- Pictorial Review
- Open Access
Magnetic resonance arthrography of the hip: technique and spectrum of findings in younger patients
© European Society of Radiology 2010
- Received: 18 February 2010
- Accepted: 28 April 2010
- Published: 8 June 2010
Magnetic resonance(MR) imaging is the reference imaging technique in the evaluation of hip abnormalities. However, in some pathological conditions—such as lesions of the labrum, cartilaginous lesions, femoroacetabular impingement, intra-articular foreign bodies, or in the pre-operative work-up of developmental dysplasia of the hip—intra-articular injection of a contrast medium is required to obtain a precise diagnosis. This article reviews the technical aspects, contraindications, normal appearance and potential pitfalls of MR arthrography, and illustrates the radiological appearance of commonly encountered conditions.
- Magnetic resonance arthography
The development of magnetic resonance (MR) imaging has allowed it to become the standard of reference in the work-up of bone and soft tissue abnormalities of the hip. However, some pathological conditions—such as lesions of the labrum, cartilaginous lesions, femoroacetabular impingement, intra-articular foreign bodies or in the pre-operative work-up of developmental dysplasia of the hip—require intra-articular injection of a contrast medium, i.e. to perform MR arthrography, in order to obtain a precise diagnosis. This article’s objectives are to refresh the technical aspects, contraindications, normal appearance and potential pitfalls of MR arthrography; and in addition, to illustrate the radiological findings of commonly encountered conditions.
Putting the patient in a dorsal decubitus position, the lower limb at 10–15 degrees of internal rotation, with the tube being positioned vertically
Homing in on the injection site under fluoroscopic guidance
Aseptic preparation of the skin
Placement of a sterile field
Local subcutaneous anaesthesia with lidocaine 1%. Up to 4 ml may be injected, but subcutaneous anaesthesia is not absolutely necessary and would be discussed with the patient
Intra-articular access under fluoroscopic guidance with a 22-gauge spinal needle
intra-articular injection under fluoroscopic guidance, 12 ml of iodinated contrast medium (Iodixanol Visipaque 270 mg I/ml, GE Healthcare) mixed with 0.06 ml gadolinium chelates (Gadopentetate Dimeglumine Magnevist 0.5 mmol/ml, Bayer)  or 10–15 ml from a pre-filled syringe of gadolinium chelates (Gadoteric acid Artirem 0.0025 mmol/ml Guerbet)
Miller proposed a technique consisting of a fluoroscopically guided landmarking of the cutaneous access point, then intra-articular access in the MR suite . Intra-articular access may also be guided by MR fluoroscopy .
MR operating systems nowadays have magnetic field strengths from 0.2–3 Tesla (T). Because it has a higher SNR, a greater magnetic field (3 T) allows for higher spatial resolution in the same time period or faster acquisition with identical spatial resolution [7, 8]. Evaluation of the labrum and cartilage would be better with a 3-T magnetic field . Phased-array coils are needed for parallel imaging techniques [simultaneous acquisition of spatial harmonics (SMASH) or sensitivity encoding (SENSE)]. These reduce imaging time and the specific absorption rate [7, 10] with, according Ryan et al. , no discernible difference in image quality or SNR between images acquired with and without SENSE.
Detailed parameters of our standard examination protocol
Fat-saturated 3D gradient echo T1-weighted
Slice thickness (mm)
Slice gap (mm)
Number of slices
Flip angle (degree)
Acquisition matrix size (pixels)
384 × 256
384 × 256
384 × 256
512 × 256
256 × 217
Field of view (mm)
As with all MR studies, absolute contraindications related to magnetic field exposure need to be respected. Principally, these are implantable material (cardiac stimulators, neurostimulators, cochlear implants etc.), certain types of cardiac valves, ferromagnetic material and metallic foreign bodies. Osteosynthesis material is not an absolute contraindication to MR studies, but when situated in close proximity to the region of interest, magnetic susceptibility artefacts may worsen image quality to the extent of rendering image interpretation impossible. For that reason, we elect not to perform MR arthrography of the hip for patients with osteosynthesis material at the level of the cotyle or at the upper extremity of the homolateral femur.
