C2–3 facet joint ”pseudo-fusion”: anatomic basis of a normal variant

 Objective. To identify the anatomic basis for apparent C2–3 facet joint fusion (pseudo-fusion) on lateral cervical spine radiographs. Design and patients. The studies of 81 consecutive blunt trauma patients who had both plain radiographs and a CT scan of the upper cervical spine were reviewed. The C2–3 facet joints were evaluated on lateral cervical spine radiographs and graded ”normal” (category 1), ”indistinct” (category 2), or ”fused” (category 3), relative to the C3–4 level. The accompanying CT scans were reviewed for the presence of fusion and the angle of orientation of the facet joints relative to the axial and coronal planes. Results. In category 1 (”normal”), the C2–3 facet joints were oriented nearly parallel to the true coronal and axial plane. In category 2 (”indistinct”), both the C2–3 facet joints were oriented obliquely to the true coronal and axial planes. In category 3 (”fused”), the C2–3 facet joints were also oriented obliquely, but at a steeper angle than in category 2. Head tilt/rotation caused a change in category rating in 5 of 81 cases (6.2%). Conclusion. The appearance of C2–3 facet joint fusion (pseudo-fusion) on lateral cervical spine radiographs may be a normal anatomic variant. This ”pseudo-fusion” is due to the oblique orientation of these facet joints relative to the X-ray beam and is usually unaffected by patient position.     

The anatomic basis for the superior acetabular roof notch “Superior acetabular notch”

Radiographic discontinuity of the acetabulum is a frequently encountered entity which has been described by various authors. We have been unable to find an explanation of the nature of this discontinuity in the literature. By correlating dried skeletal specimens with their radiographic appearances, we found the anatomic basis for this phenomenon was an accessory fossa in the apex of the acetabulum.     

肝动脉正常解剖及变异的DSA研究

目的 研究数字减影血管造影（DSA）下肝动脉正常解剖及变异。方法 回顾分析我院从1994年11月至2003年6月的1200份,常规腹腔动脉干造影和（或）选择性肝动脉造影DSA片,部分病例同时作肠系膜上动脉、胃左动脉等处的造影。结果 873例（72．8％）患者具有正常的肝血管起源,156例（13．0％）患者存在变异的肝左动脉,120例（10．0％）患者存在变异的肝右动脉,而21例（1．8％）肝左及肝右动脉同时存在变异。1200例患者中肝总动脉起源于腹腔动脉干者1170例（97．5％）;肝固有动脉有92．0％系肝总动脉的直接延续;肝右动脉大多数发自肝固有动脉（89．8％）;肝中动脉的变异较大,发自肝左动脉较多（62．2％）;肝左动脉可直接发自肝固有动脉（44．6％）,也可来源于肝右动脉（30．2％）或其他动脉（25．2％）。结论 DSA了解肝动脉的解剖变异对指导肝脏疾病的介入治疗以及肝脏外科临床具有重要的意义。     

Nutrient canals of the ilium: A normal variant simulating disease on computed tomography

The nutrient canals of the ilium are a frequent finding on computed tomography (CT), and were seen in 8 of 8 consecutive examinations of the pelvis. CT sections through these canals could be misinterpreted as fractures or metastases, especially if there is a history of pelvic trauma or malignancy elsewhere.     

The pulmonary pseudonodule: Characteristic features of a normal variant due to a bone thickening at the junction of the laminae and posterior spine

The normal thickening of bone at the junction of the laminae and posterior spine should not be confused with a pathologic process. Its appearance on the plain radiograph and computed tomography is pathognomonic.     

Crossed doubled patellar tendon: A rare anatomical variant with potential clinical significance

The patellar tendon is an integral part of the knee extensor mechanism and has been historically described as a single tendon. A doubled patellar tendon is an exceedingly rare finding. We present a case of a crossed doubled patellar tendon in a 70-year-old male with a history of right knee pain, which to our knowledge has only been reported once before in the literature. The presence of a doubled patellar tendon has a potential influence on surgical planning and in the etiology of anterior knee pain.     

