Sagittal Reconstruction Research Articles

Usefulness of lateral radiographs for detecting tuberculous lymphadenopathy in children – confirmation using sagittal CT reconstruction with multiplanar cross-referencing

Background. Diagnosis of pulmonary tuberculosis (PTB) in children remains difficult. Lateral chest radiographs are frequently used to facilitate diagnosis, but interpretation is variable. In this study, lateral chest radiographs (CXRs) are evaluated against sagittal CT reconstructions for the detection of mediastinal lymphadenopathy.
 
 Aim. To correlate suspected lymphadenopathy on lateral CXR with sagittal CT reconstructions and determine which anatomical group of lymph nodes contributes to each lateral CXR location.
 
 Methods and materials. Thirty TB-positive children’s lateral CXRs were retrospectively reviewed for presence of mediastinal lymphadenopathy in 3 pre-determined locations in relation to the carina: retrocarinal, subcarinal and precarinal. Findings of the CT sagittal reconstructions were then correlated with the CXRs for the presence of lymphadenopathy in the same 3 pre-determined areas across the width of the mediastinum. Axial and coronal CT crossreferencing confirmed the position of the lymphadenopathy.
 
 Results. The most frequent locations for lymphadenopathy were the subcarinal (28) and right hilar (25). Sensitivity and specificity values of the CXRs were moderate, with the precarinal region having the best sensitivity and specificity for presence of lymphadenopathy. Contribution to each zonal group on lateral CXR were from multiple anatomical lymph node sites.
 
 Conclusion. The precarinal zone on CXR had the best specificity and sensitivity, and represented mainly subcarinal and right hilar lymph node groups. Attention should be paid to this area on lateral CXRs for detecting lymphadenopathy in children with suspected PTB.

CT and radiographic analysis of sagittal profile changes following thoracoscopic anterior scoliosis surgery

BackgroundPrevious studies report an increase in thoracic kyphosis after anterior approaches and a flattening of sagittal contours following posterior approaches. Difficulties with measuring sagittal parameters on radiographs are avoided with reformatted sagittal CT reconstructions due to the superior endplate clarity afforded by this imaging modality.MethodsA prospective study of 30 Lenke 1 adolescent idiopathic scoliosis (AIS) patients receiving selective thoracoscopic anterior spinal fusion (TASF) was performed. Participants had ethically approved low dose CT scans at minimum 24 months after surgery in addition to their standard care following surgery. The change in sagittal contours on supine CT was compared to standing radiographic measurements of the same patients and with previous studies. Inter-observer variability was assessed as well as whether hypokyphotic and normokyphotic patient groups responded differently to the thoracoscopic anterior approach.ResultsMean T5-12 kyphosis Cobb angle increased by 11.8 degrees and lumbar lordosis increased by 5.9 degrees on standing radiographs two years after surgery. By comparison, CT measurements of kyphosis and lordosis increased by 12.3 degrees and 7.0 degrees respectively. 95% confidence intervals for inter-observer variability of sagittal contour measurements on supine CT ranged between 5-8 degrees. TASF had a slightly greater corrective effect on patients who were hypokyphotic before surgery compared with those who were normokyphotic.ConclusionsRestoration of sagittal profile is an important goal of scoliosis surgery, but reliable measurement with radiographs suffers from poor endplate clarity. TASF significantly improves thoracic kyphosis and lumbar lordosis while preserving proximal and distal junctional alignment in thoracic AIS patients. Supine CT allows greater endplate clarity for sagittal Cobb measurements and linear relationships were found between supine CT and standing radiographic measurements. In this study, improvements in sagittal kyphosis and lordosis following surgery were in agreement with prior anterior surgery studies, and add to the current evidence suggesting that anterior correction is more capable than posterior approaches of addressing the sagittal component of both the instrumented and adjacent non instrumented segments following surgical correction of progressive Lenke 1 idiopathic scoliosis.

