Random Forest-Based Bone Segmentation in Ultrasound

Ultrasound (US) imaging is a safe alternative to radiography for guidance during minimally invasive orthopedic procedures. However, ultrasound is challenging to interpret because of the relatively low signal-to-noise ratio and its inherent speckle pattern that decreases image quality. Here we describe a method for automatic bone segmentation in 2-D ultrasound images using a patch-based random forest classifier and several ultrasound specific features, such as shadowing. We illustrate that existing shadow features are not robust to changes in US acquisition parameters, and propose a novel robust shadow feature. We evaluate the method on several US data sets and report that it favorably compares with existing techniques. We achieve a recall of 0.86 at a precision of 0.82 on a test set of 143 spinal US images.     

Primary vertebral osteosarcoma: Five cases

Primary vertebral osteosarcoma is a rare type of osteosarcoma, differing from the appendicular forms by an incidence peak occurring at a higher age and a poorer prognosis, due to the difficulties of the surgical treatment. We present five cases of histologically proven primary vertebral osteosarcomas followed in our institution between 2004 and 2012. They allow to illustrate some essential radiologic features, useful to evoke this rare entity.     

The filum terminale internum and externum: A comprehensive review

Introduction: The filum terminale has oven been overlooked in the literature probably due to its small size and historical lack of research on its true morphology. However, this structure’s roll in the tethered cord syndrome has become more apparent. Therefore, the current comprehensive review seemed timely. Methods: Using standard search engines, the history, embryology, anatomy, pathology and surgery of the filum terminale were reviewed. Conclusions: It is only recently that the true anatomy and pathological involvement of the filum terminale in the tethered cord syndrome have been elucidated.     

The NEXUS criteria are insufficient to exclude cervical spine fractures in older blunt trauma patients

Background and objectiveThe National Emergency X-Radiography Utilization Study (NEXUS) criteria are used to assess the need for imaging to evaluate cervical spine integrity after injury. The aim of this study was to assess the sensitivity of the NEXUS criteria in older blunt trauma patients.MethodsPatients aged 65 years or older presenting between 1st July 2010 and 30th June 2014 and diagnosed with cervical spine fractures were identified from the institutional trauma registry. Clinical examination findings were extracted from electronic medical records. Data on the NEXUS criteria were collected and sensitivity of the rule to exclude a fracture was calculated.ResultsOver the study period 231,018 patients presented to The Alfred Emergency & Trauma Centre, of whom 14,340 met the institutional trauma registry inclusion criteria and 4035 were aged ≥65 years old. Among these, 468 patients were diagnosed with cervical spine fractures, of whom 21 were determined to be NEXUS negative. The NEXUS criteria performed with a sensitivity of 94.8% [95% CI: 92.1%–96.7%] on complete case analysis in older blunt trauma patients. One-way sensitivity analysis resulted in a maximum sensitivity limit of 95.5% [95% CI: 93.2%–97.2%].ConclusionCompared with the general adult blunt trauma population, the NEXUS criteria are less sensitive in excluding cervical spine fractures in older blunt trauma patients. We therefore suggest that liberal imaging be considered for older patients regardless of history or examination findings and that the addition of an age criterion to the NEXUS criteria be investigated in future studies.     

Unexpected Seizure Attack in a Patient with Spinal Metastasis Diagnosed as Posterior Reversible Encephalopathy Syndrome

Seizure is a foreseeable risk in patients with brain lesion. However, seizure during treating non-brain lesion is not a familiar situation to neurosurgeon. Posterior reversible encephalopathy syndrome (PRES) is a relatively common situation after systemic chemotherapy. The aim of this study is to make neurosurgeons aware of this potential medical problem. A 52-year-old woman with advanced gastric cancer, presented with low back pain due to spinal metastasis at the 4th lumbar vertebra. Ten cycles of chemotherapy with FOLFOX (5-Fluoruracil/Oxaliplatin) had been completed 23 days ago. Two days before the planned operation, a generalized tonic clonic seizure occurred. She did not have a history of hypertension or seizure. The seizure was stopped with lorazepam 4mg. The brain magnetic resonance (MR) imaging showed high signal changes in both parieto-occipital lobes on the T2-weighted images, and these were partially enhanced, suggesting PRES. The surgery was preceded by treatment with an antiepileptic drug. The MR images, taken 1.5 months after the seizure, showed that the lesion was no longer present. At 3 month follow-up, no additional seizure attack occurred without any seizure medication. The possibility of a seizure attack should be considered if the patient has a history of chemotherapy.     

