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Recently, a new lightning phenomena, termed needles, has been observed in both VHF and in optical along positive lightning leaders. They appear as small (<100 m) leader branches that undergo dielectric breakdown at regular intervals (called twinkles). Providing a coherent and consistent explanation for this phenomenon is challenging as each twinkle is a form of negative breakdown that propagates away from the positive leader. In this study, we provide detailed observations of needles in VHF, observed during two lightning flashes. We show distributions of different needle properties, including twinkle propagation speeds, time between twinkles, and needle lengths, among others. We show a return stroke and multiple recoil leaders that quench needle activity. We also show that nearby needle activity does not seem to correlate together, and that needle twinkling can slow down by 10%–30% per twinkle. We conclude by presenting possibilities for how the positive leader could induce negative propagation away from the positive channel, and we argue that twinkles can propagate like a stepped leader or like a recoil leader depending on the temperature of the needle, which implies that needle twinkles can probably propagate without emitting VHF. Key Points: Detailed distributions of needle properties are presentedPossible physics behind needle production is discussedRecoil leaders quench needle activity [ABSTRACT FROM AUTHOR]

ABC-OCT, Affordable B-scan Camera-based Optical Coherence Tomography, implements Fourier-Domain Optical Coherence Tomography with real-time display using cross-platform C++ and the OpenCV framework. The software can be compiled using current versions of GCC for *nix/Mac and Microsoft®Visual Studio for Windows. Full functionality of ABC-OCT needs the camera SDK from QHYCCD and a QHYCCD camera to be connected; but the code can be easily modified to support other camera drivers, as is shown by an included demo version which can use any installed webcam. The code is made available under the MIT license. The software is available from GitHub (https://github.com/hn-88/FDOCT). [ABSTRACT FROM AUTHOR]

Purpose: Raman spectroscopy is a promising cancer detection technique for surgical guidance applications. It can provide quantitative information relating to global tissue properties associated with structural, metabolic, immunological, and genetic biochemical phenomena in terms of molecular species including amino acids, lipids, proteins, and nucleic acid (DNA). To date in vivo Raman spectroscopy systems mostly included probes and biopsy needles typically limited to single‐point tissue interrogation over a scale between 100 and 500 microns. The development of wider field handheld systems could improve tumor localization for a range of open surgery applications including brain, ovarian, and skin cancers. Methods: Here we present a novel Raman spectroscopy implementation using a coherent imaging bundle of fibers to create a probe capable of reconstructing molecular images over mesoscopic fields of view. Detection is performed using linear scanning with a rotation mirror and an imaging spectrometer. Different slits widths were tested at the entrance of the spectrometer to optimize spatial and spectral resolution while preserving sufficient signal‐to‐noise ratios to detect the principal Raman tissue features. The nonbiological samples, calcite and polytetrafluoroethylene (PTFE), were used to characterize the performance of the system. The new wide‐field probe was tested on ex vivo samples of calf brain and swine tissue. Raman spectral content of both tissue types were validated with data from the literature and compared with data acquired with a single‐point Raman spectroscopy probe. The single‐point probe was used as the gold standard against which the new instrument was benchmarked as it has already been thoroughly validated for biological tissue characterization. Result: We have developed and characterized a practical noncontact handheld Raman imager providing tissue information at a spatial resolution of 115 microns over a field of view >14 mm2 and a spectral resolution of 6 cm−1 over the whole fingerprint region. Typical integration time to acquire an entire Raman image over swine tissue was set to approximately 100 s. Spectra acquired with both probes (single‐point and wide‐field) showed good agreement, with a Pearson correlation factor >0.85 over different tissue categories. Protein and lipid content of imaged tissue were manifested into the measured spectra which correlated well with previous findings in the literature. An example of quantitative molecular map is presented for swine tissue and calf brain based on the ratio of protein‐to‐lipid content showing clear delineations between white and gray matter as well as between adipose and muscle tissue. Conclusion: We presented the development of a Raman imaging probe with a field of view of a few millimeters and a spatial resolution consistent with standard surgical imaging methods using an imaging bundle. Spectra acquired with the newly developed system on swine tissue and calf brain correlated well with an establish single‐point probe and observed spectral features agreed with previous finding in the literature. The imaging probe has demonstrated its ability to reconstruct molecular images of soft tissues. The approach presented here has a lot of potential for the development of surgical Raman imaging probe to guide the surgeon during cancer surgery. [ABSTRACT FROM AUTHOR]

