The effect of body mass index on fluoroscopy time and radiation dose in intra-articular glenohumeral joint injections

Comparing fluoroscopic versus ultrasound guidance in glenohumeral joint aspiration

INTRODUCTION

Joint aspiration is a common technique to aid in diagnosis of glenohumeral pathology. Fluoroscopy and ultrasound are both used as image-guidance methods to increase accuracy of the procedure. There are no prior studies comparing the ability of these two methods to obtain joint fluid.

OBJECTIVE

To evaluate whether fluoroscopy or ultrasound image guidance more often obtains fluid from the glenohumeral joint and which technique obtains a greater amount fluid.

DESIGN

Retrospective cohort study SETTING: Single academic orthopaedic clinic PATIENTS: 206 patients undergoing glenohumeral aspiration, generally to rule out infection INTERVENTIONS: Fluoroscopic- or ultrasound-guided joint aspirations, performed by numerous physicians.

MAIN OUTCOME MEASURE(S)

Primarily successful aspiration of at least 0.1mL of joint fluid. Secondarily, the total amount of joint fluid obtained.

RESULTS

There was no significant difference in rate of successful aspirations between ultrasound (69.4% successful [95% CI = 54.4%, 84.5%] and fluoroscopy (70.6% successful [95% CI = 63.7%, 77.4%]). Amounts of fluid obtained by fluoroscopy and ultrasound were not significantly different (p = 0.349; mean ± SD = 7.1 ± 12.6 vs. 10.0 ± 16.8 mL; median [IQR] = 3 [7] vs. 5 [8.75] mL). Sub-analysis showed that fluoroscopy obtained significantly more fluid in patients with >35 body mass index (adjusted mean = 7.9 mL [95% CI = 4.3, 11.5]) when compared with ultrasound (2.3 mL [95% CI = 0.6, 4.0]).

CONCLUSIONS

Fluoroscopic- and ultrasound-guided aspirations of the glenohumeral joint demonstrate similar success in obtaining fluid. For non-obese patients, ultrasound guidance is typically less expensive, office-based, less uncomfortable, and allows for dynamic visualization. For obese patients, fluoroscopy appears to have an advantage with respect to the amount of fluid obtained. Prospective studies are warranted to make more robust conclusions. This article is protected by copyright. All rights reserved.

Shoulder MR Arthrography: Comparative Evaluation of Three Different Contrast Injection Techniques Using an Anterior Approach

BACKGROUND

MR arthrography (MRA) is commonly used in the assessment of shoulder internal derangements. Correct intra-articular contrast injection is required for this modality. Anterior injections under fluoroscopic, ultrasound-guidance, or without image-guidance have been described in the literature. However, no simultaneous comparison has been performed between the three techniques.

PURPOSE

To compare the accuracy and performance of fluoroscopy (FL)-guided, ultrasound (US)-guided and non-image-guided intra-articular contrast injection via an anterior approach for performing shoulder MRA.

STUDY TYPE

Prospective.

SUBJECTS

Two-hundred and ten patients (180 men and 30 women; mean age, 33 ± 12 years; range 20-60 years) with clinically suspected shoulder pathology.

FIELD STRENGTH/SEQUENCE

1.5T/fat-suppressed T₁ -weighted, T₂ -weighted, and 3D-gradient-echo images.

ASSESSMENT

Patients underwent shoulder MRA after anterior intra-articular contrast injection under FL- or US-guidance or without image-guidance. Patients were randomized among the three techniques with each group comprising 70. The techniques were compared according to the accuracy of intra-articular needle placement, attempts success rate, pain during and 24 hours after injection, procedure times, contrast extravasation rate, joint distension, and MRA diagnostic efficacy. Pain was assessed by the visual analog scale (VAS) pain-score.

STATISTICAL TESTS

Pearson's chi-squared and Kruskal-Wallis tests.

RESULTS

FL- and US-guided injections (100% accuracy) were significantly more accurate than non-image-guided (85.7% accuracy) (P < 0.05). US-guidance was the least painful, with statistical differences between image-guided and non-image-guided techniques regarding the first attempt success rate (95.7% and 92.8% for FL- and US-guided vs. 78.6% for blinded), VAS-score 24 hours-post-procedure (1.7 ± 1.7, and 1.5 ± 1.4 vs. 2.2 ± 1.4), procedure time (11.9 ± 1.6, and 7.4 ± 1.7 vs. 4.3 ± 0.76 minutes), and contrast extravasation rate (5.7%, and 8.6% vs. 30%) (all P < 0.05). Procedure time was also significantly different between FL and US-guidance (P < 0.05).