Precautions related to intra-articular injection of contrast media
Informing the patient about the different steps of the procedure, of potential allergic haemorrhagic or infectious complications, and obtaining consent
Verifying absence of anticoagulation or anti-platelet aggregation medication
Verifying the absence of allergies to the products used
When strict aseptic precautions are respected, infectious complications are avoided. Arthrography may be responsible for a temporary flare-up of joint pain, reaching its peak 4 h post-injection, independent of the quantity of local anaesthetic previously injected . Minor adverse reactions are rarely reported, such as headache, vertigo, vasovagal episode or urticaria , but Saupe and co-workers’ series of 1,085 MR arthrographies revealed no major adverse reactions .
Normal anatomy of the hip
Normal variants and pitfalls
The junctional zone between the acetabular labrum and the transverse ligament is generally indistinguishable. An irregularity of this zone is possible and may give a pseudotear aspect to the labrum .
Most often the labrum is triangular in shape, but it may be rounded or flat in asymptomatic patients [27, 28]. It appears that with age, even in the absence of symptoms, the proportion of triangular labra diminishes [29, 30], and intralabral T1 intermediate and T2 hypersignal anomalies appear [27, 30]. Complete absence of the labrum is possible [26, 28, 30]: the antero-superior labrum may not be visualised in 10% of cases; this proportion increases with age .
The existence of a sublabral recess is possible (Fig. 5). In MR imaging, it appears as a well-defined linear interposition of contrast medium partially separating the underside of the labrum without any perilabral anomalies . However, many locations have been described: Petersilge et al.n  believe it is always in an antero-superior position; on the other hand, Studler et al.  describe it in an antero-inferior location. Dinauer et al.  also reported the possibility of a postero-inferior sublabral recess.
Abnormality of the acetabular labrum may be traumatic, degenerative or related to hip dysplasia [34–36]. The clinical presentation typically consists of clicking, locking and pain on flexion and internal rotation of the hip. Conventional MR imaging of the hip is not effective, except in the study by Mintz et al. , in the evaluation of labral tears, while MR arthrography has shown good sensitivity and specificity in the detection of acetabular labral tears [22, 24, 26, 33, 38, 39]. Acetabular labral lesions are considered to be precursors of coxarthrosis. Early diagnosis and precise determination of the location and extent of labral tears may allow for a timely surgical intervention .
Stage 0 corresponds to a normal labrum
Stage 1A corresponds to the presence of an intra-labral increased T2 signal not in continuity with the labral margin of a triangular labrum
Stage 2A corresponds to a partial labral tear with extension of contrast media into an undetached triangular labrum
Stage 3A corresponds to a complete labral tear through a triangular labrum
In Stages 1B, 2B and 3B, the labrum is thickened and a labral recess is not present
An irregular labrum, i.e. irregular margins without a tear (Fig. 6a)
A flap-type labral tear, may be partial or complete (Fig. 6b)
A thickened and distorted labrum, in keeping with the instability of the labral lesion
In 30% of cases, labral lesions are associated with chondropathy . Most labral tears involve the anterior and superior labrum . Using the clock-face method to localise and describe the extent of a labral tear is more precise, besides more than 40% of labral tears extend beyond a quadrant : on a sagittal slice, 12 o’clock is above, 3 o’clock in front, 6 o’clock below and 9 o’clock behind (Fig. 6c).
Femoroacetabular impingement (FAI) is a cause of acetabular labrum abnormality and early coxarthrosis; and is potentially treatable surgically [46–49]. Clinically, as in labral tears, patients with FAI may complain of pain on hip flexion and internal rotation. A limited range of motion on internal rotation of the hip should also point to the diagnosis. Early on, radiographs may be normal or may show subtle anomalies: a prominent anterior portion of the head-neck junction, anterior synovial herniation pits, the presence of an os acetabuli, ossification of the acetabular border, coxa profunda, acetabular protrusion or acetabular retroversion [48, 50].
In this type of FAI, the so-called “pistol grip deformity” of the anterior portion of the femoral head-neck junction causes a compression and abnormal stress on the anterior labrocartilaginous complex on flexion and internal rotation. It is most frequently found in young athletic males [46, 47].