Arthroscopic Accessibility of the Talus Quantified by Computed Tomography Simulation

Background: Anterior ankle arthroscopy is the preferred surgical approach for the treatment of osteochondral defects of the talus (OCDs). However, the ankle is a congruent joint with limited surgical access. Purpose: The dual purpose of this study was (1) to quantify the anterior arthroscopic reach (defined as the proportion of the talar dome articular surface located anterior to the anterior distal tibial rim) with the ankle in full plantar flexion and (2) to identify predictive factors of the arthroscopic reach. Study Design: Descriptive laboratory study. Methods: Computed tomography scans were obtained of 59 ankles (57 patients aged 33 ± 11 years) in full plantar flexion in a nonmetallic 3-dimensional footplate. The arthroscopic reach of both the medial and lateral talar domes was assessed on sagittal reconstructions using a custom-made software routine. Intraobserver and interobserver reliability were calculated by intraclass correlation coefficients (ICCs). Various predictive factors of the arthroscopic reach were analyzed by multivariate linear regression analysis. Results: The arthroscopic reach was 48.2% ± 6.7% (range, 26.7%-60.7%) of the medial talar dome and 47.8% ± 6.5% (range, 31.2%-65.1%) of the lateral talar dome (P = .62). The intraobserver and interobserver reliability of both measurements were excellent (ICC, .99). The clinical plantarflexion angle was a statistically significant predictive factor of both the medial and lateral arthroscopic reaches (ie, increased plantar flexion corresponded to increased area of access), while joint laxity, gender, and age were not predictive. Conclusion: Almost half of the talar dome is accessible anterior to the anterior distal tibial rim. The plantarflexion angle is an independent predictive factor of the arthroscopic reach both medially and laterally. Clinical Relevance: These results may facilitate preoperative planning of the surgical approach for OCDs.

Idiopathic thoracolumbar/lumbar scoliosis treated with anterior correction and interbody fusion with calcium phosphate cement

To investigate the clinical outcome and fusion rate in patients with idiopathic thoracolumbar/lumbar scoliosis treated with anterior correction and interbody fusion with calcium phosphate cement. From October 2006 to March 2008, 24 cases undergoing anterior correction and interbody fusion with calcium phosphate cement were enrolled. All of them were female, with an age ranged from 12 to 25 years. The mean Cobb angle of main curve was 46° ± 5° (range, 40° - 56°) before surgery. During operation, the most proximal and distal disc spaces were filled with rib autograft, while the remaining levels were filled with calcium phosphate cement. The interbody fusion rate, coronal correction and sagittal profile reconstruction were evaluated respectively by using χ² test and t test. Interbody fusion was performed in 103 levels, including 48 levels with rib autograft and 55 levels with calcium phosphate cement. The mean follow-up period was 23.8 months (range, 12 - 33 months) in this series. At the follow-up of 6 months, fusion rate was found as 54.2% in the levels filled with rib autograft, while 50.9% in those filled with calcium phosphate cement. Solid fusion of the whole instrumented area was achieved in all cases with a minimum one-year follow-up. No instrumentation-related complications occurred. The correction rate of main curve was on an average of 76% ± 11% after surgery. A significant difference was found between preoperative and immediate postoperative value in terms of the main curve magnitude (46° ± 5° vs. 14° ± 5°, t = -26.95, P < 0.05). The correction loss of the main curve was -5.1° - 10.4° at the final follow-up. The coronal balance and lower instrumented vertebra tilting were significantly improved after operation. The thoracolumbar kyphosis was significantly reduced postoperatively (t = 3.11, P < 0.05). Satisfactory bone fusion and correction maintenance can be achieved in idiopathic thoracolumbar/lumbar scoliosis treated by anterior instrumentation combined with interbody fusion using calcium phosphate cement.

