Disc Height and Angle Changes on Radiographs and Magnetic Resonance Imaging after Anterior or Posterior Percutaneous Endoscopic Cervical Discectomy.

Objectives: Cervical disc herniation (CDH) leads to pain, numbness, and potential disability. Percutaneous endoscopic cervical discectomy (PECD) offers an anterior or posterior approach. This study aims to compare postoperative disc height and angle changes one year after PECD, considering both approaches. Methods: We retrospectively reviewed the data from patients with CDH who underwent PECD from October 2017 to July 2022. Cervical disc height was measured using the preoperative and one-year postoperative magnetic resonance imaging (MRI) examinations. Lordotic angle (LA), global alignment angle (GAA), segmental alignment angle (SAA), and slippage distance (SD) at the surgical level were measured on radiographs in the neutral, flexion, and extension positions. Results: Thirty-eight patients who underwent posterior PECD (PPECD) and five patients who underwent anterior PECD (APECD) were included in the evaluation. The mean age of the patients was 47.4 years (range: 29-69 years). There was a significant difference in the preoperative and one-year postoperative GAA and SAA in extension in the PPECD group (p = 0.003 and 0.031, respectively). The mean decreased disc height one-year postoperative was 1.30 mm in the APECD group and 0.3 mm in the PPECD group by MRI. A significant disc height decrease was observed in the APECD group (p < 0.001). Conclusions: Treating CDH with PPECD or APECD is feasible, as it can relieve symptoms and reduce disability. Stability remained unaffected during the first year after surgery, even though there was an increase in angulation during extension. Despite a significant decrease in disc space following APECD, patients reported significant symptom improvement and no new symptoms.

Incidence and risk factors of heterotopic ossification after cervical Baguera C disc arthroplasty.

OBJECTIVE: This retrospective study was designed to evaluate the incidence and predisposing factors of heterotopic ossification (HO) after cervical disc arthroplasty (CDA) with a specific implant at 1 and 2 levels, and to investigate the biomechanical effects related to HO. The study goal was to identify ways to reduce the likelihood of HO formation after surgery. METHODS: The study included patients who underwent only 1- or 2-level CDA with the Baguera C disc between November 2014 and December 2021 at a single medical center. All patients were operated on by the same neurosurgeon. The surgical indication included 1-level or 2-level disc herniation between C3 and C7 with radiculopathy, myelopathy, or both, with minimal spondylosis. The various factors were assessed by evaluating plain radiographs and cervical CT scans. The presence of HO was evaluated at different intervals postsurgery, and HO severity was graded using the McAfee classification. RESULTS: Of 107 patients who underwent CDA, 47 (43.9%) had HO at 63 of 171 levels (36.8%). Most cases with HO were grade 1, and no grade 4 was observed. Statistically significant risk factors for HO were the length of endplate coverage ratio and inferior anterior residual exposed endplate (AREE); sex, age, implant height and width, shell angle, and pre- and postoperative functional spinal unit (FSU) angle were not significant. More AREE and greater kyphotic postoperative FSU angle in the flexion position were significant factors differentiating HO grades 0 and 1 from grades 2 and 3. Furthermore, the non-HO group showed a trend of higher range of motion at any postoperative time compared to the HO group, especially at 1 month after surgery. CONCLUSIONS: The HO incidence after CDA was correlated with the residual length of endplate coverage and inferior AREE. Additionally, the AREE and kyphotic postoperative FSU angle in the flexion position were associated with HO grade progression. Patients with HO also showed a trend of lower range of motion at 1 month after surgery. Using an adequately sized implant and encouraging neck motion may help prevent HO development and progression.

Anterior Bone Loss after Cervical Baguera C Disc versus Bryan Disc Arthroplasty.

