Manual Scans Research Articles

A fully autonomous robotic ultrasound system for thyroid scanning

The current thyroid ultrasound relies heavily on the experience and skills of the sonographer and the expertise of the radiologist, and the process is physically and cognitively exhausting. In this paper, we report a fully autonomous robotic ultrasound system, which is able to scan thyroid regions without human assistance and identify malignant nod- ules. In this system, human skeleton point recognition, reinforcement learning, and force feedback are used to deal with the difficulties in locating thyroid targets. The orientation of the ultrasound probe is adjusted dynamically via Bayesian optimization. Experimental results on human participants demonstrated that this system can perform high-quality ultrasound scans, close to manual scans obtained by clinicians. Additionally, it has the potential to detect thyroid nodules and provide data on nodule characteristics for American College of Radiology Thyroid Imaging Reporting and Data System (ACR TI-RADS) calculation.

Analysis Of Tax Disputes On Loans From Shareholders: A Case Study On Tax Court Rulings For The Period 2018-2022

This research aims to analyze the causes of tax disputes over loans from shareholders. This research is also intended to provide recommendations for minimizing the occurrence of tax disputes over loans from shareholders. This research is qualitative research with a case study approach and was carried out using content analysis of tax court decisions and analysis of interviews with the Fiscus and Taxpayers. Loan disputes from shareholders consist of formal disputes and material disputes. The results of this research show that formal loan disputes from shareholders occur due to the implementation and application of tax regulations, while material disputes relate to loan terms, debt ratios and interest rates. Therefore, this research provides a solution for the Directorate General of Taxes (DGT) and Taxpayers to reduce loan disputes from shareholders occurring again. DGT can make policies and regulations related to cash pooling and loan interest rates. Solutions that can be given to taxpayers are holding training and Focus Group Discussions (FGD) related to taxation, holding meeting or actively consulting with Account Representatives (AR), paying attention to formal provisions for transactions even though they are carried out between companies of the same group. The limitation of this research is that there is still decision data that is not included in this research and there is decision data that cannot be read because the decision results are the results of manual scans downloaded from the Tax Court website.

Automatic Deep Learning Segmentation and Quantification of Epicardial Adipose Tissue in Non-Contrast Cardiac CT scans.

An Automatic deep learning semantic segmentation (ADLS) using DeepLab-v3-plus technique is proposed for a full and accurate whole heart Epicardial adipose tissue (EAT) segmentation from non-contrast cardiac CT scan. The ADLS algorithm was trained on manual segmented scans of the enclosed region of the pericardium (sac), which represents the internal heart tissues where the EAT is located. A level of 40 Hounsfield unit (HU) and a window of 350 HU was applied to every axial slice for contrast enhancement. Each slice was associated with two additional consecutive slices, representing the three-channel single input image of the deep network. The detected output mask region, as a post-step, was thresholded between [-190, -30] HU to detect the EAT region. A median filter with kernel size 3mm was applied to remove the noise. Using 70 CT scans (50 training/20 testing), the ADLS showed excellent results compared to manual segmentation (ground truth). The total average Dice score was (89.31%±1.96) with a high correlation of (R=97.15%, p-value <0.001), while the average error of EAT volume was (0.79±9.21).Clinical Relevance- Epicardial adipose tissue (EAT) volume aids in predicting atherosclerosis development and is linked to major adverse cardiac events. However, accurate manual segmentation is considered tedious work and requires skilled expertise.