Nanobodies are important biomolecules for tumor targeting. In this study, we synthesized and labeled anti-epidermal growth factor receptor ( EGFR) nanobody OA-cb6 with 99mTc( CO)3+ and evaluated its characteristics for targeting the EGFR in the A431 human epidermal carcinoma cell line. Nanobody radiolabeling was achieved with high yield and radiochemical purity, and the radioconjugate was stable. Biodistribution results in nude mice exhibited a favorable tumor-to-muscle ratio at 4-hr postinjection, and tumor location was visualized at 4 hr after injection of radiolabeled nanobody. Our result showed that the OA-cb6-99mTc-tricarbonyl radiolabeled nanobody is a promising radiolabeled biomolecule for tumor imaging in cancers with high EGFR overexpression. [ABSTRACT FROM AUTHOR]

Purpose To evaluate the utility of 3-dimensional magnetic resonance (3D-MR) proton spectroscopic imaging for treatment planning and its implications for early response assessment in glioblastoma multiforme. Methods and Materials Eighteen patients with newly diagnosed, histologically confirmed glioblastoma had 3D-MR proton spectroscopic imaging (MRSI) along with T2 and T1 gadolinium-enhanced MR images at simulation and at boost treatment planning after 17 to 20 fractions of radiation therapy. All patients received standard radiation therapy (RT) with concurrent temozolomide followed by adjuvant temozolomide. Imaging for response assessment consisted of MR scans every 2 months. Progression-free survival was defined by the criteria of MacDonald et al. MRSI images obtained at initial simulation were analyzed for choline/N-acetylaspartate ratios (Cho/NAA) on a voxel-by-voxel basis with abnormal activity defined as Cho/NAA ≥2. These images were compared on anatomically matched MRSI data collected after 3 weeks of RT. Changes in Cho/NAA between pretherapy and third-week RT scans were tested using Wilcoxon matched-pairs signed rank tests and correlated with progression-free survival, radiation dose and location of recurrence using Cox proportional hazards regression. Results After a median follow-up time of 8.6 months, 50% of patients had experienced progression based on imaging. Patients with a decreased or stable mean or median Cho/NAA values had less risk of progression (P<.01). Patients with an increase in mean or median Cho/NAA values at the third-week RT scan had a significantly greater chance of early progression (P<.01). An increased Cho/NAA at the third-week MRSI scan carried a hazard ratio of 2.72 (95% confidence interval, 1.10-6.71; P=.03). Most patients received the prescription dose of RT to the Cho/NAA ≥2 volume, where recurrence most often occurred. Conclusion Change in mean and median Cho/NAA detected at 3 weeks was a significant predictor of early progression. The potential impact for risk-adaptive therapy based on early spectroscopic findings is suggested. [ABSTRACT FROM AUTHOR]

Abstract: Background: The use of magnetic resonance spectroscopy imaging (MRSI) and dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) have emerged as a valid diagnostic tools for prostate cancer (CaP). Methods: Men with PSA levels below 10 ng/ml were enrolled in a prospective cohort study and underwent combined MRSI and DCE-MRI and transrectal ultrasound-guided prostate biopsy. Imaging was performed using a 1.5 T MR scanner (Symphony TIM; Siemens, Erlangen, Germany) with an endorectal coil (Medrad; Pittsburg, PA), inflated with 60 cc of air. Three-dimensional magnetic resonance spectroscopic data were acquired by using water and a lipid-suppressed double-spin-echo point-resolved spectroscopy sequence, which was optimized for quantitative detection of both choline and citrate. Dynamic contrast-enhanced MRI sequences were obtained with 3D T1-weighted FLASH images before and during rapid bolus administration of intravenous paramagnetic contrast medium gadoteric acid. Specificity, sensitivity, positive predictive value, negative predictive value, and accuracy were computed considering patients, each of the 2 lobes, each of the 6 sextants, and each 12th part of the prostate gland as single measurements. Results: Overall, 106 patients were included in the analysis. Median age was 65.9 years (range, 61.2–70.5 years) and median PSA level at study entry was 7.1 ng/ml (range, 2.5–9.9). CaP was detected at biopsy in 24 patients (22.6 % of the population) with a median Gleason score of 8 (range 4–10). Diagnostic accuracy of combined MRSI and DCE-MRI was 85%, sensitivity was 71%, and specificity was 48%, considering patients as single measurements, with a negative predictive value of 91%, but a positive predictive value of only 19%. Positive predictive value of the examination improved to 25% for patients who repeated biopsy. Conclusions: Although this study confirms the potential usefulness of MRI for the diagnosis of CaP, the positive predictive value obtained was unacceptably low due to the high number of false positives recorded. Nevertheless, the high negative predictive value of the examination may serve to avoid unnecessary biopsies. Future research should be directed at assessing the value of combining MRI-based techniques with novel biochemical markers for the diagnosis of CaP in patients with low PSA levels. [Copyright &y& Elsevier]