Objectives: The objectives of this study were to identify the risk factors and incidence of anterior bone loss (ABL) after Baguera C cervical disc arthroplasty (CDA) and identify whether design differences in artificial discs affect ABL. Methods: In this retrospective radiological review of patients who underwent single-level Baguera C CDA in a medical center, the extent of ABL and the following radiological parameters were recorded: global and segmental alignment angle, lordotic angle (or functional spinal unit angle), shell angle, global range of motion (ROM), and ROM of the index level. ABL at the index level was grade 0-2. Grade 0 was defined as no remodeling, grade 1 as spur disappearance or mild change in body contour, and grade 2 as obvious bone regression with Baguera C Disc exposure. Results: Combining grade 1 and grade 2, ABL was found in 56 upper adjacent vertebrae and 52 lower adjacent vertebrae of the 77 patients. Only 18 patients (23.4%) had no ABL. Shell angle differed significantly between ABL grades of both the upper and lower adjacent level: 0.0° in grade 0 and 1 ABL vs. 2.0° in grade 2 ABL of the upper adjacent level (p < 0.05); and 0.0° in grade 0 and 1 ABL vs. 3.5° in grade 2 ABL of the lower adjacent level (p < 0.05). A female predominance of ABL was found. Hybrid surgery and artificial disc size were also related to ABL. Conclusions: ABL is more common in Baguera C Disc arthroplasty than Bryan Disc arthroplasty. Larger shell angle was related to ABL after CDA with Baguera C Discs, which may indicate that shell angle is pivotal in determining the incidence of ABL after CDA. Females had more ABL with Baguera C Disc arthroplasty; this might be related to shorter endplate lengths as well as a smaller endplate-implant mismatch.

Anterior bone loss after cervical Bryan disc arthroplasty: insight into the biomechanics following total disc replacement.

BACKGROUND CONTEXT: Cervical disc arthroplasty (CDA) is an innovative procedure launched in the early 2000s. Compared with anterior cervical discectomy and fusion, many studies show that CDA offers equivalent clinical outcomes while reducing secondary procedures and total cost. PURPOSE: We sought to determine the incidence of anterior bone loss after CDA and the related biomechanical effects. STUDY DESIGN/ SETTING: Retrospective chart review. PATIENT SAMPLE: Patients who underwent CDA with one level Bryan Disc (Medtronic SofamorDanek, Memphis, TN, USA) at one institution. OUTCOME MEASURES: Radiological measurements, including the extent of anterior bone loss, global alignment angle, shell angle, lordotic angle, mean degree of angle of the endplate with the horizontal line, global range of motion (ROM) and ROM of the index level were recorded. The grading of anterior bone loss of the index level was defined as Grade 0, no remodeling; Grade 1, spur disappearance or mild change in body contour; Grade 2, obvious bone regression with Bryan Disc exposure. METHODS: Anatomical measures and ROM were compared by grade of bone loss. RESULTS: Of the 121 patients included in the study, anterior bone loss was found in 53 (43.8%) on the upper adjacent level and 54 (44.6%) on the lower adjacent level. Twenty-nine patients (23.9%) had anterior bone loss in both levels. The majority of cases had Grade 1 anterior bone loss. Grade 2 bone loss was noted in the upper adjacent vertebra in only 5 patients and in 4 patients in the lower adjacent vertebra. Age, sex, operative level, and hybrid surgery had no effect on anterior bone loss. Most radiological assessments, including global alignment angle, lordotic angle, mean degree of angle of the endplate with the horizontal line, global ROM, and ROM of the index level, showed no correlation to anterior bone loss. Shell angle was found to be different in groups with or without remodeling in the upper adjacent level: 5.0 degreesin the Grade 0 group and 7.0 degrees in the Grade 1-2 group, p<.05. CONCLUSIONS: Many more patients than predicted had anterior bone loss. Increasing the shell angle of the artificial disc may increase the incidence of anterior bone loss after CDA. Further study of the biomechanics following CDA should help clarify the mechanisms at work.

Treating cerebrovascular diseases in hybrid operating room equipped with a robotic angiographic fluoroscopy system: level of necessity and 5-year experiences.