DATA CONCLUSION

Imaging-guided injections are more accurate and tolerable than non-image-guided and should be considered to confirm intra-articular needle position, hence adequate capsular distension and good diagnostic quality of shoulder MRA. US guidance is a less painful, rapid, and safe alternative to the FL approach. Evidence Level: 2 Technical Efficacy Stage: 5. J. MAGN. RESON. IMAGING 2021;53:481-490.

RADIATION DOSE DURING PELVIC RADIOGRAPHY IN RELATION TO BODY MASS INDEX

The purpose of this research was to investigate the impact of body mass index (BMI) on dose area product (DAP), effective dose (E), dose to the organs and image quality (IQ) on 200 patients referred to pelvic radiography. Patients were classified into three groups according to BMI: normal (<24.99), overweight (25.0-29.99) and obese (>30). The results showed 52% and 135% higher DAP for overweight and obese patients compared to normal-weight patients (p < 0.001). A 46 and 123% rise of E for overweight and obese patients compared to normal-weight patients (p < 0.001) was discovered. Overweight patients received 37% higher dose and obese patients 107% higher dose to the organs compared to normal-weight patients. There were no statistically significant differences between IQ, except between normal weight and overweight patients. A strong correlation (r = 0.733) was found between BMI and DAP and between BMI and E (r = 0.776).

Editorial Commentary: Unguided Glenohumeral Injections-Do We Achieve Sufficient Accuracy?

Image-guided (fluoroscopy, ultrasound, computed tomography, magnetic resonance imaging) and unguided glenohumeral injection techniques are frequently used for different diagnostic and therapeutic purposes in clinical practice. Guided injections are highly accurate, reproducible, and more often performed in routine practice. Nevertheless, these techniques are more cost intensive and time consuming, and require special imaging devices. In case of fluoroscopic- or computed tomography-guided injections, radiation exposure of the patient is a disadvantage. In contrast, unguided glenohumeral injection techniques do not have these drawbacks, but rather are based on the precise identification of anatomic landmarks and depend on the experience of the provider. That is the reason they are supposed to be less accurate and less reproducible than guided techniques. But recent studies showed comparable accuracy; therefore, the use of unguided glenohumeral injection techniques should be considered in daily clinical practice in the hands of experienced shoulder arthroscopists.

Direct shoulder magnetic resonance arthrography for superior labral anterior-to-posterior (SLAP) and Bankart lesions: investigation into the appropriate dose and level of local anesthesia

OBJECTIVE

To compare contrast leakage, pain score, image quality and diagnostic performance at different doses and levels of local anaesthesia for direct shoulder magnetic resonance arthrography.

METHODS

Patients (n = 157) were prospectively enrolled and allocated to Group 1 (no local anaesthetic), Group 2 (local anaesthesia to subcutaneous fat level; lidocaine 1-2 ml), Group 3 (to deltoid muscle level; 3-5 ml), or Group 4 (to subscapularis muscle level; 6-8 ml). We evaluated the frequency of contrast leakage, periprocedural/postprocedural pain, contrast-to-noise ratio of the intra-articular signal, and subjective image noise/image sharpness. Radiological diagnoses of superior anterior-to-posterior (SLAP) and Bankart lesions were assessed. All data were analysed by one-way analysis of variance/Kruskal-Wall, Χ²/Fisher's exact and DeLong's tests.

RESULTS

The frequency of contrast leakage from the injection path and subjective image noise were significantly lower in Groups 1 and 2 than in Groups 3 and 4 (p = 0.001-0.04). Periprocedural/postprocedural pain scores among Groups 2-4 were similar and lower than those of Group 1. The contrast-to-noise ratio (p = 0.11-0.97) and image sharpness (p = 0.12-0.43) were similar among Groups 2-4 and significantly lower than those of Group 1 (p = 0.001-0.02). The diagnostic performance for the assessment of superior anterior-to-posterior and Bankart lesions was better in Groups 2-4 than in Group 1, although there were no significant differences (p = 0.23-0.99).

CONCLUSION

Local anaesthesia with 1-2 ml lidocaine at subcutaneous fat level reduced pain and provided optimal image quality in direct shoulder magnetic resonance arthrography. Advances in knowledge: This method can increase image quality, reduce periprocedural/postprocedural pain and potentially reduce the need for re-examination.