SPECT only cardiac image in 3 different orientations acquired using IQ-SPECT protocol

IQ•SPECTThe art of minimizing dose while maximizing speed

A key trend in nuclear medicine is the ever-increasing demand for faster MPI exams. IQ•SPECT™ is a cardiac imaging solution that uses a combination of converging collimators, modified cardio-centric acquisition, and special reconstruction methods to deliver ultrafast cardiac imaging that is four times faster than conventional SPECT acquisition.

Features & Benefits

Female patient lying on SPECT/CT scanner bed helped by male tech.
  • In nuclear medicine, image quality is determined by the number of detected photons, patient motion, and truncation. When imaging a small organ, such as the heart, with a conventional parallel hole collimator, much of the detector is not used.
  • As a result, to achieve the desired image quality, routine cardiac studies can take up to 16 minutes.
  • IQ•SPECT maximizes detected counts from the heart without truncation. It offers fast cardiac imaging at the lowest possible dose, all while maintaining high image quality.
  • Featuring a selection of cardiac-specific protocols, with IQ•SPECT, you can optimize your myocardial perfusion imaging (MPI) studies.
Infographic of how cardiac collimators function

This unique approach can be combined with a general-purpose Symbia™ SPECT1 or SPECT/CT, so the system is able to perform all routine clinical applications as well as ultrafast cardiac scans, with just a change in collimator and acquisition mode. This adds flexibility and versatility to your department, enabling you to perform a larger volume and a wider range of procedures without additional dedicated equipment and space requirements.

SMARTZOOM collimation

SMARTZOOM™ collimators employ the magnifying properties of a focusing collimator near the center of the field of view (FoV) and behave like a parallel hole collimator toward the edge of the FoV, reducing truncation. This enables the detectors to zoom in on the heart for four times more sensitivity.

Cardio-centric acquisition

IQ•SPECT positions the heart in the center of the collimator FoV and aligns the detectors at a 28 cm radius, establishing a cardio-centric orbit. IQ•SPECT uses the flexibility of the Symbia gantry to position each detector at an optimal distance to maximize sensitivity. 

Advanced reconstruction

Advanced IQ•SPECT reconstruction accurately incorporates the measured geometry of the SMARTZOOM collimators and the cardio-centric orbit of the detectors. Measurements of size, shape, and pointing direction for all 48,000 holes in the SMARTZOOM collimator enable accurate image reconstruction.

The value of IQ•SPECT


With IQ•SPECT, you not only have the ability to reduce scan time but, most importantly, reduce patient radiation exposure without jeopardizing image quality.

By acquiring four times more counts than conventional scans, IQ•SPECT delivers a complete cardiac workup in less than 5 minutes, improving patient comfort and satisfaction. The short scan time helps the patient remain still during the duration of the exam, reducing motion artifacts and potentially improving image quality. There is also the opportunity to reduce injected dose by up to 75%2 without degrading image quality.

Chart illustrating the value of IQ SPECT


Two challenges in healthcare today are the mandates to improve patient safety and increase productivity. From a patient care and economic perspective, each is critically important. With conventional systems, clinicians have to choose between minimum dose to protect patients or faster scanning for greater productivity. IQ•SPECT addresses these challenges and enables the lowest dose to be used, while scanning patients faster than ever before. By imaging up to 75%2 faster, you have the ability to see more patients daily without purchasing a secondary scanner. 


Time affects all aspects of daily imaging, from patient comfort to staff productivity. With increasing patient demand and decreasing reimbursement levels, efficiency is essential. IQ•SPECT helps clinicians achieve previously unattainable imaging speeds to support faster patient studies, resulting in significant time savings and improved staff efficiency. 

Technical Specifications

General Requirements

  • Symbia Evo
  • Symbia Intevo
  • Symbia Intevo Bold
  • Symbia Excel

SMARTZOOM collimators require space in an Integrated Collimator Cart (ICC) or a detached collimator cart. Requires a dedicated, standalone workplace for reconstruction.

Please Note: Additional technical pre-requisites may apply. Upon receiving your request, your local Siemens Healthineers representative will clarify whether your system meets the requirements.