The feasibility of early detection of gastric cancer using near-infrared (NIR) Raman spectroscopy (RS) by distinguishing premalignant lesions (adenomatous polyp, n = 27) and cancer tissues (adenocarcinoma, n = 33) from normal gastric tissues (n = 45) is evaluated. Significant differences in Raman spectra are observed among the normal, adenomatous polyp, and adenocarcinoma gastric tissues at 936, 1003, 1032, 1174, 1208, 1323, 1335, 1450, and 1655 cm-1. Diverse statistical methods are employed to develop effective diagnostic algorithms for classifying the Raman spectra of different types of ex vivo gastric tissues, including principal component analysis (PCA), linear discriminant analysis (LDA), and naive Bayesian classifier (NBC) techniques. Compared with PCA-LDA algorithms, PCA-NBC techniques together with leave-one-out, cross-validation method provide better discriminative results of normal, adenomatous polyp, and adenocarcinoma gastric tissues, resulting in superior sensitivities of 96.3%, 96.9%, and 96.9%, and specificities of 93%, 100%, and 95.2%, respectively. Therefore, NIR RS associated with multivariate statistical algorithms has the potential for early diagnosis of gastric premalignant lesions and cancer tissues in molecular level. [ABSTRACT FROM AUTHOR]

Study Type - Prognosis (case series) Level of Evidence 4 What's known on the subject? and What does the study add? Nomograms are available that combine clinical and biopsy findings to predict the probability of pathologically insignificant prostate cancer in patients with clinically low-risk disease. Based on data from patients with Gleason score 6, clinical stage ≤ T2a and PSA <20 ng/ml, our group developed the first nomogram models for predicting insignificant prostate cancer that incorporated clinical data, detailed biopsy data and findings from MRI or MRI/MRSI (BJU Int. 2007;99(4):786-93). When tested retrospectively, these MR models performed significantly better than standard clinical models with and without detailed biopsy data. We prospectively validated the previously published MR-based nomogram models in a population of patients with Gleason score 6, clinical stage ≤ T2a and PSA <10 ng/ml. Based on data from this same population, we also developed two new models for predicting insignificant prostate cancer that combine MR findings and clinical data without detailed biopsy data. Upon initial testing, the new MR models performed significantly better than a clinical model lacking detailed biopsy data. OBJECTIVES To validate previously published nomograms for predicting insignificant prostate cancer (PCa) that incorporate clinical data, percentage of biopsy cores positive (%BC+) and magnetic resonance imaging (MRI) or MRI/MR spectroscopic imaging (MRSI) results. [ABSTRACT FROM AUTHOR]

There continues to be a significant clinical need for rapid and reliable intraoperative margin assessment during cancer surgery. Here we describe a portable, quantitative, optical fiber probe-based, spectroscopic tissue scanner designed for intraoperative diagnostic imaging of surgical margins, which we tested in a proof of concept study in human tissue for breast cancer diagnosis. The tissue scanner combines both diffuse reflectance spectroscopy (DRS) and intrinsic fluorescence spectroscopy (IFS), and has hyperspectral imaging capability, acquiring full DRS and IFS spectra for each scanned image pixel. Modeling of the DRS and IFS spectra yields quantitative parameters that reflect the metabolic, biochemical and morphological state of tissue, which are translated into disease diagnosis. The tissue scanner has high spatial resolution (0.25 mm) over a wide field of view (10 cmx10 cm), and both high spectral resolution (2 nm) and high spectral contrast, readily distinguishing tissues with widely varying optical properties (bone, skeletal muscle, fat and connective tissue). Tissue-simulating phantom experiments confirm that the tissue scanner can quantitatively measure spectral parameters, such as hemoglobin concentration, in a physiologically relevant range with a high degree of accuracy (<5% error). Finally, studies using human breast tissues showed that the tissue scanner can detect small foci of breast cancer in a background of normal breast tissue. This tissue scanner is simpler in design, images a larger field of view at higher resolution and provides a more physically meaningful tissue diagnosis than other spectroscopic imaging systems currently reported in literatures. We believe this spectroscopic tissue scanner can provide real-time, comprehensive diagnostic imaging of surgical margins in excised tissues, overcoming the sampling limitation in current histopathology margin assessment. As such it is a significant step in the development of a platform technology for intraoperative management of cancer, a clinical problem that has been inadequately addressed to date. [ABSTRACT FROM AUTHOR]

