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Diagnósticos da América São Paulo – Brazil A NOVEL APPROACH TO USING MAGNETIC RESONACE ANGIOGRAPHY IN THE STUDY OF MAY THURNER SYNDROME: A PICTORIAL ESSAY NAKANO, E.M.; SHIGUEOKA, D.C.; SANTOS, J.E.M.; SALES, D.M.; PINETTI, R.Z.; HERNANDEZ, S.F.; SOUZA, S.A.; LEME, L.M.; UEMURA, L.. INTRODUCTION PURPOSE DISCUSSION REFERENCES INTRODUCTION Left iliac vein compression syndrome, also known as May-Thurner syndrome or Cockett's syndrome, is a result of extrinsic compression of the left common iliac vein between the fifth vertebra and the right common iliac artery. This compression leads to intimal fibrosis and local obstruction of the vein. This syndrome causes isolated left lower limb edema that was first reported by McMurrich in 1908. In 1957 May and Thurner pointed out the anatomy of this condition and in 1965 Cockett and Thomas reported its clinical presentation. INTRODUCTION PURPOSE DISCUSSION REFERENCES INTRODUCTION Due to technical advances, Computed Tomography Angiography (CTA) and Magnetic Resonance Angiography (MRA) have come to replace Venography in the study of this disease. Here we describe the use of the new MRA sequence known as “time-resolved imaging of contrast kinetics” (TRICKSTM) in combination with intravenous injection of gadolinium in both lower limbs. INTRODUCTION PURPOSE DISCUSSION REFERENCES PURPOSE To show the MRA protocol employed in the study of May-Thurner syndrome by the authors, in which TRICKS sequence is used in combination with intravenous injection of gadolinium in both lower limbs in order to ensure better detection of the left common iliac vein compression. INTRODUCTION PURPOSE DISCUSSION REFERENCES DISCUSSION Compression of the left common iliac vein by the right common iliac artery leads to marked hemodynamic modifications in the left lower limb. The principal clinical manifestation is venous hypertension, which is frequently accompanied by deep vein thrombosis. Endovascular therapy with stent placement is a minimally aggressive treatment that has yielded favorable results. Early detection allows positive treatment responses and better prognoses in severe cases. INTRODUCTION PURPOSE DISCUSSION REFERENCES DISCUSSION The diagnosis has classically been made by ascending venography using a femoral approach, allowing the pressure gradient to be determined. The less invasive techniques Doppler ultrasound, CTA and MRA also reveal vascular injury with good diagnostic accuracy. INTRODUCTION PURPOSE DISCUSSION REFERENCES DISCUSSION The standard upper limb approach leads to poor or less effective iliac vein visualization (Fig. 1 and 2). Although our results are preliminary, the novel combination of TRICKSTM and intravenous injection of gadolinium in both lower limbs was found to provide better coverage of the iliac vein compression (Fig. 3, 4, 5, and 6). INTRODUCTION PURPOSE DISCUSSION REFERENCES ▪ Figure 1. TRICKSTM Sequence – Dynamic study of an exam done to rule out left common iliac vein compression. It showed no signs of May-Thurner syndrome. The injection was performed in the left upper limb making the paramagnetic IV contrast less visible during the venous phase. INTRODUCTION PURPOSE DISCUSSION REFERENCES ▪ Figure 2. TRICKSTM Sequence – Stationary pictures of the same patient above. The dotted red arrows points out the vascular crossover during the best venous phase in upper limb IV injection. INTRODUCTION PURPOSE DISCUSSION REFERENCES ▪ Figure 3. TRICKSTM Sequence – The dynamic study of this exam showed a compression of the left common iliac vein of a symptomatic patient diagnosed with May-Thurner Syndrome. Note the left common iliac deep vein thrombosis with partial