Diagnostic Imaging in Body Packers

Drug abuse is a major health problem in Iran, particularly in youth and young adults.1 Body packing of opium is a common cause of admission to the medical toxicology ward. Because body packers are drug smugglers, they are usually brought to the hospital by police, are asymptomatic, and deny body packing. Ultrasonography, plain radiography, and computed tomography (CT) are recommended diagnostic modalities.2 We present 3 images in a case of massive body packing (Figures 1-3). A 50-year-old woman ingested 200 pellets of packed opium (Taryak) to transport them from Zahedan to Mashhad for the equivalent of US $200. She was arrested by police in Birjand for suspected body packing of drugs. She confessed to ingestion of about 200 pellets of opium for a total of 2.8 kg. FIGURE 1 CT 3D reconstruction of the abdomen and pelvis showed numerous packets of opium in the entire gastrointestinal system. FIGURE 2 Abdominal ultrasound of a body packer. Round hyperechogenic structures with dorsal echo extinction are seen within the abdomen. Curvilinear hyperechoic rim (arrowheads) and acoustic shadowing (arrow) are visible. FIGURE 3 Radiographic findings in a body packer. A plain abdominal radiograph shows multiple foreign bodies. The “double-condom” sign (arrows) outlines many packets. Because of the massive amount of drugs in her gastrointestinal system, she was referred by law enforcement to the emergency department of Vali Asr Hospital in Birjand (the main and referral hospital for poisoning cases in southern Khorasan).3 At admission, she was confused, and because of suspected opium poisoning, she received 0.8 mg of naloxone, which restored her mental status to normal. Pupil examination results were normal, but slight abdominal distention was found on her physical examination. Axial CT scans (window level of +40 and window width of 300) obtained without bowel preparation or oral or intravenous administration of contrast agent including sagittal and coronal reconstructions and 3-dimensional surface rendered images revealing a distended stomach and bowel loops loaded with numerous drug-filled packets measuring approximately 3.5 to 4 cm. Ingested drug packets appeared almost uniform in shape and were cylindrical. The number of packages was reported to be as high as 200, but it was difficult to determine the exact number. Although the stomach and bowel loops were distended, no abrupt termination of distention (cutoff sign) suggestive of mechanical obstruction was observed. No obvious leaking from the packages was seen.Plain abdominal radiographs of the abdomen (anteroposterior and lateral views) taken at the time of admission showed the stomach and bowel were entirely loaded with numerous drug packets that had density similar to soft tissue. The most useful finding in these radiographs was a thin, lucent rim of air in a cylindrical pattern caused by air trapped between the wrapping and the drug substance in each package or by a rim of air between layers of wrapping (so-called double condom sign). We administered a polyethylene glycol–electrolyte lavage solution to the patient at a rate of 2 L/h for 12 hours. The plain abdominal radiograph of the abdomen 24 hours later showed a decreased number of packets in the stomach, but numerous packets were still visible in all parts of the colon. Because of the high number of retained pellets, we continued the polyethylene glycol–electrolyte lavage solution for an additional 8 hours. On CT scanning and radiography 48 hours later, the abdomen appeared to be clear of drug packets. Customs agents collected 207 intact pellets of opium. Repeated imaging confirmed complete decontamination. This case demonstrates the appearance of multiple drug packets using different imaging modalities and the importance of serial imaging in diagnosing and treating patients who are body packing. Although abdominal radiography and ultrasonography are useful screening tools, CT appears to be more effective in the evaluation and management of patients.

Use sagittal reconstruction CT for making decisions regarding the surgical strategy for cervical ossification of the posterior longitudinal ligament

Use sagittal reconstruction CT to verify the surgical strategy for cervical ossification of the posterior longitudinal ligament (OPLL). A retrospective study of 161 patients (106 males and 55 females) who had undergone surgery for OPLL from July 2007 to November 2010 was performed. The mean age at surgery was 54.5 years (range from 26 to 77 years). The mean follow-up period was 28 months (12 - 54 months). There were 40 patients accept anterior approach surgeries (anterior group) which include 14 cases of anterior cervical corpectomy and fusion and 26 cases of anterior cervical discectomy and fusion. There were 120 patients accept posterior approach surgeries (posterior group) which was spinous process-splitting laminoplasty for cervical myelopathy using coralline hydroxyapatite. One patient accepted combined anterior and posterior approach. According to the sagittal reconstruction CT, the main reason for spinal cord compression was cervical disc herniation in anterior group, and OPLL in posterior group. The level of spinal cord compression was 1 to 2 levels in anterior group, and 1 to 5 levels in posterior group with a major of 2 to 4 levels. As the classification of OPLL, segmental type and circumscribed type were major of segmental type in anterior group and all of the four types were in posterior group, the distribution of each type was average. The patients of posterior group were classified into two groups according to the modified K-line classification, and clinical results were compared between the two groups. The modified K-line was defined as a line that connects the midpoints of the spinal canal at C(2) and C(7) on sagittal CT myelography. Compression to the spinal cord did not exceed the K-line in the modified K-line(+) group and did exceed it in the modified K-line(-) group. Clinical data were compared using t-test or χ(2) test. Correlation analysis was used to determine the relationships of C(2)-C(7) angulation between sagittal reconstruction CT and neutral position X-ray. The patient of anterior group had better recovery rate of the JOA score (72% ± 27%) than the posterior group (59% ± 35%) at the latest follow-up (t = 2.238, P = 0.027). In posterior group, the patients of modified K-line(+) group had better recovery rate of the JOA score (63% ± 37%) than the K-line(-) group (49% ± 30%) at the latest follow up (t = 2.150, P = 0.034). The C(2)-C(7) angulation on sagittal reconstruction CT was 11° ± 9° which has significantly correlated with the C(2)-C(7) angulation on neutral position X-ray which was 10° ± 10° (r = 0.947, P < 0.01). Considering the selection of surgical approach, it should be combined with the main clinical diagnosis for spinal cord compression, the level of compression, the classification of OPLL and the kyphotic alignment of the cervical spine. The modified K-line is a simple and practical tool for making decisions regarding the surgical strategy for cervical OPLL patients.

