A new breast tomosynthesis imaging method: Continuous Sync-and-Shoot - technical feasibility and initial experience.

BACKGROUND: Digital breast tomosynthesis (DBT) is gaining popularity in breast imaging. There are several different technical approaches for conducting DBT imaging. PURPOSE: To determine optimal imaging parameters, test patient friendliness, evaluate the initial diagnostic performance, and describe diagnostic advances possible with the new Continuous Sync-and-Shoot method. MATERIAL AND METHODS: Thirty-six surgical breast specimens were imaged with digital mammography (DM) and a prototype of a DBT system (Planmed Oy, Helsinki, Finland). We tested the patient friendliness of the sync-and-shoot movement without radiation exposure in eight volunteers. Different imaging parameters were tested with 20 specimens to identify the optimal combination: angular range 30°, 40°, and 60°; pixel binning; Rhodium (Rh) and Silver (Ag) filtrations; and different kV and mAs values. Two breast radiologists evaluated 16 DM and DBT image pairs and rated six different image properties. Imaging modalities were compared with paired t-test. RESULTS: The Continuous Sync-and-Shoot method produced diagnostically valid images. Five out of eight volunteers felt no/minimal discomfort, three experienced mild discomfort from the tilting movement of the detector, with the motion being barely recognized. The combination of 30°, Ag filtering, and 2 × 2 pixel binning produced the best image quality at an acceptable dose level. DBT was significantly better in all six evaluated properties (P < 0.05). Mean DoseDBT/DoseDM ratio was 1.22 (SD = 0.42). CONCLUSION: The evaluated imaging method is feasible for imaging and analysing surgical breast specimens and DBT is significantly better than DM in image evaluation.

Dislocation of hip hemiarthroplasty following posterolateral surgical approach: a nested case-control study.

PURPOSE: Hip hemiarthroplasty dislocation is a serious complication in treatment of displaced intracapsular hip fractures. We investigated factors associated with an increased risk of dislocation after cemented hip hemiarthroplasty following the posterolateral approach. METHODS: Between January 2002 and December 2008, 602 hip fractures were treated with cemented unipolar hip hemiarthroplasty. A registry-based analysis was carried out to determine the total number of hemiarthroplasty dislocations in these patients. A control group of 96 patients without dislocation was randomly selected. Logistic regression analysis was performed to evaluate clinical and operative factors associated with dislocation. RESULTS: Thirty-four patients (5.6%) experienced at least one dislocation. Most were the result of a fall and occurred within two months after surgery. There was a trend for increased dislocation in patients who had been operated on more than 48 hours after admission and in patients who had a longer operative time. Smaller centre-edge angle and hip offset were observed in patients with dislocation. Recurrent dislocation was a significant problem, as 18 patients (62%) experienced multiple dislocations. CONCLUSIONS: The risk of hemiarthroplasty dislocation following the posterolateral surgical approach may be reduced by prompt surgical treatment and fall prevention in the early postoperative period. Patients with smaller acetabular coverage seem more predisposed to dislocation after the posterolateral approach and may be more suitable for other surgical approaches.

Low bone mass in patients with motor disability: prevalence and risk factors in 59 Finnish children.

AIM: Children with motor disabilities are at increased risk of compromised bone health. This study evaluated prevalence and risk factors of low bone mass and fractures in these children. METHOD: This cross-sectional cohort study evaluated bone health in 59 children (38 males, 21 females; median age 10 y 11 mo) with motor disability (Gross Motor Function Classification System levels II-V). Bone mineral density (BMD) in the lumbar spine was measured with dual-energy X-ray absorptiometry; BMD values were corrected for bone size (bone mineral apparent density [BMAD]) and skeletal maturity, and compared with normative data. Spinal radiographs were obtained to assess vertebral morphology. Blood biochemistry included vitamin D concentration and other parameters of calcium homeostasis. RESULTS: Ten children (17%) had sustained in total 14 peripheral fractures; lower-limb fractures predominated. Compression fractures were present in 25%. The median spinal BMAD z-score was -1.0 (range -5.0 to 2.0); it was -0.6 in those without fractures and -1.7 in those with fractures (p=0.004). Vitamin D insufficiency was present in 59% of participants (serum 25-hydroxyvitamin D <50 nmol/l) and hypercalciuria in 27%. Low BMAD z-score and hypercalciuria were independent predictors for fractures. INTERPRETATION: Children with motor disability are at high risk of peripheral and vertebral fractures and low BMD. Evaluation of bone health and prevention of osteoporosis should be included in the follow-up.