Automatic Processing of Historical Japanese Mathematics (Wasan) Documents

“Wasan” is the collective name given to a set of mathematical texts written in Japan in the Edo period (1603–1867). These documents represent a unique type of mathematics and amalgamate the mathematical knowledge of a time and place where major advances where reached. Due to these facts, Wasan documents are considered to be of great historical and cultural significance. This paper presents a fully automatic algorithmic process to first detect the kanji characters in Wasan documents and subsequently classify them using deep learning networks. We pay special attention to the results concerning one particular kanji character, the “ima” kanji, as it is of special importance for the interpretation of Wasan documents. As our database is made up of manual scans of real historical documents, it presents scanning artifacts in the form of image noise and page misalignment. First, we use two preprocessing steps to ameliorate these artifacts. Then we use three different blob detector algorithms to determine what parts of each image belong to kanji Characters. Finally, we use five deep learning networks to classify the detected kanji. All the steps of the pipeline are thoroughly evaluated, and several options are compared for the kanji detection and classification steps. As ancient kanji database are rare and often include relatively few images, we explore the possibility of using modern kanji databases for kanji classification. Experiments are run on a dataset containing 100 Wasan book pages. We compare the performance of three blob detector algorithms for kanji detection obtaining 79.60% success rate with 7.88% false positive detections. Furthermore, we study the performance of five well-known deep learning networks and obtain 99.75% classification accuracy for modern kanji and 90.4% for classical kanji. Finally, our full pipeline obtains 95% correct detection and classification of the “ima” kanji with 3% False positives.

Tooth wear, growth and height in rabbits (Oryctolagus cuniculus) fed pelleted or extruded diets with or without added abrasives.

Among the different factors thought to affect dental wear, dietary consistency is possibly the least investigated. To understand tooth wear of herbivorous animals consuming different dietary consistencies with different abrasive potential, we fed 14 rabbits (Oryctolagus cuniculus) exclusively with a timothy grassmeal-based diet in either pelleted or extruded form, or the same diets with an addition of 5% fine sand abrasives (mean size 130µm). First, we offered the rabbits the pelleted and extruded diets as well as the pelleted control and pelleted abrasive diet in a two-stage preference experiment. Then, the rabbits received each diet for 2weeks in a randomised serial feeding experiment, where each animal served as its own control. Tooth measurements for wear, growth and height were achieved using a manual calliper, endoscopic examination and CT scans. The analysis of the diets as fed showed almost identical mean particle size, but the extruded diet had a lower density (volume/mass) and softer consistency compared to the pelleted one and was favoured by most rabbits. The rabbits selected against the diet with sand during the preference experiment, possibly because it caused more tooth wear, especially on the teeth most exposed to wear along the upper tooth row (upper P4 and M1). The maxillary teeth also showed evidence of an increased chewing laterality by the end of the experiment. The extruded diet led to a significantly lower cheek teeth height than the pelleted diet, potentially due to the higher chewing effort needed for a similar dry matter intake. The results suggest that dietary hardness alone is a poor predictor of dental wear. The regrowth of the teeth matched wear consistently.

Exploring a New Paradigm for the Fetal Anomaly Ultrasound Scan: Artificial Intelligence in Real Time

Background: Ultrasound (US) imaging is characterised by high levels of operator subjectivity and variability. Recent advances in artificial intelligence (AI) have demonstrated the potential to reduce both factors. This study pilots the end-to-end automation of multiple elements of the mid-trimester obstetric screening US scan using AI-enabled tools. Methods: A single centre, prospective method comparison study was conducted. Participants had both standard manual and AI-assisted US scans performed independently by different blinded sonographers. The AI-tools automated the acquisition of standard plane images, measurement of fetal biometrics and the production of a written clinical report with saved images available for review. A feedback survey captured the sonographers’ perception of scanning with both methods. Findings: Twenty-three subjects were studied. The average time saving per scan was 7.62 min (34.7%) when using the AI-assisted method (p<0.0001). There was no difference in reporting time. There were no clinically significant differences in biometric measurements between the two methods. The AI-tools saved a satisfactory view in 93% of the cases when considering the four core views only, and 73% for the full 13 views, compared to 98% for both using the manual scan. Survey responses suggest that the AI-tools helped sonographers to concentrate on image interpretation by removing disruptive recording and measurement tasks. Interpretation: Use of AI to automate tasks during the ultrasound examination changes workflow. Separating the process of freehand scanning from image capture and measurement resulted in a faster scan. Removing the need for the sonographer to focus on repetitive tasks may allow more attention to be directed towards identification of atypical fetal anatomy. Further work is required to improve the performance of the image plane detection algorithm for use in real time. In the future, high quality AI-tools could allow the sonographer to increase their focus on anatomical assessment for congenital anomaly detection and provide higher-quality parent-centred care. Trial Registration: This study was performed as part of the intelligent Fetal Imaging and Diagnosis (iFIND) project, NRES number = 14/LO/1806 (ISRCTN = 16542843). Funding: This work was supported by The Wellcome Trust, EPSRC, and NIHR. Declaration of Interests: AG reports consultancy fees from Ultromics Ltd. BK reports consultancy fees from ThinkSono Ltd, Ultromics Ltd. and Cydar Medical Ltd. DR reports consultancy fees from Heartflow, and IXICO, and in addition DR has a patent US20200027237A1 pending. All other authors report no conflict of interests. Ethics Approval Statement: The study has been granted NHS R&D and ethics approval, NRES ref no = 14/LO/1086.