BACKGROUND: A hybrid operating room (OR) equipped with robotic angiographic fluoroscopy system has become prevalent in neurosurgery. The level of necessity of the hybrid OR in treating cerebrovascular diseases (CVD) is rarely discussed. OBJECTIVE: The authors proposed a scoring and classification system to evaluate the cerebrovascular procedures according to the level of treatment necessity for CVD in a hybrid OR and shared our 5-year experiences. METHODS: From December 2009 to January 2016, the registry of cerebrovascular procedures performed in the hybrid OR was retrieved. A scoring system was used to evaluate the importance of the surgical and interventional components of a cerebrovascular procedure performed in the hybrid OR. The score of either component ranged from 1, 1.5, to 2 (1 = no role, 1.5 = supplementary or informative, 2 = important or therapeutic). The total score of a procedure was by multiplying two individual scores. Levels of necessity were classified into level A (important), level B (beneficial), and level C (replaceable). RESULTS: A total of 1027 cerebrovascular procedures were performed during this period: diagnostic angiography in 328, carotid artery stenting in 286, aneurysm coiling in 128, intra-operative DSA in 101, aspiration of ICH under image guidance in 79, intra-arterial thrombolysis/thrombectomy in 51, intracranial angioplasty/stenting in 30, hybrid surgery/serial procedures in 19, and rescue surgery during embolization in 5. According to the scoring system, hybrid surgery and serial procedures scored the highest points (2 × 2). The percentages distributed at each level: levels A (2.3%), B (17.5%), and C (80.2%). CONCLUSION: This study conveys a concept of what a hybrid OR equipped with robotic angiographic fluoroscopy system is capable of and its potential. For cerebrovascular diseases, hybrid OR exerts its value via hybrid surgery or avoiding patient transportation in serial procedures (level A), via providing real-time high-quality angiography and image guidance (level B), which constituted about 20% of the cases. The subspecialty of the group using the hybrid OR directly reflects on the number of procedures categorized in each level. In a hybrid OR, innovative treatment strategies for difficult-to-treat CVD can be developed.

Intraprocedural arterial perforation during neuroendovascular therapy: Preliminary result of a dual-trained endovascular neurosurgeon in the neurosurgical hybrid operating room.

BACKGROUND: Intraprocedural arterial perforation (IPAP) is a potentially dismal complication of neuroendovascular therapy with high mortality and morbidity rates. The management of IPAP with the techniques described has been well established, but rescue results from the dual-trained endovascular neurosurgeon in the neurosurgical hybrid operating room (OR) are rarely reported. Here, we report five cases of successful rescue of IPAP in the neurosurgical hybrid OR and compare them with other series. METHODS: Between December 2009 and December 2013, 146 intracranial neuroendovascular procedures were performed in the hybrid operating room of Taichung Veterans General Hospital. A total of five patients with IPAP were identified. Postoperative clinical outcome was evaluated by Glasgow Coma Scale scores and postoperative 3-month modified Rankin Scale. RESULTS: The causes of the IPAP were coil protrusion (n = 3), microcatheter perforation (n = 1), and microwire penetration (n = 1). Two cases involved emergent ruptured aneurysms, while three cases occurred during elective procedures. Salvage treatment with emergent external ventricular drainage (EVD) was applied in all five cases. The average time-to-first-EVD was 16.25 min, and the average time-to-patent-EVD was 32.5 min. Postoperative 3-month outcome was good recovery (mRS ≤ 2) in all five cases. The zero mortality rate in our series is the most encouraging result in the published literature. CONCLUSION: IPAP can be rescued successfully with an aggressive approach and quick conversion to backup surgery by a dual-trained endovascular neurosurgeon in the hybrid OR. The value of the hybrid OR in neuroendovascular therapy should be further investigated in the future.

Endoscope-assisted transsphenoidal puncture of the cavernous sinus for embolization of carotid-cavernous fistula in a neurosurgical hybrid operating suite.

Endovascular embolization is the treatment of choice for carotid-cavernous fistulas (CCFs), but failure to catheterize the cavernous sinus may occur as a result of vessel tortuosity, hypoplasia, or stenosis. In addition to conventional transvenous or transarterial routes, alternative approaches should be considered. The authors present a case in which a straightforward route to the CCF was accessed via transsphenoidal puncture of the cavernous sinus in a neurosurgical hybrid operating suite. This 82-year-old man presented with severe chemosis and proptosis of the right eye. Digital subtraction angiography revealed a Type B CCF with a feeding artery arising from the meningohypophyseal trunk of the right cavernous segment of the internal carotid artery. The CCF drained through a thrombosed right superior ophthalmic vein that ended deep in the orbit; there were no patent sinuses or venous plexuses connecting to the CCF. An endoscope-assisted transsphenoidal puncture created direct access to the nidus for embolization. Embolic agents were deployed through the puncture needle to achieve complete obliteration. Endoscope-assisted transsphenoidal puncture of the cavernous sinus is a feasible alternative to treat difficult-to-access CCFs in a neurosurgical hybrid operating suite.

