Hip MRI Protocol: The Complete Radiographer & Radiologist Guide
🧲 Sequences Used
- Large-FOV bilateral coronal T1 and STIR (screening/comparison)
- Small-FOV unilateral oblique T2 fat-saturated (labrum, cartilage)
- Axial T1/T2 through the symptomatic hip
- Sagittal imaging for anterosuperior labral/cartilage assessment
💉 Contrast Protocol
10–15 mL (0.1 mmol/kg) gadolinium-based agent at 2.0 mL/s, followed by a 100 mL saline chaser at 2.0 mL/s, used selectively for suspected infection, tumor, or as part of MR arthrography for labral/cartilage assessment.
🎯 Artifact Reduction
Primary artifact: phase wraparound (aliasing), where anatomy extending beyond the FOV in the phase-encoding direction wraps onto the opposite side of the image. Remedy: increase FOV in the phase-encoding direction or activate phase oversampling.
⚠️ Key Pitfalls
- Radiographers: FOV too tight in the phase direction for bilateral coverage
- Radiologists: wrapped soft tissue mistaken for a true mass or collection
- Referrers: acting on a unilateral study when contralateral comparison was needed
- Introduction
- Hip Anatomy Essentials
- MR Tissue Relaxation Values
- Scanning Technique — 10 Steps
- Contrast Media Protocol
- Specific Absorption Rate & Dose Reduction
- Top 10 Pathologies
- Pitfalls — Radiographers
- Pitfalls — Radiologists
- Pitfalls — Non-Radiology Physicians
- Pitfall Comparison Summary
- AI & Automation in Hip MRI
- Further Reading
- Reducing Artefacts with Patients and Parameters
- Parallel Imaging Protocols and Parameters
- Conclusion
- References
Introduction
A well-executed hip MRI protocol is unusual among the musculoskeletal studies in this series for combining two distinct diagnostic tasks in one examination: a wide-coverage bilateral screen that catches asymmetric marrow signal, avascular necrosis, and stress-related change that could otherwise be missed if only the symptomatic side were imaged, followed by a tightly focused unilateral study of the labrum and articular cartilage on the side of clinical concern. This two-part design is precisely what makes correct field-of-view management — and the phase wraparound artifact it prevents — the central technical theme of this protocol.
Many hip pathologies, particularly avascular necrosis and stress-related bone marrow edema, have a meaningful rate of bilateral or contralateral involvement even when only one side is symptomatic. Missing early contralateral disease because the study was scoped too narrowly is a genuine, well-recognized failure mode this protocol’s large-FOV bilateral screening step is specifically designed to prevent — but wide bilateral coverage in the phase-encoding direction is exactly the scenario in which aliasing becomes most likely if FOV and oversampling settings are not managed correctly.
This guide walks through the complete hip MRI workflow: the femoroacetabular anatomy that dictates the two-part large-FOV/small-FOV design, relevant relaxation values, a ten-step scanning technique, the contrast protocol and when it is and is not required, SAR-conscious parameter selection, the top ten pathologies the protocol is built to detect, and the distinct pitfalls that affect radiographers at the console, radiologists at the workstation, and referring orthopedic surgeons acting on the report.
Reliable Contrast Delivery with SATline
Consistent, kink-resistant tubing supports reproducible timing when infection, tumor, or arthrographic assessment requires contrast.
Hip Anatomy Essentials
The hip is a deep ball-and-socket joint formed by the femoral head and the acetabulum, stabilized by a fibrocartilaginous labrum, a strong capsuloligamentous complex, and surrounded by the powerful muscle groups this protocol’s wide FOV must fully capture without introducing aliasing.
Femoral head and neck
The femoral head receives its blood supply predominantly from the medial femoral circumflex artery via the retinacular vessels running along the femoral neck — an anatomically vulnerable supply route that underlies the pathophysiology of avascular necrosis, particularly after femoral neck fracture or dislocation where these vessels can be disrupted. The femoral neck is a common site of both traumatic and stress-related fracture, assessed on the bilateral coronal STIR sequence for marrow edema and on dedicated sequences for a discrete fracture line.
Acetabulum and labrum
The acetabulum forms the socket, deepened by the fibrocartilaginous labrum that increases joint stability and contact area. Labral tears — frequently associated with femoroacetabular impingement (FAI) morphology — are best assessed on the small-FOV unilateral oblique T2 fat-saturated sequences, where spatial resolution is prioritized over coverage.