28. Evaluation of three commercially available synthetic bone grafts in a clinically relevant ovine model of instrumented lumbar posterolateral fusion

BACKGROUND CONTEXT Synthetic bone grafts are important tools for spinal surgeons who wish to avoid the invasive harvesting of autologous bone graft for spinal fusions. Various synthetic bone grafts are available on the market, including materials based on bioglass, calcium phosphate or a combination of both. Side-by-side comparisons of synthetic bone grafts in relevant preclinical study models can provide valuable insights that can aid in the selection of treatment options. PURPOSE The current study compared three commercially available synthetic bone grafts as stand-alone grafts in a clinically relevant ovine model of instrumented posterolateral fusion (PLF). STUDY DESIGN/SETTING The three different synthetic bone grafts evaluated are: (1) putty formulation of biphasic calcium phosphate with submicron topography that was previously shown to have equivalent performance to autograft in this model (BCP; MagnetOs Putty, Kuros Biosciences BV), (2) putty formulation of 45S5 bioglass (BG; Novabone Putty, Novabone Products LLC), (3) composite of beta-tri-calcium phosphate, 45S5 bioglass and bovine type I collagen (TCP+BG; Vitoss BA2X Foam pack, Orthovita, Inc). Autograft bone (AB) was used as positive control. Twelve weeks after implantation, the treatments were evaluated. OUTCOME MEASURES Main study end points include fusion assessment by manual palpation, X-ray imaging and micro-CT scans. Range of motion (ROM) of spine levels was assessed in lateral bending (LB) and flexion-extension (FE). Quantification of fusion mass volume was performed using micro-CT. Histology was performed to evaluate bone formation and tissue responses with the different graft materials. METHODS Following ethical approval, 9 sheep underwent instrumented PLF surgery at L2-3 and L4-5 levels. Autograft was harvested from the Os Ilium and distal femur. After decortication of the transverse processes (TPs), 10 cc of each graft material (AB; n=6, BCP; n=6, BG; n=3, TCP+BG; n=3) was implanted bilaterally in the posterolateral regions, bridging the inter-transverse process space. After sacrifice, specimens were assessed by manual palpation, X-ray imaging, Micro-CT and ROM testing at 7.5 Nm after removing instrumentation. Subsequently, treated spine levels were processed for histology in polymethylmethacrylate to visualize bone tissue in the fusion mass. RESULTS Fusion assessment by manual palpation revealed a 6/6 fusion rate for AB and BCP, while for both BG and TCP+BG, a 1/3 fusion rate was determined. Fusion assessment of X-ray and Micro-CT were consistent and determined an either unilateral or bilateral robust bone bridge in 6/6 levels for both AB and BCP, while The BG group exhibited unilateral bridging in 2/3 levels and the TCP+BG group did not include a robust bone bridge in any of the levels. ROM testing revealed equivalent ROMs in LB and FE for AB and BCP, being substantially and significantly lower than those of BG and TCP+BG groups. Fusion mass volume quantification determined fusion mass volumes of 5.7 ± 1.6 cm3 for AB, 9.6 ± 0.4 cm3 for BCP, 3.0 ± 1.1 cm3 for BG and 2.4 ± 1.0 cm3 for TCP+BG. Correspondingly, histology revealed significant graft resorption for BG and TCP+BG groups, while abundant bone tissue in the inter-TP space was observed for AB and BCP. A continuous bony bridge in between TPs was frequently observed in the BCP group on histological sections. CONCLUSIONS Calcium phosphate with submicron topography was the only synthetic bone graft to perform equally well as autograft as a stand-alone graft in this PLF model. Both bioglass-based bone grafts significantly underperformed as compared to autograft and BCP on every single assessment method. The bioglass-based synthetics were observed to undergo significant resorption and were not able to induce bone formation in the soft tissue region in between the TPs. Calcium phosphate with submicron topography may be the better treatment option than bioglass-based bone grafts as a synthetic bone graft substitute. FDA DEVICE/DRUG STATUS MagnetOs Granules (Investigational/Not approved), Novabone Putty (Approved for this indication), Vitoss BA2X (Approved for this indication).