Cam-type FAI may be congenital or due to developmental dysplasia of the hip, slipped capital femoral epiphysis, trauma or avascular necrosis  but contrary to slipped capital femoral epiphysis and growth abnormalities of the femur congenital dysplasia is a rare cause of cam impingement because the head-neck junction in these patients is usually normal.
A flattening or a convexity of the antero-superior part of the normally concave femoral head-neck junction (Fig. 11) . The so-called “pistol grip deformity” is the nickname for a pronounced deformity of the femur and should not be used for slighter deformities with abnormal head-neck offset.
An alpha angle exceeding 55 degrees (Fig. 11) . The alpha angle is measured on an axial-oblique image between the axis of the femoral neck and a line connecting the femoral head centre with the point of change in the radius of the curvature on the anterior part of the femoral head. Its normal value is 42 degrees. The pistol grip deformity increases the alpha angle. The alpha angle may be underestimated if the contour anomaly is antero-superior or superior, some recommend measuring the alpha angle on radial reconstructions around the femoral neck axis .
In general, an earlier, more severe and extended involvement of the antero-superior cartilage  compared with the pincer-type FAI ; and may be associated with subchondral oedema shown by high signal intensity on fat-saturated T2-weighted and fat-saturated PD-weighted sequences.
Fibrocystic changes and subchondral microcysts in the antero-superior part of the femoral neck, not to be mistaken for physiological anterior synovial invaginations .
Found preferentially in middle-aged women [46, 48], this type of FAI is characterised by a morphological anomaly of the acetabulum causing excessive coverage of the femoral head: coxa profunda, acetabular protrusion or acetabular retroversion [59, 60]. Acetabular anteversion, normally at an angle of 22.5 ± 3 degrees , is measured on an axial slice through the centre of the femoral head, however this angle may vary with pelvis flexion . Rarely, it may be caused by trauma or labral ossification. Radiologically, retroversion manifests as the crossing sign and by the visibility of the ischial spine in the pelvis [63, 64]. It causes direct contact between the anterior acetabular border and the femoral head-neck junction, thereby explaining preferential involvement of the labrum and a relatively preserved cartilage [46, 48, 51]. Later in the course, lesions to the postero-inferior cartilage by a contrecoup mechanism may appear . Surgical management includes anterior acetabular osteoplasty for retroversion and circumferential osteoplasty in the case of a protrusion, in combination with labral lesion debridement . Acetabular retroversion may be treated by periacetabular inverted osteotomy .
MR arthrography is a high performance imaging tool in the work-up of abnormalities of the acetabular labrum and articular cartilage, intra-articular foreign bodies and in femoroacetabular impingement. Although still an invasive procedure, because there is intra-articular injection of contrast medium, this imaging technique has shown excellent tolerance. Its indications have widened in the recent years since the development of conservative surgical interventions of the hip such as arthroscopy and surgery for femoroacetabular impingement.
- Brown RR, Clarke DW, Daffner RH (2000) Is a mixture of gadolinium and iodinated contrast material safe during MR arthrography? AJR Am J Roentgenol 175(4):1087–1090PubMedView ArticleGoogle Scholar