Femoroacetabular impingement morphology
Cam-type impingement refers to an aspherical femoral head-neck junction that abuts the acetabular rim during flexion, while pincer-type impingement refers to acetabular over-coverage. Both patterns predispose to labral and chondral injury and are assessed through a combination of morphological measurement (alpha angle, acetabular coverage) and direct labral/cartilage signal assessment.
MR Tissue Relaxation Values
Understanding baseline T1 and T2 relaxation times of normal femoral head marrow, cartilage, and labrum underpins correct recognition of the marrow edema and structural signal changes this protocol is designed to detect.
| Structure | T1 (ms) @ 1.5T | T1 (ident) @ 3T | T2 (ms) @ 1.5T | T2 (ms) @ 3T |
|---|---|---|---|---|
| Normal femoral head marrow (fatty) | ~250–350 | ~350–450 | ~60–80 | ~50–70 |
| Bone marrow edema | ~1000–1300 | ~1300–1600 | ~90–130 | ~75–110 |
| Avascular necrosis (subchondral band) | ~600–800 (variable, often hypointense) | ~750–1000 | ~30–50 (hypointense band) | ~25–42 |
| Acetabular labrum (fibrocartilage) | ~700–900 | ~900–1150 | ~20–30 | ~18–26 |
| Hyaline articular cartilage | ~900–1100 | ~1150–1400 | ~40–55 | ~35–48 |
| Skeletal muscle (reference) | ~870 | ~1420 | ~47 | ~32 |
This relaxation profile explains why bone marrow edema — the earliest and most sensitive MRI marker of avascular necrosis, stress reaction, transient osteoporosis, and occult fracture — shows up so clearly against normal fatty marrow once fat-suppressed STIR imaging is applied, and why the classic “double line sign” of avascular necrosis (a hypointense outer band and hyperintense inner band on T2) reflects the reparative-versus-necrotic tissue interface at the lesion margin.
Scanning Technique — 10 Steps
- Coil selection. Use a torso or dedicated pelvic phased-array coil positioned to cover both hips symmetrically for the bilateral screening component.
- Patient positioning. Position the patient supine, legs in slight internal rotation to reduce femoral neck foreshortening, with both hips centered in the coil.
- Localizer and FOV planning. Acquire a tri-plane localizer, then deliberately set the bilateral coronal FOV wide enough in the phase-encoding direction to include both hips plus a margin of surrounding soft tissue — this single decision is the primary defense against phase wraparound.
- Large-FOV bilateral coronal T1. Acquire for baseline marrow signal assessment and symmetric comparison between hips.
- Large-FOV bilateral coronal STIR. Acquire for sensitive detection of marrow edema, effusion, and early avascular necrosis across both hips simultaneously.
- Activate phase oversampling or confirm adequate FOV margin. Before proceeding, explicitly verify that phase-encoding FOV coverage or oversampling is sufficient to prevent wraparound from lateral soft tissue or the contralateral limb.
- Small-FOV unilateral oblique T2 fat-saturated. Acquire through the symptomatic hip, oriented along the femoral neck axis, for detailed labral and articular cartilage assessment.
- Axial T1/T2 through the symptomatic hip. Acquire for additional labral, capsular, and periarticular soft tissue detail.
- Sagittal imaging through the symptomatic hip. Acquire for anterosuperior labral and cartilage assessment, a common site of FAI-related pathology.
- Quality review before release. Confirm no visible wraparound artifact overlaps the hips or surrounding soft tissue on the bilateral sequences, and that the unilateral small-FOV sequences provide adequate spatial resolution for labral/cartilage detail before releasing the patient.
Scanner comparison table (1.5T vs. 3.0T)
| Parameter | 1.5T | 3.0T |
|---|---|---|
| Labral/cartilage conspicuity on small-FOV imaging | Good, standard resolution | Improved, supports finer labral and chondral detail |
| SNR | Baseline | ~1.7–2× higher, supporting higher in-plane resolution |
| Phase wraparound risk | Present if FOV/oversampling mismanaged | Equally present — field strength does not change the underlying Nyquist/FOV relationship |
| Metal artifact (from prior hip hardware) | Less pronounced | More pronounced — metal artifact reduction sequences more frequently needed |
| SAR headroom for the multi-sequence bilateral/unilateral block | Greater | More restrictive; turbo factor moderation typically required |
Precision-Filled Syringes with SATSyringe
Accurately dosed, air-bubble-minimized syringes support reliable timing on the occasions contrast-enhanced hip MRI is indicated.
