For optimal placement of the BC-FMT of the BB, preoperative 3D planning is recommended especially in primarily small poorly pneumatized mastoids, hypoplastic mastoids in malformations, reduced bone volume after canal wall down mastoidectomy, or the small mastoids in children. Effort should be made to reduce segmentation and surgical planning time by means of automation.

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Purpose:To assess the value of plain vs. iron oxide-enhanced MRI vs. the combined study (plain ϩ postcontrast) based on qualitative and quantitative parameters of three pulse sequences. Materials and Methods:Data from two sites were acquired using the same technique; therefore, this data could be pooled. T1W-SE, T2W-FSE, and 3D-PSIF were used before and 24 -36 hours after MRI with ultra small particles of iron oxide (USPIO) was performed. A total of 52 lymph nodes (LNs) in nine patients (25 benign, 27 malignant) were evaluated by two readers who were visually and quantitatively blinded to the histology. Combinations of the following diagnostic parameters were compared using logistic regression analysis: the short-axis diameter of the LN, the signal distribution of the LN on postcontrast agent MRI (homogeneous or heterogeneous), and qualitatively and quantitatively determined signal changes of the LN following administration of contrast agent in the three evaluated sequences. Results:Using pre-and postcontrast data, the optimized accuracy based on the statistically most significant parameters (LN diameter Ͼ 6 mm, visual assessment of signal change on T2W-SE) was 87% (81% sensitivity, 92% specificity). Precontrast data alone yielded 75% accuracy (63% sensitivity, 86% specificity). Postcontrast data alone yielded 75% accuracy (56% sensitivity, 96% specificity). Conclusion:Based on our results, USPIO-MRI improved the diagnosis of metastatic axillary LNs compared with precontrast MRI alone. Both pre-and postcontrast studies are needed. T1W-SE and T2W-PSIF did not yield significant additional information. This study may help to further improve the technique of USPIO imaging.

IntroductionFatal clinical fat embolism is a rare complication in elective orthopaedic surgery. Microscopic fat embolism caused by bone marrow fat drops have been described in over 90% of intramedullary procedures in long bones during total hip and knee implantations, and in trauma patients, especially with femoral shaft fractures. The incidence of clinically noticeable fat embolism syndrome in those patients is 0.5-23% [6,7], with a mortality of 10-20% [5]. Usually clinical symptoms appear within 3 days, depending on the seriousness of the fat embolism syndrome. Clinical manifestation is restricted by the progression of capillary damage, leading to leakage of fluid, protein loss and haemorrhages in the lung tissues. The correlation between the absolute mass of fat embolism and degree of clinical lung failure is not clear. Intravascular fat drops from the bone marrow activate the coagulation mechanism, leading to hypercoagulation and venous stasis with macroemboli. Embolism of lungs gives rise to local release of inflammatory mediators with damage of the basement membrane, resulting in respiratory insufficiency, with secondary brain and heart failure [3,4]. Case reportA 56-year-old slender housewife with severe radicular complaints, because of lumbar spinal stenosis, underwent a dorsal bilateral decompression of L4/L5 and L5/S1 in combination with an instrumented dorsolateral spinal fusion. Transpedicular fixation of L4/ L5/S1 was accomplished by titanium (Rodegerdts) implants (Fig. 1).Both iliac crests were used for harvesting autologous bone grafts. The surgical procedure itself was uneventful. However, 6 h after surgery the patient was found unconscious, deeply snoring and with an asystole. Signs of hypoxia due to respiratory obstruction were not present, there were also no signs of an elevated stiffness of the lungs during the resuscitation period. During the resuscitation efforts she expired. Autopsy revealed macroscopic gross fatty infiltration of lung parenchyma with oedema, no obstructed airways and no proof of air embolism (Fig. 2).No other relevant abnormalities were found.Abstract Fatal pulmonary fat embolism is a rare complication in elective orthopaedic surgery. It has been described previously as occuring during intramedullary manipulations and in trauma patients. We present the case of a 56-year-old slender housewife with severe radicular complaints because of lumbar spinal stenosis. She underwent a dorsal bilateral decompression of L4/L5 and L5/S1 in combination with an instrumented dorsolateral spinal fusion. Transpedicular fixation of L4/L5/S1 was accomplished by titanium Rodegerdts implants. Both iliac crests were used for harvesting autologous bone grafts. The intra-operative course was uneventful; however, 6 h after surgery, despite resuscitation, she expired. Autopsy revealed macroscopic gross fatty infiltration of lung parenchyma with oedema. We believe there is no relation between this complication and the transpedicular instrumentation. The position of the patient and the extent of the h...

CT findings in patients with vertigo after stapes surgery include a prosthesis shaft entering the vestibule and compressing the saccule, a complete dislocation of the stapes prosthesis, air bubbles and fluid collections within the vestibule and outside the oval window indicating a perilymphatic fistula, and bony fragments leading to compression of the basal saccule. Although immediate post-operative vertigo is often transient, patients with persistent or recurrent vertigo should be imaged as high resolution CT will determine the underlying cause in the majority of cases.