- Duc SR, Hodler J, Schmid MR et al (2006) Prospective evaluation of two different injection techniques for MR arthrography of the hip. Eur Radiol 16(2):473–478PubMedView ArticleGoogle Scholar
- Andreisek G, Duc SR, Froehlich JM, Hodler J, Weishaupt D (2007) MR arthrography of the shoulder, hip, and wrist: evaluation of contrast dynamics and image quality with increasing injection-to-imaging time. AJR Am J Roentgenol 188(4):1081–1088PubMedView ArticleGoogle Scholar
- Wagner SC, Schweitzer ME, Weishaupt D (2001) Temporal behavior of intraarticular gadolinium. J Comput Assist Tomogr 25(5):661–670PubMedView ArticleGoogle Scholar
- Miller TT (2000) MR arthrography of the shoulder and hip after fluoroscopic landmarking. Skeletal Radiol 29(2):81–84PubMedView ArticleGoogle Scholar
- Graves MJ, Wakely S, Bearcroft PW et al (2008) MR-guided direct arthrography of the hip. J Magn Reson Imaging 28(2):462–465PubMedView ArticleGoogle Scholar
- Guglielmi G, Biccari N, Mangano F, Toffanin R (2010) 3 T magnetic resonance imaging of the musculoskeletal system. Radiol Med. doi:10.1007/s11547–010–0521–4Google Scholar
- Niitsu M, Nakai T, Ikeda K, Tang GY, Yoshioka H, Itai Y (2000) High–resolution MR imaging of the knee at 3 T. Acta Radiol 41(1):84–88PubMedView ArticleGoogle Scholar
- Ramnath RR (2006) 3T MR imaging of the musculoskeletal system (Part II): clinical applications. Magn Reson Imaging Clin N Am 14(1):41–62PubMedView ArticleGoogle Scholar
- Peterson DM, Carruthers CE, Wolverton BL et al (1999) Application of a birdcage coil at 3 Tesla to imaging of the human knee using MRI. Magn Reson Med 42(2):215–221PubMedView ArticleGoogle Scholar
- Ryan M, Cunningham P, Cantwell C, Brennan D, Eustace S (2005) A comparison of fast MRI of hips with and without parallel imaging using SENSE. Br J Radiol 78(928):299–302PubMedView ArticleGoogle Scholar
- Plotz GM, Brossmann J, von Knoch M, Muhle C, Heller M, Hassenpflug J (2001) Magnetic resonance arthrography of the acetabular labrum: value of radial reconstructions. Arch Orthop Trauma Surg 121(8):450–457PubMedView ArticleGoogle Scholar
- Kubo T, Horii M, Harada Y et al (1999) Radial–sequence magnetic resonance imaging in evaluation of acetabular labrum. J Orthop Sci 4(5):328–332PubMedView ArticleGoogle Scholar
- Hong RJ, Hughes TH, Gentili A, Chung CB (2008) Magnetic resonance imaging of the hip. J Magn Reson Imaging 27(3):435–445PubMedView ArticleGoogle Scholar
- Saupe N, Zanetti M, Pfirrmann CW, Wels T, Schwenke C, Hodler J (2009) Pain and other side effects after MR arthrography: prospective evaluation in 1085 patients. Radiology 250(3):830–838PubMedView ArticleGoogle Scholar
- Hugo PC 3rd, Newberg AH, Newman JS, Wetzner SM (1998) Complications of arthrography. Semin Musculoskelet Radiol 2(4):345–348PubMedView ArticleGoogle Scholar
- Watanabe W, Itoi E, Yamada S (2002) Early MRI findings of rapidly destructive coxarthrosis. Skeletal Radiol 31(1):35–38PubMedView ArticleGoogle Scholar
- Wyler A, Bousson V, Bergot C et al (2007) Hyaline cartilage thickness in radiographically normal cadaveric hips: comparison of spiral CT arthrographic and macroscopic measurements. Radiology 242(2):441–449PubMedView ArticleGoogle Scholar
- Engel A, Hajek PC, Kramer J (1990) Magnetic resonance knee arthrography. Acta Orthop Scand 61(Suppl 240):1–47Google Scholar
- Keene GS, Villar RN (1994) Arthroscopic anatomy of the hip: an in vivo study. Arthroscopy 10(4):392–399PubMedView ArticleGoogle Scholar
- Tschauner C, Hofmann S, Czerny C (1997) Hip dysplasia. Morphology, biomechanics and therapeutic principles with reference to the acetabular labrum. Orthopade 26(1):89–108PubMedView ArticleGoogle Scholar
