Desempeño del método de suma de discos comparado con el método bidimensional en la estimación cuantitativa del derrame pericárdico / Performance of the method of disks compared to the bidimensional method in the quantitative estimation of pericardial effusion

Resumen Introducción: La ecocardiografía bidimensional es la técnica más efectiva para el diagnóstico del derrame pericárdico, gracias a sus altas sensibilidad y especificidad. Objetivo: Analizar la superioridad del método de suma de discos comparado con el método bidimensional en la estimación del derrame pericárdico por medio de ecocardiografía, tomando como referencia el volumen de líquido pericárdico extraído por pericardiocentesis o cirugía abierta. Método: Estudio retrospectivo de seguimiento de una cohorte basado en registros médicos y archivos de ecocardiografía. Se empleó un diseño pareado en el que cada imagen fue leída por el método bidimensional y por el método de suma de discos. Se incluyeron derrames pericárdicos graves, definidos clínicamente o por parámetros ecocardiográficos, que requirieran drenaje. El desempeño de los métodos de estimación bidimensional y de suma de discos, tomando como referencia la extracción por intervención, se cuantificó mediante áreas bajo la curva operador-receptor (auROC). Resultados: Se analizaron 40 registros, tomando como referencia el volumen obtenido por extracción; con un auROC de 0.81 (intervalo de confianza del 95% [IC95%]: 0.73-0.89), el desempeño diagnóstico del método de suma de discos fue significativamente mayor (p = 0.0335) que el del método bidimensional (auROC: 0.73; IC95%: 0.63-0.83). La estimación realizada por el método de suma de discos subestimó en promedio 51.3 ml (IC95%: −156.2-53.5). Conclusiones: En pacientes con derrame pericárdico e indicación de drenaje o taponamiento cardíaco, el método de suma de discos es superior en comparación con el método bidimensional en el estudio ecocardiográfico para la estimación cuantitativa del derrame pericárdico, ya que discrimina mejor respecto al método bidimensional.

Abstract Introduction: Two-dimensional echocardiography is the most effective technique for diagnosing pericardial effusion due to its high sensitivity and specificity. Objective: The superiority of the method of disks was compared with the bidimensional method in the estimation of pericardial effusion by echocardiography, taking as reference the volume of pericardial fluid removed by pericardiocentesis or open surgery. Method: Retrospective follow-up study of a cohort, based on medical records and echocardiography files. A paired design was used, each image was read by the bidimensional method and by the method of disks. Severe pericardial effusions defined clinically or by echocardiographic parameters, that required drainage were included. The performance of the bidimensional and disks estimation methods, taking the volume removed as a reference, was quantified using areas under the receiver operating characteristic curve (auROC). Results: 40 records were analyzed, taking as a reference the volume obtained by extraction, with an auROC of 0.81 (95% CI: 0.73-0.89) the diagnostic performance of the disks method was significantly higher (p = 0.0335) than the bidimensional method (auROC 0.73, 95% CI: 0.63-0.83). The estimate made by the disks method underestimated an average of 51.3 ml (95% CI: -156.2-53.5). Conclusions: In patients with pericardial effusion with indication of cardiac drainage or tamponade, the disks method is superior in comparison with the bidimensional method in the echocardiographic study of the quantitative estimation of pericardial effusion, discriminating better than the bidimensional method.

Nuclear physics and astronomical observations of compact objects / Física nuclear y observaciones astronómicas de objetos compactos

Abstract We discuss our predictions of two astrophysics observations: neutrino emission and element abundances. We studied the emission and possible detection of neutrinos from past black hole accretion disks. We find neutrinos are copiously emitted from these sites and encourage the development of large facilities for detection. We also studied changes in the synthesis of neutron-rich elements due to the suppression of key nuclear processes. We find important changes in the element abundances due to the, previously overlooked, alpha decay.

Resumen Discutimos nuestras predicciones de dos observaciones astrofísicas: la emisión de neutrinos y las abundancias de elementos. Hemos estudiado la emisión y posible detección de neutrinos emitidos por discos de acreción alrededor de agujeros negros en el pasado. Encontramos que los neutrinos son emitidos en abundancia por discos de acreción y sugerimos el desarrollo de detectores de gran escala para mejorar su detección. También hemos estudiado los cambios en la síntesis de elementos ricos en neutrones, debido a la supresión de procesos nucleares claves. Encontramos que hay cambios importantes en la abundancia de elementos debido al decaimiento alfa.

