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Updated: Aug 6, 2026

A Multicenter MRI Protocol for the Evaluation and Quantification of Deep Vein Thrombosis
Published on: June 2, 2015
How do we know who has had deep vein thrombosis?
1Department of Medicine, University Hospital, Queen's Medical Centre, Nottingham, UK.
Insights
This study found that many deep vein thrombosis (DVT) diagnoses were unconfirmed, with Hospital Activity Analysis (HAA) records showing frequent misclassifications. Venography confirmed fewer than half of suspected DVT cases, especially in medical patients.
Area of Science:
- Medical Diagnostics
- Radiology
- Health Informatics
Background:
- Deep vein thrombosis (DVT) is a significant vascular condition requiring accurate diagnosis.
- Diagnostic accuracy and classification of DVT impact patient management and hospital resource allocation.
- Previous studies have highlighted challenges in identifying and confirming DVT cases within hospital settings.
Purpose of the Study:
- To evaluate the diagnostic accuracy of venography for deep vein thrombosis (DVT).
- To assess the reliability of Hospital Activity Analysis (HAA) data in identifying DVT cases.
- To compare DVT confirmation rates between medical and surgical patient populations.
Main Methods:
- Retrospective review of radiology records for venograms performed for suspected DVT.
- Analysis of Hospital Activity Analysis (HAA) data for episodes classified as phlebitis or thrombophlebitis.
- Comparison of diagnoses confirmed by venography against HAA classifications.
Main Results:
- Of 154 venograms for suspected DVT, 57 (46%) were confirmed.
- HAA records identified 174 'phlebitis or thrombophlebitis' episodes, with only 37 (21%) confirmed by venography.
- At least 29 patients were misclassified by HAA; medical patients had more unconfirmed DVTs (75%) than surgical patients.
Conclusions:
- Venography confirms less than half of suspected DVT cases, indicating potential diagnostic gaps.
- Hospital Activity Analysis (HAA) data is unreliable for accurately identifying confirmed DVT cases, particularly in medical patients.
- Improved diagnostic protocols and data validation are needed to ensure accurate DVT identification and classification.
Abstract:
An attempt was made to identify all patients diagnosed as having deep vein thrombosis (DVT) in a large teaching hospital during one year. A review of the radiology records showed that 124 (81%) of the 154 venograms performed were for suspected DVT, and that the diagnosis was confirmed in 57 (46%). During the same period, the Hospital Activity Analysis (HAA) records revealed 174 episodes classified as 'phlebitis or thrombophlebitis' in 162 patients. Only 37 of these episodes (21%) had been confirmed by X-ray venography and at least 29 patients were incorrectly classified by HAA. 'Medical' patients accounted for 54% of the episodes of DVT, yet in only 25% of these was the diagnosis confirmed by venography, while 'surgical' DVTs were less frequent but were more often confirmed by venography.
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