Stationary Blood Particle Aggregates and Vein Valve Shape: A New Classification of Vein Damage

By use of novel high-resolution ultrasound systems, valvular structures and low-flow microaggregates may be depicted today in a more detailed way. The existence of particle aggregations within a valve sinus that are neither sludge nor thrombus, detected by high-resolution ultrasound (American Venous Forum Servier Travel Award 2017), was recently reported. This consecutive study of 180 single-vein valves showing motion-resistant aggregates compares valve structures, cusp motility, and extent of aggregates, resulting in a new approach to vein damage classification. In 100 consecutive patients (68 female, 32 male; 42-64 years old) presenting with unilateral epifascial venous insufficiency, a total of 180 saphenous vein valves with motion-resistant aggregates were selected for closer high-resolution ultrasound analysis (14-16 MHz, peak up to 40 MHz; Vevo MD [SonoSite, Bothell, Wash]). Video recordings (manual three-dimensional scans) were provided for review and analysis by five experienced ultrasound investigators. Six different stages of valve changes could be determined. In stage 1, alteration of sinus hemodynamics (reduction of flushed sinus volume) was present in 102 of 180 cases (56.7%). In stage 2, restriction of cusp function due to aggregates while maintaining valve closure was seen in 64 cases (35.6%). Of 180 cases, 6 (3.3%) showed fixation of cusps (without visible motility) but yet without reflux (stage 3), whereas in 8 cases (4.5%), there was fixation of cusps causing diastolic gap and reflux (stage 4; Fig). Stages 5 and 6 were related to segments with significant reflux (>1000 ms, >10 cm/s), showing valve regression and finally loss of valve structures and aggregates. Permanent blood cell aggregates at the valve sinus seem to indicate successive stages of venous insufficiency, correlating with specific relations of sinus shape and flow. Analysis of valves and aggregates allows a new staging of vein damage and thus a more detailed determination of the individual history of disease with potential impact for early-stage treatment or prevention.

A Streamlined Laboratory Process for Obtaining Band Counts in Hospitalized Neonates

Objective: Band neutrophil counts are helpful for the detection of neonatal sepsis. Our goal was to optimize our laboratory process to detect elevated band neutrophils whenever present, without performing unnecessary manual differential counts. Methods: We retrospectively tracked consecutive complete blood count with differential (CBCD) orders from neonatal intensive care unit (NICU) specimens according to the level of manual review. We identified specimens for which manual differential counts were performed due to telephone request and categorized them according to band percentage. Results: Our laboratory routinely performed manual scans on 96% of NICU specimens, but only 87% of specimens required manual differential counts. Abnormal band counts were present in 5 of 70 specimens for which manual differential counts were requested because of clinically suspected sepsis. We elected to perform universal manual scans on all NICU specimens. Conclusion: The revised laboratory process could be useful for other hospitals treating neonatal patients at risk of sepsis.