Liposomes and lipid disks traverse the BBB and BBTB as intact forms as revealed by two-step Förster resonance energy transfer imaging

The blood-brain barrier (BBB) and the blood-brain tumor barrier (BBTB) prevent drug and nano-drug delivery systems from entering the brain. However, ligand-mediated nano-drug delivery systems have significantly enhanced the therapeutic treatment of glioma. In this study we investigated the mechanism especially the integrity of liposomes and lipid disks while traversing the BBB and BBTB both and . Fluorophores (DiO, DiI and DiD) were loaded into liposomes and lipid disks to form Förster resonance energy transfer (FRET) nano-drug delivery systems. Using brain capillary endothelial cells as a BBB model, we show that liposomes and disks are present in the cytoplasm as their intact forms and traverse the BBB with a ratio of 0.68‰ and 1.67‰, respectively. Using human umbilical vein endothelial cells as BBTB model, liposomes and disks remained intact and traversed the BBTB with a ratio of 2.31‰ and 8.32‰ at 3 h. imaging and immunohistochemical results revealed that liposomes and disks could traverse the BBB and BBTB as intact forms. In conclusion, these observations explain in part the mechanism by which nano-drug delivery systems increase the therapeutic treatment of glioma.

Long-Term Outcomes of Posterior Lumbar Interbody Fusion Using Stand-Alone Ray Threaded Cage for Degenerative Disk Disease: A 20-Year Follow-Up

STUDY DESIGN: Retrospective study. PURPOSE: To analyze outcomes of posterior lumbar interbody fusion (PLIF) stand-alone cages. OVERVIEW OF LITERATURE: PLIF for degenerative disk disease using stand-alone cages has lost its popularity owing to implant-related complications and pseudoarthrosis. METHODS: We analyzed the records of 45 patients (18 women, 27 men), operated between January 1994 and December 1996, with a mean follow-up of 18 years 3 months (20 years 3 months–22 years 3 months). Clinical outcomes were measured using visual analogue score (VAS), Oswestry disability index (ODI), Odom's criteria, and radiological measurements of fusion rate, Cobb angle, and implant-related complications conducted at the preoperative evaluation, hospital discharge, 12-month follow-up, and final follow-up. RESULTS: Preoperative mean VAS (back) was 6.9 and VAS (radicular) was 7.2, with mean improvements (p <0.05) of 2.9 and 3.1, respectively, at the final follow-up. Median preoperative ODI was 64.5, with a mean improvement to 34 and 42 at the 12-month and final follow-ups, respectively (p <0.05). Odom's criteria at the 12-month follow-up were excellent in 11.2% patients, good in 57.7%, fair in 31.1%, and poor in none of the patients; at the final follow-up, no patient was classified as excellent, 71.1% as good, 22.2% as fair, and 6.7% as poor (p <0.05). Pseudoarthrosis was observed in five patients (11.1%), of whom, three (6.6%) required re-operation. Preoperative disk height was 9.23 mm, which increased to 13.33 mm in the immediate postoperative evaluation and was maintained at 10.0 mm at the final follow-up (p <0.05). The preoperative mean L1–S1 Cobb angle was 34.7°, which changed to 44.7° in the immediate postoperative evaluation and dropped to 39.7° at the final follow-up (p <0.005). CONCLUSIONS: PLIF stand-alone cages were associated with good clinical outcomes. Although the fusion rate was excellent, maintenance of disk heights and a lordotic alignment were not achieved in the long term.

Characteristics of the gustatory organs on the tongue of the chinese fire-bellied newt (Cynops orientalis): light and scanning electron microscopy study / Características de los órganos gustativos en la lengua del tritón vientre de fuego chino (Cynops orientalis): estudio por microscopía de luz y electrónica de barrido

The dorsal surface of the tongue gustatory organs of Chinese fire-bellied newt (Cynops orientalis) was observed by employing the light and scanning electron microscopy (SEM) techniques. The results revealed that the rostral and median part of the tongue presents a round apex and covered by taste disks (TDs). They are usually roundish or ellipsoidal in shape and are 20-35 mm in diameter. The many openings of the lingual glands are 4-8 mm in diameter exist in the lateral border or median part of lingual body. The gustatory organs on the tongue did not differed form those presented in other species in Caudates. These may indicate the functions of gustatory organs on the tongue related to their life habit.