Anomalous Tendon to the Middle Finger for Sagittal Band Reconstruction: Report of 2 Cases

Multiple techniques with good outcomes have been described for sagittal band reconstruction. We describe 2 cases of sagittal band reconstruction using an anomalous slip of the extensor tendon to the middle finger. This anomalous slip can be a resource for surgical reconstruction that can add stability to primary sagittal band repair.

An Uncommon Case of Abdominal Pain: Superior Mesenteric Artery Syndrome

Superior mesenteric artery (SMA) syndrome is a rare cause of abdominal pain, nausea and vomiting that may be undiagnosed in patients presenting to the emergency department (ED). We report a 54-year-old male presenting to a community ED with abdominal pain and the subsequent radiographic findings.The patient’s computed tomgraphy (CT) of the abdomen and pelvis demonstrates many of the hallmark findings consistent with SMA syndrome, including; compression of the duodenum between the abdominal aorta and superior mesenteric artery resulting in intestinal obstruction, dilation of the left renal vein, and gastric distension. Patients diagnosed with SMA syndrome have a characteristically short distance between the superior mesenteric artery and the aorta (usually 2–8 mm) in contrast to healthy patients (10–34 mm). Our patient’s aortomesenteric distance was measured to be approximately 4 mm. Furthermore, the measured angle between the superior mesenteric artery and the aorta is reduced in patients with SMA syndrome from a normal range of 28°–65° to a measurement between 6°–22°. Our patient’s aortomesenteric angle was difficult to measure secondary to poor sagittal reconstructions, but appears to be approximately 30°. Following radiographic evidence suggesting SMA syndrome together with our patient’s constellation of presenting symptoms, a diagnosis of SMA syndrome was made and the patient was admitted to the general surgery service. However, our patient decided to leave against medical advice owing to improvement of his symptoms following the emptying of two liters of gastric contents via nasogastric tube evacuation.

Missed iatrogenic partial dysruption of the male urethra, caused by catheterization

This 37-year-old male presented at the emergency room with shortness of breath (SOB), a distended abdomen and a history of anuria for 2 days. Clinical examination revealed a left pleural effusion, cardiomegaly and ascites. An abdominal ultrasound confirmed the presence of massive ascites. The bladder appeared to be distended on ultrasound. The abdomen was not tender to palpation. The admission temperature was 37.6 C, BP 134/58, PR 86, and RR 20. Blood-chemistries showed the RBC 4.2 mil, WBC 6800, BUN 32, creatinine 2.6, glucose 106, K 4.2.In view of the anuric status and apparently distended bladder, retrograde placement of a Foley catheter was attempted by the nurse. When she failed, a junior resident made a second attempt, but failed likewise. He did not introduce a parallel micro-catheter, which could have been used to inject contrast-laced jell to further outline the path of the urethra. A scout film of the abdomen revealed an ominous deviation of the tip of the catheter to the left (Figure-1 arrow), which was not appreciated. Urologic consult was requested. After a 6 hour delay the urologist noted the penile shaft to be swollen, the scrotum to be distended with fluid. The patient’s temperature was now 38.4oC, and he complained of vague prepubic pain.A computed tomogram of the pelvis with sagittal reconstruction was performed, demonstrating a distended bladder and significant fluid accumulation with interspersed gas in the pre- and retrourethal space (Figure-2 arrow). The tip of the catheter (Figure-2 dotted arrow) appeared to be outside the urethra and angled posteriorly. A suprapubic catheter was then inserted, decompressing the bladder. Prior to removal of the Foley catheter a small amount of dilute non-ionic contrast medium was injected to delineate the urethra. The urethra was noted (Figure-3 arrow) to be displaced downward and posteriorly by massive urine extravasation in the anterior peri-urethral space (Figure-3 arrow-heads). Furthermore, note the subcutaneous air delineating the corpora cavernosa in the penile shaft (Figure-3 curved arrow). Finally an 8 French catheter was passed with an antegrade approach, via the suprapubic access site