- Hodler J, Yu JS, Goodwin D, Haghighi P, Trudell D, Resnick D (1995) MR arthrography of the hip: improved imaging of the acetabular labrum with histologic correlation in cadavers. AJR Am J Roentgenol 165(4):887–891PubMedView ArticleGoogle Scholar
- Edwards DJ, Lomas D, Villar RN (1995) Diagnosis of the painful hip by magnetic resonance imaging and arthroscopy. J Bone Joint Surg Br 77(3):374–376PubMedGoogle Scholar
- Petersilge CA, Haque MA, Petersilge WJ, Lewin JS, Lieberman JM, Buly R (1996) Acetabular labral tears: evaluation with MR arthrography. Radiology 200(1):231–235PubMedView ArticleGoogle Scholar
- Williams PL, Warwick R (1980) Arthrology: the joints of the lower limb—the hip (coaxial) joint. Saunders, PhiladelphiaGoogle Scholar
- Czerny C, Hofmann S, Urban M et al (1999) MR arthrography of the adult acetabular capsular–labral complex: correlation with surgery and anatomy. AJR Am J Roentgenol 173(2):345–349PubMedView ArticleGoogle Scholar
- Aydingoz U, Ozturk MH (2001) MR imaging of the acetabular labrum: a comparative study of both hips in 180 asymptomatic volunteers. Eur Radiol 11(4):567–574PubMedView ArticleGoogle Scholar
- Cotten A, Boutry N, Demondion X et al (1998) Acetabular labrum: MRI in asymptomatic volunteers. J Comput Assist Tomogr 22(1):1–7PubMedView ArticleGoogle Scholar
- Abe I, Harada Y, Oinuma K et al (2000) Acetabular labrum: abnormal findings at MR imaging in asymptomatic hips. Radiology 216(2):576–581PubMedView ArticleGoogle Scholar
- Lecouvet FE, Vande Berg BC, Malghem J et al (1996) MR imaging of the acetabular labrum: variations in 200 asymptomatic hips. AJR Am J Roentgenol 167(4):1025–1028PubMedView ArticleGoogle Scholar
- Studler U, Kalberer F, Leunig M et al (2008) MR arthrography of the hip: differentiation between an anterior sublabral recess as a normal variant and a labral tear. Radiology 249(3):947–954PubMedView ArticleGoogle Scholar
- Dinauer PA, Murphy KP, Carroll JF (2004) Sublabral sulcus at the posteroinferior acetabulum: a potential pitfall in MR arthrography diagnosis of acetabular labral tears. AJR Am J Roentgenol 183(6):1745–1753PubMedView ArticleGoogle Scholar
- Czerny C, Hofmann S, Neuhold A et al (1996) Lesions of the acetabular labrum: accuracy of MR imaging and MR arthrography in detection and staging. Radiology 200(1):225–230PubMedView ArticleGoogle Scholar
- Dameron TB (959) Bucket–handle tear of acetabular labrum accompanying posterior dislocation of the hip. 1 41:131–134Google Scholar
- Dorrell JH, Catterall A (1986) The torn acetabular labrum. J Bone Joint Surg Br 68(3):400–403PubMedGoogle Scholar
- Fitzgerald RH Jr (1995) Acetabular labrum tears. Diagnosis and treatment. Clin Orthop Relat Res 311:60–68PubMedGoogle Scholar
- Mintz DN, Hooper T, Connell D, Buly R, Padgett DE, Potter HG (2005) Magnetic resonance imaging of the hip: detection of labral and chondral abnormalities using noncontrast imaging. Arthroscopy 21(4):385–393PubMedView ArticleGoogle Scholar
- Ghebontni L, Roger B, El-khoury J, Brasseur JL, Grenier PA (2000) MR arthrography of the hip: normal intra–articular structures and common disorders. Eur Radiol 10(1):83–88PubMedView ArticleGoogle Scholar
- Leunig M, Werlen S, Ungersbock A, Ito K, Ganz R (1997) Evaluation of the acetabular labrum by MR arthrography. J Bone Joint Surg Br 79(2):230–234PubMedView ArticleGoogle Scholar
- Blankenbaker DG, De Smet AA, Keene JS, Fine JP (2007) Classification and localization of acetabular labral tears. Skeletal Radiol 36(5):391–397PubMedView ArticleGoogle Scholar