Contrast Media Protocol
Contrast use in hip MRI is selective rather than routine — many indications, including avascular necrosis staging and stress fracture assessment, are well served by non-contrast bilateral T1/STIR and unilateral T2 fat-saturated imaging alone.
- Volume: 10–15 mL (0.1 mmol/kg) gadolinium-based contrast agent
- Flow rate: 2.0 mL/s
- Chaser: 100 mL saline at 2.0 mL/s
- Indication: Suspected infection (septic arthritis, osteomyelitis), tumor characterization, or MR arthrography for labral/cartilage assessment
Contrast is most clearly indicated when the clinical question involves distinguishing infected from sterile fluid collections, characterizing a soft tissue or osseous mass, or — via direct MR arthrography with intra-articular dilute gadolinium — improving labral tear detection sensitivity in equivocal cases. For the large majority of avascular necrosis, stress fracture, and impingement-related studies, non-contrast imaging is both sufficient and preferred.
Specific Absorption Rate & Dose Reduction
The combination of large-FOV bilateral STIR imaging and multiple small-FOV fat-saturated sequences makes this a moderately RF-intensive protocol, particularly at 3T.
| Regulatory Body | Whole-body SAR limit (normal mode) | Relevance to hip MRI protocol |
|---|---|---|
| ICRP | Guidance framework for RF exposure, not device-specific limits | Underpins the general ALARA principle applied to RF exposure across this two-part bilateral/unilateral protocol |
| IEC 60601-2-33 / adopted by EC RP 185 | 2 W/kg whole-body (normal operating mode) | Governs the cumulative RF load of bilateral STIR plus multiple unilateral fat-saturated sequences performed in one sitting |
| AAPM | Practice guidance aligned with IEC limits; emphasizes local monitoring | Recommends departmental SAR auditing for multi-sequence pelvic/hip protocols, particularly at 3T |
Five dose reduction strategies
- Use STIR selectively where fat-sat T2 with spectral suppression is unreliable, since STIR is more RF-efficient in some configurations but should be matched to the specific field homogeneity challenge at hand.
- Employ parallel imaging on both bilateral and unilateral sequences to reduce total RF pulses.
- Limit the small-FOV unilateral sequence set to the symptomatic side unless bilateral symptoms specifically warrant duplicating the detailed unilateral protocol.
- Reserve contrast-enhanced imaging for the specific infection/tumor/arthrography indications described above rather than acquiring it routinely.
- Moderate turbo factor on fat-saturated sequences to balance the fine labral and cartilage detail this protocol depends on against RF duty cycle.
Consistent Bolus Geometry with SATMix
Standardized contrast-to-saline mixing supports reliable enhancement assessment when infection or tumor characterization is indicated.
Top 10 Pathologies
Avascular necrosis of the femoral head
Frequently bilateral — the primary rationale for this protocol’s large-FOV bilateral screening component.
Femoroacetabular impingement (cam/pincer)
Morphological measurement (alpha angle) combined with direct labral/cartilage assessment on small-FOV imaging.
Acetabular labral tear
Best assessed on the small-FOV unilateral oblique T2 fat-saturated sequence.
Femoral neck stress fracture
Compression-side (inferior) fractures are typically stable; tension-side (superior) fractures carry higher displacement risk.
Transient osteoporosis / bone marrow edema syndrome
Self-limited condition that must be distinguished from early avascular necrosis and stress fracture.
Hip osteoarthritis
Often the end-stage of untreated FAI or labral pathology, assessed across both bilateral and unilateral sequences.
Septic arthritis / osteomyelitis
A genuine indication for contrast-enhanced imaging; time-sensitive diagnosis requiring urgent communication.
Greater trochanteric pain syndrome
A common extra-articular mimicker of intra-articular hip pathology, requiring specific attention to the lateral soft tissues.
Insufficiency fracture (pelvis/sacrum)
Relevant when bilateral coverage extends to include the sacrum and pubic rami in osteoporotic patients.
Synovial pathology (e.g., pigmented villonodular synovitis)
Characteristic hemosiderin-related signal loss on gradient-echo sequences supports the diagnosis.
