This demonstrates that veterinarians continue to incorporate and expand the use of diagnostics in their care protocols while pet owners continue to show willingness to spend on their pets. This focus supported solid 7% gains in same-store diagnostic revenue gain at the practice level growth that is being achieved despite ongoing headwinds in clinical visit growth in a resource constrained and challenging macro environment. This performance shows that pet owners continue to prioritize healthcare for their pets, which reinforces the resiliency of our sector. And IDEXX customers are growing even faster supported by our direct customer engagement model and superior, integrated diagnostic solutions. IDEXX’s experienced sales professionals’ deep partnership with the veterinarians they serve supported sector diagnostic revenue growth that outpaced both practice revenue and clinical revenue growth by 200 plus basis points in Q3 building on our strong momentum in helping to advance pet healthcare through diagnostics testing.
Growing our commercial footprint in a disciplined way is a key element of our customer engagement strategy. As we shared at Investor Day, extensive practice data analysis shows that customers using our broader diagnostics offering generate approximately 200 basis points higher practice clinical and diagnostics revenue growth consistent with our execution trends. This benefits the patient, practice economics and, by extension, IDEXX. Our U.S. commercial expansion is progressing to plan, and we expect to enter the New Year with the expanded team in place. This is the first U.S. expansion in four years, and many territories have appreciably increased in size since then. Increasing reach and engagement with clinics in our largest and most developed region prepares us well to support the growing portfolio of IDEXX innovations.
Outside of the U.S., we remain focused on deploying our commercial playbook in countries across the world and are encouraged to report that third quarter International CAG Diagnostics recurring revenues benefited from another quarter of improving volume growth. Higher reach-to-revenue metrics strengthen relationships between IDEXX commercial professionals and in-region veterinarians. Our increased commercial presence as a result of seven international commercial expansions since 2020 helped drive solid double-digit year-over-year gains in our international premium instrument installed base across platforms. This includes record third quarter instrument placements in the Asia-Pacific region which helped drive 13% growth in our international installed base.
This growth demonstrates that our highly capable sales teams have the right products at the right time and reinforces significant potential associated with the development of international regions. These geographies represent an outsized portion of our long-term opportunity of over 200,000 incremental premium placements for existing instrument categories. Turning to our innovation agenda, software is a key pillar in our growth strategy and an area of important focus in the clinic, a trend that we are well positioned to facilitate and enable. Clinics are embracing software to improve efficiency in all aspects of their business, from patient processing and billing to diagnostics interpretation and pet owner communication. Higher software adoption is driven by the desire to realize the benefits of modern technology and applications to address these significant workflow pain points.
It also positions practices to incorporate solutions that increase engagement with pet owners through scheduling and other tools that they use and rely on in other aspects of their lives. The multiplier benefit to our business from the adoption of IDEXX software is significant, reflected in third quarter growth in our software and diagnostic imaging segment with high-teen organic gains in our highly profitable recurring annuity stream. Excellent commercial execution and strong customer interest drove outstanding third quarter PIMS placements. Most notably, our cloud-based PIMS products represented 95% of total PIMS placements and as a result now comprise over 50% of our PIMS installed base. This achievement reflects broad-based adoption of cloud-based products that reflects an inflection point in technology adoption.
While veterinarians earlier in their careers are more digitally native, sales profiles indicate that customers of all career stages appreciate the workflow benefits and ease-of-use of our wide-ranging software stack. The common denominator is that contemporary software solutions allow them to better focus on the delivery of care and minimize non-value add administrative activities. Our software product offering also includes an integrated diagnostics portal, VetConnect PLUS with IDEXX DecisionIQ, that not only provides testing results, but also decision support, clinical insights, and next step considerations across a growing range of clinical use cases. IDEXX software and data solutions situate us well to benefit from these trends, as well as the accretion in operating margin drop through associated with a revenue base that is increasingly recurring in nature.
Our software innovation is deeply integrated with our diagnostics innovation approach as evidenced by our highly successful instrument platform strategy, enabled by cloud-based capabilities and connectivity that enhance practice insight and workflow. We’re very excited about our continued progress in bringing transformative solutions to point of care and we are on plan to announce our new platform at VMX in January. Our product development efforts continue to advance aligned to our timing expectations and we are excited to share more details in just a few short months and how it will add to our over 200,000 placement opportunity estimate for existing instrument categories. We also continue to advance our innovation engine in other areas like advanced test menu.
Innovation in assays that provide new clinical insights earlier in disease states is especially valued by veterinarians, since they drive higher standards of care aligned with the goal of improving health outcomes for their patients. Earlier this year, we announced the launch of an important new testing assay, Cystatin B, that expands our industry leading renal portfolio and will be available in early December beginning with our North American lab networks. This will be followed by international launches over the course of 2024. This novel marker uses IDEXX IP to help clinicians detect kidney injury earlier and more definitively and is receiving broad support from key opinion leaders. Notably, a recent article in the Journal of Internal Veterinary Medicine, co-authored by multiple International Renal Interest Society members, highlights the beneficial insights in distinguishing progressive from stable kidney disease by detecting active injury.
These clinical insights represent important medical contributions and the test will be included in close to 2 million urine panels run at IDEXX reference labs in our first year post launch. Looking forward, we will announce an additional expansion to our reference lab testing menu in Q1. In addition to these examples of product and service innovation, we continue to advance differentiated service delivery as a key element of our expansion strategy. We made a notable advancement in this area early in the third quarter when we opened our newest reference laboratory in Perth, Western Australia. Perth is an economically vibrant city that is a five-and-a-half-hour flight from our Brisbane laboratory including a two-hour time difference making it particularly difficult to service in the past.