薄化深度烧伤坏死层的方法与疗效观察

目的：观察自制创面磨削器薄化坏死层与MEBT配合应用治疗烧伤的临床效果。方法：用骨科手持电钻和磨皮柱状磨头组合制成创面磨削器。选择相对标准的深Ⅱ度深型和浅Ⅲ度烧伤各30例，行自身对照。在同一部位，同一深度分别应用MEBT 磨削(称薄化组)和单纯MEBT(单纯MEBT组)对比观察，比较创面液化开始时间、液化结束时间及创面愈合时间。结果：MEBT 磨削方法使液化时间、液化结束时间及创面愈合时间提前。结论：MEBT 磨削能较早地使生命物质：MEBO激发潜能干细胞，使创面提前愈合。     

变异的原始三叉动脉夹层动脉瘤的血管内治疗一例并文献复习

目的探讨夹层动脉瘤的发生机制及变异性原始三叉动脉(primitive trigeminal PTA)动脉瘤的血管内治疗。方法报道并分析我院治疗存在PTA并发夹层动脉瘤的病例;Medline数据库检索PTA动脉瘤及所有关于变异型原始三叉动脉(PTAV)的文献,行文献复习。结果通过闭塞夹层动脉瘤及PTAV本身的术式治愈患者,出院及1年随访的MRS评分均为0分。存在原始三叉动脉者颅内动脉瘤的发病率约为3%,其中动脉瘤发自PTA本身约占2%,见37例报道,其中2例为夹层动脉瘤。PTAV动脉瘤的发生率约为9.8%,其中夹层动脉瘤的发生率在PTAV组及PTA组分别为50%和5.4%。结论血管发育异常是除血流动力学因素以外的动脉瘤,特别是夹层动脉瘤的发病原因之一,在无其他并存血管异常时,闭塞载瘤动脉是对PTAV动脉瘤安全和有效的治疗方法。     

The femoral linea aspera: radiological pattern

The femoral linea aspera has the radiographic appearance of two dense parallel lines. This is a normal variant but it can look like osteonecrosis or periostitis. We have demonstrated the relationship between prominent development of the linea aspera and the appearance of a linear opacity on the femur on the frontal view. Correspondence to: C. Hoeffel     

脑动静脉畸形栓塞治疗中正常灌注压突破防治的研究进展

正常灌注压突破综合征(NPPB)是脑动静脉畸形栓塞术中或术后的严重并发症。因NPPB的高致残率和病死率,近年来各国学者逐渐重视并研究其防治方法。本文就NPPB的研究进展进行综述,主要从发病机制、预测和预防进行探讨。     

Metabolic alterations: A biomarker for radiation‐induced normal brain injury—an MR spectroscopy study

Purpose

To assess if interval changes in metabolic status in normal cerebral tissue after radiation therapy (RT) can be detected by 2D CSI (chemical shift imaging) proton spectroscopy.

Materials and Methods

Eleven patients with primary brain tumors undergoing cranial radiation therapy (RT) were included. 2D‐CSI MRS was performed before, during, and after the course of RT with the following parameters: TE/TR 144/1500 ms, field of view (FOV) 24, thickness 10 mm, matrix 16 × 16. The metabolic ratios choline/creatine (Cho/Cr), N‐acetylaspartate (NAA)/Cr, and NAA/Cho in normal brain tissue were calculated.

Results

NAA/Cr and Cho/Cr were significantly decreased at week 3 during RT and at 1 month and 6 months after RT compared to values prior to RT (P < 0.01). The NAA/Cr ratio decreased by ?0.19 ± 0.05 (mean ± standard error [SE]) at week 3 of RT, ?0.14 ± 0.06 at the last week of RT, ?0.14 ± 0.05 at 1 month after RT, and ?0.30 ± 0.08 at 6 months after RT compared to the pre‐RT value of 1.43 ± 0.04. The Cho/Cr ratio decreased by ?0.27 ± 0.05 at week 3 of RT, ?0.11 ± 0.05 at the last week of RT, ?0.26 ± 0.05 at 1 month after RT and ?0.25 ± 0.07 at 6 months after RT from the pre‐RT value of 1.29 ± 0.03. Changes in Cho/Cr were correlated with the interaction of the radiation dose and dose‐volume at week 3 of RT, during the last week of RT (P < 0.005), and at 1 month after RT (P = 0.017).

Conclusion

The results of this study suggest that MRS can detect early metabolic changes in normal irradiated brain tissue. J. Magn. Reson. Imaging 2009;29:291–297. © 2009 Wiley‐Liss, Inc.

