I do not routinely use MR arthrography for evaluation of labral pathology. One, it's a painful exam, the volume of the injection is painful, with minimal local anesthetic. Thus, the ability to determine the adequacy of response is mitigated. Further, a painful prior injection with the arthrogram confounds the injection that I typically like to do myself in the office using ultrasound guidance. I give my patients a pain diary to quantitatively document their pre-injection VAS and their VAS at 5, 30, 60 minutes, 2, 3, 6, 12, 24 hours, and 2, 3, 7, 14 days.

The literature demonstrates no significant advantage of addition of intra-articular gadolinium over non-arthrogram images. Reurink et al, J Bone Joint Surg Am 2012, among others. The diagnosis of labral pathology, especially in conjunction with femoroacetabular impingement, is largely clinical with corroboration of plain film radiographs (weight-bearing AP, false profile, 45 degree Dunn, 90 degree Dunn). If surgical intervention planned, CT is added with axial, axial oblique, sagittal, coronal, and 3D images obtained.

Dear Joshua the study you mention: J Bone Joint Surg Am. 2012 Sep 19;94(18):1643-8 - Reliability and validity of diagnosing acetabular labral lesions with magnetic resonance arthrography; show a high positive predicted value compares the acetabular labrul lesions on magnetic resonance arthrograms of patients who underwent hip arthroscopy, which was defined as the gold standard, and demostrate a high positive predictive value and a low negative predictive value showing that MR arthrography is superior at ruling in, rather than ruling out, labral lesions, chondral lesions, and loose bodies.

However, a large scale study is needed comparing the accuracy diagnostic values of MRI versus MR-arthrography regarding following hip arthroscopy.

Do you know these results???

Thank you Gustavo. The Reurink study is a high quality diagnostic study that compares MRA to arthroscopy. Unfortunately, it did not have a comparison group with non-enhanced imaging (1.5-T or 3.0-T) MRI. Further, there is minimal literature that compares these two imaging techniques, using arthroscopy as the gold standard. Sundberg TP et al in 2006 (Radiology) compared non-arthrogram 3.0-T MRI and 1.5-T MRA and showed no significant difference in detection of labral injury. The Reurink study has several limitations that preclude the widespread use of MRA (aside from the pain of the injection, the potential complications, the timing of the injection required to be performed by a radiologist, the inability to be around the patient to assess the response to the local anesthetic, the scheduling difficulties for performance of the exam, and the confounding nature for future injections) and these include the inter-observer reliability of only 0.268 (fair), an imperfect sensitivity and specificity (86% and 75%/50%) that is not significantly better than that of non-arthrogram MRI, a very low NPV, and a high PPV that is almost certainly elevated due to the fact that labral injury is so prevalent in the population (and especially the population getting a hip MRI for hip pain) (up to 70% prevalence in even asymptomatic athletes).

When ordering my non-arthrogram MRI, i recommend evaluating the labrum with fluid sensitive sequences (STIR, T2-weighting) using at least a 1.5-T magnet (preferably 3.0-T) and correlating with history and physical examination. Thank you Gustavo. Please let me know your thoughts.

In fact MRA is an invasive technique that requires coordination between conventional radiology room and MR room and can have complications as extravasation of contrast outside ends leading to over distension - be confused with a capsular rupture; air injection - and be confused with loose bodies and the most frequent the pain with movement aprox. during first 2 days and other no less important as vaso-vagal reactions, infections - 0.003% or anaphylactic shocks, undoubtedly facts to consider when thinking about MRA versus MRI!!!

Thank you very much, Joshua for sharing with us your trick, avoiding all those problems.

I think that training of each physician looking at MRI/MRA could also influence the accuracy of the interpretation of those images. Differences could be in minimal details.

It could be interesting to make a study comparing the inter-observer reliability of MRI versus MRA…

Dear Gustavo

This article may be useful for you

Thank you Dear Nelson. The article seems a classic...17 years have passed through it!!!Can you share with us your experience/opinion about MR-artrography of the hip??

