Is hybrid SPECT/CT necessary for

pre-interventional 3D quantification of relative lobar lung function?

Daniela Knollmann et al.

Abstract

In pulmonary malignancies pre-interventional 3D estimation of relative lobar perfusion is established to predict post-interventional functional outcome particularly in patients with borderline lung function. Aim was to test whether quantification from SPECT-scanners (non-hybrid) is as accurate as from SPECT/CT-scanners (hybrid) when using dedicated software.

Methods
Sixty-one patients suffering from pulmonary tumours underwent lung SPECT/CT using Tc-99m MAA to predict postoperative residual lung function prior to surgical treatment. Quantification was done using “HERMES Hybrid 3D–Lung Lobe Quantification”. In the hybrid approach SPECT and combined lowdoseCT/diagnosticCT were used. In the non-hybrid approach SPECT and diagnosticCTs were used, lowdoseCTs were omitted. Bland Altman analysis was done to test for agreement.

Results
Three hundred five lobes were quantified. Evaluation time was 6:37 ± 0.55 min (hybrid) versus 6:34 ± 0.51 min (non-hybrid). Mean lobar value was 20.0 ± 10.5% (range from 0 to 55%) for hybrid and 20.0 ± 10.6% (range from 0 to 58%) for the non-hybrid approach, mean absolute difference was 1.31%, no significant differences were found when analysing all values (p > 0.9). Correlation was excellent (R = 0.984, slope of the regression line 1.001 (p < 0.0001)). Intraclass correlation coefficient was 0.9843. Bland Altman limits were -3.67% and 3.67%.

Conclusion
Excellent concordance was found for 3D-quantification of relative lung perfusion when comparing a hybrid vs. non-hybrid approach. Using sophisticated software combining the generally available diagnosticCT and conventional SPECT-data reliable results for lobar perfusion can be obtained without the need for costly investment of SPECT/CT systems for this clinical question.

 

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Z-score maps from low-dose ¹⁸F-FDG PET

of the brain in neurodegenerative dementia

Fällmar D. et al.

Z-score maps from low-dose ¹⁸F-FDG PET of the brain in neurodegenerative dementia

Neuroimaging is a central part of diagnostic work-up of patients with suspected neurodegenerative disease. FDG-PET can reveal pathological changes earlier and more reliably than morphological imaging. Diagnostic accuracy can be improved by constructing 3D SSP Z-score maps, showing patterns of significant deficits. During FDG-PET, the subject receives a moderate but not insignificant dose of ionizing radiation, and a dose reduction with retained image quality is desirable. With lower dose, repeated examinations can become a useful tool for monitoring disease progress and potential effects of disease-modifying interventions.

The aim of this study was to evaluate Z-maps created from low-dose and normal-dose FDG-PET of the brain, with quantitative and qualitative methods. Nine patients with neurodegenerative disorders were prospectively enrolled and nine age-matched controls were recruited through advertising. All subjects (n=18) underwent two FDG-PET scans on separate occasions; a routine and a low-dose scan. The routine dosage of FDG was 3 MBq/kg, and low dosage was 0.75 MBq/kg. 3D-SSP images showing Z-scores of < -1.96 were created from 10-minute summations.

The study was comprised of a quantitative part comparing the Z-scores, and a qualitative part where experienced nuclear medicine specialists visually assessed the images. Regarding the quantitative part, Bland-Altman analysis showed a slight constant bias (0.206). Regarding qualitative discrimination between patients and controls, the performance between normal- and low-dose were equal, both showing 72% sensitivity, 83% specificity and 78% accuracy. In this study, visual assessment of 3D-SSP Z-score maps from low-dose FDG-PET provided diagnostic information highly comparable to normal-dose, with minor quantitative discrepancies.

 

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Selective Internal Radiation Therapy

Targeting for Better Care

François Hébert, m.i.t.