Osteoporosis imaging: state of the art and advanced imaging.

Osteoporosis is becoming an increasingly important public health issue, and effective treatments to prevent fragility fractures are available. Osteoporosis imaging is of critical importance in identifying individuals at risk for fractures who would require pharmacotherapy to reduce fracture risk and also in monitoring response to treatment. Dual x-ray absorptiometry is currently the state-of-the-art technique to measure bone mineral density and to diagnose osteoporosis according to the World Health Organization guidelines. Motivated by a 2000 National Institutes of Health consensus conference, substantial research efforts have focused on assessing bone quality by using advanced imaging techniques. Among these techniques aimed at better characterizing fracture risk and treatment effects, high-resolution peripheral quantitative computed tomography (CT) currently plays a central role, and a large number of recent studies have used this technique to study trabecular and cortical bone architecture. Other techniques to analyze bone quality include multidetector CT, magnetic resonance imaging, and quantitative ultrasonography. In addition to quantitative imaging techniques measuring bone density and quality, imaging needs to be used to diagnose prevalent osteoporotic fractures, such as spine fractures on chest radiographs and sagittal multidetector CT reconstructions. Radiologists need to be sensitized to the fact that the presence of fragility fractures will alter patient care, and these fractures need to be described in the report. This review article covers state-of-the-art imaging techniques to measure bone mineral density, describes novel techniques to study bone quality, and focuses on how standard imaging techniques should be used to diagnose prevalent osteoporotic fractures.

This Month inRadiology

Osteoporosis is becoming an increasingly important public health issue, and effective treatments to prevent fragility fractures are available. Osteoporosis imaging is of critical importance in identifying individuals at risk for fractures who would require pharmacotherapy to reduce fracture risk and also in monitoring response to treatment. Dual x-ray absorptiometry is currently the state-of-the-art technique to measure bone mineral density and to diagnose osteoporosis according to the World Health Organization guidelines. Motivated by a 2000 National Institutes of Health consensus conference, substantial research efforts have focused on assessing bone quality by using advanced imaging techniques. Among these techniques aimed at better characterizing fracture risk and treatment effects, high-resolution peripheral quantitative computed tomography (CT) currently plays a central role, and a large number of recent studies have used this technique to study trabecular and cortical bone architecture. Other techniques to analyze bone quality include multidetector CT, magnetic resonance imaging, and quantitative ultrasonography. In addition to quantitative imaging techniques measuring bone density and quality, imaging needs to be used to diagnose prevalent osteoporotic fractures, such as spine fractures on chest radiographs and sagittal multidetector CT reconstructions. Radiologists need to be sensitized to the fact that the presence of fragility fractures will alter patient care, and these fractures need to be described in the report. This review article covers state-of-the-art imaging techniques to measure bone mineral density, describes novel techniques to study bone quality, and focuses on how standard imaging techniques should be used to diagnose prevalent osteoporotic fractures.