- Lage LA, Patel JV, Villar RN (1996) The acetabular labral tear: an arthroscopic classification. Arthroscopy 12(3):269–272PubMedView ArticleGoogle Scholar
- Magee T, Hinson G (2000) Association of paralabral cysts with acetabular disorders. AJR Am J Roentgenol 174(5):1381–1384PubMedView ArticleGoogle Scholar
- Kramer J, Recht MP (2002) MR arthrography of the lower extremity. Radiol Clin North Am 40(5):1121–1132PubMedView ArticleGoogle Scholar
- McCarthy JC, Busconi B (1995) The role of hip arthroscopy in the diagnosis and treatment of hip disease. Orthopedics 18(8):753–756PubMedGoogle Scholar
- Beaule PE, Zaragoza E, Copelan N (2004) Magnetic resonance imaging with gadolinium arthrography to assess acetabular cartilage delamination. A report of four cases. J Bone Joint Surg Am 86-A(10):2294–2298PubMedGoogle Scholar
- Beck M, Leunig M, Parvizi J, Boutier V, Wyss D, Ganz R (2004) Anterior femoroacetabular impingement: part II. Midterm results of surgical treatment. Clin Orthop Relat Res 418:67–73PubMedView ArticleGoogle Scholar
- Bredella MA, Stoller DW (2005) MR imaging of femoroacetabular impingement. Magn Reson Imaging Clin N Am 13(4):653–664PubMedView ArticleGoogle Scholar
- Ganz R, Parvizi J, Beck M, Leunig M, Notzli H, Siebenrock KA (2003) Femoroacetabular impingement: a cause for osteoarthritis of the hip. Clin Orthop Relat Res(417):112–120Google Scholar
- Tanzer M, Noiseux N (2004) Osseous abnormalities and early osteoarthritis: the role of hip impingement. Clin Orthop Relat Res 429:170–177PubMedView ArticleGoogle Scholar
- Tannast M, Siebenrock KA, Anderson SE (2007) Femoroacetabular impingement: radiographic diagnosis-what the radiologist should know. AJR Am J Roentgenol 188(6):1540–1552PubMedView ArticleGoogle Scholar
- Beck M, Kalhor M, Leunig M, Ganz R (2005) Hip morphology influences the pattern of damage to the acetabular cartilage: femoroacetabular impingement as a cause of early osteoarthritis of the hip. J Bone Joint Surg Br 87(7):1012–1018PubMedView ArticleGoogle Scholar
- Notzli HP, Wyss TF, Stoecklin CH, Schmid MR, Treiber K, Hodler J (2002) The contour of the femoral head-neck junction as a predictor for the risk of anterior impingement. J Bone Joint Surg Br 84(4):556–560PubMedView ArticleGoogle Scholar
- Rakhra KS, Sheikh AM, Allen D, Beaule PE (2009) Comparison of MRI alpha angle measurement planes in femoroacetabular impingement. Clin Orthop Relat Res 467(3):660–665PubMedPubMed CentralView ArticleGoogle Scholar
- Kassarjian A, Yoon LS, Belzile E, Connolly SA, Millis MB, Palmer WE (2005) Triad of MR arthrographic findings in patients with cam-type femoroacetabular impingement. Radiology 236(2):588–592PubMedView ArticleGoogle Scholar
- Leunig M, Beck M, Kalhor M, Kim YJ, Werlen S, Ganz R (2005) Fibrocystic changes at anterosuperior femoral neck: prevalence in hips with femoroacetabular impingement. Radiology 236(1):237–246PubMedView ArticleGoogle Scholar
- Ganz R, Leunig M, Leunig-Ganz K, Harris WH (2008) The etiology of osteoarthritis of the hip: an integrated mechanical concept. Clin Orthop Relat Res 466(2):264–272PubMedPubMed CentralView ArticleGoogle Scholar
- Lavigne M, Parvizi J, Beck M, Siebenrock KA, Ganz R, Leunig M (2004) Anterior femoroacetabular impingement: part I. Techniques of joint preserving surgery. Clin Orthop Relat Res 418:61–66PubMedView ArticleGoogle Scholar
- Neumann M, Cui Q, Siebenrock KA, Beck M (2009) Impingement-free hip motion: the 'normal' angle alpha after osteochondroplasty. Clin Orthop Relat Res 467(3):699–703PubMedPubMed CentralView ArticleGoogle Scholar