Selective Internal Radiation Therapy: Targeting for Better Care

Although cancer is likely to affect all parts of the body, it may be more difficult to treat depending on its location. This is particularly the case of unresectable cancers, i.e. cancers that cannot be completely removed by surgery. Liver cancer fits this profile. In addition, this organ has the disadvantage of being particularly sensitive to the radiation of external radiotherapy, so that the dose that can be administered is limited. But a technique, currently used as a last resort, may well change the situation: selective internal radiotherapy, also known as radioembolization. The principle is that of radiotherapy and its ionizing radiation (radioactive) to treat the patient. The peculiarity of this treatment is that the ionizing rays are delivered from the inside. The huge advantage is of course that they specifically attack the cancer cells, thus sparing the surrounding normal cells as much as possible and resulting, of course, in much less side effects.

Microspheres to the Rescue 
The treatment involves administering microspheres filled with radioactive material into the arteries that supply the tumor. The intervention is done in interventional radiology by placing a catheter in the femoral artery and guiding it to the arterial vessels. These microspheres are made of glass or resin and are thinner than a hair. They play two important roles: they allow high-energy radiation to be deposited locally without irradiating healthy cells and, because of their size, they agglomerate in the blood vessels that supply the tumor, thus depleting its blood supply. For each patient the dose to be injected is determined according to tumoral and normal liver volumes. Once calibration is done, it should be ensured that the microspheres travel safely. There are indeed natural links between different parts of the human body, and there may be a leak. In that case it is necessary to evaluate the liver-lung shunt, i.e. the quantity of radioactivity which would pass in the lungs instead of going towards the liver. Up to 10% is tolerated.

The last step is to determine if the treatment has worked. "The quantification of the dose to be administered is extremely important, especially for this treatment, says Dr. François Lamoureux, Associate Professor of Clinical Medicine in Nuclear Medicine at the Faculty of Medicine of the University of Montreal and president elect of the Canadian association of nuclear medicine. It is also necessary to be able to evaluate the doses of radiation actually transmitted on the site of the tumor as well as in the surrounding tissues". Using imaging techniques, specialists can estimate whether the treatment is working or not, that is, they can determine whether the proposed amount of radioactivity has a positive effect in attacking the tumor or whether they should reevaluate the procedure.

If several companies offer analysis and/or follow-up at key moments of the treatment, Hermes Medical Solutions is the only company currently to offer imaging follow-ups along the entire chain of work: before, to plan the dose to administer, during, to follow the evolution of the microspheres, and after, to evaluate the effect of the radioactivity on the tumor. Selective internal radiotherapy is still considered a "rescue" technique, but it could be one of the most promising avenues to treat cancer and become a first-line treatment.

Spatial Normalization of [¹⁸F]Flutemetamol Pet Images

utilizing an adaptive principal components template

Johan Lilja et al.

Abstract

Though currently approved for visual assessment only, there is evidence to suggest that quantification of amyloid-β (Aβ) PET images may reduce inter-reader variability and aid in the monitoring of treatment effects in clinical trials. Quantification typically involves a regional atlas in standard space, requiring PET images to be spatially normalized. Different uptake patterns in Aβ-positive and Aβ-negative subjects, however, makes spatial normalization challenging. In this study we propose a method to spatially normalize [¹⁸F]flutemetamol images, using a synthetic template based on principal component images to overcome these challenges.

Methods
[¹⁸F]flutemetamol PET and corresponding MR images from a phase II trial (n = 70), including subjects ranging from Aβ-negative to Aβ-positive, were spatially normalized to standard space using an MR driven registration method (SPM12). [¹⁸F]flutemetamol images were then intensity normalized using the pons as reference region. Principal component images were calculated from the intensity normalized images. A linear combination of the first two principal component images was then used to model a synthetic template, spanning the whole range from Aβ-negative to Aβ-positive. The synthetic template was then incorporated in our registration method, where the optimal template was calculated as part of the registration process, providing a PET only driven registration method. Evaluation of the method was done in two steps. First, co-registered gray matter masks generated using SPM12 were spatially normalized using the PET and MR driven methods, respectively. The spatially normalized gray matter masks were then visually inspected and quantified. Secondly, to quantitatively compare the two registration methods, additional data from an ongoing study were spatially normalized using both methods with correlation analysis on the resulting cortical SUVR values.