vein rechanneling and collateral pudendal vein circulation. The injection was performed in both lower limbs, at the same time, making the paramagnetic IV contrast more visible at the venous phase. INTRODUCTION PURPOSE DISCUSSION REFERENCES ▪ Figure 4. TRICKSTM Sequence – Stationary pictures of the same case above. The red arrows shows the vascular vein compression at the best venous phase during both lower limb IV injection. INTRODUCTION PURPOSE DISCUSSION REFERENCES ▪ Figure 5. TRICKSTM Sequence – The dynamic study of this exam showed partial compression of the left common iliac vein of a symptomatic patient diagnosed with May-Thurner Syndrome. Note the left common iliac vein partial duplication. The injection was performed in both lower limbs, at the same time, making the paramagnetic IV contrast more visible at the venous phase. INTRODUCTION PURPOSE DISCUSSION REFERENCES ▪ Figure 6. TRICKSTM Sequence – Same case above: The full red arrow points out the vascular vein compression at the best venous phase during both lower limb IV injection. The dotted red arrow shows the vein duplication. INTRODUCTION PURPOSE DISCUSSION REFERENCES DISCUSSION Our protocol also uses T1WI 3D Ultrafast Spoiled GRE and Coherent These SSFP Sequences (Figures 7 and 8). sequences aid to display the venous compression. The angiographic sequence used in this protocol is “time-resolved imaging of contrast kinetics” (TRICKSTM), which prioritizes temporal resolution, and intravenous injection of gadolinium in both limbs. The Chart 1 shows the paramaters of our protocol. INTRODUCTION PURPOSE DISCUSSION REFERENCES ▪ Figure 7. T1WI 3D Ultrafast Spoiled GRE Sequence – Axial View – The red arrow points out the left common iliac vein compression. INTRODUCTION PURPOSE DISCUSSION REFERENCES ▪ Figure 8. Coherent Steady-State Free Precession (SSFP) Sequence – Oblique View – The red arrow shows the left common iliac vein compression by the right iliac common artery in this symptomatic patient. INTRODUCTION PURPOSE DISCUSSION REFERENCES DISCUSSION Chart 1 – MRI Sequence Parameters Sequence TR/TE Flip Angle Coherent SSFP T1WI 3D Ultrafast Spoiled GRE TRICKSTM 4.3 / 2.2 ms 7.0 / 4.2 ms 3.2 / 1.2 ms 80o 12o 30o Coil Body / Phase array FOV 400 mm Anatomic Coverage Superior renal edge to inferior portion of symphisis pubis Slice Thickness / Gap 6 mm / 0.6 mm Volume Volume INTRODUCTION PURPOSE DISCUSSION REFERENCES REFERENCES 1. Wolpert LM, Rahmani O, Stein B, Gallagher JJ, Drezner AD. Magnetic resonance venography in the diagnosis and management of May-Thurner syndrome. Vasc Endovascular Surg 2002;36(1):51-7. 2. Ludwig B, Han T, Amundson D. Postthrombotic syndrome complicating a case of May-Thurner syndrome despite endovascular therapy: case report and review. Chest 2006;129(5):1382-6. 3. Oğuzkurt L, Ozkan U, Tercan F, Koç Z. Ultrasonographic diagnosis of iliac vein compression (May-Thurner) syndrome. Diagn Interv Radiol 2007;13(3):152-5. 4. Kwak HS, Han YM, Lee YS, Jin GY, Chung GH. Stents in common iliac vein obstruction with acute ipsilateral deep venous thrombosis: early and late results. J Vasc Interv Radiol 2005;16(6):815-22. INTRODUCTION PURPOSE DISCUSSION REFERENCES REFERENCES 5. Cil BE, Akpinar E, Karcaaltincaba M, Akinci D. May-Thurner syndrome. Radiology 2004;233(2):361-5. 6. Oguzkurt L, Tercan F, Pourbagher MA, Kizilkilic O, Turkoz R, Boyvat F. Computed tomography findings in 10 cases of iliac vein compression (May-Thurner) syndrome. Eur J Radiol 2005;55(3):421-5. 7. Mell M, Tefera G, Thornton F, et al. Clinical utility of timeresolved imaging of contrast kinetics (TRICKS) magnetic resonance angiography for infrageniculate arterial occlusive disease. J Vasc Surg. 2007; 45(3):543-8.