Stickler syndrome in children: a radiological review.

AIM: To review the radiological findings of the largest cohort to date of paediatric patients with Stickler syndrome, all with confirmed molecular genetic analysis and sub-typing. PATIENTS AND METHODS: It is understood that the National Health Service (NHS) commissioned service at Addenbrookes Hospital, Cambridge, UK has the largest cohort of Stickler syndrome patients in the paediatric age group worldwide with 240 registered children. Fifty-nine were assessed radiologically and for their genotypes. These radiographs were reviewed and 74 knee, 45 pelvic, and 47 spinal examinations were evaluated. RESULTS: Radiological features were noted in 45.9% of knee radiographs, 11.1% of pelvic radiographs, and 42.6% of spinal radiographs. The findings were reviewed in the light of each patient's specific genetic Stickler syndrome subtype. CONCLUSION: The prevalence of orthopaedic abnormalities overall in the present series is substantially below those published in previous smaller case series. This would support the more recent findings of an array of ocular only phenotypes of Stickler syndrome described in the literature.

The reliability of measuring the density of the L1 vertebral body on CT imaging as a predictor of bone mineral density.

AIM: To determine whether the density of the L1 vertebra measured on computed tomography (CT) images correlates with the bone mineral density (BMD) as measured by quantitative computed tomography (QCT), and to determine the reliability of L1 density measurements by different observers to see if this measure could help identify patients who would benefit from formal BMD assessment. MATERIALS AND METHODS: Non-contrast CT along with a phantom for determination of BMD was performed on 30 healthy patients. The L1 density was measured by 3 observers at two time-points separated by at least 2 weeks. RESULTS: L1 density was well correlated to the QCT BMD (correlation coefficient 0.83; 95% confidence interval [CI]: 0.67-0.92). There was excellent intra- and interobserver agreement in L1 density measurements. There were excellent intra-class correlation coefficients for each observer's measurements at two separate time points with a coefficient for observer 1 of 0.94 (95% CI: 0.88-0.97) and for observer 2 and 3 of 0.99 (95% CI: 0.98-1). The interobserver measurements had an intra-class correlation coefficient of 0.98 (95% CI: 0.96-0.99). CONCLUSION: L1 vertebral density can be reliably measured on CT images and might be used as an indicator of BMD for opportunistic screening of patients with osteoporosis. Low bone density detected incidentally on CT imaging could be used to identify patients who should be further investigated and treated for osteoporosis.

Variations in the MRI appearance of the insertion of the tendon of subscapularis.

Standard anatomical textbooks describe the insertion of the subscapularis tendon on to the lesser tuberosity of the humerus. The transverse humeral ligament is also described at this level, as a band of tissue attached to the greater and lesser tuberosities, overlying the long tendon of biceps as it emerges from the capsule of the shoulder joint. The shoulder is a notorious site for anatomical variation but until recently little has been published with regard to the tendon of subscapularis. In this study, we illustrate that considerable variation in the insertion site of the tendon of subscapularis can be demonstrated using magnetic resonance imaging and that only 20% conform to the classic textbook description. In addition, a distinct transverse humeral ligament was identifiable in only a minority of shoulders examined (36%).

CT of the musculoskeletal system: what is left is the days of MRI?

Magnetic resonance imaging (MRI) plays a central role in the modern imaging of musculoskeletal disorders, due to its ability to produce multiplanar images and characterise soft tissues accurately. However, computed tomography (CT) still has an important role to play, not merely as an alternative to MRI, but as being the preferred imaging investigation in some situations. This article briefly reviews the history of CT technology, the technical factors involved and a number of current applications, as well as looking at future areas where CT may be employed. The advent of ever-increasing numbers of rows of detectors has opened up more possible uses for CT technology. However, diagnostic images may be obtained from CT systems with four rows of detectors or more, and their ability to produce near isotropic voxels and therefore multiplanar reformats.

MR-guided direct arthrography of the glenohumeral joint.