Results
All scans were successfully spatially normalized using the proposed method, with no manual adjustments performed. Both visual and quantitative comparison between the PET and MR driven methods showed high agreement in cortical regions. [¹⁸F]flutemetamol quantification showed strong agreement between the SUVR values for the PET and MR driven methods (R2=0.996; pons reference region).

Conclusion
The principal component template registration method allows for robust and accurate registration of [¹⁸F]flutemetamol images to a standardized template space, without the need for an MR image.

 

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Theranostics Against Cancer

A Personalized Medicine... Well Dosed

Benoit Galarneau Eng., M.Sc.A., MBA

Cancer is the insatiable evil of the century. According to the World Health Organization, it caused 8.8 million deaths in 2015. Nearly one in six deaths worldwide is due to this disease. Even worse, the number of new cases is expected to increase by about 70% over the next two decades. Doctors, researchers and scientists are multiplying their efforts and competing ingeniously to try to overcome it, or at least refine the means of detecting, diagnosing and treating it.

The new weapon against cancer is called theranostics, a contraction of the words "therapy" and "diagnostic". "It's the one-word expression of the combined activity and the same continuum of a diagnostic and therapeutic process for a patient," says Dr. François Lamoureux, Associate Professor of Clinical Medicine in Nuclear Medicine at the Faculty of Medicine, University of Montreal and President of the l’Association des médecins spécialistes en médecine nucléaire du Québec (Quebec Association of Medical Specialists in Nuclear Medicine).

The objective of the technique is to study the behavior of a tumor closely in order to choose the most appropriate treatment. It is therefore a question of mapping the cancer cells (thanks to functional imaging) and then targeting them with a localized treatment.

How Does it Work?
On their surface, cancer cells present various physiological targets, such as receptors, enzymes or proteins. The theranostic approach consists in targeting them specifically by targeting molecules (specific ligands) labeled with radioactive elements. These are intended for diagnosis, they emit radiation that can be visualized by imaging, or in therapy, it is to directly irradiate the tumor with a powerful radionuclide. Typically, it would be to use, for example, a tracer labeled with gallium 68 for diagnosis and then a therapeutic radionuclide such as lutetium 177.

Here we are in the long-awaited era of personalized medicine. "With the theranostic approach in cancer, one can more judiciously choose not only for a very specific patient the most suitable treatment – both at the level of molecules and doses –, but also apply innovative treatments", details the specialist. And since each treatment is specifically chosen for each patient, it avoids the mass treatments that could prove to be little or not effective.

The Right Dose
In addition to offering a personalized medicine, it must be ensured that it is as well dosed... And it is even more indispensable when using radioactive elements. While radioactivity offers patients significant benefits, it is important to avoid its deleterious consequences. For that, one must know the cumulative dose of radiation that is being received or has been received by a patient: their dosimetry.

In this connection, the European Atomic Energy Community (EAEC or Euratom) has legislated on exposure to ionizing radiation. Thus, Directive 2013/59/Euratom of December 5, 2013 is laying down basic safety standards for protection against the dangers from exposure to ionizing radiation for patients and professionals. In other words, when a doctor chooses a theranostic approach, he will have to calculate the adequate dose of radioactive elements that the patient will receive to minimize its adverse effects and focus on the cells to be eradicated.

Now it’s North America's turn to legislate to make this personalized medicine more precise.

Implementation of GPU Accelerated Spect Reconstruction

with Monte Carlo-based scatter correction

Tobias Bexelius, Antti Sohlberg

Abstract

Objective
Statistical SPECT reconstruction can be very time-consuming especially when compensations for collimator and detector response, attenuation, and scatter are included in the reconstruction. This work proposes an accelerated SPECT reconstruction algorithm based on graphics processing unit (GPU) processing.

