Role of MRI in detecting lower limb incompetent perforator veins

Transcription

1 Role of MRI in detecting lower limb incompetent perforator veins Poster No.: B-0880 Congress: ECR 2017 Type: Authors: Keywords: DOI: Scientific Paper B. K. Soni 1, H. SAHNI 2, A. N 1 ; 1 Bangalore/IN, 2 Jorhat/IN Vascular, Extremities, MR, Ultrasound-Colour Doppler, Diagnostic procedure /ecr2017/B-0880 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 10

2 Purpose Introduction Varicose veins is a common disability. The reported prevalence of chronic venous insufficiency varies from < 1% to 40% in females and from < 1% to 17% in males in various studies. In addition, prevalence estimates for varicose veins are even higher which has been reported <1% to 73% in females and 2% to 56% in males in various studies [1]. This could be asymptomatic or cause disfiguring telangiectasis [2]. These disorders in its severe form can cause skin hyperpigmentation and ulceration. Varicose veins in the lower limbs occur mainly due to venous valvular incompetence. It is very important to determine the primary cause of varicosities as certain congenital anomalies and abdominal masses can also cause varicose veins. Phlebography used to be investigation of choice which has almost disappeared from clinical practice as it is an invasive procedure with potential risk of contrast reaction despite having greater accuracy of diagnosis. Colour Doppler is used routinely for the assessment of recurrent varicose veins [3]. Colour Doppler is an accurate modality to diagnose pathology of the venous system because it is possible to evaluate morphology of the veins, wall imaging (resilience) and flow in the venous vessel (spontaneous flow or reflux, which is the excessive retrograde flow in the venous trunk). It is also noninvasive and cost effective [4]. However Cavezzi Altilio etal reported that even though Colour Doppler is the most widely accepted investigation of choice for varicose veins, the greatest limitation of Doppler is its operator dependence and reproducibility and it is a time consuming modality [5]. Therefore, there is need of a noninvasive imaging modality which is reproducible, less time consuming and is not operator dependednt. MRI fulfills the criteria of being non operator dependent and reproducible. No intra venous contrast medium is required. All the images acquired by MRI are available for review in the future if required. These advantages of MRI can play a pivotal role in the minimally invasive management of varicose veins. Moreover the MRI protocol used for the study does not necessitate contrast administration and is devoid of radiation exposure. Till date, to the best of our knowledge there is no published study on this subject. Hence we tried to establish the role of MRI in detecting lower limb incompetent perforators and correlated it with color Doppler correlation. Page 2 of 10

3 Methods and materials This prospective study was carried out in thirty patients during a period of one year at a tertiary care hospital after approval from institutional ethical committee. The written informed consent was obtained from all participants. Patients were recruited from individuals who reported for evaluation of varicose vein by color Doppler. The study included patients between years of age group. There were 18 (60%) females and 12 (40%) males. A total of 39 legs were assessed as bilateral legs were evaluated in 9 patients. Inclusion criteria: Clinical diagnosis of varicose veins Patients willing to undergo additional investigation of MRI Exclusion criteria were Individuals with contraindication to MRI, Claustrophobic patients and pregnancy. The patients were examined in a standing position clinically for varicose veins. A Colour Doppler was done on ultrasound machine (Logic P5, GE Health care) using 7-12 MHz probe in standing and supine position. Any perforator which showed a reflux in valsalva (Sustained reflux for more than 3 seconds) was considered incompetent. Further, diameter of the perforator were obtained on cross sectional 2D image using vendor provided software up to first decimal. Colour Doppler study results were considered gold standard in detection of incompetent perforators. MRI was done using 1.5 Tesla machine (Siemens magneto avanto). True FISP sequence (TR-3.64 msec,te-1.57 msec, Slice thickness 3.0 mm with Distance factor - 0%, Phase encoding direction- Anterior>Posterior) was used. Patients were evaluated in supine position. The incompetent perforators detected in Colour Doppler were corroborated on MR images. The maximum diameter of each incompetent perforator was measured at the level of fascia. The caliber of dilated perforator leading to varicose veins on MRI was recorded. Statistical analysis was done using Statistical software SAS 9.2, SPSS 15.0, Stata 10.1, MedCalc 9.0.1, Systat Page 3 of 10

4 Results 30 patients underwent both colour Doppler and MRI. There were 18 females and 12 males. A total of 39 legs were assessed as bilateral legs were evaluated in 9 patients. There were total 81 perforators including 56 incompetent and 25 competent perforators identified on Colour Doppler. All the 81 perforators were also identified on MRI. 77 perforators measured greater than or equal to 2.0 mm in diameter on MRI. The mean diameter of incompetent perforators on MRI was 3.56 mm for male and 3.51 mm for female and that of competent perforators was 2.27 mm for male and 2.25 mm in female(table 1). Minimum diameter of an incompetent perforator detected in study was 2.2 mm and maximum diameter of a competent perforator was 3.3 mm. Thus in this study all the perforators with a diameter of more than 3.3 mm on MRI were incompetent and all the perforators below 2.2 mm on MRI were found to be competent (Fig 1,2). Twenty two perforators with diameter between mm were identified. Fourteen of them were competent and eight of them were incompetent (Fig 3). Tab 1: Mean Diameters of Incompetent and competent perforators on MRI. Reflex No. of Patients Mean diameter on MRI (mm) Male Female Present Absent The sensitivity, specificity, positive predictive value and negative predictive value were calculated for the perforators measuring between 2.2 mm to 3.5 mm (Tab 2). The perforator more than or equal to 2.8 mm diameter has a positive predictive value of more than 96 percentage and perforator more than or equal to 3.4 mm diameter has a 100 percentage positive predictive value for being incompetent (Tab 2). Tab 2 : Sensitivity, specificity, positive predictive value and negative predictive value of MRI at different diameters Diameter Greater Than or Equal To a Sensitivity Specificity Positive predictive value Negative Predictive Value 2.2 mm mm Page 4 of 10