Confident Lesion Characterization Starts with SATline
Reliable, consistent contrast delivery lines support enhancement assessment when infection or tumor characterization is indicated.
Pitfalls — Radiographers
Primary scanning pitfall (from protocol data): Phase wraparound (aliasing) occurring when the bilateral coronal FOV is set too narrow in the phase-encoding direction, causing soft tissue outside the FOV to wrap onto the opposite side of the image.
| Category | Description | Mitigation |
|---|---|---|
| FOV too narrow in the phase-encoding direction | Setting bilateral coronal FOV to just cover both hips without margin allows lateral soft tissue (thigh, contralateral anatomy) to wrap onto the image, potentially overlapping the hips themselves. | Deliberately widen FOV in the phase-encoding direction to include a margin of soft tissue beyond both hips, rather than cropping tightly. |
| Phase oversampling not activated | Relying on FOV size alone without activating phase oversampling (when available) as an additional safeguard against aliasing. | Activate phase oversampling by protocol default for the bilateral coronal sequences, accepting the modest scan time increase this requires. |
| Phase-encoding direction chosen without considering anatomy width | Applying a phase-encoding direction that places the widest anatomic dimension (side-to-side, spanning both hips) along the more aliasing-prone axis without compensating FOV/oversampling adjustment. | Consider anatomic width specifically when choosing phase-encoding direction, and compensate with adequate FOV or oversampling regardless of the direction chosen. |
| Small-FOV unilateral sequence mis-angled | Prescribing the oblique unilateral T2 fat-saturated sequence without correct reference to the femoral neck axis, degrading labral/cartilage detail. | Reference the oblique plane directly from the axial or coronal localizer at the level of the femoral neck for the symptomatic hip. |
| Incomplete bilateral coverage | FOV or coil positioning that inadvertently excludes part of the contralateral hip from the bilateral screening sequence. | Confirm both femoral heads and necks are fully included in the bilateral coronal sequences before proceeding to the unilateral component. |
Pitfalls — Radiologists
Primary interpretation pitfall (from protocol data): Wrapped soft tissue signal from phase aliasing mistaken for a true mass, fluid collection, or bone marrow abnormality overlapping the hip or pelvis.
| Pitfall | Mechanism | Consequence | Mitigation |
|---|---|---|---|
| Aliased tissue misread as pathology | Soft tissue from outside the FOV wraps onto the image and superimposes over the hip or pelvis, creating an apparent signal abnormality that does not correspond to a real anatomic structure at that location. | False-positive mass, collection, or marrow abnormality reported, triggering unnecessary follow-up. | Recognize the characteristic appearance of wraparound artifact (anatomically implausible tissue type or position, sharp cutoff at FOV edge) and confirm any suspicious finding is anatomically consistent before reporting it as pathology. |
| True pathology obscured by superimposed aliasing | Genuine pathology at the FOV edge is partially obscured or distorted by overlapping wrapped signal from the opposite side. | Missed or under-characterized true finding at the periphery of the image. | Specifically scrutinize the lateral margins of bilateral coronal images for aliasing-related signal confusion, and recommend a repeat sequence with corrected FOV/oversampling if genuine uncertainty remains. |
| Contralateral hip under-assessed after focusing on the symptomatic side | Attention concentrated on the clinically symptomatic hip causes early or subtle bilateral avascular necrosis on the asymptomatic side to be overlooked on the bilateral screening sequences. | Missed early contralateral disease, delaying monitoring or treatment of a second, asymptomatic lesion. | Systematically and explicitly assess both femoral heads on the bilateral sequences, regardless of which side is clinically symptomatic. |
| Bone marrow edema pattern misclassified | Diffuse marrow edema without a discrete fracture line or double-line sign is misclassified as avascular necrosis rather than transient osteoporosis or stress reaction. | Incorrect diagnosis affecting management and prognosis communication. | Apply the specific morphological criteria (double-line sign, focal versus diffuse edema pattern) that distinguish these overlapping entities rather than treating any marrow edema as necrosis. |
Pitfalls — Non-Radiology Physicians
| Pitfall | What they see | What it actually is | Clinical danger | What to do |
|---|---|---|---|---|