Methods
Ordered subset expectation maximization (OSEM) algorithm with CT-based attenuation modelling, depth-dependent Gaussian convolution-based collimator-detector response modelling, and Monte Carlo-based scatter compensation was implemented using OpenCL. The OpenCL implementation was compared against the existing multi-threaded OSEM implementation running on a central processing unit (CPU) in terms of scatter-to-primary ratios, standardized uptake values (SUVs), and processing speed using mathematical phantoms and clinical multi-bed bone SPECT/CT studies.

Results
The difference in scatter-to-primary ratios, visual appearance, and SUVs between GPU and CPU implementations was minor. On the other hand, at its best, the GPU implementation was noticed to be 24 times faster than the multi-threaded CPU version on a normal 128 × 128 matrix size 3 bed bone SPECT/CT data set when compensations for collimator and detector response, attenuation, and scatter were included.

Conclusions
GPU SPECT reconstructions show great promise as an every day clinical reconstruction tool.

 

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Dynamic 99mTc-Mebrofenin Hepatobiliary Scintigraphy (HBS) and SPECT/CT

at Sant’Orsola-Malpighi Hospital

Matteo Serenari MD*, Chiara Bonatti MD*, Cinzia Pettinato MD§
*Department of Medical and Surgical Sciences – DIMEC, S.Orsola – Malpighi Hospital, Alma
Mater Studiorum, University of Bologna
§Medical Physics Unit, Radiology Unit, S Orsola-Malpighi Hospital, Bologna, Italy

We recently started to use dynamic 99mTc-mebrofenin hepatobiliary scintigraphy (HBS) combined with Single Photon Emission Computed Tomography/ Computed Tomography (SPECT/CT) in the preoperative evaluation of patients candidate for major hepatic resection. The leading center in Europe in the application of hepatobiliary scintigraphy with SPECT is the Academic Medical Center (Amsterdam The Netherlands), where hepatobiliary scintigraphy data are routinely analyzed by an experienced nuclear medicine physician (R. J. Bennink) using a Hermes workstation (Hermes Medical Solutions, Stockholm, Sweden)1. According to AMC standardized protocol2, between November 2016 and November 2017, 99mTc-mebrofenin HBS combined with SPECT/CT were preoperatively performed in 27 patients who underwent a major hepatectomy at S.Orsola-Malpighi Hospital. HBS was performed with 99mTc-labeled (2,4,6 trimethyl-3-bromo) iminodiacetic acid (99mTc-mebrofenin, Bridatec, GE Healthcare) at the Nuclear Medicine Unit.

Patients were acquired in supine position with a large-field-of-view (FOV) SPECT/CT camera (Discovery NM/CT 670 ES, GE) covering the liver and the heart region. The SPECT/CT camera was equipped with low-energy high-resolution collimators. First, a dual-head dynamic acquisition (36 frames of 10 s/frame,128 matrix), was obtained immediately after the intravenous administration of approximately 200 MBq freshly prepared 99mTc-mebrofenin, which was used for the calculation of the hepatic mebrofenin uptake rate (TL-F). Subsequently, a fast SPECT acquisition was performed (60 projections of 5s/projection, 128 matrix), approximately centered on the peak of the hepatic time-activity curve, which was used to calculate the 3-dimensional distribution of function within the future liver remnant (FLR-C). Directly after SPECT, a low-dose, non-contrast-enhanced CT scan was acquired for attenuation correction and anatomic mapping.

Hepatic mebrofenin uptake rate was calculated using a standard software package. Three region of interest (ROI) were drawn manually on the dynamic images around the heart/large vessels, the total liver and the total field of view (FOV). These 3 ROI datasets were saved to make sure that identical ROIs were used for every frame of acquisition of the gmean dataset provided by our Workstation Xeleris GE. Three different time–activity curves were generated. Total liver function was expressed as percent per minute per square meter (%/min/m2). Afterwards, volumes of interest (VOI) were manually outlined to calculate total liver and future liver remnant (FLR-C) counts. The FLR was delineated on every transversal frame of the SPECT image. Future liver remnant function (FRL-F) was then calculated, as previously described3. We did not use any masking volume for the bile ducts. This procedure took approximately 20 minutes for each patient.