La superficie dorsal de la lengua de los órganos gustativos del tritón de vientre de fuego chino (Cynops orientalis) se observó mediante microscopía de luz y electrónica de barrido (SEM). Los resultados revelaron que la parte rostral y mediana de la lengua presenta un ápice redondo y cubierto por discos sensoriales. Estos por lo general tienen una forma redondeada o elipsoidal con un diámetro de 20-35 mm. Las numerosas aperturas de las glándulas linguales tienen un diámetro de 4-8 mm en el margen lateral o en la parte mediana de cuerpo lingual. No se observaron diferencias en los órganos gustativos linguales al comparar estos con otras especies de caudados. Estos pueden indicar funciones de los órganos gustativos de la lengua relacionadas con su hábito de vida.

Discos de poco espesor de hidroxiapatita cubana sinterizada como sistema de liberacion de fármacos / Cuban low-thickness sintered hydroxyapatite disks as a drug release system

Objetivo: el objetivo principal de este trabajo es estudiar la posibilidad de que sean empleados como sistema de liberación controlada de fármacos, discos de Hidroxiapatita (HA) cubana, fabricados por prensado y sinterizado en hornos eléctrico, sin el empleo de agentes formadores de poros, con porosidades aparentes de 12, 20 y 40 por ciento que fueron dopados por sobre presión con una solución acuosa de alginato de sodio al 5 por ciento y 55 ppm de ceftazidima. Métodos: se estudió la relación entre la penetración del polímero y la porosidad aparente con la liberación del fármaco. Resultados: se demostró que estos discos infiltrados con el polímero que encapsula el fármaco pueden ser utilizados como sistema de liberación controlada. Se demuestra que la porosidad aparente y el tamaño de los poros son influyentes en la penetración del polímero y la masa de fármaco liberado. Conclusiones: En las curvas de liberación obtenidas se observa que los discos pueden ser un potencial material para soportar medicamentos porque se evidencia como el material es capaz de controlar la liberación del medicamento remanente ocluido por un método de dopaje a sobre presión.El perfil indica que en un periodo de siete días se libera controladamente el medicamento

Objective: the main purpose of this study is to examine the potential use of Cuban hydroxyapatite (HA) disks as a controlled drug release system. These disks are manufactured by pressing, and sintered in electric furnaces without using pore-forming agents, with apparent porosities of 12, 20 and 40 percent , and doped by overpressure with a 5 percent sodium alginate aqueous solution and 55 ppm ceftazidime. Methods: a study was conducted of the relationship between penetration of the polymer and apparent porosity with the release of the drug. Results: it was shown that when infiltrated with the polymer encapsulating the drug, these disks may be used as a controlled release system. It was also found that apparent porosity and pore size influence polymer penetration and the mass of drug released. Conclusions: the release curves obtained show that the disks may be a potential drug-supporting material, capable of controlling the release of the remnant drug occluded by an overpressure doping method. The profile reveals that controlled release of the drug is completed in seven days

The Use of Magnetic Resonance Imaging to Predict the Clinical Outcome of Non-Surgical Treatment for Lumbar Interverterbal Disc Herniation

