pertechnetate and 99mTc HMPAO to make comparison with labelled BN and B) a 99mTc BN- like peptide. Study A was performed on 3 , study B on 5 rats. Images were acquired under mild anaesthesia with a 2mm space resolution, high sensitivity, 25 cm2 FOV Imaging Probe ( Patented, 4 Patents US and EU). Study B was performed with the BN-like peptide 99mTc BN1.1 ( Patented), 37 MBq in the tail vein. HR Images were acquired at 10, 30 and 60 min after injection. Autopsy was performed at 60 min. Brains were removed, chilled, dissected and the per cent of brain dose was calculated for each brain region. Results: Labelling yield of 99mTc BN1.1 was 97± 0.3%. HR images of 99mTc BN1.1 were significantly different from those of pertechnetate and 99mTc HMPAO. 99mTc BN1.1 showed clear, well defined images of fronto-lateral, temporal cortex, cerebellum and brain stems. Hypothalamus, basal ganglia and amygdala were also detected, though with some difficulties. 10, 30 and 60 min images of 99mTc BN1.1 were very similar, confirming the already-reported-by-us very fast uptake of 99mTc BN. Biodistribution after autopsy showed that only 0.035 of the injected dose is taken up by CNS. Of the dose detected in brain, amygdala and hypothalamus took up 10% each, cerebellum 14%, hippocampus 7.5 %, basal ganglia 6.5% and frontal cortex 4.0 %. Comments: We obtained a map of BNR distribution in rat brain. HR camera images of BNR distribution inside rat brain were consistent with biodistribution after autopsy. Though this distribution is much more complex than prevision, it is consistent with known circuits for regulation of feeding and sleep. Cortical uptake is an intriguing finding that deserves further studies.

Molecular electroactive monolayers have been produced from vinylferrocene (VFC) via light-assisted surface anchoring to H-terminated n- and p-Si(100) wafers prepared via wet chemistry, in a controlled atmosphere. The resulting Si–C bound hybrids have been characterized by means of XPS and AFM. Their performance as semiconductor functionalized electrodes and their surface composition have been followed by combining electrochemical and XPS measurements on the same samples, before and after use in an electrochemical cell.

In human blood, breakdown of gastrin-releasing peptide and other bombesin-related peptides occurs in less than 15 min. This quick enzymatic cleavage might impair the diagnostic use of labelled bombesin (BN). 99mTc-labelled bombesin (99mTc BN1) was injected intravenously and dynamic uptake data were acquired for diagnosing 26 cancers of different origin: 15 breast, 3 prostate, 5 colo-rectal, 1 pancreas, 2 small cell lung cancers and 1 gastrinoma. Background subtracted tumour uptake data were plotted against time and fitted with known mathematical functions. Twenty-three out of 26 cancers showed rapid increase of radioactivity followed by a radioactivity plateau, with some oscillations around the average plateau value. The time to 80% of max activity (T80) was the reference parameter to measure and to compare the uptake speeds. The slowest T80 was 7 min in one T1b breast cancer, gastrinoma reached T80 in 5 min and node-positive prostate cancers in 2 min. N+ breast cancers showed T80 at 3.62 +/- 0.75 min, N- breast cancers at 5.5 +/- 0.88 min (p0.02). When all the tumours were considered, N+ tumours showed T80 at 2.68 +/- 1.03 min and N- cancers at 5.5 +/- 0.82 min. In all the cancer types, the uptake of 99mTc BN was faster than 10 min. This result shows the ability of 99mTc BN to image tumours. The faster uptake by N+ versus N- cancers probably depends on the higher blood flow in N+ cancers.

The chemical reactions and diffusion processe at the interference of a metal with oxides and nitrides are a critical issue in the production of metal-dielectric optical filters. The optical properties of these filters depend on the quality of the interfaces between the metal layer and the adjacent dielectric layers. The chemical and physical processes occuring at the silver-dielectric interface are studied by means of ellipsometry and XPS analysis and comprise the subject of the present work.