Textural Analysis and Effect of ROI Size on Infrared Thermography in Athletes With Patellar Tendinopathy

NCT ID: NCT07095738

Last Updated: 2025-09-24

Basic Information

• Recruitment Status: COMPLETED
• Total Enrollment: 54 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2025-08-01
• Study Completion Date: 2025-09-19

Brief Summary

Patellar tendinopathy (PT) is a common knee disorder, particularly among elite athletes, with a reported prevalence of approximately 14.2%. Athletes affected by PT may experience persistent pain, functional impairment, reduced quality of life, decreased physical performance, and even premature career termination. Diagnosing PT remains challenging due to the absence of a gold standard diagnostic method. Although imaging techniques such as ultrasonography (US) and magnetic resonance imaging (MRI) can aid in confirming the diagnosis and assessing severity, MRI is costly and less accessible, and US shows poor correlation with clinical symptoms. Consequently, diagnosis largely relies on clinical examination and medical history. Infrared thermography (IT) has emerged as a potential alternative imaging technique, offering a low-cost, reliable, and non-invasive method to detect thermal asymmetries indicative of underlying pathologies. Technological advancements have enhanced the precision of IT, reducing the thermal asymmetry threshold from 2-3 ºC in the 1970s to 0.5 ºC in current knee assessments. First-order statistics, such as mean gray intensity, and second-order features based on the gray-level co-occurrence matrix (GLCM), have been extensively used in medical image analysis, including IT, to quantify structural and textural characteristics. The size of the region of interest (ROI) is also a critical factor in thermal and texture analyses, as it can influence sensitivity and diagnostic accuracy. Given these considerations, the objectives of this study were: (1) to evaluate differences in thermal and GLCM-based textural features between athletes with PT and healthy controls; (2) to compare the diagnostic performance of IT and GLCM features applied to thermographic images; and (3) to identify the most appropriate ROI size for optimal characterization of PT using both thermal and textural analysis.

Conditions

Patellar Tendinopathy; Diagnostic Accuracy; Infrared Thermography

Study Design

• Observational Model Type: OTHER
• Study Time Perspective: CROSS_SECTIONAL

Study Groups

athletes with unilateral PT

diagnosed through a combination of clinical criteria, specific functional tests, and ultrasound evaluation. Additional inclusion criteria for this group include a symptom evolution time of more than 3 months, a VISA-P score of less than 80, and the performance of a differential diagnosis to rule out other potential causes of anterior knee pain

thermal images (IT)

Intervention Type: DIAGNOSTIC_TEST

The IT images were recorded with an OPTRIS PI 450 IRT camera coupled to Optris PI Connect Software (Germany). The IRT camera has a Noise Equivalent Temperature Difference \<40 mK with 38º x 29º FOV, a wide range of temperature from -20°C to +100°C, spectrum range of 7.5-13 μm, focal plane array sensor size of 382 × 288 pixels, emissivity set at 0.98 and a measurement uncertainty of ± 2% of the overall temperature reading. The size of the capture frame will be 55.4 × 40.63 cm (1.5 mm/px).

healthy volunteer athletes

recruited under the inclusion criteria of no previous history of PT and a VISA-P score of 100

thermal images (IT)

Intervention Type: DIAGNOSTIC_TEST

The IT images were recorded with an OPTRIS PI 450 IRT camera coupled to Optris PI Connect Software (Germany). The IRT camera has a Noise Equivalent Temperature Difference \<40 mK with 38º x 29º FOV, a wide range of temperature from -20°C to +100°C, spectrum range of 7.5-13 μm, focal plane array sensor size of 382 × 288 pixels, emissivity set at 0.98 and a measurement uncertainty of ± 2% of the overall temperature reading. The size of the capture frame will be 55.4 × 40.63 cm (1.5 mm/px).

Interventions

thermal images (IT)

The IT images were recorded with an OPTRIS PI 450 IRT camera coupled to Optris PI Connect Software (Germany). The IRT camera has a Noise Equivalent Temperature Difference \<40 mK with 38º x 29º FOV, a wide range of temperature from -20°C to +100°C, spectrum range of 7.5-13 μm, focal plane array sensor size of 382 × 288 pixels, emissivity set at 0.98 and a measurement uncertainty of ± 2% of the overall temperature reading. The size of the capture frame will be 55.4 × 40.63 cm (1.5 mm/px).

Intervention Type: DIAGNOSTIC_TEST

Eligibility Criteria

Inclusion Criteria

• Specific functional tests.
• Ultrasound evaluation.
• Symptom evolution time of more than 3 months.
• A VISA-P score of less than 80.
• The performance of a differential diagnosis to rule out other potential causes of anterior knee pain.

Exclusion Criteria

• Lower limb pathology.
• Nerve or vascular disorder, or skin lesion in the knee area that could alter thermal information in the patellar tendon region.

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 65 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

Cardenal Herrera University

OTHER

Sponsor Role: lead

Responsible Party

SERGIO MONTERO NAVARRO

Clinical Professor

Responsibility Role: PRINCIPAL_INVESTIGATOR

Locations

Ceu Cardenal Herrera University

Elche, Alicante, Spain

Countries

Spain

Provided Documents

Document Type: Study Protocol, Statistical Analysis Plan, and Informed Consent Form

View Document

Related Links

https://www.uchceu.es/grupos-lineas-investigacion/fisioterapia-activa-terapia-manual-y-analisis-de-imagen-fami

Group investigation

Other Identifiers

CE111803

Identifier Type: -

Identifier Source: org_study_id