Comparison of Image Quality of Shoulder CT Arthrography Conducted Using 120 kVp and 140 kVp Protocols

OBJECTIVE: To compare the image quality of shoulder CT arthrography performed using 120 kVp and 140 kVp protocols. MATERIALS AND METHODS: Fifty-four CT examinations were prospectively included. CT scans were performed on each patient at 120 kVp and 140 kVp; other scanning parameters were kept constant. Image qualities were qualitatively and quantitatively compared with respect to noise, contrast, and diagnostic acceptability. Diagnostic acceptabilities were graded using a one to five scale as follows: 1, suboptimal; 2, below average; 3, acceptable; 4, above average; and 5, superior. Radiation doses were also compared. RESULTS: Contrast was better at 120 kVp, but noise was greater. No significant differences were observed between the 120 kVp and 140 kVp protocols in terms of diagnostic acceptability, signal-to-noise ratio, or contrast-to-noise ratio. Lowering tube voltage from 140 kVp to 120 kVp reduced the radiation dose by 33%. CONCLUSION: The use of 120 kVp during shoulder CT arthrography reduces radiation dose versus 140 kVp without significant loss of image quality.

The Usefulness of Multidetector CT Arthrography in the Diagnosis of Shoulder Pathology: Comparison with MR Arthrography and Arthroscopic Findings in the Same Patient

PURPOSE: The purpose of the study is to evaluate the usefulness of CT arthrography (CTA) by conducting a comparative study of CTA and MR arthrography (MRA) with the arthroscopic findings in the same patients. MATERIALS AND METHODS: Forty nine patients who suffered from shoulder disease underwent MRA and CTA concurrently. The sensitivity and specificity of CTA was evaluated, as compared to MRA, in the case of four types of shoulder pathological lesions. The accuracy of CTA was evaluated by analyzing the arthroscopic findings of thirty four patients. RESULTS: Compared to MRA, CTA showed a sensitivity of 90% and a specificity of 100% for diagnosing supraspinatus tendon (SST) full thickness tear, and CTA showed a sensitivity of 100% and a specificity of 97.5% for making the diagnosis of superior labrum anterior to posterior (SLAP) lesion. For diagnosing partial articular side supraspinatus avulsion (PASTA) lesion, some studies have shown the usefulness of CTA with a sensitivity of 71.4% and a specificity of 97.7%. However, for diagnosing SST bursal side partial tear, the sensitivity of CTA was as low as 10%. CTA has been shown to be relatively accurate when the diagnoses were verified with the arthroscopic findings; diagnosing SST full thickness tear and SLAP lesion with CTA has shown an accuracy of 100% and87.5% respectively, and CTA showed 71.4% diagnostic accuracy for PASTA lesion. CONCLUSION: CTA was a useful tool and it was equivalent to MRA for the assessment of SST full thickness tear, SLAP lesion and PASTA lesion, but not bursal side partial tear. Thus, it may be used preferably to diagnose shoulder pathology and for follow up as an inexpensive tool after operation.

Clinical Outcomes After Arthroscopic Double-Row Rotator Cuff Repair and Evaluation of Cuff Integrity by CT Arthrography

PURPOSE: Our goal for this study was to prospectively evaluate the functional & structural outcomes, by means of CT arthroscopy, of arthroscopic double-row fixation for treating rotator cuff tear. We also attempted to determine the variants that affect the functional & structural outcomes. MATERIALS AND METHODS: Twenty seven consecutive patients underwent arthroscopic rotator cuff repair with double-row fixation. The average age at the time of the operation was fifty six years. The preoperative and postoperative examinations consisted of determining the Constant score, the score for the visual analogue scale for pain, the UCLA score, the American Shoulder and Elbow Surgeons (ASES) score, as well as a full physical examination of the shoulder. Preoperative MR arthrography was used to evaluate the integrity and atrophy of the rotator cuff. We measured the intraoperative tear size in the sagittal and coronal planes. Postoperative CT arthrography was used at one year postoperatively to evaluate the integrity and atrophy of the repaired tendons and muscles. RESULTS: Preoperative MR arthrography revealed an average 29.22 mm tear size in the sagittal plane and an average 22.72 mm tear size in the coronal plane. Twelve cases of supraspinatus muscle atrophy and two cases of infraspinatus atrophy were observed on the preoperative MR arthrography. The average clinical outcome scores all significantly improved at the time of follow-up. At a mean of one year postoperatively, CT arthrography revealed 48.1% of the shoulders had healed, 11.1% showed incomplete healing and 40.7% showed retear of the repaired tendon. CONCLUSION: Arthroscopic double-row repair can result in improved clinical outcomes and good patient satisfaction. However, the problems about how to enhance healing of the repaired tendon still remain.