Preoperative Computed Tomography Angiography for Evaluation of Feasibility of Free Flaps in Difficult Reconstruction of Head and Neck.

BACKGROUND: Free tissue transfer has been advocated for anatomic and functional reconstruction of soft tissue defects after surgical removal of an extensive recurrent tumor and/or arising from previous irradiation in the head and neck. We report a case series of difficult reconstruction in the head and neck in which preoperative computed tomography (CT) angiography was utilized to evaluate the feasibility of free flap reconstruction. The preoperative radiological evaluation was performed to determine the availability of reliable vessels for anastomosis in free flap reconstruction. If none was found, regional pedicle flap or palliative treatment was applied instead. The use of CT angiography allows the clinical surgeon to perform precise surgical planning with greater confidence. This may improve surgical results, thereby potentially reducing perioperative morbidity. METHODS: Twenty CT angiograms were obtained from 20 patients. All patients were men with a mean age of 57.2 years (range, 42-72 years) and were scheduled to undergo difficult reconstruction in the head and neck. All patients (20/20 [100%]) suffered from oral squamous cell carcinoma. They had all received extensive operations and radiation therapy. Eighteen patients (18/20 [90%]) had completed a course of perioperative irradiation. The CT angiography reports were used to perform detailed preoperative surgical planning accordingly. The findings of CT angiography were classified into 3 groups: group I: normal CT angiography (patent recipient arteries) (Fig. 3); group II: abnormal CT angiography (recipient vessels were present but stenosis or atherosclerotic lesions were noted) (Fig. 4); group III: abnormal CT angiography with no patent recipient arteries in bilateral sides of the neck (Fig. 5); CT angiography results were correlated to the operative findings. RESULTS: The patients were classified into 3 groups based on the angiographic findings. Six patients (6/20 [30%]) were assigned to group I, 8 patients (8/20 [40%]) to group II, and 6 patients (6/20 [30%]) to group III. In groups I and III, all patients (12/12 [100%]) underwent the treatment according to the original preoperative detailed planning. No flap failure was noted in these 2 groups. In group II, 4 patients' recipient vessels (4/8 [50%]) possessed adequate blood flow intraoperatively; hence, microvascular free flaps were transplanted. Venous congestion in 1 case (1/4 [25%]) was noted. The remaining patients in this group (4/8 [50%]) underwent reconstruction with pedicle flaps rather than free flaps because of the lack of suitable target vessels intraoperatively. All flaps (4/4 [100%]) survived. Among the patients who were treated surgically, intraoperative findings were in accordance with those predicted by CT angiography. The total abnormality rate of CT angiography was 70%. Vascular abnormalities detected as a result of preoperative CT angiography led to changes in the operative plan in 50% (10/20) of the patients. CONCLUSIONS: The use of CT angiography should be considered for difficult microsurgical reconstructions in the head and neck. When an abnormality in vascular anatomy is detected by CT angiography, the surgeon is advised to consider altering the operative plan accordingly. This allows precise operation, thereby maximizing the possibility of an optimal outcome. Changing the operative plan based on results of CT angiography may also help to avoid the difficult situation in which the surgeon finds that there are no suitable recipient vessels for free flap reconstruction during the operation. In addition, CT angiography enables surgeons to conduct the preoperative surgical planning with greater confidence, thereby potentially enhancing the success rate of difficult reconstructions in the head and neck, which in turn would tend to improve the perioperative course for the patient and consequently to improve results by decreasing vascular complication rates.

Time-Resolved Magnetic Resonance Angiography in the Evaluation of Intracranial Vascular Lesions and Tumors: A Pictorial Essay of Our Experience.

