MR arthrography of the hip: comparison of IDEAL-SPGR volume sequence to standard MR sequences in the detection and grading of cartilage lesions.

PURPOSE: To compare the diagnostic performance of iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL)-spoiled gradient-recalled echo (SPGR) with that of standard magnetic resonance (MR) arthrography sequences for detecting and grading cartilage lesions within the hip joint during MR arthrography. MATERIALS AND METHODS: Following institutional review board approval, 67 consecutive hip MR arthrograms were retrospectively reviewed independently by three musculoskeletal radiologists and one musculoskeletal fellow. IDEAL-SPGR images and the two-dimensional images, the latter from the routine MR arthrography protocol, were evaluated at separate sittings to grade each articular surface of the hip joint. By using arthroscopy as the reference standard, the sensitivity and specificity of the two techniques for detecting and grading cartilage lesions were determined. The McNemar test was used to compare diagnostic performance. Interreader agreement was calculated using Fleiss κ values. RESULTS: For all readers and surfaces combined, the sensitivity and specificity for detecting cartilage lesions was 74% and 77%, respectively, for IDEAL-SPGR and 70% and 84%, respectively, for the routine MR arthrography protocol. IDEAL-SPGR had similar sensitivity (P = .12) to and significantly lower specificity (P < .001) than the routine MR arthrography protocol for depicting cartilage lesions. When analyzing the differences in sensitivity and specificity by reader, the two readers who had experience with IDEAL-SPGR had no significant difference in sensitivity and specificity for detecting cartilage lesions between the two sequences. For all readers and surfaces combined, IDEAL-SPGR had a higher accuracy in correctly grading cartilage lesion (P = .012-.013). Interobserver agreement for detecting cartilage lesions did not differ between the two techniques. CONCLUSION: IDEAL-SPGR had similar sensitivity and significantly lower specificity for detecting cartilage lesions and higher accuracy for grading cartilage lesions than did a routine MR arthrography protocol; the lower specificity of IDEAL-SPGR for detecting cartilage lesions was not seen in experienced readers.

Cryoablation in the musculoskeletal system.

Pain palliation can be challenging in patients with metastases to the musculoskeletal system, and conventional therapy can be less than optimal for pain management. Recent advances in technology have allowed for the addition of image-guided ablation to the armamentarium for treating musculoskeletal metastases. This article focuses on one such technique, percutaneous cryoablation, and the experiences with this technique at the authors' institution. After a brief review of the history and theory behind cryoablation, the basic technique of percutaneous cryoablation of musculoskeletal metastases is described. This is followed by a review of the cases that have been performed at the authors' institution. A discussion on the many advantages and relatively few disadvantages of this exciting new technique is then put forth. Percutaneous cryoablation is beginning to emerge as a useful method of image-guided ablation of musculoskeletal metastases. As data continue to mount on this exciting application of new technology, image-guided cryoablation of musculoskeletal metastases appears to hold much promise in the treatment of pain related to these lesions.

Correlation of MRI findings with clinical findings of trochanteric pain syndrome.

OBJECTIVE: Greater trochanter pain syndrome due to tendinopathy or bursitis is a common cause of hip pain. The previously reported magnetic resonance (MR) findings of trochanteric tendinopathy and bursitis are peritrochanteric fluid and abductor tendon abnormality. We have often noted peritrochanteric high T2 signal in patients without trochanteric symptoms. The purpose of this study was to determine whether the MR findings of peritrochanteric fluid or hip abductor tendon pathology correlate with trochanteric pain. MATERIALS AND METHODS: We retrospectively reviewed 131 consecutive MR examinations of the pelvis (256 hips) for T2 peritrochanteric signal and abductor tendon abnormalities without knowledge of the clinical symptoms. Any T2 peritrochanteric abnormality was characterized by size as tiny, small, medium, or large; by morphology as feathery, crescentic, or round; and by location as bursal or intratendinous. The clinical symptoms of hip pain and trochanteric pain were compared to the MR findings on coronal, sagittal, and axial T2 sequences using chi-square or Fisher's exact test with significance assigned as p < 0.05. RESULTS: Clinical symptoms of trochanteric pain syndrome were present in only 16 of the 256 hips. All 16 hips with trochanteric pain and 212 (88%) of 240 without trochanteric pain had peritrochanteric abnormalities (p = 0.15). Eighty-eight percent of hips with trochanteric symptoms had gluteus tendinopathy while 50% of those without symptoms had such findings (p = 0.004). Other than tendinopathy, there was no statistically significant difference between hips with or without trochanteric symptoms and the presence of peritrochanteric T2 abnormality, its size or shape, and the presence of gluteus medius or minimus partial thickness tears. CONCLUSIONS: Patients with trochanteric pain syndrome always have peritrochanteric T2 abnormalities and are significantly more likely to have abductor tendinopathy on magnetic resonance imaging (MRI). However, although the absence of peritrochanteric T2 MR abnormalities makes trochanteric pain syndrome unlikely, detection of these abnormalities on MRI is a poor predictor of trochanteric pain syndrome as these findings are present in a high percentage of patients without trochanteric pain.

Utility of percutaneous treatment in spontaneous renal artery dissection: case report and review of the literature.

Spontaneous renal artery dissection (SRAD) is a relatively rare entity that has been described in several case reports and small series in the medical literature. The condition is best diagnosed with angiography, with renal ischemia or infarction a common complication. Conservative medical management, surgical intervention, and percutaneous intervention are all discussed in the current literature. However, there is no consensus on which treatment option provides the best clinical outcome. Percutaneous stent placement has only recently been considered as an option for treatment of SRAD. This case report reviews the course of an otherwise healthy patient with a solitary right kidney who had SRAD complicated by renal infarction and was treated by percutaneous renal artery stent placement. Subsequently, we discuss and review the literature on SRAD treatment.