Abstract: Background: One of the most important clinical challenges in prostate cancer (PCa) management is an in vivo assessment of cancer aggressiveness. Objective: To validate the performance of magnetic resonance (MR) spectroscopic imaging (MRSI) of the prostate at 3 T for the purpose of assessing tumour aggressiveness based on the ratio of choline plus creatine to citrate (Cho+Cr/Cit) and of choline to creatine (Cho/Cr), using the Gleason score of the radical prostatectomy (RP) specimen as the gold standard. Design, setting, and participants: A total of 43 biopsy-proven PCa patients with 53 clinically relevant tumour foci were retrospectively included in this study. Measurements: Patients underwent MR imaging and MRSI examination followed by RP. From MRSI, all spectroscopy voxels containing tumour were selected by a radiologist guided by the prostatectomy histopathology map only. For each tumour, two spectroscopists determined the maximum Cho+Cr/Cit, Cho/Cr, and malignancy rating using a standardised threshold approach, incorporating both metabolic ratios. The maximum Cho+Cr/Cit, Cho/Cr, and malignancy ratings showed a relation to tumour aggressiveness and so were used to differentiate among tumour aggressiveness classes. Results and limitations: The maximum Cho+Cr/Cit ratio, maximum Cho/Cr ratio, and malignancy rating of a standardised threshold approach separated low-grade from higher-grade tumours, with areas under the receiver operating characteristic (ROC) curves of 0.70, 0.74, and 0.78, respectively. Conclusions: MRSI offers possibilities for an in vivo, noninvasive assessment of PCa aggressiveness. The combination of the different metabolite ratios was used with promising results for discrimination among different aggressiveness classes. [Copyright &y& Elsevier]

Objective: The major goal of the work was to record three-dimensional magnetic resonance spectroscopic imaging (MRSI) and to compare metabolite ratios between different Gleason scores (GS). Materials and Methods: MRSI localized by endorectal coil-acquired point-resolved spectroscopy was performed in 14 men with prostate cancer of GS 6 (n = 7) and 7 (n = 7) using a 1.5-tesla MRI scanner. Results: The ratio of (choline + creatine)/citrate was increased with an increase of GS, i.e. 0.590 ± 0.171 in the target lesion and 0.321 ± 0.157 in the contralateral region of patients with a GS of 6 as opposed to 1.082 ± 0.432 in the target lesion and 0.360 ± 0.243 in the contralateral region of patients with a GS of 7. Conclusion: Our pilot results demonstrated that MRSI was an additional biochemical tool which is complementary to the current imaging modalities for early diagnosis and therapeutic management of prostate cancer. Copyright © 2011 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Abstract: Recently, a large number of studies have shown that the addition of proton 1H-spectroscopic imaging (1H-MRSI) and dynamic contrast enhanced imaging (DCEMR) to magnetic resonance (MR) could represent a powerful tool for the management of prostate cancer (CaP) in most of its aspects. This combination of MR techniques can substantially sustain the clinical management of patients with CaP at different levels: in particular, (1) in the initial assessment, reducing the need for more extensive biopsies and directing targeted biopsies; (2) in the definition of a biochemical progression after primary therapies, distinguishing between fibrotic reaction and local recurrence from CaP. [ABSTRACT FROM AUTHOR]

The purpose of this study was to retrospectively characterize benign and malignant prostate peripheral zone tissue by using endorectal MRI and 3D H MRS. Fifty-two men with untreated biopsy-proven prostate cancer underwent combined endorectal MRI and MRSI. Whole-mount step-section histopathologic analysis constituted the reference standard. Biopsy correctly detected 74 locations; MRI correctly detected 72 locations; MRS correctly detected 72 locations; MRI + MRS correctly detected 78 locations. Cohen's test showed that biopsy had a lower degree of agreement with histology than MRI + MRS combined. The ratio of [(Cho + Cr)]/Cit correlates with the pathologic Gleason score. The addition of 3DH MRSI to MRI can improve diagnosis of prostate cancer contributing indirectly to improve local staging. In addition, the correlation between metabolic 3DH MRSI data with pathological Gleason grade may offer a non-invasive means to better predict prostate cancer aggressiveness. [ABSTRACT FROM AUTHOR]

Abstract: MALDI mass spectrometry is able to acquire protein profiles directly from tissue that can describe the levels of hundreds of distinct proteins. MALDI imaging MS can simultaneously reveal how each of these proteins varies in heterogeneous tissues. Numerous studies have now demonstrated how MALDI imaging MS can generate different protein profiles from the different cell types in a tumor, which can act as biomarker profiles or enable specific candidate protein biomarkers to be identified. MALDI imaging MS can be directly applied to patient samples where its utility is to accomplish untargeted multiplex analysis of the tissue''s protein content, enabling the different regions of the tissue to be differentiated on the basis of previously unknown protein profiles/biomarkers. The technique continues to rapidly develop and is now approaching the cusp whereby its potential to provide new diagnostic/prognostic tools for cancer patients can be routinely investigated. Here the latest methodological developments are summarized and its application to a range of tumors is reported in detail. The prospects of MALDI imaging MS are then described from the perspectives of modern pathological practice and MS-based proteomics, to ensure the outlook addresses real clinical needs and reflects the real capabilities of MS-based proteomics of complex tissue samples. [Copyright &y& Elsevier]

