True TOF technology

True TOF technology
Set the standard in PET/CT

This year marks 25 years of Biograph leading the way as the first commercial medical imaging device to combine PET and CT.

With the advent of fast scintillator detectors with lutetium oxyorthosilicate (LSO) crystals, true time of flight (TOF) became a realistic innovation for the clinical setting.��

Intensified research since the 2000s focusing on true TOF PET/CT systems has shown numerous advantages that LSO-based TOF brings, such as better definition of small lesions, improved uniformity, reduced noise, and sensitivity gain.

Scientific presentation

Timing is of the essence: ��Unlocking the potential of PET/CT with time of flight, presented by Dr. Ian Armstrong.

Time of flight and PET/CT

Explore the future of TOF in PET/CT imaging with the experts as they explore the benefits of using TOF available across all Biograph PET/CT systems.

Ask the experts

Watch a series of interviews from key industry experts.

Features & Benefits

Optimized performance and clinical advantages

The ability to offer true TOF depends on the timing response of the detector. Biograph™��PET/CT scanners’ fast LSO crystals and optimized electronics are designed to convert the analog signal from the crystals into a digital signal that allows measurement of the TOF resolution.��

True TOF enables improved signal-to-noise ratio—faster scans, lower injected dose, and better image quality.¹��
TOF gain amplifies¹ scanner sensitivity for faster scans and lower doses.��
True TOF creates segments in the line-of-response, significantly increasing the accuracy of locating the annihilation event.

PET/CT SiPM technology

All Biograph PET/CT scanners are TOF-capable, empowering lower doses and faster scan times. By measuring the difference between the detection of each coincidence photon, they can better determine the event location along the line-of-response. This makes small segments of response—increasing the accuracy of locating the annihilation event.��

With the development of silicon photomultiplier (SiPM) detectors, PET/CT systems are now able to deliver faster TOF performance, which further reduces the segments of response, helps to better localize each event, and decreases noise within the reconstructed image.

Clinical Use

Data courtesy of University Hospital Erlangen, Erlangen, Germany

True time of flight (TOF) enables high contrast to help facilitate precise staging in prostate cancer with PSMA

High contrast within primary prostate lesion reflects TOF performance
Sharp definition of small pelvic lymph node lesions confirm advanced-stage disease
Both point spread function (PSF) and TOF provide individual advantages to image reconstruction; however, the combination of the two (ultraHD•PET) provides additional value, particularly in this case

Biograph™ mCT PET/CT
PET
Scan acquisition: ��200 x 200 matrix, PSF+TOF 2i21s
200 x 200 matrix, PSF 2i12s
TrueV
Scan time: ��3 minutes per bed
Injected dose: 68Ga-labelled PSMA ligand^[b]
3.1 mCi (116 MBq)

CT
Scan parameters: ��100 kV/92 ref mAs

Data courtesy of Manchester University NHS Foundation Trust, Manchester, United Kingdom.

True time of flight (TOF) improves definition and contrast for cardiac imaging with ⁸²Rb

Sharper definition of myocardial edge in left ventricle with TOF��
Higher iteration reconstruction along with higher contrast for improved LV dimension definition and ischemia assessment��
65-yr-old male��
182 cm (5’ 9”)��
81 kg (179 lb)��
26.4 BMI

Biograph Vision™ PET/CT
PET
Scan acquisition: ��220 x 220 matrix, PSF+TOF 4i5s Gaussian 6
Scan time: ��1 bed position / 5 min per bed
5 min total scan time
Injected dose: Rubidium 82 (⁸²Rb)
Stress 20 mCi (740 MBq)

CT
Scan parameters:��120 kV/7 ref mAs

Data courtesy of Research Institute for Brain and Blood Vessels-Akita, Akita, Japan.

True time of flight (TOF) performance improves definition and contrast

High contrast and sharp definition of supraclavicular lung mediastinal and liver metastases with TOF, reflect potential for improved small lesion detectability

Biograph Vision��PET/CT
PET
Scan acquisition: ��13.48 minutes
Image reconstruction: ��440 x 440 matrix, OSEM+PSF 3i5s
440 x 440 matrix, PSF+TOF 3i5s
All-pass filter
Injected dose: Fludeoxyglucose F 18 (¹⁸F FDG) Injection^[a]
5.5 mCi (204 MBq)

Data courtesy of Osaka City University Hospital, Osaka, Japan.