Osteoporosis Imaging: State of the Art and Advanced Imaging

Osteoporosis is becoming an increasingly important public health issue, and effective treatments to prevent fragility fractures are available. Osteoporosis imaging is of critical importance in identifying individuals at risk for fractures who would require pharmacotherapy to reduce fracture risk and also in monitoring response to treatment. Dual x-ray absorptiometry is currently the state-of-the-art technique to measure bone mineral density and to diagnose osteoporosis according to the World Health Organization guidelines. Motivated by a 2000 National Institutes of Health consensus conference, substantial research efforts have focused on assessing bone quality by using advanced imaging techniques. Among these techniques aimed at better characterizing fracture risk and treatment effects, high-resolution peripheral quantitative computed tomography (CT) currently plays a central role, and a large number of recent studies have used this technique to study trabecular and cortical bone architecture. Other techniques to analyze bone quality include multidetector CT, magnetic resonance imaging, and quantitative ultrasonography. In addition to quantitative imaging techniques measuring bone density and quality, imaging needs to be used to diagnose prevalent osteoporotic fractures, such as spine fractures on chest radiographs and sagittal multidetector CT reconstructions. Radiologists need to be sensitized to the fact that the presence of fragility fractures will alter patient care, and these fractures need to be described in the report. This review article covers state-of-the-art imaging techniques to measure bone mineral density, describes novel techniques to study bone quality, and focuses on how standard imaging techniques should be used to diagnose prevalent osteoporotic fractures.

Repair of Pars Defects by Segmental Transverse Wiring for Athletes With Symptomatic Spondylolysis

Retrospective study of surgery for spondylolysis patients. To assess clinical outcome of bony union using multislice computed tomography after segmental wiring fixation. How bony union affects surgical outcome of spondylolysis repair is unclear. Forty-four athletes with symptomatic spondylolysis (33 men and 11 women; mean age, 24.2 ± 5.4 years) who underwent segmental wiring fixation were evaluated retrospectively at a mean follow-up of 85 ± 17 months. The level of spondylolysis was L5 in 42 cases, and both L4 and L5 in 2 cases, giving a total of 46 operative levels of vertebrae. Bony union using axial and sagittal reconstruction images of computed tomography, the Japanese Orthopaedic Association (JOA) score for back pain, and complications were reviewed. State of bony union was classified as bilateral union, unilateral union, or nonunion. The total score and the improvement ratio of the JOA score were compared among the 3 groups. Bilateral bony union was obtained in 29 cases (31 of 46 vertebrae, 67.4%). Six cases (13%) showed unilateral union, and 9 cases (19.6%) showed nonunion. JOA score increased significantly after surgery in all groups, average improvement rate was 78.9% in the bilateral group, 63.6% in the unilateral group, and 29.8% in the nonunion group; differences among the 3 groups were significant (P < 0.05). JOA score was significantly higher in the bilateral group than in the other 2 groups. Although symptoms were significantly ameliorated in all groups, the bilateral group showed the greatest improvement ratio in JOA score showing bony union to be an important factor in clinical outcome. However, there were a few exceptional cases with contradictory clinical and radiological outcomes. Thus, further studies are required to gain a better understanding of the other multiple factors affecting clinical outcome after spondylolysis repair.

The daunting task of “clearing” the cervical spine

The evaluation of the cervical spine in the emergency department is a common and often challenging task. We report the case of a 70-year-old female who presented intoxicated with evidence of a recent fall. A 64-slice computed tomographic (CT) scan with sagittal and coronal reconstructions revealed no acute injury. The patient was re-examined when alert and had persistent neck pain. Flexion-extension static views revealed severe subluxation of C5 on C6 with jumped facets, and subsequent magnetic resonance imaging confirmed significant ligamentous injury. The evidence available suggests that although CT with reconstruction is highly sensitive for clinically significant cervical injury, the possibility of severe injury remains.

Frontal Infundibular Cells: Pathway to the Frontal Sinus

A frontal infundibular cell (FIC) is an uncommon anatomic variant of an anterior ethmoid pneumatization that originates from the frontal recess and typically extends into the lumen of the frontal sinus ostium. FICs may show several anatomic variants that impact the anatomy of the frontal recess. Familiarity with these variants is required for safe endoscopic sinus surgical procedures. We conducted a retrospective chart review, examining 1,040 frontal recesses in 520 adults with no frontal sinus disease, to explore the anatomy of the healthy frontal recess and to describe the prevalence of FICs in patients without a history of conditions that cause frontal pneumatization. Review of axial and coronal computed tomography data, which were reformatted for sagittal reconstruction, was performed at a computer workstation. Bent and Kuhn's classification was used to define types of FICs. We identified 167 patients (32.1%) as having unilateral or bilateral FICs. Type I infundibular cells were the most common type (found in 15.7% of the entire study population). Type II and type III FICs were found in 3.8% and 12.1%, respectively; type IV FICs were present in 0.4%. The FIC has not been emphasized as an important potential cause of frontal sinus obstruction in the radiology literature, but clinicians should specifically watch for it on all routine computed tomography of the frontal sinus. Fine-cut computed tomography scans aid in the identification of each individual cell and allow the surgeon to formulate a clear and precise surgical plan. A surgical plan with a thorough understanding of the anatomy enables confident dissection of this complex and difficult area.

