Power Doppler analysis of tendon vascularization

Forty-nine patients with tendonitis (patellar in 16, quadriceps in two, Achilles in 12, rotator cuff disease in 19) and 47 patients with tenosynovitis (acute tenosynovitis in 25, stenosing tenosynovitis in 22) underwent ultrasound (US) and Power Doppler (PD)-US examination. Spectral analysis of flow signals was performed in all patients. Ten patients (six with tendonitis, four with tenosynovitis) were rewired after medical therapy. Six healthy volunteers were also examined for control purposes. Three different patterns of flow distribution were found in patients with tendonitis and active tenosynovitis. The vessels of tendons without tendon sheaths began with great peduncles at the level of the peritendinous soft tissues and were then distributed inside the tendon (pattern I). A clear peritendinous hypervascular pattern was found in all active tenosynovitis, but no vessels were found inside the tendons (pattern II). In some cases of intratendinous or partial lesions PD-US revealed some vessels located near or inside the lesion (pattern II). On spectral analysis these vessels corresponded to arteries with a low resistance index or small venules. PD-US revealed a significant reduction of flow signals in patients rewired after medical therapy. No pathological flow signals were found either in patients with stenosing tenosynovitis or in the control group. PD-US gives us an in vivo confirmation of tendon vascularity. Spectral analysis adds further information to gray-scale US.     

Multidetector computed tomography arthrography of the knee: diagnostic accuracy and indications

Purpose

To evaluate the diagnostic accuracy and indications of arthrography with multidetector computed tomography (arthro-MDCT) of the knee, in patients with absolute or relative contraindications to MRI and in patients with periarticular metal implants using diagnostic arthroscopy as the gold standard.

Materials and methods

After intra-articular injection of iodixanol and volumetric acquisition, 68 knees in patients of both sexes (30 females, 38 males, age range 32–60 years) were examined with a 16-detector-row CT scanner. The patients had arthralgia but no radiologically detected fractures. They could not be studied by MRI either because of absolute contraindications (subcutaneous electronic implants), surgical metal implants or claustrophobia. In 37 of 68 patients who had had previous knee surgery, the arthro-CT examination was preceded by an MRI on the same day.All examinations were interpreted by two experienced musculoskeletal radiologists.The findings were compared with arthroscopic findings carried out within 28 days of the CT study.

Results

In non-operated patients the comparison between arthro-MDCT and arthroscopy showed sensitivity and specificity ranging between 86% and 100%. In the 37 operated knees, arthro-MDCT had an accuracy of 95% compared with 53% of the MRI.Inter-observer agreement was almost perfect (K = 0.97) in the evaluation of all types lesions, both on MDCT and MRI.When arthro-MDCT was compared with MRI in post-operative patients by a McNemar test, a significant difference (p < 0.05) was found between these two techniques.

Conclusions

Arthro-MDCT of the knee is a safe technique that provides accurate diagnosis in identifying chondral, fibrocartilaginous and intra-articular ligamentous lesions, in patients that cannot be evaluated by MRI, and in patients after surgical.     

Multimodal imaging in the differential diagnosis of soft tissue calcinosis

Soft tissue calcinosis is a common radiographic finding, which may be related to different types of pathological processes. Multimodality imaging, combined with analysis of clinical and laboratory data, plays an important role for the differential diagnosis of these conditions. Conventional radiography is considered the first line approach to soft tissue calcinosis; CT and MRI may provide further information to better characterize calcified deposits. Imaging may help to distinguish metabolic calcification, such as primary tumoral calcinosis and the secondary one (associated with acquired disorders of calcium or phosphate regulation), from dystrophic calcification, which is associated to normal blood values of phosphate. The sedimentation sign typical of tumoral calcinosis has been demonstrated by plain film radiography, CT, MRI, and, more recently, by ultrasonography. Other types of soft tissue calcinosis may have a degenerative, metaplastic or neoplastic origin, and their characterization strongly relies on multimodality imaging.     

Dynamic gadolinium‐enhanced magnetic resonance imaging of the wrist in patients with rheumatoid arthritis can discriminate active from inactive disease

Objective

To determine the efficacy of dynamic gadolinium‐enhanced magnetic resonance imaging (MRI) of the wrist in the evaluation of disease activity in patients with rheumatoid arthritis (RA).

Methods

Thirty‐six patients with RA (with different degrees of disease activity) and 5 healthy controls were studied. MRI was performed with a low‐field (0.2T), extremity‐dedicated machine. After an intravenous bolus injection of gadolinium–diethylenetriamine pentaacetic acid, 20 consecutive fast spin‐echo images of 3 slices of the wrist were obtained every 18 seconds.

Results

The curves of synovial membrane enhancement identified the following 2 groups: controls and RA patients in remission, and RA patients with active or intermediately active disease. Both the rate of early enhancement (REE) and relative enhancement (RE) were significantly higher in patients with active RA than in those with inactive RA and controls. The REE and RE were significantly correlated with the number of swollen joints (P < 0.00001 and P = 0.003, respectively), the number of tender joints (P < 0.00001 and P = 0.004, respectively), the Ritchie index (P = 0.0002 for both REE and RE), the Disease Activity Score (P = 0.0004 and P = 0.0008, respectively), the Health Assessment Questionnaire (HAQ) (P = 0.0002 and P = 0.0007, respectively), early morning stiffness (P = 0.001 and P = 0.009, respectively), the C‐reactive protein level (P = 0.015 and P = 0.03, respectively), the erythrocyte sedimentation rate (P = 0.03, RE only), and α2 globulins (P = 0.036 and P = 0.028, respectively).