     

MR- arthrography: anatomic variant from link between lateral meniscus and anterior and posterior cruciate ligaments. A case report and review of the literature

Menisci congenital anomalies are rare morphologic abnormalities including accessory meniscus, discoid meniscus, double-layered meniscus, hypoplastic meniscus and ring-shaped meniscus (RSM). In a 35 year-old male patient, MR arthrography showed a bridging accessory bundle connecting the anterior cruciate ligament and posterior cruciate ligament with the posterior horn of the lateral meniscus. Arthroscopic examination showed a fan-like obstacle embracing the posterior horn of the lateral meniscus. It would be important to correctly identify this anatomical variant, because the bundle connecting the external meniscus to the ligaments of the central pivot can be misinterpreted as a meniscal fragment.     

The prevalence and CT appearance of the levator claviculae muscle: a normal variant not to be mistaken for an abnormality.

BACKGROUND AND PURPOSE: The levator claviculae muscle is an infrequently recognized variant in humans, occurring in 2% to 3% of the population, and has rarely been reported in the radiologic or anatomic literature. The importance of this muscle to radiologists is in distinguishing it from an abnormality; most commonly, cervical adenopathy. After discovering this muscle on the CT scans of two patients during routine clinical examinations, we conducted a study to determine the prevalence and appearance of the muscle on CT studies. METHODS: We evaluated 300 CT scans that adequately depicted the expected location of the muscle. The most superior level in which the muscle could be identified and the apparent location of insertion on the clavicle were recorded for all subjects in whom the muscle was detected. RESULTS: Seven levator claviculae muscles were identified in six subjects (2%). It was bilateral in one, on the left in four, and on the right in one. It was identified up to the level of the transverse process of C3 in all cases. The insertion was the middle third of the clavicle for two muscles and the lateral third of the clavicle for the remaining five muscles. CONCLUSION: Because the levator claviculae muscle will most likely be encountered during a radiologist's career, it is important to recognize this muscle as a variant and not as an abnormality.     

The importance of population-specific normal database for quantification of myocardial ischemia: comparison between Japanese 360 and 180-degree databases and a US database

Objectives  We aimed to develop a Japanese normal database for specific acquisition conditions, to compare US and Japanese normal populations, and to examine effects of camera rotation angle range on the normal limits. Methods and Results  Stress-rest ^99mTc myocardial perfusion databases for 360° (Jp360) and 180° (Jp180) acquisitions were created by the working group activity of the Japanese Society of Nuclear Medicine using Japanese patients. A standard 180° database (US180) had been previously generated by the Cedars Sinai Medical Center based on American patients. Additionally, 90 Japanese patients underwent coronary arteriography and stress-rest ^99mTc perfusion study with 360° acquisition for validation purposes, and quantitative evaluation was performed by QPS software using the above three normal database sets. Major differences between US180 and Jp360 databases were found in the apex and in the anterior wall in females and in the inferior wall in males. When the diagnostic performance was evaluated by receiver-operating characteristic analysis, area under the curve was the highest for Jp360 (0.842), followed by Jp180 (0.758) and US180 (0.728) databases (P = .019, Jp360 vs US180; P = .035, Jp360 vs Jp180). The coronary territory score at stress was highest with the Jp360 database in male patients with right coronary artery stenosis (n = 26, Jp360: 4.92 ± 4.61 [mean ± SD], Jp180: 4.23 ± 4.29, US180: 2.92 ± 3.53; P < .0001 between Jp360 and US180) and in female patients with left anterior descending artery stenosis (n = 12, Jp360: 6.33 ± 4.76, Jp180: 5.25 ± 4.83, US180: 4.50 ± 4.15; P = .0076 between Jp360 and US180). Conclusion  Because of the differences between US and Japanese normal databases, it is essential to use population- and acquisition-specific databases when using quantitative perfusion SPECT software.     

Metaphyseal cortical irregularities in children: A new perspective on a multi-focal growth variant

The occurrence of metaphyseal cortical irregularities in adolescents in many different bones indicates a commonality of these lesions as a variation of normal growth, rather than a stress or avulsive by-product. The histologically recognized incomplete nature of the metaphysial cortex in children offers an attractive explanation for this phenomenon.     

Correlation of computed tomography and postmortem findings of a diffuse astrocytoma: A case report

Diffusely infiltrating astrocytomas often present diagnostic difficulties. We herein correlate the radiologic and postmortem findings of a diffuse astrocytoma and conclude that recognition of abnormal bilateral and fairly symmetric enlargement and increased density of normal structures in CT scans may lead to an antemortem diagnosis of the tumor.