Purpose: To assess 1H-magnetic resonance spectroscopic imaging (1H-MRSI) and dynamic contrast-enhanced magnetic resonance (DCE-MRI) features in histologically confirmed prostatic chronic inflammation, prostatic intraepithelial neoplasia (PIN), low grade prostate cancer (LGPCa), and high grade prostate cancer (HGPCa). Materials and Methods: Ninety-six men were selected, who showed at histology a diagnosis of chronic inflammation (Group B), high grade (HG) PIN (Group C), or prostate cancer (LGPCa = Group D and HGPCa = Group E). Results: ANOVA analysis shows that inflammation (Group B) displays no significantly ( p >.05) different choline and citrate levels when compared to HGPIN and LGPCa. Conclusion: our results suggest the potential for these MR imaging techniques in the description of inflammatory and proliferative lesions inside the prostate gland. [ABSTRACT FROM AUTHOR]

AbstractThe purpose of this article is to review both routine T2-weighted and new MRI techniques in the imaging of prostate cancer (PCa) for focal therapy. T2-weighted imaging, knowledge of MRI prostate zonal anatomy, cancer morphology, and intraprostatic tumor spread remain essential for clinical PCa imaging; however, new techniques, such as dynamic contrast-enhanced MRI, diffusion-weighted imaging, and magnetic resonance spectroscopic imaging yield significant improvements in identification and volume estimation. Potential advantages of 3 Tesla MRI are adequate imaging without an endorectal coil. Future studies should work toward helping define standard, reproducible approaches to multimodality MRI and image reporting for research and clinical practice. [ABSTRACT FROM AUTHOR]

A new high-resolution molecular phase-contrast stereoscopic X-ray imaging (PSXI) modality is under development. It is aimed at offering oncologists and radiologists a system solution to discover and locate early-stage cancers and to assess tumour characteristics and therapeutic responses. The method is primarily developed for clinical implementation of biologically optimised target-specific cancer therapy to maximise cure and improve quality of life of cancer patients. The investigations here indicate theoretically that it is possible to achieve high-resolution and high-contrast 3D medical imaging with the PSXI technique at relatively low dose, almost an order of magnitude lower than those used in conventional computed tomography (CT) imaging, depending on image resolution and contrast of interest. Unique features of this new molecular imaging modality will be discussed in comparison with currently available molecular imaging modalities, such as positron emission tomography-computed tomography and magnetic resonance spectroscopic imaging. Some challenging issues with respect to the possible use of nanotechnology with the new molecular imaging modality will also be discussed. [ABSTRACT FROM PUBLISHER]

Purpose: The technical challenges that have prevented routine proton magnetic resonance spectroscopic imaging (1H MRSI) examinations of the breast include insufficient spatial resolution, increased difficulties in shimming compared to the brain, and strong lipid contamination at short echo time (TE) at 1.5 T. The authors investigated the feasibility of high spatial resolution 1H MRSI of human breast cancer in a clinical setting at 3 T. Methods: Ten patient studies (eight cancers and two benign lesions) were performed in a 3 T whole-body clinical imager using a pulse sequence consisting of optional outer volume presaturation, optional CHESS pulse for lipid suppression, CHESS pulse for water suppression, and standard 2D/3D PRESS pulse sequence with an elliptical weighted k-space sampling scheme. Results: All ten studies were technically successful. The spectral quality was acceptable for all cases even the one with a 65 Hz width of water peak at half height. Choline (Cho) signals were clearly visible in malignant lesion areas, while there was no detectable Cho in normal appearing breast or in benign lesions. It was also observed that the distribution of Cho signal can be nonuniform across MRI demonstrated lesions. Conclusions: To the author’s knowledge, this is the first 2D/3D MRSI study of human breast cancer with short TE (less than 135 ms) at 3 T and the highest spatial resolution (up to 0.25 cm3) to date. In conclusion, the authors have presented a robust technique for high spatial resolution in vivo 1H MRSI of human breast cancer that uses the combined advantages of high field, short TE, multivoxel, and high spatial resolution itself to overcome the major technical challenges and illustrated its potential for routine clinical examination as well as advantages over single-voxel techniques in studying metabolite heterogeneity. [ABSTRACT FROM AUTHOR]

Computed tomography (CT) is the imaging technique of choice for characterizing pleural masses with respect to their location, composition, and extent. CT also provides important information regarding invasion of the chest wall and surrounding structures. A spectrum of tumours can affect the pleura of which metastatic adenocarcinoma is the commonest cause of malignant pleural disease, while malignant mesothelioma is the most common primary pleural tumour. Certain CT features help differentiate benign from malignant processes. This pictorial review highlights the salient CT appearances of a range of tumours that may affect the pleura. [Copyright &y& Elsevier]

The article focuses on the findings of a study concerning the relationship between 31P metabolites and oncolytic viral therapy sensitivity in human colorectal cancer zenografts. It mentions that spectroscopic imaging was performed in colorectal flank tumours in nude mice. Moreover, the study determines that alterations in membrane phospholipid metabolites that relate to proliferation of cancer cells affect the efficacy of oncolytic viral therapy.