A Review of Literature on Access to Primary Health Care

The purpose of this review was to acquaint health care planners, policy-makers and health services researchers with the complexities and dimensions of the concept of access to primary health care as reflected in the international medical literature of the past three decades. The review provides a comprehensive and accessible summary of the numerous definitions and ideas about access, which have been suggested over this time, together with a synthesis of current thinking informed by these past perspectives. Critical Interpretive Synthesis (CIS) methodology was used to review the literature on access. Medline and Australasian Medical Index were searched for English-language articles published between 1970 and August 2005. The results were supplemented by an internet search of the World Wide Web, augmented by manual scans of material from deeper levels within the sites. The process by which the initial list of 665 potential references was reduced to the final list of 48 references was based on manual inspection of both abstracts and full articles using specific prioritisation criteria. Inter-observer agreement for reference selection using these criteria was checked by two investigators and found to be good (Kappa=0.83). Measuring and monitoring access to primary health care is challenging due to the complexity of the concept of access. To address this shortcoming, a single outcome-based measure of access to primary health care is proposed, pointing to a possible way forward for the concept of access as a practical tool with significant application to future health policy.

The Concept and Usefulness of Ambulatory Care Sensitive Conditions as Indicators of Quality and Access to Primary Health Care

The purpose of this review is to introduce health services researchers, especially in the area of primary health care, to the meaning and concept of ambulatory care sensitive conditions (ACSCs). More specifically, this review explores the validity of ACSC admissions as proxy indicators of access to primary health care, provides a description of the factors that cause variations in ACSC admission rates, and presents a discussion of the potential usefulness and policy implications of these indicators for primary health care. Critical Interpretive Synthesis (CIS) methodology was used to review the literature on ACSC admissions indicators. Medline and Australasian Medical Index were searched for English language articles published between 1970 and August 2005. The results were supplemented by an internet search of the World Wide Web, further augmented by manual scans of material from deeper levels within the sites. Main finding from the review indicates that ACSC admissions are valid proxy indicators of access to primary health care. Socioeconomic factors are most important in explaining variations in ACSC admissions. Several uses and policy implications of ACSC admission indicators are discussed, including their potential for identifying gaps in the primary health care system and providing opportunities for targeted public health and health services interventions.

Laboratory Productivity and the Rate of Manual Peripheral Blood Smear Review: A College of American Pathologists Q-Probes Study of 95 141 Complete Blood Count Determinations Performed in 263 Institutions

Automated laboratory hematology analyzers are capable of performing differential counts on peripheral blood smears with greater precision and more accurate detection of distributional and morphologic abnormalities than those performed by manual examinations of blood smears. Manual determinations of blood morphology and leukocyte differential counts are time-consuming, expensive, and may not always be necessary. The frequency with which hematology laboratory workers perform manual screens despite the availability of labor-saving features of automated analyzers is unknown. To determine the normative rates with which manual peripheral blood smears were performed in clinical laboratories, to examine laboratory practices associated with higher or lower manual review rates, and to measure the effects of manual smear review on the efficiency of generating complete blood count (CBC) determinations. From each of 3 traditional shifts per day, participants were asked to select serially, 10 automated CBC specimens, and to indicate whether manual scans and/or reviews with complete differential counts were performed on blood smears prepared from those specimens. Sampling continued until a total of 60 peripheral smears were reviewed manually. For each specimen on which a manual review was performed, participants indicated the patient's age, hemoglobin value, white blood cell count, platelet count, and the primary reason why the manual review was performed. Participants also submitted data concerning their institutions' demographic profiles and their laboratories' staffing, work volume, and practices regarding CBC determinations. The rates of manual reviews and estimations of efficiency in performing CBC determinations were obtained from the data. A total of 263 hospitals and independent laboratories, predominantly located in the United States, participating in the College of American Pathologists Q-Probes Program. There were 95,141 CBC determinations examined in this study; participants reviewed 15,423 (16.2%) peripheral blood smears manually. In the median institution (50th percentile), manual reviews of peripheral smears were performed on 26.7% of specimens. Manual differential count review rates were inversely associated with the magnitude of platelet counts that were required by laboratory policy to trigger smear reviews and with the efficiency of generating CBC reports. Lower manual differential count review rates were associated with laboratory policies that allowed manual reviews solely on the basis of abnormal automated red cell parameters and that precluded performing repeat manual reviews within designated time intervals. The manual scan rate elevated with increased number of hospital beds. In more than one third (35.7%) of the peripheral smears reviewed manually, participants claimed to have learned additional information beyond what was available on automated hematology analyzer printouts alone. By adopting certain laboratory practices, it may be possible to reduce the rates of manual reviews of peripheral blood smears and increase the efficiency of generating CBC results.