| Requesting unilateral-only imaging when bilateral screening was indicated | An order for “MRI of the symptomatic hip” without specifying bilateral concern | A clinical scenario (e.g., corticosteroid use, alcohol use disorder, known risk factors for avascular necrosis) where contralateral involvement is genuinely possible and worth screening for | Missed early contralateral avascular necrosis that a bilateral protocol would have caught | Specify relevant risk factors on the request so the bilateral large-FOV component is included by default rather than only imaging the symptomatic side |
| Treating transient osteoporosis and avascular necrosis as clinically equivalent | A report describing bone marrow edema in the femoral head | Two distinct entities with different natural histories — transient osteoporosis is typically self-limited, while avascular necrosis often requires more active management | Over- or under-treatment based on conflating two conditions with a similar but distinguishable MRI appearance | Confirm which specific diagnosis the report supports (checking for the double-line sign and other distinguishing features) rather than treating “marrow edema” as a single diagnostic category |
| Assuming a normal MRI excludes early stress fracture | A normal or equivocal MRI in a patient with high clinical suspicion for femoral neck stress fracture | A potential false-negative in the earliest stages of stress reaction, before marrow edema becomes clearly apparent | Continued high-risk activity in an athlete with a true early stress injury, risking progression to a displaced fracture | Maintain clinical suspicion and consider short-interval follow-up imaging in high-risk patients (e.g., distance runners) with a compelling clinical picture despite an initially unremarkable MRI |
| Ordering contrast for routine avascular necrosis or FAI workup | A standing order including gadolinium regardless of clinical indication | Unnecessary gadolinium exposure for indications where non-contrast bilateral T1/STIR and unilateral T2 fat-sat imaging is fully sufficient | Avoidable contrast exposure and cost without added diagnostic value | Reserve contrast requests specifically for suspected infection, tumor, or arthrography-indicated labral assessment |
Reduce Repeat Scans with SATSyringe
Consistent, accurately dosed contrast delivery reduces mistimed enhancement assessment that leads to equivocal infection or tumor characterization.
Pitfall Comparison Summary
🟡 Scanning (Radiographers)
- FOV too narrow in phase-encoding direction
- Phase oversampling not activated
- Phase direction chosen without anatomy consideration
- Small-FOV unilateral sequence mis-angled
- Incomplete bilateral coverage
🔴 Interpretation (Radiologists)
- Aliased tissue misread as pathology
- True pathology obscured by aliasing
- Contralateral hip under-assessed
- Marrow edema pattern misclassified
🟣 Clinical (Physicians)
- Requesting unilateral-only when bilateral indicated
- Conflating transient osteoporosis and AVN
- Assuming normal MRI excludes early stress fracture
- Ordering contrast for routine AVN/FAI workup
AI & Automation in Hip MRI
Automated femoral head segmentation and avascular necrosis lesion quantification tools, along with alpha angle and acetabular coverage measurement software for FAI assessment, are increasingly available as CE-marked adjuncts to hip MRI reporting. These tools support more consistent bilateral comparison — directly relevant to the contralateral under-assessment pitfall discussed above — and can flag asymmetric marrow signal for radiologist attention even when clinical focus is concentrated on the symptomatic side.
As with other structured frameworks in this series, these tools support rather than replace radiologist judgment, particularly for distinguishing overlapping bone marrow edema patterns and correctly identifying wraparound artifact versus true pathology.
Consistent Inputs Make Better Outputs — SATMix
Whatever quantification or scoring software your department uses, standardized contrast mixing keeps the enhancement data feeding it reliable.
Further Reading
- 7 Proven Strategies for Optimizing MRI Sequences in 2026
- 2026 Contrast Media Guidelines: eGFR Thresholds & Safe Administration Protocol
- Top 100 Free Radiology Websites in 2026: A Global Guide
- MRCP Pancreas Protocol: 10 Proven Scanning Steps
- Liver MRI Protocol: 10 Critical Multiphasic Steps
Reducing Artefacts with Patients and Parameters
The most critical scanning parameters that impact image quality include:
1. Spatial Resolution
Spatial resolution defines the ability to distinguish small details in an image. Matrix Size: Increasing the matrix size (frequency × phase) increases spatial resolution, but decreases SNR because the voxel (3D pixel) size becomes smaller. Field of View (FOV): Reducing the FOV increases spatial resolution. However, smaller FOV results in smaller voxels and reduces SNR — and, critically for this protocol, an FOV set too small in the phase-encoding direction is the direct cause of the phase wraparound artifact this guide is built around. Slice Thickness: Thinner slices provide higher spatial resolution and reduce partial volume averaging, but significantly decrease SNR.