- Ruelle M, Dubois JL (1962) The protrusive malformation and its arthrosic complication. I. Radiological and clinical symptoms. Etiopathogenesis. Rev Rhum Mal Osteoartic 29:476–489PubMedGoogle Scholar
- Siebenrock KA, Schoeniger R, Ganz R (2003) Anterior femoro-acetabular impingement due to acetabular retroversion. Treatment with periacetabular osteotomy. J Bone Joint Surg Am 85-A(2):278–286PubMedGoogle Scholar
- Frot B, Duparc J (1973) Radiologic measurement of anteversion, inclination and depth of the acetabulum. J Radiol Electrol Med Nucl 54(3):213–222PubMedGoogle Scholar
- Aubry S, Marinescu A, Forterre O, Runge M, Garbuio P (2005) Definition of a reproducible method for acetabular anteversion measurement at CT. J Radiol 86(4):399–404PubMedView ArticleGoogle Scholar
- Jamali AA, Mladenov K, Meyer DC et al (2007) Anteroposterior pelvic radiographs to assess acetabular retroversion: high validity of the "cross-over-sign". J Orthop Res 25(6):758–765PubMedView ArticleGoogle Scholar
- Kalberer F, Sierra RJ, Madan SS, Ganz R, Leunig M (2008) Ischial spine projection into the pelvis: a new sign for acetabular retroversion. Clin Orthop Relat Res 466(3):677–683PubMedPubMed CentralView ArticleGoogle Scholar
- Knuesel PR, Pfirrmann CW, Noetzli HP et al (2004) MR arthrography of the hip: diagnostic performance of a dedicated water-excitation 3D double-echo steady-state sequence to detect cartilage lesions. AJR Am J Roentgenol 183(6):1729–1735PubMedView ArticleGoogle Scholar
- Schmid MR, Notzli HP, Zanetti M, Wyss TF, Hodler J (2003) Cartilage lesions in the hip: diagnostic effectiveness of MR arthrography. Radiology 226(2):382–386PubMedView ArticleGoogle Scholar
- Nishii T, Tanaka H, Nakanishi K, Sugano N, Miki H, Yoshikawa H (2005) Fat-suppressed 3D spoiled gradient-echo MRI and MDCT arthrography of articular cartilage in patients with hip dysplasia. AJR Am J Roentgenol 185(2):379–385PubMedView ArticleGoogle Scholar
- Llopis E, Cerezal L, Kassarjian A, Higueras V, Fernandez E (2008) Direct MR arthrography of the hip with leg traction: feasibility for assessing articular cartilage. AJR Am J Roentgenol 190(4):1124–1128PubMedView ArticleGoogle Scholar
- Nakanishi K, Tanaka H, Nishii T, Masuhara K, Narumi Y, Nakamura H (1999) MR evaluation of the articular cartilage of the femoral head during traction. Correlation with resected femoral head Acta Radiol 40(1):60–63PubMedGoogle Scholar
- Wettstein M, Guntern D, Theumann N (2008) Direct MR arthrography of the hip with leg traction: feasibility for assessing articular cartilage. AJR Am J Roentgenol, 191(5):W206; author reply W207Google Scholar
- Neumann G, Mendicuti AD, Zou KH et al (2007) Prevalence of labral tears and cartilage loss in patients with mechanical symptoms of the hip: evaluation using MR arthrography. Osteoarthritis Cartilage 15(8):909–917PubMedView ArticleGoogle Scholar
- Noguchi Y, Miura H, Takasugi S, Iwamoto Y (1999) Cartilage and labrum degeneration in the dysplastic hip generally originates in the anterosuperior weight-bearing area: an arthroscopic observation. Arthroscopy 15(5):496–506PubMedView ArticleGoogle Scholar
- Felson DT, Chaisson CE, Hill CL et al (2001) The association of bone marrow lesions with pain in knee osteoarthritis. Ann Intern Med 134(7):541–549PubMedView ArticleGoogle Scholar
- Kramer J, Laub G, Czerny C, Recht M (2006) MR and MR arthrography in imaging of the hip and bony pelvis. Springer, Berlin HeidelbergGoogle Scholar
- Gray AJ, Villar RN (1997) The ligamentum teres of the hip: an arthroscopic classification of its pathology. Arthroscopy 13(5):575–578PubMedView ArticleGoogle Scholar