Conclusion

Our data support use of dynamic MRI for discriminating active from inactive RA. Enhancement curves are associated not only with laboratory and clinical indicators of inflammation, but also with the HAQ, a relevant predictor of RA functional outcome. This technique can be repeated frequently and is an excellent candidate for the ideal method for the followup of patients with RA.

     

Seronegative spondyloarthropathies: what radiologists should know

Inflammatory involvement of the spine and sacroiliac joints is the most peculiar feature of seronegative spondyloarthropathies (SpA), which include ankylosing spondylitis, psoriatic arthritis, reactive arthritis (Reiter’s syndrome), enteropathic spondylitis (related to inflammatory bowel diseases) and undifferentiated spondyloarthropathies. SAPHO syndrome may also be considered a SpA, but there is no clear agreement in this respect. Imaging, along with clinical and laboratory evaluation, is an important tool to reach a correct diagnosis and to provide a precise grading of disease progression, influencing both clinical management and therapy. Conventional radiography, which is often the first-step imaging modality in SpA, does not allow an early diagnosis. Computed tomography (CT) demonstrates with a very high spatial resolution the tiny structural alterations of cortical and spongy bone before they become evident on plain film radiographs. Magnetic resonance imaging (MRI) is the only modality that provides demonstration of bone marrow oedema, which reflects vasodilatation and inflammatory hyperaemia. The primary aim of this review article was to examine the involvement of the spine and sacroiliac joints in SpA using a multimodal radiological approach (radiography, CT, MRI), providing a practical guide for the differential diagnosis of these conditions.     

Clinical use of latex tests. II. Evaluation of latex tests in C-reactive protein determination

We compared the most reliable and practical laboratory methods for the quantitative determination of serum C-reactive protein that is polistyrene latex particles together with purified anti-C-reactive protein rabbit globulin, the precipitation test using anti-C-reactive protein serum and finally, radial immunodiffusion on agar-gel plates. We examined 163 serum specimens from ambulatory patients and from various hospitalized patients in Istituti Clinici di Perfezionamento of Milan (Italy). All the methods tested showed a good qualitative discrimination for serum C-reactive protein presence or absence at pathological levels. We also compared the two latex methods. In conclusion, radial immunodiffusion confirmed to be the best method for accurate C-reactive protein dosage during inflammatory and degenerative processes.     

Effect of somatostatin on blood sugar, plasma growth hormone, and glucagon levels in diabetic children.

In nine children with clinically overt insulin-dependent diabetes mellitus the authors injected cyclic somatostatin (3 mug./kg. bolus, followed by infusion of 13 mug./kg. in 60 minutes) and measured blood glucose, plasma growth hormone, and glucagon concentrations throughout the infusion. The rapid administration produced no significant changes of these parameters. With the prolonged infusion there was a significant reduction of blood glucose from a mean of 148 +/- 19.7 to a mean of 88.5 +/- 18.1 mg./100 ml. (P less than 0.005) and of plasma glucagon from a basal mean of 33.3 +/- 2.4 to a minimum mean of 22.1 +/- 1.7 pg./ml. (P less than 0.01). There was a statistically significant correlation between the two parameters (0.01 less than P less than 0.05). Plasma GH values also diminished during the infusion, but the reduction was not statistically significant. These results show that somatostatin lowers blood glucose concentrations as a secondary effect of inhibition of glucagon secretion. Somatostatin is not suitable for therapy in diabetes. We speculate that a similar substance with a more prolonged and specific action on glucagon might prove of practical value in the treatment of diabetes mellitus.     

An appraisal of magnetic resonance imaging of the wrist in rheumatoid arthritis

OBJECTIVES: To evaluate the role of magnetic resonance imaging (MRI) in the diagnosis, staging, and follow-up of the rheumatoid wrist. METHODS: A Medline search was performed to identify all publications from the years 1985 to 1999 concerning MRI of the wrist in patients with rheumatoid arthritis (RA). Additional papers were retrieved by scanning the references to the Medline-listed articles. Details of the MRI technique, as well as clinical data, were analyzed and compared. RESULTS: A total of 55 papers were identified. There were considerable variations in imaging sequence, section type, and slice thickness. Erosions and synovitis were the conditions that mostly profited from the adoption of MRI. Although the visualization of erosions was better detailed with MRI than with conventional radiography, erosions were only rarely related to clinical and laboratory parameters. Another advantage was that synovitis imaging, which can be enhanced by contrast agents, was amenable to quantitation. The extent of the synovial surface and the rate of contrast enhancement in a series of consecutive, rapidly acquired images were the most common measures. CONCLUSIONS: MRI of the rheumatoid wrist is a useful technique to ascertain the criteria for diagnosis and progression of RA, and to monitor the effects of treatment. Implementation of a standardized protocol could further increase its value.