AIM: To evaluate the feasibility of magnetic resonance (MR)-guided direct arthrography of the glenohumeral joint with a 1.5 T MR system, performing the entire procedure in a single MR examination. MATERIALS AND METHODS: MR-guided direct arthrography was performed on 11 patients. MR imaging guidance and interactive MR fluoroscopy, with in-room control and display system, were used for needle placement and contrast medium injection. The outcome measures were success or failure of joint puncture, the time taken for introduction of contrast medium, and the diagnostic quality of the subsequent MR arthrography images. RESULTS: Contrast medium was successfully instilled into the joint and diagnostic quality MR arthrography images were obtained in all cases. The median time from initial placement of the skin marker to introduction of the contrast medium was 17 min (range 11-29 min). There were no immediate post-procedure complications. CONCLUSION: Accurate needle placement is feasible in a single MR examination on a commercial 1.5 T closed-bore MR system, using an in-room control and display system together with interactive fluoroscopic imaging, and this was used to provide direct MR arthrography in this study.

High resolution imaging of the knee on 3-Tesla MRI: a pictorial review.

The recent introduction of 3-Tesla MRI offers substantial advances in musculoskeletal applications. High resolution images can now be obtained with shorter data acquisition times. This article provides a pictorial review of 3-Tesla imaging in the knee with descriptions of both normal anatomy and the more common lesions involving the menisci, ligaments, and articular cartilage. A discussion of the issues associated with imaging at higher field strengths is also included.

16-Detector multislice CT in the detection of stress fractures: a comparison with skeletal scintigraphy.

AIMS: To test the hypothesis that the improved resolution afforded by 16-detector computed tomography (CT) would translate to better stress fracture detection when compared with skeletal scintigraphy. MATERIALS AND METHODS: Thirty-three cases of suspected stress fractures in 26 patients were investigated using skeletal scintigraphy and 16-detector CT performed on the same day. Planar images of the lower limbs were taken 3h post-injection of 400MBq (99m)Tc-methylene diphosphonate ((99m)Tc-MDP). (99m)Tc-MDP uptake was quantified at suspected fracture sites. CT was performed using a 16-detector multisection machine employing 0.75mm detectors and images reconstructed in 0.5mm increments. Examinations were reported independently and discordant results were compared at follow-up. RESULTS: At initial reporting scintigraphy identified fractures in 13 of the 33 cases and CT identified four of the 33. In one case, on review of the CT images, a fracture was present in the distal fibula that was not initially identified. This resulted in eight scintigraphic-positive CT-negative discordant cases. The (99m)Tc-MDP uptake was significantly lower in the discordant fracture group compared with the concordant group (p<0.01). CONCLUSIONS: Despite technological advances in CT, scintigraphy appeared to detect more stress fractures. As such, multidetector CT should not be used as a routine initial investigation in stress fracture detection. The potential use of (99m)Tc-MDP quantification at fracture sites is of interest and may be worth further investigation.

16 detector multislice CT versus skeletal scintigraphy in the diagnosis of wrist fractures: value of quantification of 99Tcm-MDP uptake.

To compare the measured uptake of 99Tcm-methylene diphosphonate (99Tcm-MDP) in those scaphoid fractures seen on both 16 detector multislice CT and scintigraphy, with those seen only on scintigraphy. Over a 12 month period a total of 51 patients with suspected fracture underwent both conventional 99Tcm-MDP scintigraphy and 16 detector multislice CT on the same day. The 99Tcm-MDP uptake was then quantified in patients with identified fracture. This was measured by placing a region of interest (ROI) over the fracture site and the mean and maximum number of counts were compared with those in a similar size ROI placed over background bone activity. A total of 23 fractures were identified on scintigraphy of which 16 were also detected on CT (concordant). In seven cases the fracture was not seen on CT, even in retrospect (discordant). In the discordant cases, follow-up radiographs and MRI (where available) also failed to demonstrate a fracture. The mean fracture count to background bone activity ratio averaged 7.7 (range 3.2-18.5) for concordant fractures and 3.8 (range 1.7-5.3) for discordant fractures (t-test p=0.04). The maximum fracture count to background bone activity ratio averaged 12.7 (range 4.3-27.7) for concordant fractures and 6.3 (range 2.6-9.5) for discordant fractures (t-test p=0.03). It is speculated whether these discordant fractures with less 99Tcm-MDP uptake may represent a less severe injury such as bone bruise.