OBJECTIVE: We wanted to investigate the relationship between the magnetic resonance (MR) findings and the clinical outcome after treatment with non-surgical transforaminal epidural steroid injections (ESI) for lumbar herniated intervertebral disc (HIVD) patients. MATERIALS AND METHODS: Transforaminal ESI were performed in 91 patients (50 males and 41 females, age range: 13-78 yrs) because of lumbosacral HIVD from March 2001 to August 2002. Sixty eight patients whose MRIs and clinical follow-ups were available were included in this study. The medical charts were retrospectively reviewed and the patients were divided into two groups; the successful (responders, n = 41) and unsatisfactory (non-responders, n = 27) outcome groups. A successful outcome required a patient satisfaction score greater than two and a pain reduction score greater than 50%. The MR findings were retrospectively analyzed and compared between the two groups with regard to the type (protrusion, extrusion or sequestration), hydration (the T2 signal intensity), location (central, right/left central, subarticular, foraminal or extraforaminal), and size (volume) of the HIVD, the grade of nerve root compression (grade 1 abutment, 2 displacement and 3 entrapment), and an association with spinal stenosis. RESULTS: There was no significant difference between the responders and non-responders in terms of the type, hydration and size of the HIVD, or an association with spinal stenosis (p > 0.05). However, the location of the HIVD and the grade of nerve root compression were different between the two groups (p < 0.05). CONCLUSION: MRI could play an important role in predicting the clinical outcome of non-surgical transforaminal ESI treatment for patients with lumbar HIVD.

Treatment of Various Auricular Diseases Using Magnetic Disks

PURPOSE: The earlobe is one of the areas which are most vulnerable to trauma. Various auricular diseases need compression treatment. We report a new compression method using magnetic disks. METHODS: Seventeen patients with auricular diseases were treated from October 2002 to September 2006. The mean age was 29.1 years. The diseases details were osteochondroma in 2 patients; cauliflower's ears in 2 patients; acute otohematoma in 1 patient; and hypertrophic scars in 11 patients. The most common cause of their disease was ear piercing. The mean follow-up period was 8.9 months. All surgical procedures were performed under local anesthesia. To compress immediately, a pair of magnetic disks was applied to the anterior and posterior surface of the earlobe. RESULTS: The results were generally good. Major complications, such as recurrence, necrosis, dehiscence, or infection, did not occur. CONCLUSION: A pair of magnetic disks are useful compression tool in various auricular diseases.

A Comparison of the Efficacy of Epidural Steroid Injections in Terms of the Dosages and Frequency of Triancinolone Injections for the Pain Related to Lumbar Spinal Stenosis or Herniated Disks / 대한통증학회지

BACKGROUND: The objective of this study was to describe the extent of pain relief after an epidural steroid injection in the patients suffering from chronic low back pain from herniated disks or lumbar spinal stenosis. METHODS: The study was prospectively designed for patients suffering with lumbar spinal stenosis (LSS) and herniated disks (HD) who were referred to a hospital-based pain clinic for epidural steroid injections (ESI). The pain was assessed with using a visual analog scale at baseline, two weeks after the first ESI and two weeks after the third ESI. RESULTS: Eighty patients were enrolled, and all of them provided pain ratings before and after the injections. The LSS patients seemed to improve less than did the HD patients. The results showed no significant differences in the triamcinolone dosage and the frequency of injections for determining the efficacy of ESI. CONCLUSIONS: The LSS patients tended to have a less effective respond to ESIs than did the HD patients. The unsatisfactory response to ESI by the LSS patients underscores the need for randomized controlled trials of performing ESI in this population.

Value of Preoperative Cervical Discography

PURPOSE: The aim of this study was to describe the method and the value of cervical discography as correlated with the MR findings. MATERIALS AND METHODS: Twenty-one discs in 11 consecutive patients who underwent cervical discography were analyzed. MR and CT discography (CTD) were performed in all patients. Discography was performed after swallowing barium for visualizing the pharynx and the esophagus to prevent penetration. We also analyzed the preceding causes of the subjects' cervical pain. The results of the pain provocation test were classified into concordant pain, discordant pain and a negative test. MRI was analyzed according to the T2-signal intensity (SI) of the disc, disc height, annular bulging and disc herniation. The CTD was analyzed for degeneration or radial tear of the disc, epidural leakage of the contrast agent and pooling of the contrast agent at the periphery of the disc. The pain provocation tests were correlated with the MR and CTD findings. We used the chi-square test to analyze the results. RESULTS: Concordant pain was observed in 14 cases, discordant pain in 3 cases and there were negative tests in 4 cases. There were no complications related to the procedure. Four patients had undergone anterior cervical fusion and four patients had pain that developed after traffic injuries. The decreased T2-SI and annular bulging on MRI, disc degeneration and peripheral pooling of the contrast agent on CT were significantly correlated with pain provocation. CONCLUSION: When the diagnosis of disc disease is difficult with performing MRI, cervical discography with using swallowed barium solution to reduce the penetration of the esophagus or hypopharynx may play be helpful. The decreased T2-SI and annular bulging on MRI correlated significantly with a positive result on the pain provocation test.