5 2.4 mm mm mm mm mm mm mm mm mm mm mm mm Page 5 of 10

6 Images for this section: Fig. 1: Fig 1(a,b) : Colour Doppler image of an incompetent perforator at 12 cms above Left lateral malleolus at rest(left) and during valsalva(right) showing reversal of flow (Reflux) (a) Corroborative TRUFI Fat sat axial sequence showing the perforator with a diameter of 3.4 mm (b). Dept Of Radiology, Command Hospital AirForce - Bangalore/IN Fig. 2: Fig 2(a,b): Colour Doppler image of an incompetent perforator at 15 cm above Right medial malleolus at rest (Left) and during Valsalva (Right) showing reversal of flow / Reflux (a), Corroborative TRUFI Fat sat axial sequence showing the perforator with a diameter of 3.5 mm (b) Dept Of Radiology, Command Hospital AirForce - Bangalore/IN Page 6 of 10

7 Fig. 3: Fig 3(a-b): Colour Doppler image of an incompetent perforator at 17 cms above Left medial malleolus at rest(left) and during valsalva(right) showing reversal of flow (Reflux )(a), Corroborative TRUFI Fat sat axial sequence shows the perforator with a diameter of 2.3 mm (b) Dept Of Radiology, Command Hospital AirForce - Bangalore/IN Page 7 of 10

8 Conclusion The prevalence of varicose veins and the cost of treating complications such as chronic venous ulcers contribute to a high burden on health care infrastructure. Chronic venous ulcerations result in the loss of 2 million workdays and poor quality of life. It costs an estimated $3 billion per year to treat in the United States alone. [6] Varicose veins are common cause of disfigurement, discomfort and disability. The advent of minimally invasive treatments such as foam sclerotherapy, radiofrequency and Laser ablations have resulted in lower morbidity and duration of hospitalization resulting in increasing number of patients seeking treatment [7]. Colour Doppler ultrasonography (US) is a most used and is gold standard modality to employ, with the ability to demonstrate venous hemodynamic reflux [8]. Pathological perforating veins were defined as those exhibiting greater than 3 seconds of reversal of flow on Valsalva manoeuvre [9]. In this study, we found that positive predictive value and specificity for detecting incompetence increases with the increasing diameter of perforator, however sensitivity and negative predictive value decreases. The drop in sensitivity is explained by inability to differentiate incompetent from competent perforator just by size criteria whereas it is possible on color Doppler ultrasound by detecting reflux (Table 2). We also inferred from our study that any perforator with a diameter of 3.3 mm or more in MRI are definitely incompetent and any perforator with a diameter of 2.2 mm or less are definitely competent. The findings of our study reveal that MRI can be used as an adjunct to Colour Doppler in the detection of incompetent perforators in cases of varicose veins. It is non-operator dependent and entire set of images being available for review are a great advantage. The role of MRI in comparing with previous imaging and follow up of the patient is more comprehensive than Colour Doppler by virtue of being able to store all contiguous images in multiple planes. The perforators are well visualized on MRI and cut off diameter of the incompetent perforators can be used as a criterion to further evaluation of the perforator using the labour intensive Colour Doppler. Any perforator leading to superficial varicosities can be another clue for incompetence. Such perforators can be evaluated again in Colour Doppler and confirmed for its competency. This reduces the time and labour of Colour Doppler evaluation. Page 8 of 10

9 Personal information Brijesh K Soni, D.N.B Department of Radiology Command Hospital Air Force Bangalore INDIA Hirdesh Sahni, M.D, D.N.B, D.M (Neuroradiology) Air Officer Commanding 5 Air Force Hospital Jorhat INDIA Anas N, M.D Department of Radiology Command Hospital Air Force Bangalore INDIA Page 9 of 10

10 References 1. Jennifer L. Beebe-Dimmer, John R. Pfeifer, Jennifer S. Engle, David Schottenfeld. The Epidemiology of Chronic Venous Insufficiency and Varicose Veins. Annals of Epidemiology. 2005; 15(3): Callam MJ. Epidemiology of varicose veins.br J Surg 1994;81: H S Khaira et al. Colour flow duplex in the assessment of recurrent varicose veins. Ann R Coll Surg Engl 1996; 78: Miros#aw Rozenbajgier, Tomasz Michalski etal. Ultrasonography with colour Doppler blood flow imaging as a method of choice in the preoperative diagnosis of varicose veins of the lower extremities, Acta Angiol. 2011; 17 (2): Cavezzi Altilio et al. An article on colour flow duplex investigation in superficial venous insufficiency of the lower limbs. R Coll Surg Engl. 2002; 82: Gregory Piazza. Varicose Veins. Circulation. 2014; 130 (7) : S subramania, Ta Lees. The treatment of varicose veins. Ann R Coll Surg Engl 2007; 89: Seung chai jung et al. Unusual Causes of Varicose Veins in the Lower Extremities: CT Venographic and Doppler US Findings. Radiographics 2009;29 (2): Rutherford EE, Kianifard B, Cook SJ, Holdstock JM, WhiteleyMS. A study on Incompetent perforating veins are associated with recurrent varicose veins. Eur J Vasc Endovasc Surg. 2001; 21(5): Page 10 of 10