Related Experiment Video
Updated: Nov 24, 2025
Intravital Microscopy of the Spleen: Quantitative Analysis of Parasite Mobility and Blood Flow
Published on: January 14, 2012
Selected advanced imaging techniques were unable to quantify in vivo parasitic burden in heartworm-infested dogs
Assaf Lerer1, Dwight D Bowman2, Wen-Ming Luh3
1College of Veterinary Medicine, Department of Clinical Sciences, Cornell University, Ithaca, New York.
Abstract:
This prospective exploratory study aimed to determine whether certain noninvasive advanced imaging techniques could estimate parasitic burden in heartworm-infested dogs; a noninvasive method is needed for ethical considerations and permitting longitudinal drug studies. Three cardiac-gated and respiratory-gated 3T MRI techniques and CT pulmonary angiography (CTPA) were performed in three healthy beagles to optimize imaging techniques. Once the imaging techniques were established, a pilot study was performed to determine which one of the MRI techniques would be used in an observer comparison study. Ultimately, spoiled gradient recalled (SPGR)-cine-MRI and CTPA were performed in four and five heartworm-infested dogs, respectively. Heartworms were detected in the pulmonary arteries in all dogs during SPGR-cine-MRI and in no dog during CTPA. However, counting the number of worms was unsuccessful. In conclusion, CTPA and SPGR-cine-MRI were unable to replace necropsy for quantifying parasitic burden in heartworm-infested dogs.
Insights
Advanced imaging like CTPA and SPGR-cine-MRI cannot yet replace necropsy for quantifying heartworm parasitic burden in dogs. Further research is needed to develop noninvasive methods for ethical heartworm studies.
Area of Science:
- Veterinary Medicine
- Diagnostic Imaging
- Parasitology
Background:
- Noninvasive methods are crucial for ethical heartworm studies in dogs, enabling longitudinal drug evaluations.
- Current methods for assessing parasitic burden often require invasive procedures, posing ethical challenges.
Purpose of the Study:
- To explore advanced noninvasive imaging techniques for estimating parasitic burden in heartworm-infested dogs.
- To evaluate the efficacy of cardiac-gated and respiratory-gated 3T MRI and CT pulmonary angiography (CTPA) in detecting and quantifying heartworms.
Main Methods:
- Optimized three 3T MRI techniques and CTPA in healthy beagles.
- Performed SPGR-cine-MRI in four heartworm-infested dogs and CTPA in five heartworm-infested dogs.
- Compared imaging findings with necropsy results to assess parasitic burden estimation.
Main Results:
- Heartworms were visualized in pulmonary arteries using SPGR-cine-MRI in all dogs.
- CTPA failed to detect heartworms in any of the infested dogs.
- Quantifying the number of heartworms using either imaging technique was unsuccessful.
Conclusions:
- CTPA and SPGR-cine-MRI are currently unable to replace necropsy for quantifying heartworm parasitic burden.
- Noninvasive imaging techniques require further development to accurately assess heartworm infestation levels.