Time-resolved magnetic resonance angiography (TR MRA) is a promising less invasive technique for the diagnosis of intracranial vascular lesions and hypervascular tumors. Similar to 4-dimensional computed tomographic angiography obtaining high frame rate images, TR MRA utilizes acceleration techniques to acquire sequential arterial and venous phase images for identifying, localizing, and classifying vascular lesions. Because of the good agreement with digital subtraction angiography for grading brain arteriovenous malformations with the Spetzler-Martin classification and the good sensitivity for visualizing arteriovenous fistulas, studies have suggested that TR MRA could serve as a screening or routine follow-up tool for diagnosing intracranial vascular disorders. In this pictorial essay, we report on the use of TR MRA at 3.0 T to diagnose intracranial vascular lesions and hypervascular tumors, employing DSA as the reference technique.

Postirradiated carotid blowout syndrome in patients with nasopharyngeal carcinoma: a case-control study.

BACKGROUND: Carotid blowout syndrome is one of the most devastating complications of nasopharyngeal carcinoma (NPC) therapy. METHODS: A retrospective review was conducted from January 2004 to April 2013. Thirty-one patients with carotid blowout syndrome were enrolled and a case control study was conducted to analyze the risk factors. RESULTS: When a comparison was made between the carotid blowout syndrome and matched non-bleeding group, there was a significantly higher local recurrence rate and prevalence of skull base osteoradionecrosis (ORN) in the carotid blowout syndrome group compared to those of the control group (both p < .001). The hazard ratio of carotid blowout syndrome was 3.599 between patients with or without reirradiation (95% confidence interval, 1.465-8.839; p = .005, adjusted for nasopharyngectomy and chemotherapy) using a Cox proportional hazard model. CONCLUSION: Reirradiation and skull base ORN are strong predisposing factors for carotid blowout syndrome, and therefore they should be mentioned in the informed consent form before treatment.

Hybrid surgery for dural arteriovenous fistula in the neurosurgical hybrid operating suite.

Treatment of a dural arteriovenous fistula (AVF), which is difficult to access by either the surgical or endovascular approach, is challenging. A hybrid technique, combining a microsurgical approach and endovascular embolization, can provide less invasive management of dural AVFs in a modern neurosurgical hybrid operating suite. We present a case of intracerebral hemorrhage in the left cerebellum secondary to dural AVF, Cognard type IV with numerous tiny feeders from the ascending pharyngeal artery branches. No adequate arterial or venous route for endovascular embolization was found by neuroangiography. The hybrid technique, combining keyhole pterional craniotomy and embolization with n-butyl cyanoacrylate glue injection via direct cannulation of the periclival venous plexus, succeeded in obliterating the dural AVF. Intraoperative angiography showed successful embolization of the dural AVF without any complication. This report illustrates the usefulness of the neurosurgical hybrid operating suite for the treatment of difficult dural AVFs.

Risk factors for subsidence in anterior cervical fusion with stand-alone polyetheretherketone (PEEK) cages: a review of 82 cases and 182 levels.

INTRODUCTION: To determine risk factors for subsidence in patients treated with anterior cervical discectomy and fusion (ACDF) and stand-alone polyetheretherketone (PEEK) cages. MATERIALS AND METHODS: Records of patients with degenerative spondylosis or traumatic disc herniation resulting in radiculopathy or myelopathy between C2 and C7 who underwent ACDF with stand-alone PEEK cages were retrospectively reviewed. Cages were filled with autogenous cancellous bone harvested from iliac crest or hydroxyapatite. Subsidence was defined as a decrease of 3 mm or more of anterior or posterior disc height from that measured on the postoperative radiograph. Eighty-two patients (32 males, 50 females; 182 treatment levels) were included in the analysis. RESULTS: Most patients had 1-2 treatment levels (62.2 %), and 37.8 % had 3-4 treatment levels. Treatment levels were from C2-7. Of the 82 patients, cage subsidence occurred in 31 patients, and at 39 treatment levels. Multivariable analysis showed that subsidence was more likely to occur in patients with more than two treatment levels, and more likely to occur at treatment levels C5-7 than at levels C2-5. Subsidence was not associated with postoperative alignment change but associated with more disc height change (relatively oversized cage). CONCLUSION: Subsidence is associated with a greater number of treatment levels, treatment at C5-7 and relatively oversized cage use.

Hybrid surgery for dural arteriovenous fistula in the neurosurgical hybrid operating suite.