Radiological Evaluation of Percutaneous Endoscopic Lumbar Discectomy: A Three-Year Follow-Up Study

PURPOSE: We wanted to analyze the radiological changes of the patients who underwent percutaneous endoscopic lumbar discectomy (PELD) for treating soft disc herniation. MATERIALS AND METHODS: We retrospectively reviewed 30 patients (32 cases) who were observed for a minimum of 3 years after they underwent PELD. The authors investigated the postoperative radiological changes after PELD and the related clinical outcomes. All the patients received plain X-rays, CT and MRI both preoperatively and at the final follow-up. The radiological parameters were evaluated, including the disc height, the disc signal intensity, the subchondral marrow signal intensity, the sagittal plane instability and the facet joint osteoarthritis. RESULTS: The average amount of removed disc was 1.363 g and a significant correlation was detected between the narrowing of disc height and the amount of removed disc. Although the disc height and the disc height ratio were significantly decreased (-0.97 mm and 86.9%, respectively), the angle of sagittal rotation was well maintained. There were 18 (56.3%) cases of disc signal changes, six cases (18.8%) of subchondral marrow signal changes, and three cases (9.4%) of facet joint osteoarthritis. The success rate was 90.6%. CONCLUSION: Although disc height narrowing was observed, there was no postoperative instability and the overall clinical outcome was satisfactory. Our results show that PELD is a useful and minimal invasive procedure for the selected patients who are suffering with lumbar disc herniation.

Lumbar Internal Disc Derangement in Patients with Chronic Low Back Pain: Diagnostic Value of the MR Imaging Findings as Compared with Provoked Discography as the Standard

PURPOSE: The aim of this study was to evaluate the diagnostic value of the MR Imaging findings with provoked discography used as the standard for painful lumbar disc derangement. MATERIALS AND METHODS: Two hundred patients (412 discs), (age range: 21-77 years), with chronic low back pain underwent MRI and provoked discography. We evaluated the MRI T2-WI findings such as disc degeneration, high-Intensity zones and endplate abnormalities. Subsequently, provocative discography was independently performed with using MR imaging, and a painful disc was defined when moderate to severe and concordant pain was provoked. We calculated the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the MRI findings with using provoked discography as the standard. RESULTS: 400 discs showed abnormal findings such as disc degeneration, HIZ and endplate abnormalities on the T2-WI images. 12 discs showed normal findings. HIZ or endplate abnormalities were always combined with disc degeneration. The prevalence of each findings were disc degeneration (400 discs: 97.1%), HIZ (111 discs: 26.9%), type I endplate abnormalities (34 discs: 8.3%), type II endplate abnormalities (75 discs: 18.2%), the combined findings of HIZ and type I endplate abnormalities (2 discs: 0.5%) and the combined findings of HIZ and type II endplate abnormalities (7 discs: 1.7%). The disc degeneration showed high sensitivity (99.5%) and low specificity (5.0%), so only the NPV (91.7%) was significant, and not the PPV (47.8%). Each findings of HIZ (sensitivity, 36.5%; specificity, 81.4%; PPV, 63.18%; NPV, 59.5%), type I endplate abnormalities (11.0%, 94.1%, 61.8% and 54.8%, respectively), type II endplate abnormalities (19.8%, 83.2%, 50.7% and 54.3%, respectively), the combined findings of HIZ and type I endplate abnormalities (0.5%, 99.6%, 50.0% and 53.4%, respectively) and the combined findings of HIZ and type II endplate abnormalities (26.0%, 99.1%, 71.4% and 53.8%, respectively) show high specificity, but low sensitivity, so the PPV and NPV were also not significant. CONCLUSION: For diagnosing painful lumbar disc derangement, the MR imaging findings seem to be inadequate as predictive factors when provoked discography was used as the standard.