Recent literature on government information

The purpose of this column is to provide government information scholars and students with a broad overview of recent publications about government information from the literature of librarianship, archives, information technology management, public policy, and law. Given the volume of literature produced in this field, a columnist cannot claim comprehensive coverage. This column seeks to provide a broad, representative survey of literature that illustrates significant trends in the field. Entries were identified through searches of bibliographic databases such as Library Literature, PAIS International, Ebsco Academic Elite, The Index to Legal Periodicals and Books, Science Direct, Westlaw's JLR database, WorldCat, and from manual scans of journals, newsletters, and Internet sites. Citations are to monographs and serials, journal and periodical articles, books, newsletters, and Internet sites. Coverage for this edition of the column includes items from both 2001 and 2002. Each citation is listed once under its primary topic and annotated if its content cannot be adequately determined from the title. Book reviews and Internet site reviews are generally excluded.

Recent literature on government information

The purpose of this column is to provide government information scholars and students with a broad overview of recent publications about government information from the literature of librarianship, archives, information technology management, public policy and law. Given the volume of literature produced in this field, a columnist cannot claim comprehensive coverage. This column seeks to provide a broad, representative survey of literature that illustrates significant trends in the field. Entries were identified through searches of bibliographic databases such as Library Literature, PAIS International, Ebsco Academic Elite, The Index to Legal Periodicals and Books, Science Direct, Westlaw's JLR database, WorldCat, and from manual scans of journals, newsletters, and Internet sites. Citations are to monographs and serials, journal and periodical articles, books, newsletters, and Internet sites. Coverage for this edition of the column includes items from 2002 and 2003, with a smattering of 2001 items that have come to my attention since the last installment of this column. Each citation is listed once under its primary topic and annotated if its content cannot be adequately determined from the title. Book reviews and Internet site reviews are generally excluded. Contributions and suggestions for the next column may be addressed to the column editor at the address below. Material for this column is grouped into the following categories: Freedom of Information/Secrecy, E-Gov/Technology, Archives/Libraries/History, Government Printing Office, Federal, State/Local, and International.

Elimination of instrument-driven reflex manual differential leukocyte counts. Optimization of manual blood smear review criteria in a high-volume automated hematology laboratory.

Automated peripheral blood leukocyte differential counts (LDCs) are widely accepted in routine practice. However, many laboratories still reflexively perform manual LDCs based solely on abnormal automated results or instrument "flags," before any manual triage step. We describe our transition to a procedure that uses manual methods to validate, rather than to replace, automated LDCs (an approach recommended early in the development of automated methods, but still not used in many clinical laboratories). Manual microscopic scans were performed in lieu of manual LDCs. Each scan that revealed cell types not quantifiable by the instrument triggered a manual LDC. However, if the manual scan simply confirmed the cell types seen on automated LDC, then the automated result was released, even if clinically significant quantitative abnormalities were present. This policy reduced manual LDCs by more than 70% and was validated by a manual retrospective audit. Patient care and laboratory operations can be optimized by using manual microscopic examination as a validation procedure rather than as a reflexive substitute for automated methods. There is no clinical rationale for reflex performance of manual LDCs based solely on instrument warnings.