Hermes Gold3 Processing
Hermes Hybrid Viewer NM processing on TeleHERMES ™ (by Hermes Medical Solutions) was provided to us from Hermes company after our first cases of HBS, since we were looking for a software able to do all the measurements in a shorter time and also to make our results as much as possible comparable with those calculated by the Academic Medical Center. R.J. Bennink helped us to contact Hermes.

After a very clear demonstration via Skype (manual of instructions is also provided inside the TeleHERMES Green USB access tool), installation of the program encountered some difficulties due to the firewall settings but logining in as administrator was able to fix this initial problem. The upload of DICOM files was really intuitive and easy. Gmean dataset provided by own workstation or anterior and posterior datasets separately, could be both uploaded. Of note, there was a little difference between these two gmean datasets, with lower values if anterior and posterior projections were uploaded separately. After that the manual delineation of the liver and blood pool ROI was completed, TL-F was immediately calculated by the software. Thereafter, FRL was manually delineated on a single frame of the low-dose, non-contrast-enhanced CT scan linked to the SPECT images. Then, the outlined constraint was applied automatically to every frame of acquisition. This did not allow us to modify the transection plane as radiologists do when they perform hepatic volumetry. More importantly, the CT scans from other study in particular contrast enhanced scans, could not be uploaded to delineate more anatomically the remnant liver VOI. Future research will focus on showing whether a totally manual or semi-automatic method to delineate VOIs is comparable with this automatically but less time-consuming method. The masking volume for the bile ducts was applied only in 3 patients but in the other cases we were not able to solve this problem. However, difference with and without masking volume seemed not too big in terms of %FLR-C. In median, calculations of liver function parameters for each patient with TeleHERMES Green USB took 3 minutes.

In conclusion, standardization of the technique and use of a shared imaging software as Hermes Hybrid Viewer NM processing on TeleHERMES™ seems in our opinion of utmost importance to enable comparisons among different centers.

 

References

1. Bennink RJ, Dinant S, Erdogan D, et al. Preoperative assessment of postoperative remnant liver function using hepatobiliary scintigraphy. J Nucl Med; 2004;45:965-71.
2. De Graaf W, Van Lienden KP, Van Gulik TM, et al. 99m Tc-Mebrofenin Hepatobiliary Scintigraphy with SPECT for the Assessment of Hepatic Function and Liver Functional Volume Before Partial Hepatectomy. J Nucl Med; 2010;51:229–236.
3. Dinant S, de Graaf W, Verwer BJ, et al. Risk Assessment of Posthepatectomy Liver Failure Using Hepatobiliary Scintigraphy and CT Volumetry. J Nucl Med; 2007;48:685–692.

Phantom and Clinical Evaluation of the Effect of Full Monte Carlo Collimator Modelling

in post-SIRT yttrium-90 Bremsstrahlung SPECT imaging

Charlotte A. Porter et al.

Abstract

Background
Post-therapy SPECT/CT imaging of ⁹⁰Y microspheres delivered to hepatic malignancies is difficult, owing to the continuous, high-energy Bremsstrahlung spectrum emitted by ⁹⁰Y. This study aimed to evaluate the utility of a commercially available software package (HybridRecon, Hermes Medical Solutions AB) which incorporates full Monte Carlo collimator modelling. Analysis of image quality was performed on both phantom and clinical images in order to ultimately provide a recommendation of an optimum reconstruction for post-therapy ⁹⁰Y microsphere SPECT/CT imaging.

A 3D-printed anthropomorphic liver phantom was filled with ⁹⁰Y with a sphere-to-background ratio of 4:1 and imaged on a GE Discovery 670 SPECT/CT camera. Datasets were reconstructed using ordered-subsets expectation maximization (OSEM) 1–7 iterations in order to identify the optimal OSEM reconstruction (5 iterations, 15 subsets). Quantitative analysis was subsequently carried out on phantom datasets obtained using four reconstruction algorithms: the default OSEM protocol (2 iterations, 10 subsets) and the optimised OSEM protocol, both with and without full Monte Carlo collimator modelling. The quantitative metrics contrast recovery (CR) and background variability (BV) were calculated.