Intradural Cervical Disc Herniation: A Case Report

Intradural cervical disc herniation is an extremely rare condition and its pathogenesis is not certain. We experienced a case of intradural cervical disc herniation at the C4-5 level in a 56-year-old man. The preoperative sagittal T1- and T2- weighted images revealed an intradural iso-intensity lesion, with the spinal cord behind the posterior longitudinal ligament at the C4-5 disc level. The post-contrast T1-weighted image revealed a peripheral enhanced intradural lesion. We report here on a case of an intradural cervical disc herniation that was diagnosed by radiological examination, and we include a review of the related literature.

Internal Disc Derangement in Patients with Low Back Pain: Correlation of MR Imaging and Provocative Discography and CT Discography

PURPOSE: The aim of this study was to correlate the MR imaging abnormalities of the lumbar intervertebral discs, with emphasis being placed on the high intensity zone (HIZ) with the use of discography for pain provocation and disc morphologic evaluation of the disc. MATERIALS AND METHODS: Consecutive patients with low back pain unresponsive to conservative treatment, and who were being considered for spinal fusion had MRI performed, and this was followed by lumbar discography. The MR imaging, discography and CT discography (CTD) were evaluated for all of the 19 patients. Forty-three lumbar discs in 19 patients were included in this study. The findings of MR and CTD images were evaluated retrospectively with the professional opinion and agreement of two radiologists. MR images were assessed for the presence or absence of decreased T2-wighted signal intensity, decreased disc height, annular bulging, HIZ on T2-weighted images and disc herniation. The results of pain provocation were graded as 0, nonconcordant pain; 1, definite pain, but only as part of the symptom complex; 2, concordant pain. The morphology of CTD was analyzed for presence or absence of disc degeneration, radial tearing and extravasation of the contrast agent. The presence of radial tearing was defined as contrast extension to the outer third of the annulus. The prevalence of all MR abnormalities was calculated, and the data were compared with disc morphologic characteristics and the pain response on provocative discography. We used the chi-square test to analyze the results. RESULTS:Grade 1 and 2 discogenic pain was observed in 8 (19%) and 12 disc levels (28%), respectively. All of the seven non-degenerated discs on MR had no pain response. The decreased SI on T2-weighted image, annular bulging and HIZ were significantly correlated with discogenic pain. Extravasation of contrast media had good correlation with annular bulging and disc herniation on MRI. Radial tearing on CT discography correlated significantly with HIZ. The HIZ was detected in 14 levels (32.6%). The HIZ on MRI correlated significantly with the pain provocation and radial tearing noted on the discograms. CONCLUSION: Several MR imaging findings correlated significantly with the severity of pain provocation to discography. For patients with symptomatic low back pain, the HIZ observed on MR may represent a painful outer annular disruption.

Comparison of MRI and Discography in Disc Extrusion: Low Signal Intensity Change in the Anterior Epidural Space at Sagittal T1-weighted Imaging

PURPOSE: To determine the significance of low signal intensity change in the anterior epidural space at sagittal T1-weighted (ST1WI) magnetic resonance imaging (MRI) of patients in whom discography revealed disc extrusion, and to correlate interruption of the solid dark line seen at sagittal T2-weighted imaging (ST2WI) with discographic findings of extrusion. MATERIALS AND METHODS: One hundred and forty-two patients (159 cases) with lumbar disc disease proven at MRI underwent discography. Disc extrusion was diagnosed in cases in which contrast media leaked into the anterior epidural space. The findings of ST1WI were used to determine whether low signal intensity change had occurred in the anterior epidural space between the posterior aspect of the vertebral body and the posterior longitudinal ligament, and whether ST2WI depicted interruption of the solid dark line at the posterior aspect of the disc was also assessed. RESULTS: At discography, disc extrusion was diagnosed in 134 of 159 cases. At ST1WI, low signal intensity change was noted in 75 (56%) of the 134 cases, and at ST2WI interruption of the solid dark line was observed in 63 (47%). In the remaining 25 cases, there was no evidence of disc extrusion, and at ST2WI the solid dark line was well-preserved. At ST1WI, 22 (88%) of 25 cases showed normal signal intensity in the anterior epidural space, but in the remaining three, low signal intensity change was evident. Correlation between the findings of MRI and discography was statistically significant. CONCLUSION: In disc disease, low signal intensity change at ST1WI, as well as interruption of the solid dark line seen at ST2WI, are useful indicators of disc extrusion.