The proximal extent of the ankle capsule and safety for the insertion of percutaneous fine wires.

We have assessed the proximal capsular extension of the ankle joint in 18 patients who had a contrast-enhanced MRI ankle arthrogram in order to delineate the capsular attachments. We noted consistent proximal capsular extensions anterior to the distal tibia and in the tibiofibular recess. The mean capsular extension anterior to the distal tibia was 9.6 mm (4.9 to 27.0) proximal to the anteroinferior tibial margin and 3.8 mm (-2.1 to 9.3) proximal to the dome of the tibial plafond. In the tibiofibular recess, the mean capsular extension was 19.2 mm (12.7 to 38.0) proximal to the anteroinferior tibial margin and 13.4 mm (5.8 to 20.5) proximal to the dome of the tibial plafond. These areas of proximal capsular extensions run the risk of being traversed during the insertion of finewires for the treatment of fractures of the distal tibia. Surgeons using these techniques should be aware of this anatomy in order to minimise the risk of septic arthritis.

Case report: False negative 16 detector multislice CT for scaphoid fracture.

We discuss a case of a 19-year-old man with scaphoid trauma. We describe the imaging findings on three sets of radiographs, bone scintigraphy, CT and MRI. CT failed to identify a scaphoid fracture, which was present on 6 week radiographs, MRI and scintigraphy. The case illustrates that despite multidetector technology, CT still relies upon cortical and or trabecular displacement to demonstrate fractures.

Vitreoretinopathy with phalangeal epiphyseal dysplasia, a type II collagenopathy resulting from a novel mutation in the C-propeptide region of the molecule.

A large family with dominantly inherited rhegmatogenous retinal detachment, premature arthropathy, and development of phalangeal epiphyseal dysplasia, resulting in brachydactyly was linked to COL2A1, the gene encoding proalpha1(II) collagen. Mutational analysis of the gene by exon sequencing identified a novel mutation in the C-propeptide region of the molecule. The glycine to aspartic acid change occurred in a region that is highly conserved in all fibrillar collagen molecules. The resulting phenotype does not fit easily into pre-existing subgroups of the type II collagenopathies, which includes spondyloepiphyseal dysplasia, and the Kniest, Strudwick, and Stickler dysplasias.

MR imaging of the wrist: effect on clinical diagnosis and patient care.

PURPOSE: To evaluate the effect of magnetic resonance (MR) imaging of the wrist on clinicians' diagnoses, diagnostic certainty, and patient care. MATERIALS AND METHODS: A controlled observational study was performed. Referring clinicians completed questionnaires about diagnosis and intended management before and after wrist MR imaging. One hundred eighteen consecutive patients referred for MR imaging of the wrist were recruited from the MR imaging units at a regional teaching hospital and a large district general hospital. The main measures were changes in the clinicians' leading and subsidiary diagnoses after MR imaging, their certainty in these diagnoses, and changes in intended patient care. RESULTS: Questionnaires were incorrectly completed for five patients, questionnaires were not returned for three, appointments were canceled for 10, and two could not tolerate the MR examination. Complete follow-up data were available for 98 patients. The clinical diagnosis changed in 55 of 98 patients; in the remaining 43 patients, diagnostic certainty increased in 23. Clinicians reported that MR imaging had substantially improved their understanding of the disease in 67 of 98 patients. The care plan changed in 45 of 98 patients, with a shift away from surgical treatment. Twenty-eight patients were discharged without further investigation. MR imaging was similarly effective in the regional teaching center and the district general hospital. CONCLUSION: MR imaging of the wrist influences clinicians' diagnoses and management plans.