The four algorithms were then used to retrospectively reconstruct 10 selective internal radiation therapy (SIRT) patient datasets which were subsequently blind scored for image quality by a consultant radiologist.

Results
The optimised OSEM reconstruction (5 iterations, 15 subsets with full MC collimator modelling) increased the CR by 42% (p < 0.001) compared to the default OSEM protocol (2 iterations, 10 subsets). The use of full Monte Carlo collimator modelling was shown to further improve CR by 14% (30 mm sphere, CR = 90%, p < 0.05).

The consultant radiologist had a significant preference for the optimised OSEM over the default OSEM protocol (p < 0.001), with the optimised OSEM being the favoured reconstruction in every one of the 10 clinical cases presented.

Conclusions
OSEM (5 iterations, 15 subsets) with full Monte Carlo collimator modelling is quantitatively the optimal image reconstruction for post-SIRT ⁹⁰Y Bremsstrahlung SPECT/CT imaging. The use of full Monte Carlo collimator modelling for correction of image-degrading effects significantly increases contrast recovery without degrading clinical image quality.

Keywords
Quantitative SPECT - Yttrium-90 Bremsstrahlung - Image reconstruction - Monte Carlo scatter correction

 

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Hermes in an Evolving Multi-Site Organization

The Ottawa Hospital Experience

By Ran Klein, PhD and Lionel S. Zuckier, MD

Department of Nuclear Medicine, The Ottawa Hospital

The Ottawa Hospital (TOH) has one of the largest nuclear medicine departments in Canada with 8 attending physicians, over twenty technologists, a dozen cameras and 14,000 nuclear imaging exams performed annually (in addition to 9,000 bone mineral density studies). TOH is the product of the amalgamation of three regional hospitals, with the Department of Nuclear Medicine spanning two geographical sites. The University of Ottawa Heart Institute (UOHI) nuclear cardiology group maintains close relations with TOH and performs an addition 6,000 cardiac scans annually. Through its academic affiliations, the Department has an active teaching portfolio that draws domestic and international medical students, residents, fellows, sabbatical researchers, graduate students and technologist students.

 

TOH Nuclear Medicine by the numbers
Equipment
PET-CT (GE)	1
SPECT-CT (Siemens)	3
SPECT (Siemens, Philips)	5
Gamma only (Mediso)	3
Staff
Physicians	8
Technologists	26
Physicists	1
Procedures per Year
FDG PET	2,400
Bone scintigraphy	3,700
Cardiovascular	2,200
Gastrointestinal	1,600
Lung ventilation-perfusion	900
Renal function	500

 

Hermes is the primary image storage and analysis system within the Department of Nuclear Medicine and has served the department’s needs and challenges since 1995 – the first installation in Canada. The current iteration of our Hermes network consists of a single image archive server for both sites, aggregating imaging data from all imaging modalities. It interfaces our hospital wide HIS, RIS and PACS systems, the Hermes network at UOHI, and several other diagnostic and research systems. Eleven dedicated workstations are utilized by our physicians and researchers. Hermes systems have continued to evolve over time, delivering improved services and efficiencies:

Standardization
In the past, data were processed and analyzed using proprietary software on the vendor workstation. Hermes offers vendor-neutral analysis solutions that have enabled us to gradually shift image processing and analysis tasks away from the vendor environment to the Hermes system. In our current practice all image acquisition data is sent to Hermes for archiving, SPECT reconstruction, visualization and analysis. This operational change has enhanced standardization regardless of the specific data acquisition device, has harmonization procedures and nomenclature between our sites and users, and has enabled us to apply state-of-the-art technologies across all modalities with a single system update.