The Influence of Changes in Cervical Lordosis on Bulging Disk and Spinal Stenosis: Functional MR Imaging

PURPOSE: To assess the effect of lordotic curve change of the cervical spine on disk bulging and spinal stenosis by means of functional cervical MR imaging at the flexion and extension position. MATERIALS AND METHODS: Using a 1.5T imager, kinematic MR examinations of 25 patients with degenerative spondylosis (average age, 41 years) were performed at the neutral, flexed and extended position of the cervical spine. Sagittal T2-weighted turbo spin-echo images were obtained during each of the three phases. Lordotic an-gle, bulging thickness of the disk, AP diameter of the spinal canal, and distance between the disk and spinal cord were measured on the workstation at each disk level. After qualitative independent observation of disk bulging, one of four grades(0, normal; 1, mild; 2, moderate; 3, marked) was assigned at each phase, and after further comparative observation, one of five scores (-2, prominent decrease; -1, mild decrease; 0, no change; 1, notable increase; 2 prominent increase) was also assigned. In addition, bulging thickness of the disk was measured and compared at the neutral, flexed, and extended positions. RESULTS: Average angles of the cervical spine were 160.5+/-5.9 degrees (neutral position, lordotic angle); 185.4+/-8.5 degrees (flexion, kyphotic angle); and 143.7+/-6.7 degrees (extension, lordotic angle). Average grades of disk bulging were 0.55 at the neutral position, 0.16 at flexion, and 0.7 at extension. Comparative observation showed that average scores of disk bulging were -0.39 at flexion and 0.31 at extension. The bulging thickness of the disk decreased by 24.2% at flexion and increased by 30.3% at extension, while the diameter of the spinal canal increased by 4.5% at flexion and decreased by 3.6% at extension. The distance from the posterior margin of the disk to the anterior margin of the spinal cord decreased at both flexion(6.6%) and extension(19.1%). CONCLUSION: Functional MRI showed that compared with the neutral position, disk bulging and spinal stenosis are less prominent at flexion and accentuated at extension. The results demonstrate the need to consider the extent to which changes in the cervical lordotic curve affect the degree of disk bulging and spinal stenosis.

Magnetic resonance imaging signal intensity of temporomandibular joint disk and posterior attachment in patients with internal derangement / 대한구강악안면방사선학회지

PURPOSE: To analyze the possible association between magnetic resonance imaging signal intensity of temporo-mandibular joint disk and posterior attachment, and the type and extent of disk displacement, disk configuration, effusion and clinical signs in patients with internal derangement. MATERIALS AND METHODS: Magnetic resonance images of the 132 temporomandibular joints of 66 patients with temporomandibular joint displacement were analyzed. The clinical findings were obtained by retrospective review of the patients' records. The type and extent of disk displacement, disk configuration and effusion were evaluated on the proton density MR images. The signal intensity from the anterior band, posterior band and posterior attachment were measured on MR images. The associations between the type and extent of disk displacement, disk configuration, effusion and clinical signs and the MR signal intensity of disk and posterior attachment were statistically analyzed by student's t-test. RESULTS: Of 132 joints, 87 (65.9%) showed anterior disk displacement with reduction (ADR) and 45 (34.1%) showed anterior disk displacement without reduction (ADnR). The signals from posterior attachments were lower in joints with ADnR than those of ADR (p<0.05). The results showed statistically significant (p<0.05) association between the type and extent of disk displacement and disk configuration, and decreased signal intensity of posterior attachment. There were no statistical associations between pain, noise and limited mouth opening, and signal intensity of disk and posterior attachment. Conclusions : The average signal from posterior attachment was lower in joints with ADnR than that of ADR. The type and extent of disk displacement and disk configuration appeared to be correlated with the signal intensity from posterior attachment.