2. Signal-to-Noise Ratio (SNR)
SNR represents the strength of the diagnostic signal relative to inherent background noise. A high SNR produces crisp, clear images, whereas a low SNR looks grainy. Number of Averages (NEX/NSA): Increasing averages acquires data multiple times, which improves SNR. However, doubling the averages roughly doubles the scan time. Receiver Bandwidth: Decreasing the bandwidth limits the amount of noise recorded, boosting SNR. However, a lower bandwidth increases scan times and chemical shift artifacts. Coil Selection: Using dedicated, localized surface coils rather than whole-body coils captures much stronger signals and heavily improves SNR.
3. Image Contrast
Contrast determines how different tissues are distinguished from one another (e.g., highlighting bone vs. fluid vs. muscle). Repetition Time (TR): TR is the time between consecutive RF pulses. A short TR maximizes T1 tissue contrast, while a long TR minimizes it. Echo Time (TE): TE is the time between the RF pulse and the peak of the echo signal. A short TE minimizes T2 effects, and a long TE maximizes T2 weighting, making fluid-filled areas appear very bright. Flip Angle: Controls the excitation of protons. Adjusting the flip angle changes tissue contrast and is especially critical in gradient echo sequences.
4. Artifact Control
Artifacts are visual distortions or ghosting that degrade image quality. Phase Encoding Direction: Swapping the phase and frequency axes can shift motion-induced artifacts (like breathing or blood flow) away from the primary region of interest — and, as this protocol illustrates, the choice of phase-encoding direction relative to the widest anatomic dimension directly determines aliasing risk. Flow Compensation / Gating: Utilizes physiological triggers (e.g., electrocardiogram) to minimize blurring and ghosting caused by pulsatile motion. Parallel Imaging: Utilizes multiple coil elements simultaneously to reduce phase encoding steps, significantly cutting down scan time and reducing motion artifacts.
Parallel Imaging Protocols and Parameters
Parallel imaging acceleration in hip MRI must be balanced against the specific FOV and phase-encoding decisions this protocol’s primary artifact depends on, since acceleration factor and phase FOV interact directly in most vendor implementations.
| Sequence | Parameter | 1.5T typical setting | 3.0T typical setting | Adjustment for optimal quality |
|---|---|---|---|---|
| Bilateral coronal T1/STIR | Phase FOV / oversampling | 100–120% of anatomic width, or oversampling active | 100–120% of anatomic width, or oversampling active | Deliberately set generous phase FOV or activate oversampling regardless of field strength — this parameter, not field strength, governs aliasing risk |
| Bilateral coronal T1/STIR | Turbo factor | 12–16 | 12–16 | Moderate turbo factor acceptable given this sequence’s screening rather than fine-detail role |
| Small-FOV unilateral oblique T2 FS | Turbo factor | 8–12 | 8–12 | Keep conservative to preserve labral and cartilage fiber detail, this protocol’s fine-resolution component |
| Parallel imaging factor (all sequences) | Acceleration factor | 2× | 2–3× | Standard acceleration acceptable, but confirm phase FOV/oversampling settings remain adequate when acceleration is combined with a reduced phase FOV in some implementations |
As a general principle: unlike most other artifacts in this series, phase wraparound is not primarily solved by acceleration or turbo factor adjustment — it is solved by deliberate FOV and oversampling decisions made at the planning stage, before acquisition parameters are even considered. Radiographers should treat phase FOV verification as a discrete, non-skippable step in the protocol workflow rather than an implicit byproduct of other settings.
Conclusion
A technically sound hip MRI protocol rests on four pillars: deliberate, generous phase-encoding FOV or oversampling on the bilateral coronal sequences to prevent the wraparound artifact that most directly threatens this protocol’s screening function; correctly angled small-FOV unilateral imaging referenced to the femoral neck axis for labral and cartilage detail; a clear, indication-specific approach to contrast use reserved for infection, tumor, and arthrographic indications; and disciplined awareness of the distinct pitfall patterns that affect radiographers at acquisition, radiologists at interpretation, and referring orthopedic surgeons acting on the final report.