Today we perform almost all SPECT image reconstruction with Hermes HybridRecon using iterative methods that include attenuation, scatter and resolution corrections, enabling state-of-the-art SPECT reconstruction on all our devices without the need to purchase individual licenses for each camera. We have leveraged these technologies to reduce our injected activities while maintaining diagnostic image quality - even with older imaging equipment. Interestingly, for research purposes, we have been able to retrieve previously acquired SPECT data and reprocess it using the most-current Hermes reconstruction algorithms. After an extensive, independent evaluation of HybridRecon quantitative SPECT, we have adopted its routine use for all SPECT-CT studies, enabling us to measure standard-uptake-values (SUV) with almost any radiopharmaceutical, which has enabled novel research even in long established clinical exams.

Our physicians and technologists utilize Hermes HybridViewer with predefined, application-specific protocols for most image analysis and visualization. Because system configuration is centralized across the Hermes network, technologists and physicians use the exact same tools throughout the Department, mitigating inconsistencies and the need to maintain duplicate tools. Furthermore, configuration changes can be deployed across the entire Hermes networks simultaneously with minimal maintenance overhead.

TOH has capitalized on Hermes’ promise to provide vendor-neutral data storage and processing to eliminate the needs for duplicate software for each camera installation. This approach has dramatically reduced capital expenditures associated with acquiring these software, while enhancing standardization of processing across the department to the benefit of simplifying teaching and maintenance of a single set of tools.

Virtualization of Services
Through a substantial system update in 2014, dedicated Hermes workstations in each camera control room were replaced by a single application server providing access to all Hermes services via thin client on standard enterprise hospital computers. This virtualization produced substantial cost savings, reduced the number of computer systems requiring maintenance, and freed up valuable physical space, by eliminating the need for an additional task-specific computer system at each workstation. Since the application server is accessible from anywhere on the TOH computer network, it has been further leveraged by our clinicians and physicist for remote access and for presentation of clinical cases at board rounds within the full-featured clinical environment.

Tailored Solutions
Throughout our 20+ year relationship with Hermes, their team of technical experts and application specialists have enabled tailored solutions to our evolving needs in a timely manner. Over the past year alone, their support team have delivered custom clinical solutions including quantitative count-rate based image display, modified gastric emptying protocols for oatmeal studies and a semi-automated quantification protocol for right-to-left shunt studies. Using built-in, powerful and simple to use scripting features, we have tailored numerous other protocols to suite our needs. Collectively we have developed predefined protocols for commonly performed exams which standardize display and automate analysis of complex procedures. These efforts have dramatically reduced variability between operators, reduced human errors, increased clinician confidence, and enabled development of more complex analyses.

Automation & Integration
Hermes has been a collaborative partner in streamlining our workflow by continually improving automation and integration with other clinical and research systems. In 2016 we were the first Hermes site to integrate between our Hermes and radiology PACS system (McKesson), which in turn is linked to our voice-recognition dictation system (PowerScribe). Through this integration, patient selection by the interpreting physician is synchronized across all three systems with the click of the mouse, reducing repetitive work, increasing efficiency, and mitigating patient selection errors. Our physicians now regard this feature as a key desirable-attribute for other clinical systems.

Integration with well-established third-part vendors is expected in the field, but Hermes systems have enabled us to easily integrate proprietary tools for research and clinical use through simple scripting and standardized, vendor-neutral, image data formatting. At UOHI, for example, we were able to seamlessly integrate our quantitative myocardial flow reserve software (FlowQuant^TM) into our clinical routine enabling our technologists to process cardiac PET studies from their Hermes workstation to produce graphical quantitative flow reserve reports that are automatically appended to the Hermes database. Consequently, we were able to transition our research technology into routine clinical use and to increase our research samples sizes from dozens of patients to thousands.

A look to the future
Hermes has empowered Nuclear Medicine in Ottawa for over two decades. With its current research and development efforts in the realms of multi-modality image visualization, machine learning and artificial intelligence Hermes holds promise to further propel molecular imaging. Thus, at TOH we remain confident that Hermes, as a clinical solutions provider, is well positioned to meet our evolving needs well into the future.

Disclaimer
Ran Klein and Lionel Zuckier have collaborative research agreements with Hermes Medical Solutions which include in-kind financial support.