Magnetic resonance imaging of the wrist: diagnostic performance statistics.

AIM: To review the published diagnostic performance statistics for magnetic resonance imaging (MRI) of the wrist for tears of the triangular fibrocartilage complex, the intrinsic carpal ligaments, and for osteonecrosis of the carpal bones. MATERIALS AND METHODS: We used Medline and Embase to search the English language literature. Studies evaluating the diagnostic performance of MRI of the wrist in living patients with surgical confirmation of MR findings were identified. RESULTS: We identified 11 studies reporting the diagnostic performance of MRI for tears of the triangular fibrocartilage complex for a total of 410 patients, six studies for the scapho-lunate ligament (159 patients), six studies for the luno-triquetral ligament (142 patients) and four studies (56 patients) for osteonecrosis of the carpal bones. CONCLUSIONS: Magnetic resonance imaging is an accurate means of diagnosing tears of the triangular fibrocartilage and carpal osteonecrosis. Although MRI is highly specific for tears of the intrinsic carpal ligaments, its sensitivity is low. The diagnostic performance of MRI in the wrist is improved by using high-resolution T2* weighted 3D gradient echo sequences. Using current imaging techniques without intra-articular contrast medium, magnetic resonance imaging cannot reliably exclude tears of the intrinsic carpal ligaments. Hobby, J. L. (2001). Clinical Radiology, 56, 50-57.

Communication of doubt and certainty in radiological reports.

We have investigated the reliability of communication of uncertainty in radiological reports. The 18 most commonly used verbal expressions of probability were identified from a series of radiological reports. 11 clinicians (three radiologists, three rheumatologists and five orthopaedic surgeons) recorded the probability that they ascribed to each of the 18 expressions using visual analogue scales. Each subject was re-tested on four occasions at least 1 week apart. The results were analysed to assess reproducibility within and between individuals. We found considerable variation in the probabilities assigned to many commonly used expressions between subjects, and between repeated testing of the same subject. Some expressions were rated much more consistently than others. "Absent", "excludes", "unlikely", "probable", "certain" and "definite" were the most consistently rated expressions. We have identified a potential source of misunderstanding in radiological reports owing to differences in interpretation of expressions used by radiologists and referring clinicians.

Incidence of vertebral fractures in the first three months after orthotopic liver transplantation.

BACKGROUND AND OBJECTIVES: High rates of bone loss and increased fracture incidence have been reported in patients undergoing liver transplantation, mainly within the first post-operative year. The pathogenesis of post-transplantation bone disease has not been clearly established, but the high doses of glucocorticoids used for immunosuppression may contribute. The use of lower doses in recent years has been associated, in some studies, with lower rates of bone loss and decreased fracture incidence. The aim of this prospective study was to establish the incidence of vertebral fractures in the first 3 months in patients undergoing liver transplantation for chronic liver disease and to identify risk factors for fracture in these patients. DESIGN AND METHODS: Thirty-seven adults with end-stage liver disease were studied prospectively prior to and 3 months after liver transplantation. Vertebral fractures were assessed semi-quantitatively from lateral spine X-rays and bone mineral density measured using dual energy X-ray absorptiometry. RESULTS: Prior to transplantation, prevalent vertebral fractures were present in 13 patients (35%). New fractures developed after transplantation in 10 patients (27% of total) and were significantly more common in those with a prevalent vertebral fracture pre-operatively (P<0.02). Osteoporosis, defined as a bone mineral density T score below -2.5, was present in 39% of patients prior to transplantation, but bone mineral density was not helpful in predicting incident fracture, whether measured before or after transplantation. Over the 3-month study period, significant bone loss occurred in the femoral neck (P<0.05) but not the lumbar spine. CONCLUSIONS: Our results demonstrate a high incidence of vertebral fracture in the first 3 months after liver transplantation and indicate that prevalent vertebral fracture is an important risk factor for the subsequent development of fracture in these patients. Prevention of post-transplantation bone disease should focus both on optimizing bone mass prior to transplantation and preventing bone loss in the early post-operative period.