From avascular necrosis and femoroacetabular impingement through femoral neck stress fracture and the genuinely important transient-osteoporosis-versus-necrosis distinction, the protocol’s diagnostic power depends on respecting its two-part bilateral/unilateral design and the specific FOV discipline that design requires. Departments that standardize phase-encoding FOV verification, oversampling activation, and bilateral comparison consistently produce more diagnostic, less ambiguous hip MRI reports.
References
- American College of Radiology. (2023). ACR manual on contrast media (Version 2023). American College of Radiology. acr.org/Clinical-Resources/Contrast-Manual
- Mitchell, D. G., Rao, V. M., Dalinka, M. K., Spritzer, C. E., Alavi, A., Steinberg, M. E., Fallon, M., Kressel, H. Y. (1987). Femoral head avascular necrosis: Correlation of MR imaging, radiographic staging, radionuclide imaging, and clinical findings. Radiology, 162(3), 709–715. https://doi.org/10.1148/radiology.162.3.3809484
- Stevens, K., Tao, C., Lee, S. U., Salem, N., Vandevenne, J., Cheng, C., Neumann, G., Valentin-Opran, A., Lang, P. (2003). Subchondral fractures in osteonecrosis of the femoral head: Comparison of radiography, CT, and MR imaging. American Journal of Roentgenology, 180(2), 363–368. https://doi.org/10.2214/ajr.180.2.1800363
- Tannast, M., Siebenrock, K. A., & Anderson, S. E. (2007). Femoroacetabular impingement: Radiographic diagnosis — what the radiologist should know. American Journal of Roentgenology, 188(6), 1540–1552. https://doi.org/10.2214/AJR.06.0921
- James, S. L., Ali, K., Malara, F., Young, D., O’Donnell, J., & Connell, D. A. (2006). MRI findings of femoroacetabular impingement. American Journal of Roentgenology, 187(6), 1412–1419. https://doi.org/10.2214/AJR.05.1414
- Pfirrmann, C. W., Mengiardi, B., Dora, C., Kalberer, F., Zanetti, M., & Hodler, J. (2006). Cam and pincer femoroacetabular impingement: Characteristic MR arthrographic findings in 50 patients. Radiology, 240(3), 778–785. https://doi.org/10.1148/radiol.2403050767
- Kim, Y. H., Kim, J. S., Cho, S. H. (1999). Total hip arthroplasty for the treatment of osteonecrosis of the femoral head in systemic lupus erythematosus. Journal of Bone and Joint Surgery. American Volume, 81(11), 1587–1591. https://doi.org/10.2106/00004623-199911000-00012
- Yamamoto, T., Bullough, P. G. (2000). The role of subchondral insufficiency fracture in rapid destruction of the hip joint: A preliminary report. Arthritis & Rheumatism, 43(11), 2423–2427. https://doi.org/10.1002/1529-0131(200011)43:11<2423::AID-ANR8>3.0.CO;2-3
- Yao, L., Lee, J. K. (1988). Occult intraosseous fracture: Detection with MR imaging. Radiology, 167(3), 749–751. https://doi.org/10.1148/radiology.167.3.3363131
- Grangier, C., Garcia, J., Howarth, N. R., May, M., & Rossier, P. (1997). Role of MRI in the diagnosis of insufficiency fractures of the sacrum and acetabular roof. Skeletal Radiology, 26(9), 517–524. https://doi.org/10.1007/s002560050280
- Kim, S., Chang, J. D., & Chung, Y. K. (2012). Transient osteoporosis of the hip: MRI findings and its differentiation from avascular necrosis. Journal of the Korean Orthopaedic Association, 47(3), 194–200. https://doi.org/10.4055/jkoa.2012.47.3.194
- Kenny, P., Rice, J., Quinlan, W. (1990). Transient osteoporosis of the hip: A case report and review of the literature. Irish Journal of Medical Science, 159(7), 202–204. https://doi.org/10.1007/BF02937303
- Robertson, D. D., Armfield, D. R., Towers, J. D., & Irrgang, J. J. (2008). Radiographic assessment of femoroacetabular impingement. Journal of Bone and Joint Surgery. British Volume, 90(11), 1436–1445. https://doi.org/10.1302/0301-620X.90B11.21052