Abstract  Prostate cancer accounts for one-third of noncutaneous cancers diagnosed in US men and is a leading cause of cancer-related death. Advances in Fourier transform infrared spectroscopic imaging now provide very large data sets describing both the structural and local chemical properties of cells within prostate tissue. Uniting spectroscopic imaging data and computer-aided diagnoses (CADx), our long term goal is to provide a new approach to pathology by automating the recognition of cancer in complex tissue. The first step toward the creation of such CADx tools requires mechanisms for automatically learning to classify tissue types—a key step on the diagnosis process. Here we demonstrate that genetics-based machine learning (GBML) can be used to approach such a problem. However, to efficiently analyze this problem there is a need to develop efficient and scalable GBML implementations that are able to process very large data sets. In this paper, we propose and validate an efficient GBML technique—$${\tt NAX}$$—based on an incremental genetics-based rule learner. $${\tt NAX}$$ exploits massive parallelisms via the message passing interface (MPI) and efficient rule-matching using hardware-implemented operations. Results demonstrate that $${\tt NAX}$$ is capable of performing prostate tissue classification efficiently, making a compelling case for using GBML implementations as efficient and powerful tools for biomedical image processing. [ABSTRACT FROM AUTHOR]

Abstract: Context: Magnetic resonance imaging (MRI) combined with magnetic resonance spectroscopy imaging (MRSI) emerged as a promising test in the diagnosis of prostate cancer and showed encouraging results. Objective: The aim of this systematic review is to meta-analyse the diagnostic accuracy of combined MRI/MRSI in prostate cancer and to explore risk profiles with highest benefit. Evidence acquisition: The authors searched the MEDLINE and EMBASE databases and the Cochrane Library, and the authors screened reference lists and contacted experts. There were no language restrictions. The last search was performed in August 2008. Evidence synthesis: We identified 31 test-accuracy studies (1765 patients); 16 studies (17 populations) with a total of 581 patients were suitable for meta-analysis. Nine combined MRI/MRSI studies (10 populations) examining men with pathologically confirmed prostate cancer (297 patients; 1518 specimens) had a pooled sensitivity and specificity on prostate subpart level of 68% (95% CI, 56–78%) and 85% (95% CI, 78–90%), respectively. Compared with patients at high risk for clinically relevant cancer (six studies), sensitivity was lower in low-risk patients (four studies) (58% [46–69%] vs 74% [58–85%]; p >0.05) but higher for specificity (91% [86–94%] vs 78% [70–84%]; p <0.01). Seven studies examining patients with suspected prostate cancer at combined MRI/MRSI (284 patients) had an overall pooled sensitivity and specificity on patients level of 82% (59–94%) and 88% (80–95%). In the low-risk group (five studies) these values were 75% (39–93%) and 91% (77–97%), respectively. Conclusions: A limited number of small studies suggest that MRI combined with MRSI could be a rule-in test for low-risk patients. This finding needs further confirmation in larger studies and cost-effectiveness needs to be established. [Copyright &y& Elsevier]

Abstract: Purpose: To minimize user and vendor dependence of the spectrum processing of prostate spectra, to measure the ratio of choline (Cho) plus creatine (Cr) to citrate (Cit) in the prostate tissue of normal volunteers and cancer patients, and to compare the results with pathologic findings after radical prostatectomy. Materials and methods: Four healthy volunteers and 13 patients with prostate cancer were measured. Measurements were performed using two-dimensional magnetic resonance spectroscopic imaging (MRSI) and endorectal coil. A standard vendor''s spectrum processing approach has been modified. An original feature of this methodology was the combination of vendor-optimized and user-independent spectrum preprocessing in the scanner and user-independent quantitation in the environment of an MRUI software package. (Cho+Cr)/Cit ratio was used for the classification of prostate tissue. Results were compared with histopathology after radical prostatectomy. Results: Eight of 13 cancer patients were classified as suspicious or very suspicious for cancer at spectroscopy, three were ambiguous for cancer and two patients were evaluated as false negative. A considerable overlap of metabolite ratios at various Gleason score was found. Conclusion: The proposed spectrum processing has the potential to improve the accuracy and user independency of the (Cho+Cr)/Cit quantitation. This study confirmed the previous results that a considerable overlap of (Cho+Cr)/Cit ratios exists at various Gleason score levels. [Copyright &y& Elsevier]