Treatment of a dural arteriovenous fistula (AVF), which is difficult to access by either the surgical or endovascular approach, is challenging. A hybrid technique, combining a microsurgical approach and endovascular embolization, can provide less invasive management of dural AVFs in a modern neurosurgical hybrid operating suite. We present a case of intracerebral hemorrhage in the left cerebellum secondary to dural AVF, Cognard type IV with numerous tiny feeders from the ascending pharyngeal artery branches. No adequate arterial or venous route for endovascular embolization was found by neuroangiography. The hybrid technique, combining keyhole pterional craniotomy and embolization with n-butyl cyanoacrylate glue injection via direct cannulation of the periclival venous plexus, succeeded in obliterating the dural AVF. Intraoperative angiography showed successful embolization of the dural AVF without any complication. This report illustrates the usefulness of the neurosurgical hybrid operating suite for the treatment of difficult dural AVFs.

Hybrid surgery for symptomatic chronic total occlusion of carotid artery: a technical note.

BACKGROUND AND IMPORTANCE: Although medical treatment has been considered a dogma for chronic total occlusion (CTO) of the carotid artery, use of endovascular recanalization has also been reported. However, there are some difficulties in performing endovascular recanalization. We present the novel technical details and advantages of hybrid surgery for recanalization of symptomatic CTO of the internal carotid artery (ICA). CLINICAL PRESENTATION: Three cases with recurrent ischemic attacks due to thrombotic occlusion of the right ICA above the bifurcation were successfully treated by this hybrid surgery, combining endarterectomy of the proximal ICA with endovascular angioplasty of the distal ICA. Using this hybrid technique, complete recanalization was achieved in all 3 cases. Follow-up computed tomography angiography with perfusion imaging showed improved brain perfusion. At 6-month follow-up, ischemic symptoms had not recurred. CONCLUSION: We consider this hybrid surgery to be a feasible and good alternative surgical procedure for the treatment of CTO of the internal carotid artery.

Cervical sympathetic chain schwannoma.

Schwannomas are benign, slow-growing tumors that arise from Schwann cells of the nerve sheath. Those originating from the sympathetic cervical chain are rare. Herein, we present three cases of cervical sympathetic chain schwannoma (CSCS) and describe our experience with the clinical presentation, surgical management, and outcomes of patients with this pathology. All three patients were found to have a pulsatile, non-tender mass located at the level of the angle of the mandible without cervical nerve function deficit. On imaging study, the location of the mass between the prevertebral muscle and carotid artery with outward displacement of the carotid sheath is a typical characteristic of CSCS. Operative excision and sacrifice of a portion of the sympathetic chain remains the treatment of choice. Postoperative Horner's syndrome is predictable and vagus nerve dysfunction or first bite syndrome is also possible.

Local metastases along the tract of needle: a rare complication of vertebroplasty in treating spinal metastases.

STUDY DESIGN: Needle tract seeding after biopsy has been reported by many authors. Since the procedure of needle insertion in vertebroplasty is the same as in biopsy, tumor metastasis along the tract of the needle in vertebroplasty should be possible. OBJECTIVE: We report local metastases along the needle tract as a rare complication of percutaneous vertebroplasty in treating spinal metastases in a lung cancer patient. SUMMARY OF BACKGROUND DATA: The true incidence of tumor implantation along the needle tract may be underestimated as many patients die before the metastases become clinically significant. METHODS: A 76-year-old man diagnosed with adenocarcinoma of lung underwent percutaneous vertebroplasty at L1 and L3 vertebral levels due to painful spinal metastases. His condition worsened 3 months later, however, with recurrent back pain and weakness of both legs. RESULTS: MRI of lumbar spine performed post-percutaneous vertebroplasty revealed new contrast-enhanced lesions at the posterior aspect of L1 vertebral body with extension to the adjacent anterior epidural space of L1 and posterior epidural space along T12 to L3 levels with compression of the adjacent dural sac and additional paraspinal involvement. CONCLUSION: To our knowledge, local metastasis after vertebroplasty in treating spinal metastases has not been reported in the literature. However, this may be a potential complication of vertebroplasty in treating spinal metastases as improvement in cancer treatments occurs with subsequent longer survival times.

Nasal NK/T-cell lymphoma: computed tomography and magnetic resonance imaging findings.