Optimization of the Contrast Mixture Ratio for Simultaneous Direct MR and CT Arthrography: an in Vitro Study

OBJECTIVE: This study was designed to determine the optimal mixture ratio of gadolinium and iodinated contrast agent for simultaneous direct MR arthrography and CT arthrography. MATERIALS AND METHODS: An in vitro study was performed utilizing mixtures of gadolinium at six different concentrations (0.625, 1.25, 2.5, 5.0, 10 and 20 mmol/L) and iodinated contrast agent at seven different concentrations (0, 12.5, 25, 37.5, 50, 75 and 92-99.9%). These mixtures were placed in tissue culture plates, and were then imaged with CT and MR (with T1-weighted sequences, proton-density sequences and T2-weighted sequences). CT numbers and signal intensities were measured. Pearson's correlation coefficients were used to assess the correlations between the gadolinium/iodinated contrast agent mixtures and the CT numbers/MR signal intensities. Scatter diagrams were plotted for all gadolinium/iodinated contrast agent combinations and two radiologists in consensus identified the mixtures that yielded the optimal CT numbers and MR signal intensities. RESULTS: The CT numbers showed significant correlation with iodinated contrast concentrations (r = 0.976, p < 0.001), whereas the signal intensities as measured on MR images showed a significant correlation with both gadolinium and iodinated contrast agent concentrations (r = -484 to -0.719, p < 0.001). A review of the CT and MR images, graphs, and scatter diagram of 42 combinations of the contrast agent showed that a concentration of 1.25 mmol/L gadolinium and 25% iodinated contrast agent was the best combination for simultaneous CT and MR imaging. CONCLUSION: A mixture of 1.25 mmol/L gadolinium and 25% iodinated contrast agent was found to be optimal for simultaneous direct MR arthrography and CT arthrography.

Treatment of posterior shoulder instability with bone block procedure and posterior capsulorrhaphy / 中华创伤骨科杂志

Objective To investigate clinical results of the treatment of posterior shoulder instability in a combined way of bone block procedure and posterior capsulorrhaphy. Methods The double contrast CT arthrography was performed for 5 patients suffering from posterior shoulder instability so as to detect the pathology. The treatments combining bone block procedure and posterior capsulorrhaphy were carried out according to the pathological conditions of bone and soft tissue. Results The double contrast CT arthrography showed posterior bone defects, posterior glenoid labrum tear and enlargement of posterior capsular cavity. After the bone block procedure and posterior capsulorrhaphy, no patients complained shoulder instability in the follow-up of 5 to 38 months. Conclusions Many pathological factors may induce posterior shoulder instability, which should be corrected by an appropriate operation rather than a “standard”method of operation. For patients involving several pathological factors, a combined operation may be needed in order to correct various pathological changes.

Glenohumeral Instability Manifestation on CT Arthrography / 实用放射学杂志

Objective To evaluate the manifestations of glenohumeral instability on CT arthrography.Methods 16 cases of glenohumeral instability were examined both by CT arthrography and arthroscopy and to analyze the manifestations on CT arthrography.Results Intraarticular injury included labral tear, capsular stripping or laxity, anterior glenoid fracture and lateral posterior humeral head impacted fracture.Conclusion Shoulder arthrography has good contrast, and because the imaging no overlaps, can clearly show the intraarticular injures. It is a good examine method of glenohumeral instability.

C. T. arthrography on Bankart lesion / 대한정형외과학회잡지

Accompanying to the development of the knowledgment of mechanism and pathology of recurrent dislocation of the shoulder, accurate diagnostic tools to detect that pathology have been developed. During the period from May 1990 to May 1992, we treated 28 cases of recurrent anterior dislocation of the shoulder. Twenty-eight cases were examined with C.T. arthrography before the operation. Among the 28 cases, we identified the Bankart lesion in 20 cases by C.T. arthrography, and in 21 cases intraoperatively. We concluded that the C.T. arthrography is an accurate method for confirming the clinical diagnosis of recurrent dislocation of the shoulder and to be helpful in detecting the Bankart lesion and its severity or pathologic findings.

Assessment of anterior shoulder instability by CT arthrography

Computed tomography (CT) immediately after double-contrast shoulder arthrography was taken in twenty-two young male patients with anterior shoulder instability including recurrent dislocation and subluxation. This recently developed technique called CT arthrography can provide significant information about patients with glenohumeral instability which is difficult to obtain by conventional arthrography. Information about glenoid labrum pathology is useful for proper management of the shoulder with instability. Lesions identified in this study include anterior labral defects (attenuation, tear, displacement), anterior capsular distension and/or detachment, Hill-Sachs lesion, anterior glenoid rim compression fracture, and fracture of scapula. This article describes the method used in CT arthrography of the glenohumeral joint, reviews the normal cross-sectional anatomy, and emphasizes the importance of the application of CT arthrography in the shoulder disorder with instability. CT arthrography of the glenohumeral joint is easy to perform, is accurate, and has lower radiation dose than arthrotomography.