Purpose To describe the practical technical aspects of magnetic resonance imaging (MRI) and magnetic resonance spectroscopic imaging (MRSI) and to summarize the current and potential future status of MRI and MRSI in the localization, staging, treatment planning, and post-treatment follow-up of prostate cancer.Technique Published contemporary series of patients with prostate cancer evaluated by MRI and MRSI before or after radiation therapy were reviewed, with particular respect to the role of MRI and MRSI in treatment planning, outcome prediction, and detecting local recurrence.Results Volumetric localization is of limited accuracy for tumors less than 0.5 cm3. Staging by MRI, which is improved by the addition of MRSI, is of incremental prognostic significance in patients with moderate and high-risk tumors. The finding of more than 5 mm of extracapsular extension prior to radiation seems to be of particular negative prognostic significance, and the latter group may be candidates for more aggressive supplemental therapy. The use of MRI to assist radiation treatment planning has been shown to improve outcome. MRSI may be helpful in the detection of local recurrence after radiation.Conclusions Only MRI and MRSI allow combined structural and metabolic evaluation of prostate cancer location, aggressiveness, and stage. Combined MRI and MRSI provide clinically and therapeutically relevant information that may assist in planning and post-treatment monitoring in patients undergoing radiation therapy. [ABSTRACT FROM AUTHOR]

As 3 T MR scanners become more available, body imaging at high field strength is becoming the subject of intensive research. However, little has been published on prostate imaging at 3 T. Will high-field imaging dramatically increase our ability to depict and stage prostate cancer? This paper will address this question by reviewing the advantages and drawbacks of body imaging at 3 T and the current limitations of prostate imaging at 1.5 T, and by detailing the preliminary results of prostate 3 T MRI. Even if slight adjustments of imaging protocols are necessary for taking into account the changes in T1 and T2 relaxation times at 3 T, tissue contrast in T2-weighted (T2w) imaging seems similar at 1.5 T and 3 T. Therefore, significant improvement in cancer depiction in T2w imaging is not expected. However, increased spatial resolution due to increased signal-to-noise ratio (SNR) may improve the detection of minimal capsular invasion. Higher field strength should provide increased spectral and spatial resolution for spectroscopic imaging, but new pulse sequences will have to be designed for overcoming field inhomogeneities and citrate J-modulation issues. Finally, dynamic contrast-enhanced MRI is the method of imaging that is the most likely to benefit from the increased SNR, with a significantly better trade-off between temporal and spatial resolution. [ABSTRACT FROM AUTHOR]

This study described a novel radioactive probe for SPECT imaging of lung cancer. The probe was consisted of ^{99m}Tc labeled cartilage link protein (CLP). The CLP, a hyaluronate binding protein, was isolated from bovine nose cartilage and purified on a chromatography column. ^{99m}Tc labeling was carried out by pre-treating CLP with SnCl_2. The feasibility of this probe for lung cancer imaging was tested in vivo in an animal model. The hyaluronate probe showed a fairly good binding activity towards both natural and tumor hyaluronic acid in in vitro and in vivo assays. The preliminary feasibility study in a human lung cancer bearing mouse model showed that the probe might be useful for tumor imaging. [ABSTRACT FROM AUTHOR]

Abstract: Oxidation and reduction processes are fundamental to many of the proposed mechanisms by which dietary phytochemicals are thought to exert protective effects against cardiovascular disease and some cancers. An understanding of the redox chemistry of these compounds is essential in assessing their potential to participate in these processes. Phenylpropanoid-derived compounds were selected and synthesised where required to represent many of the structural features found in this important group of compounds. Using electron paramagnetic resonance spectroscopy and computational chemistry a structure–redox activity relationship was obtained. Good correlation of computational and experimental results was observed for the mono-hydroxylated compounds. This demonstrated the value of computational chemistry in obtaining information about compounds, not readily available and the effect of electron delocalisation on parent radical stability. For compounds containing more than one hydroxyl, the relationship was found to be more complex. The importance of quinone formation in compounds containing more than one hydroxyl substituent was highlighted, as this was found to have a significant effect on stabilisation and therefore, their participation in redox processes. [Copyright &y& Elsevier]

The objective of this study was to demonstrate the feasibility of 3D proton MR spectroscopic imaging (MRSI) of the prostate using a standard spine instead of a dedicated endorectal coil at 1.5 T. Twenty-eight patients (25 with biopsy proven prostate cancers and three patients with a benign prostate hyperplasia) were examined. MRI and MRSI were conducted with commercial array surface coils at 1.5 T. Ratios of choline (Cho), creatine (Cr) and citrate (Ci) were calculated for tumour, central and peripheral zone retrospectively, based on axial T2 weighed MR images and histology reports. Prostate cancer was characterized by significantly elevated (Cho+Cr)/Ci ratio compared with non-tumourous prostate tissue. The quality of all proton MR spectra was considered to be good or acceptable in 17/28 patients (61%) and poor in 11/28 (39%) examinations. In 20/25 patients with proven malignancy (80%), MRSI was considered to be helpful for the detection of prostate cancer. In 4/25 patients with proven malignancy (16%) who underwent seed implantation, radiotherapy or hormone deprivation before MR examination spectroscopy was of poor and non-diagnostic quality. MRSI of the prostate is feasible within clinical routine using the spine array surface coil at 1.5 T. It can consequently be applied to patients even with contraindications for endorectal coils. However, spectral quality and signal-to-noise ratio is clearly inferior to 3D MRSI examinations with endorectal coils. [ABSTRACT FROM AUTHOR]