- Cerezal, L., Kassarjian, A., Canga, A., Dobado, M. C., Montero, J. A., Llopis, E., Rolón, A., & Pérez-Carro, L. (2010). Anatomy, biomechanics, imaging, and management of ligamentum teres injuries. RadioGraphics, 30(6), 1637–1651. https://doi.org/10.1148/rg.306105516
- Byrd, J. W., & Jones, K. S. (2004). Diagnostic accuracy of clinical assessment, magnetic resonance imaging, magnetic resonance arthrography, and intra-articular injection in hip arthroscopy patients. American Journal of Sports Medicine, 32(7), 1668–1674. https://doi.org/10.1177/0363546504266480
- Blankenbaker, D. G., De Smet, A. A. (2010). Hip injuries in athletes. Radiologic Clinics of North America, 48(6), 1155–1178. https://doi.org/10.1016/j.rcl.2010.07.003
- Kingzett-Taylor, A., Tirman, P. F., Feller, J., McGann, W., Prieto, V., Wischer, T., Cameron, J. A., Cvitanic, O., & Genant, H. K. (1999). Tendinosis and tears of gluteus medius and minimus muscles as a cause of hip pain: MR imaging findings. American Journal of Roentgenology, 173(4), 1123–1126. https://doi.org/10.2214/ajr.173.4.10511191
- Levin, A., & Stevens, P. E. (2024). Executive summary of the KDIGO 2024 clinical practice guideline for the evaluation and management of chronic kidney disease. Kidney International, 105(4), 684–701. https://doi.org/10.1016/j.kint.2023.10.016
- European Society of Urogenital Radiology. (2018). ESUR guidelines on contrast agents (Version 10.0). ESUR. esur.org/esur-guidelines-on-contrast-agents
- International Commission on Radiological Protection. (2020). ICRP publication 147: Use of dosimetric quantities for regulatory purposes. ICRP. icrp.org/publication.asp?id=ICRP Publication 147
- SATMED Health. (2026, May 31). 7 proven strategies for optimizing MRI sequences in 2026. https://www.satmed-health.com/optimizing-mri-sequences/
- SATMED Health. (2026, March 1). 2026 contrast media guidelines: eGFR thresholds & safe administration protocol. https://www.satmed-health.com/2026-worldwide-guidelines…
- Guerra, F. M., Bergman, A. G., Vidal, A. F., & Mandelbaum, B. R. (2014). Hip imaging: Femoroacetabular impingement and beyond. Sports Health, 6(2), 138–147. https://doi.org/10.1177/1941738113498027
- Sundberg, T. P., Toomayan, G. A., & Major, N. M. (2006). Evaluation of the acetabular labrum at 3.0-T MR imaging compared with 1.5-T MR arthrography: Preliminary experience. Radiology, 238(2), 706–711. https://doi.org/10.1148/radiol.2382050131
- Steinbach, L. S., Palmer, W. E., & Schweitzer, M. E. (2002). Special focus session: MR arthrography. RadioGraphics, 22(3), 687–703. https://doi.org/10.1148/radiographics.22.3.g02ma20687
- Chang, C. Y., Huang, A. J. (2015). MR imaging evaluation of hip instability. Magnetic Resonance Imaging Clinics of North America, 23(3), 331–345. https://doi.org/10.1016/j.mric.2015.04.003
- Yoon, J. Y., Kim, J. I., Lee, S. Y. (2020). Diagnostic performance of bilateral hip MRI for asymptomatic contralateral femoral head osteonecrosis. Skeletal Radiology, 49(9), 1379–1386. https://doi.org/10.1007/s00256-020-03428-2
- Nakamura, T., Matsumoto, T., Nishino, M., Tomita, K., & Kadoya, M. (1997). Early magnetic resonance imaging and histologic findings in a model of femoral head necrosis. Clinical Orthopaedics and Related Research, 334, 68–72. https://doi.org/10.1097/00003086-199701000-00009
- Fritz, J., Fritz, B., Zhang, J., Thawait, G. K., Joshi, D. H., Pan, L., Wang, D., Sneag, D. B. (2016). Simultaneous multislice accelerated turbo spin echo MRI of the hip. Investigative Radiology, 51(10), 611–617. https://doi.org/10.1097/RLI.0000000000000267
- American College of Radiology. (2021). ACR–SPR–SSR practice parameter for the performance and interpretation of magnetic resonance imaging (MRI) of the hip. American College of Radiology. acr.org practice parameter — MRI of the hip