Computed Tomography of the Ankle in Full Plantar Flexion: A Reliable Method for Preoperative Planning of Arthroscopic Access to Osteochondral Defects of the Talus

The purpose of this study was to determine whether preoperative computed tomography (CT) of the ankle joint in full plantar flexion is a reliable and accurate tool to determine the anterior arthroscopic accessibility of talar osteochondral defects (OCDs). Twenty consecutive patients were prospectively studied. All patients had an OCD of the talar dome and had a preoperative CT scan of the affected ankle in maximum plantar flexion. Accessibility of the OCD was defined by the distance between the anterior border of the OCD and the anterior distal tibial rim. This distance was measured on sagittal CT reconstructions by 2 investigators. The reference standard was the distance between the same landmarks measured during anterior ankle arthroscopy by an orthopaedic surgeon blinded to the CT scans. Intraobserver and interobserver reliability of CT, as well as the correlation and agreement between CT and arthroscopy, were calculated. The measured distance between the anterior border of the OCD and the anterior distal tibial rim ranged from -3.1 to 9.1 mm on CT and from -3.0 to 8.5 mm on arthroscopy. The intraobserver and interobserver reliability of the measurements made on CT scans (intraclass correlation coefficients >0.99, P < .001), as well as the correlation between CT and arthroscopy, were excellent (r = 0.98, P < .001). Measurements on CT scans of the ankle in full plantar flexion are a reliable and accurate preoperative method to determine the in situ arthroscopic location of talar OCDs.

Computed tomography dacryocystography research of nasolacrimal duct of unilateral congenital nasolacrimal obstruction

Background The three-dimensional configuration of the nasolacrimal canal is highly variable with age,gender,and race.But enlargement of the nasolacrimal canal has sparsely been reported in the literature.Objective Computed tomography dacryocystography was performed in patients with unilateral congenital nasolacrimal duct obstruction and normal children to analyze the difference of bilateral nasolacrimal canal. Methods This is a retrospective study.Axial scan with sagittal and coronal reconstruction was applied in computed tomography dacryocystography.Diameters of bilateral nasolacrimal canal of 20 unilateral congenital nasolacrimal duct obstruction patients and 20 normal children were measured.Written informed consent was obtained from each child ' s parents before examination. Results The lacrimal sac,nasolacrimal duct and the peripheral tissue were clearly exhibited by computed tomography dacryocystography.The diameters of the origination,the middle part and the distal end of affected nasolacrimal duct were(5.5±1.4),(5.3±1.2),(5.3±1.6) mm,and normal ones were(3.9±0.8 ),(3.5± 0.8 ),( 3.9± 1.3 ) mm,respectively.These results were statistically significant ( t =5.200,6.967,2.932,P＜ 0.05 ).There was no statistically significant difference in bilateral nasolacrimal canal of normal children (t =0.346,0.281,0.312,P＞0.05 ). Conclusions Computed tomography dacryocystography can image lacrimal passage and their peripheral tissues clearly.The affected nasolacrimal canal diameters of unilateral congenital nasolacrimal duct obstruction were much larger than the fellow sides.The pathogenesis of this phenomenon need much research. Key words: Nasolacrimal obstruction/congenital/unilateral; Computed tomography; Dacryocystography; Nasolacrimal canal