Dear Gustavo

The MR- arthrography is a procedure that I use infrequently because the traditional MR has been sufficient

Dear Gustavo, I also think that MRI-arthrography should be performed in extremely rare cases. Usually, MRI or CT with 3D-reconstruction (Siebenrock) is sufficiently informative. Especially, for femoroacetabular impingement syndrome the dynamic motion simulation with MRI can be very useful. The advantages of the latter methods are that they are non-invasive.

http://www.clinicalgraphics.com

Thank you Dear Panayot for the suggestion bringing us this new system of visualizing images.

The 3D-reconstruction is the future of the imagiology and it will improve until almost in-vivo real images!!!!

Do you think that this type of technology will boost radiology or may decrease the need of physicians so specialized in medical images?

http://youtu.be/82jSftX-1C0

The 3D-reconstruction is really a great achievement, but it does not give enough information about the infrastructure (under the surface) of the objects examined. So far the conventional MRI and CT imaging have their place in the diagnostics.

Correct injection site for intra-articular contrast

I aim for the red dot when using fluoro. When the needle is going in, I assure that the bevel is facing medially so that it will glide off the lateral side of head and not penetrate the cartilage or bone. I attached Dr Byrd's recent paper that looks at both fluoroscopic and ultrasound-guided injections into the hip. Great simple read on both techniques.

What are your thoughts on "landmark-guided" intra-articular injections? see attached paper from Dr Mei-Dan.

Thank you Joshua for sharing with us such high-quality articles regarding the technique of an intra-articular hip injection.

Let me ask you if you think that traction is key to perform a good artrography?Did you perform it routinely as part of the technique???

Thank you Gustavo. When I perform an intra-articular injection, I have the patient lie supine and have their feet/toes pointed up toward the ceiling with a loose rubber band to prevent natural lower extremity external rotation while laying in this position. I use ultrasound to identify the anterior capsule via Byrd technique from 2013 Arthroscopy article referenced above. I feel it probably would be easier to use traction. However, since all my injections are performed in the office and not the operating room, I am unable to perform traction. The use of the ultrasound has helped my technique significantly to assure correct needle placement without traction.

Intraarticular hip injection: Pat. lies supine, legs with some external rotation. Palpable points are SIAS and Symphysis. Where the longitudinal and transversal lines from SIAS, respect. Symphysis cross at the inguinal region lies in most cases the hip joint. For safety I palpate the femoral art. pulse and place the needle. In case of bony contact, I perform the injection. If uncertain, I use ultrasound to identify the joint.

Hi Douglas, you are right. And you are providing radiation with each hip injection, unessarily.

Hello dear professionals, I want to share with you a problem case demonstrating the need for adequate clinical evaluation and diagnostic suspicion properly using the methods of images. the radiological study is the first ever review, should never be overlooked. in relation to the traumatic history CT should be performed afterwards. should not make a arthroMR directly. This test notes intraarticular estrucutras well but can not assess the periarticular lesions. The study should include a STIR render sequence to evaluate bone edema. as shown in the case I present the bone edema in the posterior margin of the acetabulum helps us to think of a fracture associated with a negative test lidocaine. finding confiirmado with multislice CT. It would have been useful to perform CT first, but with an acetabular fracture, should ask what happens to the adjacent labrum? I can say that this injury ?, only arthrographic study confirms and changes the SURGICAL behavior. Well, I hope will be helpful. Greetings.

Thank you Douglas and Rafael for you contribution in this debate. The question is that your patient have a “special” rare fracture of the posterior acetabular rim and in that case the R-Ray can dismiss it. The order of the complementary exams is a good question to be consider, in that case I think that the clinical findings could certainly be the key. In your case you have a Rugby athlete of 36 years-old that falls on a tackle...by the lesion mechanism, age, weight and with a well-performed physical exam I´d ask for a CT rather than a MRA! But speaking about a know case It´s very different of taking the correct “in situ” live decision...