Magnetic resonance imaging signal intensity of temporomandibular joint disk and posterior attachment in patients with internal derangement / 대한구강악안면방사선학회지

PURPOSE: To analyze the possible association between magnetic resonance imaging signal intensity of temporo-mandibular joint disk and posterior attachment, and the type and extent of disk displacement, disk configuration, effusion and clinical signs in patients with internal derangement. MATERIALS AND METHODS: Magnetic resonance images of the 132 temporomandibular joints of 66 patients with temporomandibular joint displacement were analyzed. The clinical findings were obtained by retrospective review of the patients' records. The type and extent of disk displacement, disk configuration and effusion were evaluated on the proton density MR images. The signal intensity from the anterior band, posterior band and posterior attachment were measured on MR images. The associations between the type and extent of disk displacement, disk configuration, effusion and clinical signs and the MR signal intensity of disk and posterior attachment were statistically analyzed by student's t-test. RESULTS: Of 132 joints, 87 (65.9%) showed anterior disk displacement with reduction (ADR) and 45 (34.1%) showed anterior disk displacement without reduction (ADnR). The signals from posterior attachments were lower in joints with ADnR than those of ADR (p<0.05). The results showed statistically significant (p<0.05) association between the type and extent of disk displacement and disk configuration, and decreased signal intensity of posterior attachment. There were no statistical associations between pain, noise and limited mouth opening, and signal intensity of disk and posterior attachment. Conclusions : The average signal from posterior attachment was lower in joints with ADnR than that of ADR. The type and extent of disk displacement and disk configuration appeared to be correlated with the signal intensity from posterior attachment.

Regional Disc Change in Segmental Hypoplasia of the Lumbosacral Vertebral Bodies: MR Findings

PURPOSE: To classify types of vertebral hypoplasia and to investigate the prevalence and patterns of associated disc degeneration. MATERIALS AND METHODS: Defining vertebral hypoplasia as occurring when the AP diameter of a lower vertebral body is smaller than that of an upper ones, we retrospectively reviewed the MR images obtained in 34 cases of this condition invloving young adults. Two major types and two subtypes, a total of four different entities were classified as follows; type I: hypoplasia involving a single vertebral body; type II: hypoplasia in-volving serial lower segmental vertebral bodies; subtype a: hypoplastic body located anteriorly along the anterior spinal line; subtype b: hypoplastic body located posteriorly along the posterior spinal line. We also investigated each type of vertebral hypopla-sia and patterns of associated disc changes. RESULTS: Three different types were observed. In type IIa(n= 29), posterior disc occurred in 8/29 cases, diffuse degeneration in 21/29 patients, and posterior disc herniation in all. All type Ia cases(3/3) showed diffuse disc degeneration at both upper and lower disc levels, with posterior disc herniation, while both type IIb cases(2/2) showed diffuse disc degeneration, with bidirectional disc herniation. CONCLUSION: By identifying the exact patterns of vertebral hypoplasia, we were able to predict which portion of the disc was likely to degenerate.

High Signal Intensity on T1-Weighted MR Image Related to Vacuum Cleft in the Intervertebral Disk: Clinical and Phantom Study

PURPOSE: To determine the possible mechanism by which an area of high signal intensity appears on T1-weighted MR images adjacent to a vacuum cleft in intervertebral disks. MATERIALS AND METHODS: We analyzed a total of 14 disks in nine patients in whom a vacuum cleft with T1-signal hyperintensity was observed. Lesions were present from T11-12 to L5-S1 using a 1.5-T whole-body imager, sagittal spine-echo T1-weighted and gradient-echo images (flip angle, 20 'and 60 ) were obtained. In order to identify the vacuum cleft, using plain radiographs in all patients and CT scans in two were also obtained. A 3% agar-gel block containing empty slits to form a magnetic susceptibility difference, a phantom was designed. The air spaces were 1.6 mm in thickness, 25 mm in width, and 20 to 25 mm in depth with 1.6-mm spacing. RESULTS: In all patients, vacuum clefts were confirmed by plain radiographs and CT scans. At the level containing air, T1-weighted images (both spin-echo and gradient-echo) showed a signal void resulting from the intervertebral disk vacuum cleft. A hyperintense band adjacent to the vacuum cleft was, however, observed. A gradient-echo image with a 60 'flip angle showed a brighter signal intensity than one with a 20 'angle. Our phantom study gave the same results. CONCLUSION: The magnetic susceptibility artifact may be responsible for the T1-signal hyperintensity observed adjacent to the vacuum cleft in intervertebral disks. In addition, in order to generate signal hyperintensity, the desiccating disk material must contain a certain amount of water molecules.