Dens fracture in a patient with extensive craniocervical bone pneumatization

Craniocervical bone pneumatization in humans is very rare: only a handful of cases have been reported, predominantly in males (1). The characteristic air-filled bones are prone to fracture, even following minor trauma. Our case report (2) recently published in the December 2011 issue of Diagnostic and Interventional Radiology described abnormal extensive craniocervical bone pneumatization in a 47-year-old man; the same patient again presented to our hospital 10 months later with cervical pain after minor trauma (collapse). The patient complained of neck pain. No evidence of a neurological deficit was found. Initially performed plain radiographs of the upper cervical spine showed no evidence of a fracture. Because clinical symptoms persisted, we performed multislice computed tomography (MSCT) of the skull base and upper cervical spine using a 64-detector-row computed tomography (CT) scanner (Siemens Sensation 64, Siemens AG Sector Healthcare, Erlangen, Germany). Axial, coronal, and sagittal reconstructions were made using 0.75-mm slices. In addition to pre-existing extensive pneumatization of the skull base and atlas (Fig. a), submillimeter-scale axial images showed two thin lines at the dens at 7 and 9 o’clock (Fig. b), suspicious for thin fractures. In contrast to the previous CT findings (Fig. a), ambient soft-tissue emphysema could be observed on axial reconstructions (Fig. b, arrow). Although pre-trauma coronal reconstructions (Fig. c) showed pneumatization of the right hemicorpus of the axis, post-trauma MSCT depicted an Anderson and D’Alonzo Type III dens fracture (3) extending through the vertebral body of the axis (Fig. d, arrows). Patients who have been diagnosed with extensive craniocervical bone pneumatization need to be aware of the fragility of that anatomic region, and treating physicians should consider that even minor head or neck trauma may have serious consequences, such as fractures of the craniocervical region, in these patients. As reported earlier, the complex anatomy of the craniocervical region aggravates

Analysis of Sphenoid Sinus and Surrounding Structures Using Multidetector Computed Tomography

Background and ObjectivesZZSphenoid sinus is surrounded by several important structures and this can make sphenoid sinus surgeries difficult. The aim of this study was to clarify the anatomical features of the sphenoid sinus with its surrounding structures based on 3-dimensional multidetector computed tomography. Subjects and MethodZZWe obtained the sagittal reconstruction images of the sphenoid sinus from of 110 participants and measured various distances in the sphenoid sinus. In addition, we analyzed the impact of anatomical variation on the results of measured distances, such as presence of Onodi cell (Onodi type vs. non-Onodi type) and the location of sphenoid ostium corresponding to the level of sella floor (superior type vs. inferior type). ResultsZZIn the Onodi type, the mean distance from the sphenoid ostium to the roof of sphenoid sinus (5.81±1.12 mm vs. 10.31±2.90 mm, p=0.001) and the mean length of sphenoid sinus roof (4.52±1.00 mm vs. 9.89±4.17 mm, p=0.001) were significantly shorter than those in the non-Onodi type. In superior type, the mean distance from the sphenoid ostium to the floor of sphenoid sinus (12.44±2.63 mm vs. 9.90±2.31 mm, p＜0.001) and that from sphenoid ostium to the posterior wall of sphenoid sinus (13.44±3.27 mm vs. 20.38±7.63 mm, p＜0.001) were significantly longer compared with those in the inferior type. However, the mean distance from the sphenoid ostium to the roof of sphenoid sinus was shorter (7.49±1.86 mm vs. 10.51±3.03 mm, p＜0.001). ConclusionZZThe present study provides anatomical information about sphenoid sinus with important surgical distance measured between the sphenoid ostium and the surrounding structures, which is essential to avoid the complications during sphenoid surgery. � Korean J Otorhinolaryngol-Head Neck Surg 2012;55:95-100 Key WordsZZSphenoid sinus ㆍAnatomic landmarks ㆍRadioanatomic analysis ㆍMultidetector computed tomography.

Utility of intravascular ultrasound in intracranial and extracranial neurointerventions: experience at University at Buffalo Neurosurgery–Millard Fillmore Gates Circle Hospital

Intravascular ultrasound (IVUS) generates high-resolution cross-sectional images and sagittal reconstructions of the vessel wall and lumen. As a result, this imaging modality can provide accurate measurements of the degree of vessel stenosis, allow the detection of intraluminal thrombus, and analyze the plaque composition. The IVUS modality is widely used in interventional cardiology, and its use in neurointerventions has gradually increased. With case examples, the authors illustrate the utility of IVUS as an adjunct to conventional angiography for a wide range of intracranial and extracranial neurointerventions.