High-Frequency Micro-Ultrasound Imaging and Optical Topographic Imaging for Spinal Surgery: Initial Experiences

High frequency micro-ultrasound (µUS) transducers with central frequencies up to 50?MHz facilitate dynamic visualization of patient anatomy with minimal disruption of the surgical work flow. Micro-ultrasound improves spatial resolution over conventional ultrasound imaging from millimeter to micrometer, but compromises depth penetration. This trade-off is sufficient during an open surgery in which the bone is removed and theultrasound probe can be placed into the surgical cavity. By fusing µUS with pre-operative imaging and tracking the ultrasound probe intra-operatively using our optical topographic imaging technology, we can provide dynamic feedback during surgery, thus affecting clinical decision making. We present our initial experience using high-frequency µUS imaging during spinal procedures. Micro-ultrasound images were obtained in five spinal procedures. Medical rationale for use of µUS was provided for each patient. Surgical procedures were performed using the standard clinical practice with bone removal to facilitate real-time ultrasound imaging of the soft tissue. During surgery, the µUS probe was registered to the pre-operative computed tomography and magnetic resonance images. Images obtained comprised five spinal decompression surgeries (four tumor resections, one cystic synovial mass). Micro-ultrasound images obtained during spine surgery delineated exquisite detailing of the spinal anatomy including white matter and gray matter tracts and nerve roots and allowed accurate assessment of the extent of decompression/tumor resection. In conclusion, tracked µUS enables real-time imaging of the surgical cavity, conferring significant qualitative improvement over conventional ultrasound.     

Clinical reasoning for manual therapy management of tension type and cervicogenic headache

In recent years, there has been an increasing knowledge in the pathogenesis and better management of chronic headaches. Current scientific evidence supports the role of manual therapies in the management of tension type and cervicogenic headache, but the results are still conflicting. These inconsistent results can be related to the fact that maybe not all manual therapies are appropriate for all types of headaches; or maybe not all patients with headache will benefit from manual therapies. There are preliminary data suggesting that patients with a lower degree of sensitization will benefit to a greater extent from manual therapies, although more studies are needed. In fact, there is evidence demonstrating the presence of peripheral and central sensitization in chronic headaches, particularly in tension type. Clinical management of patients with headache needs to extend beyond local tissue-based pathology, to incorporate strategies directed at normalizing central nervous system sensitivity. In such a scenario, this paper exposes some examples of manual therapies for tension type and cervicogenic headache, based on a nociceptive pain rationale, for modulating central nervous system hypersensitivity: trigger point therapy, joint mobilization, joint manipulation, exercise, and cognitive pain approaches.     

Detection of progressive idiopathic scoliosis during growth using back surface topography: A prospective study of 100 patients

The progression of adolescent idiopathic scoliosis is typically monitored via regular radiographic follow-up. The Cobb angle (as measured on whole-spine radiographs) is considered as the gold standard in scoliosis monitoring.ObjectiveTo determine the sensitivity and specificity of back surface topography parameters, with a view to detecting changes in the Cobb angle.Patient and methodOne hundred patients (mean age: 13.3) with Cobb angles greater than 10 degrees were included. Topographic parameters were measured in a standard position and in a position with hunched shoulders. Gibbosities and spinal curvatures were evaluated.ResultsAn increase of more than 2 degrees in any one gibbosity or in the sum of the gibbosities (in either of the two examination positions) enabled the detection of a five-degree increase in the Cobb angle with a sensitivity of 86% and a specificity of 50%.ConclusionIf the present results are confirmed by other studies, analysis with back surface topography parameters may reduce the number of X-ray examinations required to detect increases in the Cobb angle.     

乌司他丁对脊柱手术患者围术期凝血功能的影响

[目的]观察胰蛋白酶抑制剂乌司他丁对脊柱手术患者围术期凝血功能及血小板聚集率的影响.[方法]选择36例无血液疾病及凝血功能障碍、肝肾功能异常或未服用影响血小板功能药物的择期脊柱手术患者(ASAⅡ～Ⅲ),随机分为乌司他丁组(W组,5000 U/kg,n=18)和生理盐水组(C组,n=18)；分别于注射前(T0)、注射后1 h(T1)、注射后2 h(T2)、注射后3 h(T3)抽出静脉血测定凝血酶原时间(PT)、部分凝血活酶时间(APTT)、凝血酶时间(TT)、纤维蛋白原(FIB)、国际标准化比值(INR)、及血小板1 min,5 min和最大聚集率(PAG1、PAG5、PAGM),并记录两组手术出血量.[结果]注射乌司他丁组后1h,W组APTT,PT较注射前明显延长(P＜0.05),用药后2h,TT较注射前明显延长(P＜0.05),用药后3h,APTT,PT,TT差异无统计学意义(P＞0.05).与C组比较,注射后1h,APTT显著性延长(P＜0.01),用药后2h,PT显著性延长(P＜0.05),用药后3h,APTT,PT,TT差异无统计学意义(P＞0.05).两组注射前后及组间比较PAgT差异无统计学意义(P＞0.05).两组患者出血量比较差异无统计学意义(P＞0.05).[结论]围术期应用5000 U/kg乌司他丁可改善脊柱手术患者术中患者的凝血状态,减少术中微血栓综合征,预防术中术后血栓形成.