True time of flight (TOF) images displays high cortical and basal ganglia contrast of high-resolution brain PET

Normal brain reconstructed at highest matrix with and without TOF and point spread function (PSF)��
TOF and PSF combination shows high cortical and basal ganglial signal intensity, sharp edge definition, and grey-white matter interface��
TOF with PSF combination resulting in ultraHD•PET shows low noise level, reflecting high TOF capability and impact of PSF

Biograph Vision��PET/CT
PET
Scan acquisition: ��1 bed position/10 minutes
Image reconstruction: ��880 x 880 matrix, PSF 8i5s
880 x 880 matrix, PSF+TOF 8i5s
All-pass filter
Injected dose: Fludeoxyglucose F 18 (¹⁸F FDG) Injection^[a]
4.2 mCi (157 MBq)

CT
Scan parameters: ��120 kV/232 ref mAs

Data courtesy of University Hospital Erlangen, Erlangen, Germany

True time of flight (TOF) enables high contrast to help facilitate precise staging in prostate cancer with PSMA

High contrast within primary prostate lesion reflects TOF performance
Sharp definition of small pelvic lymph node lesions confirm advanced-stage disease
Both point spread function (PSF) and TOF provide individual advantages to image reconstruction; however, the combination of the two (ultraHD•PET) provides additional value, particularly in this case

CT
Scan parameters: ��100 kV/92 ref mAs

Data courtesy of Manchester University NHS Foundation Trust, Manchester, United Kingdom.

True time of flight (TOF) improves definition and contrast for cardiac imaging with ⁸²Rb

Sharper definition of myocardial edge in left ventricle with TOF��
Higher iteration reconstruction along with higher contrast for improved LV dimension definition and ischemia assessment��
65-yr-old male��
182 cm (5’ 9”)��
81 kg (179 lb)��
26.4 BMI

Biograph Vision™ PET/CT
PET
Scan acquisition: ��220 x 220 matrix, PSF+TOF 4i5s Gaussian 6
Scan time: ��1 bed position / 5 min per bed
5 min total scan time
Injected dose: Rubidium 82 (⁸²Rb)
Stress 20 mCi (740 MBq)

CT
Scan parameters:��120 kV/7 ref mAs

Data courtesy of Research Institute for Brain and Blood Vessels-Akita, Akita, Japan.

True time of flight (TOF) performance improves definition and contrast

High contrast and sharp definition of supraclavicular lung mediastinal and liver metastases with TOF, reflect potential for improved small lesion detectability

Data courtesy of Osaka City University Hospital, Osaka, Japan.

True time of flight (TOF) images displays high cortical and basal ganglia contrast of high-resolution brain PET

Normal brain reconstructed at highest matrix with and without TOF and point spread function (PSF)��
TOF and PSF combination shows high cortical and basal ganglial signal intensity, sharp edge definition, and grey-white matter interface��
TOF with PSF combination resulting in ultraHD•PET shows low noise level, reflecting high TOF capability and impact of PSF

CT
Scan parameters: ��120 kV/232 ref mAs

Data courtesy of University Hospital Erlangen, Erlangen, Germany

True time of flight (TOF) enables high contrast to help facilitate precise staging in prostate cancer with PSMA

High contrast within primary prostate lesion reflects TOF performance
Sharp definition of small pelvic lymph node lesions confirm advanced-stage disease
Both point spread function (PSF) and TOF provide individual advantages to image reconstruction; however, the combination of the two (ultraHD•PET) provides additional value, particularly in this case

CT
Scan parameters: ��100 kV/92 ref mAs

The outcomes achieved by the Siemens Healthineers customers described herein were achieved in the customer’s unique setting. Since there is no “typical” hospital and many variables exist (eg, hospital size, case mix, level of IT adoption) there can be no guarantee that others will achieve the same results.

[a]

See below for Indications and Important Safety Information for Fludeoxyglucose F 18 (¹⁸F FDG) Injection.

[b]

The tracer used in this case is a research pharmaceutical. It is neither recognized to be safe and effective by the FDA nor commercially available in the United States or in other countries worldwide. Its future availability cannot be guaranteed. Please contact your local Siemens Healthineers organization for further details.

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Based on internal measurements at time of publication. Data on file.

The features herein are not commercially available in all countries. Its future availability cannot be guaranteed. Please contact your local Siemens Healthineers organization for further details.

Biograph Vision is not commercially available in all countries. Its future availability cannot be guaranteed. Please contact your local Siemens Healthineers organization for further details.

Header image data courtesy of Manchester University NHS Foundation Trust, Manchester, United Kingdom.

The statements by Siemens Healthineers customers described herein are based on results that were achieved in the customer's unique setting. Because there is no “typical” hospital or laboratory and many variables exist (e.g., hospital size, samples mix, case mix, level of IT and/or automation adoption) there can be no guarantee that other customers will achieve the same results.

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