BACKGROUND: Primary nasal natural killer (NK)/T-cell lymphoma is the most common cellular subtype seen in nasal lymphomas. It is rare in the Western population but occurs more frequently in Asia, South America, and Mexico. The purpose of this study was to describe the computed tomography (CT) and magnetic resonance (MR) imaging findings of primary nasal NK/T-cell lymphoma. METHODS: During the period between January 1990 and June 2006, the CT (n=24) and MR (n=6) images of 24 patients with biopsy-proved nasal NK/T-cell lymphoma were reviewed retrospectively. Both CT and MR images were evaluated for site and extent of disease and for pattern of involvement of adjacent areas. RESULTS: The most common symptoms at presentation were nasal obstruction, nasal discharge, and epistaxis. There was involvement of the unilateral nasal cavity in 16, bilateral nasal cavity including nasal septum in 5 and nasal choana in 3. Sites of extension outside the nasal cavity included tumor extension into paranasal sinuses (n=15), nasopharynx (n=5), nasal labial fold (n=3), oropharynx (n=2), infratemporal fossa (n=2), other subcutaneous soft tissue of the face (n=2) and anterior cranial fossa base (n=1). Bony destruction was demonstrated in 18 cases, involving the sinus bony wall (n=15), nasal turbinate (n=10), lamina papyracea (n=6), orbital floor (n=3), and hard palate (n=2). Regional lymphadenopathy was also detected in 3 patients with nasal NK/T-cell lymphoma. CONCLUSION: The CT and MR appearances of nasal NK/T-cell lymphoma are nonspecific, and the diagnosis requires histologic confirmation. However, the differential diagnosis of nasal NK/T-cell lymphoma should be included if the images present soft tissue of the nasal cavity with bony erosion or destruction; involvement of the orbital cavity, nasopharynx and infratemporal fossa; and subcutaneous or nasolabial fold soft tissue infiltration, especially in Asian populations.

Assessment with magnetic resonance imaging and spectroscopy in Lhermitte-Duclos disease.

Lhermitte-Duclos disease (LDD) is a rare benign lesion of uncertain pathogenesis characterized by distortion of the normal cerebellar laminar cytoarchitecture. We report a 22-year-old man admitted for injury sustained in a traffic accident with the incidental finding of a cerebellar mass. Magnetic resonance imaging (MRI) revealed a mass lesion within the right cerebellar hemisphere. The final diagnosis of LDD was made by obtaining a surgical specimen and identifying the characteristic appearance of the lesion by MRI study. The images showed the typical striated pattern of hyperintensity on T2-weighted images and corresponding hypointensity on T1-weighted images, as well as the typical absence of enhancement following gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA) administration. In addition, no disturbance of water diffusion on diffusion-weighted MRI, and associations of decreases in the N-acetylaspartate/creatine (NAA/Cr) and NAA/Choline (Cho) ratios with near normal values of Cho/Cr, as well as an obvious lactate peak gave supplemental information for diagnosis.

Intradural cement leakage: a devastatingly rare complication of vertebroplasty.

STUDY DESIGN: The aim of this case report is to examine the devastating complication that may follow vertebroplasty. OBJECTIVES: To report 1 case of intradural cement leakage caused by percutaneous vertebroplasty with polymethyl methacrylate. SUMMARY OF BACKGROUND DATA: Cement leakage is not a rare complication of vertebroplasty. But intradural cement leakage is rare. We herein report a rare but devastating complication of vertebroplasty. METHODS: A 90-year-old woman with a T12 and L1 osteoporotic compression fracture underwent percutaneous vertebroplasty using polymethyl methacrylate at local hospital. A literature search was performed to assess complications of vertebroplasty. RESULTS: She was transferred to our hospital due to abdominal pain. Physical examination revealed distended abdomen with local tenderness and weakness of both legs (muscle power: Grade 2). Plain radiograph of abdomen showed ileus and intradural cement leakage. Conservative treatment with nasogastric decompression was done, and her abdominal pain subsided 1 week later. CONCLUSIONS: Percutaneous vertebroplasty with polymethyl methacrylate is relatively safe, but it still should be proceeded under careful safeguard. The needle tip should not cross the medial border of the pedicle on the anteroposterior view before it has crossed the posterior cortex of the vertebral body on the lateral view. Good quality of image monitoring and clear visualization of cement should be helpful to prevent complications.