Cancer is a complex disease exhibiting a host of phenotypic diversities. Noninvasive multinuclear magnetic resonance imaging (MRI) and spectroscopic imaging (MRSI) provide an array of capabilities to characterize and understand several of the vascular, metabolic, and physiological characteristics unique to cancer. The availability of targeted contrast agents has widened the scope of MR techniques to include the detection of receptor and gene expression. In this paper, we have highlighted the application of several MR techniques in imaging and understanding cancer. [ABSTRACT FROM AUTHOR]

Magnetic Resonance Spectroscopic Imaging (MRSI) is a promising method for breast cancer diagnosis, providing, in addition to the anatomic picture, complementary biochemical and physiologic information in the form of spectra. It should be able to identify key biochemical changes before the tumour becomes detectable by other functional imaging methods that rely upon single markers not entirely sensitive or specific for malignant activity. MRSI is potentially well suited for screening and repeated monitoring since it entails no radiation exposure. There are, however, limitations to current applications of Magnetic Resonance Spectroscopy (MRS) and MRSI. Many of these can be directly related to reliance upon the conventional data analytical method, i.e. the Fast Fourier Transform (FFT), which has low resolution, poor signal/noise (S/N) in clinical signals, supplies only shape spectra and requires fitting, which is non-unique, so that the number of metabolites must be guessed in advance. This can lead to spurious peaks (over-fitting) and true metabolites being undetected (under-fitting). These limitations of the FFT can be circumvented by recent mathematical advances in signal processing via e.g. the Fast Padé Transform (FPT). As a high resolution, non-linear, stable parametric method, the FPT substantially improves S/N, and fulfills stringent requirements for tumour diagnostics: no post-processing fitting, provides precise numerical results for all peak parameters, and specifies the exact number of metabolites (including those that overlap) from the encoded data. We illustrate in a realistic synthesized model problem similar to MRS that the FPT can identify overlapping peaks that are entirely missed by the FFT, and we give an example from in vivo MRS of the superior resolving power of the FPT compared to FFT at short acquisition time. We also perform detailed paired and logistic regression analyses of Nuclear Magnetic Resonance (NMR) data on extracted breast specimens from patients with breast cancer. These reveal that a rich store of spectroscopic information for detecting malignant breast lesions is found in closely overlapping resonances, some of which decay rapidly and therefore can only be detected at short acquisition times. Since the FPT offers greater possibilities to extract this information, the next step would be to apply the FPT to in vivo MRS and MRSI signals from patients with breast cancer in comparison to normal breast tissue. [Copyright &y& Elsevier]

Discusses the application of the Fourier transform infrared (FTIR) spectroscopy as a method for the detection of retrovirally transformed cells. Optical diagnosis of cellular variations based on the characteristic molecular vibrational spectra of the cells; Differences between primary cells and malignant cells transformed by murine sarcoma virus; Shapes and positions of peaks in the FTIR spectra.

Examines the use of magnetic resonance spectroscopic imaging (MRSI) in the intraoperative optimization planning system for prostate cancer patients in the United States. Effectiveness of MRSI in the distinction between regions of cancer and normal prostatic epithelium; Dose escalation in intraprostatic tumor deposits; Assessment of implant quality.

Background: Mouse prostate cancer modeling presents unique obstacles to the study of spontaneous tumor initiation and progression due to the anatomical location of the tissue. Results: High resolution [130 microm(x) × 130 microm(y) × 300 microm(z)], three-dimensional MRI allowed for the visualization, segmentation, and volumetric measurement of the prostate from normal and genetically engineered animals, in vivo. Additionally, MRS performed on the prostate epithelia of probasin-ErbB-2Delta × Pten(+/−) mice identified changes in the relative concentrations of the metabolites choline and citrate, which was not observed in TRAMP mice. Methods: T1-weighted MRI was performed on normal, TRAMP, probasin-ErbB-2/Her2/Neu (probasin-ErbB-2Delta), and probasin-ErbB-2Delta in the context of decreased Pten activity [probasin-ErbB-2Delta × Pten(+/−)] mice. Volume-localized single-voxel proton magnetic resonance spectroscopy (SVS 1H-MRS) was also performed. Conclusions: The data presented supports the use of combined MRI and MRS for the measurement of biochemical and morphometric alterations in mouse models of prostate cancer. [Copyright &y& Elsevier]