Elimination of Instrument-Driven Reflex Manual Differential Leukocyte Counts

Automated peripheral blood leukocyte differential counts (LDCs) are widely accepted in routine practice. However, many laboratories still reflexively perform manual LDCs based solely on abnormal automated results or instrument “flags,” before any manual triage step. We describe our transition to a procedure that uses manual methods to validate, rather than to replace, automated LDCs (an approach recommended early in the development of automated methods, but still not used in many clinical laboratories). Manual microscopic scans were performed in lieu of manual LDCs. Each scan that revealed cell types not quantifiable by the instrument triggered a manual LDC. However, if the manual scan simply confirmed the cell types seen on automated LDC, then the automated result was released, even if clinically significant quantitative abnormalities were present. This policy reduced manual LDCs by more than 70% and was validated by a manual retrospective audit. Patient care and laboratory operations can be optimized by using manual microscopic examination as a validation procedure rather than as a reflexive substitute for automated methods. There is no clinical rationale for reflex performance of manual LDCs based solely on instrument warnings.

Non-destructive tests on the HDR pressure vessel

The non-destructive tests conducted within the HDR Safety Program serve the objective to detect and interpret the flaw conditions of the reactor pressure vessel and their changes during load test. The following main tests have been carried out: baseline manual and automatic scans of the entire RPV, inspections of pressure vessel bolts, eddy current scans of the cladding, internal and external inspections of thermal shock induced nozzle corner cracks, real time monitoring of thermal shock tests using the acoustic emission technique. The report gives an overview about the used methods and the main results achieved.

Signal averaging system for ion kinetic energy spectrometry

Ion kinetic energy spectra have been ensemble averaged by interfacing a Hewlett-Packard 2100A computer with a mass-analyzed ion kinetic energy spectrometer (MIKES). Under computer control, the electric sector voltage is scanned repeatedly over a range of up to 30% of the maximum voltage. The data for each scan is automatically averaged and this average may be plotted at any time. A paper tape may also be punched so that the data may be saved for later usage and/or further averaging. The linearity of the scan and reproducibility of the starting position have been tested in detail. The expected increase in signal to noise ratio is observed with no distortion in peak shapes. Kinetic energy release measurements agree with the results obtained by manual scans and an improvement in kinetic energy resolution is noted.

An automatic brain scanner for use with gamma-ray-emitting isotopes.

Two scintillation detectors are simultaneously carried over the surface of a sphere which is concentric with the skull. The collimators for the detectors are arranged so that they accept only those gamma rays which emerge nearly normal to the skull. At present, RISA is being used as the tracer. However, any radioactive element which emits suitable gamma rays and which is preferentially absorbed by the tumor could be used with the scanner. The number of counts received by the two detectors are continually subtracted, so that any asymmetry in the distribution of the tracer is immediately indicated. The difference in count rate from the left and right detector, as well as the total number of counts received from each, are recorded on a circular chart of a size comparable to that of the actual head. By applying this chart directly to the patient's head, the point at which abnormal activity is observed on the chart may be located on the patient. The patient is scanned while supine with his head immobilized in a sling, so designed that it does not interfere with the motion of the detectors. Two points on the record charts are marked to correspond to two points on the head. These points are sufficient for interpretation of the actual position on the patient of any abnormal activity indicated on the chart. While the scan is in progress, the operation of the machine is completely automatic. The procedure, including time for setting up the patient, takes about forty minutes. Suitable scans are obtained with a dose of 250 microcuries of RISA. Scans are taken twenty-four hours after injection of the radioactive tracer. While the device uses the same principle as is employed in manual scans with one detector, it incorporates all the features of an automatic scanning system. The scans are reproducible, since the angles of the detectors with respect to the patient are identical for each scan. The scanner is operating in the Saskatoon Cancer Clinic and a second unit is being constructed for use in the Ontario Cancer Institute. Tests are being carried out on phantom models to establish the limits of the technic from a purely physical point of view. A complete description of the apparatus is being published elsewhere.