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Loo J, Kwok HC, Leung CCH, Wu SY, Law ILG, Cheung YK, Cheung YY, Chin ML, Kwan P, Hui M, Kong SK, Ho HP. Sample-to-answer on molecular diagnosis of bacterial infection using integrated lab--on--a--disc. Biosens Bioelectron 2017; 93:212-219. [PMID: 27660018 DOI: 10.1016/j.bios.2016.09.001] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 08/27/2016] [Accepted: 09/01/2016] [Indexed: 12/25/2022]
Abstract
Sepsis by bacterial infection causes high mortality in patients in intensive care unit (ICU). Rapid identification of bacterial infection is essential to ensure early appropriate administration of antibiotics to save lives of patients, yet the present benchtop molecular diagnosis is time-consuming and labor-intensive, which limits the treatment efficiency especially when the number of samples to be tested is extensive. Therefore, we hereby report a microfluidic platform lab-on-a-disc (LOAD) to provide a sample-to-answer solution. Our LOAD customized design of microfluidic channels allows automation to mimic sequential analytical steps in benchtop environment. It relies on a simple but controllable centrifugation force for the actuation of samples and reagents. Our LOAD system performs three major functions, namely DNA extraction, isothermal DNA amplification and real-time signal detection, in a predefined sequence. The disc is self-contained for conducting sample heating with chemical lysis buffer and silica microbeads are employed for DNA extraction from clinical specimens. Molecular diagnosis of specific target bacteria DNA sequences is then performed using a real-time loop-mediated isothermal amplification (RT-LAMP) with SYTO-9 as the signal reporter. Our LOAD system capable of bacterial identification of Mycobacterium tuberculosis (TB) and Acinetobacter baumanii (Ab) with the detection limits 103cfu/mL TB in sputum and 102cfu/mL Ab in blood within 2h after sample loading. The reported LOAD based on an integrated approach should address the growing needs for rapid point-of-care medical diagnosis in ICU.
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Affiliation(s)
- J Loo
- Biochemistry Programme, School of Life Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong; Department of Electronic Engineering, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong
| | - H C Kwok
- Department of Electronic Engineering, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong
| | - C C H Leung
- Department of Anaesthesia and Intensive Care, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong
| | - S Y Wu
- Department of Electronic Engineering, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong
| | - I L G Law
- Biochemistry Programme, School of Life Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong
| | - Y K Cheung
- Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong
| | - Y Y Cheung
- Department of Microbiology, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong
| | - M L Chin
- Department of Microbiology, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong
| | - P Kwan
- Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong
| | - M Hui
- Department of Microbiology, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong
| | - S K Kong
- Biochemistry Programme, School of Life Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong
| | - H P Ho
- Department of Electronic Engineering, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong.
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Tan A, Yin JDC, Tan LWL, van Dam RM, Cheung YY, Lee CH. Using the Berlin Questionnaire to Predict Obstructive Sleep Apnea in the General Population. J Clin Sleep Med 2017; 13:427-432. [PMID: 27855742 DOI: 10.5664/jcsm.6496] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Accepted: 10/18/2016] [Indexed: 01/06/2023]
Abstract
STUDY OBJECTIVES The Berlin questionnaire is a self-administered questionnaire that was developed to identify subjects with obstructive sleep apnea (OSA) in primary care settings. This study evaluated the performance of the questionnaire to predict OSA in the general population. METHODS A sample of 242 subjects in a population-based cohort completed a home-based sleep study with an Embletta device (type 3 monitor). Subjects completed the Berlin questionnaire on the evening just prior to the sleep study. The sleep studies were manually scored according to the 2012 American Academy of Sleep Medicine (AASM) criteria. RESULTS The prevalence of moderate-to-severe and severe OSA defined as apnea-hypopnea index (AHI) of ≥ 15 and ≥ 30 was 28.1% and 10.7%, respectively. Seventy-nine subjects (32.6%) were classified as high risk according to the Berlin questionnaire. The sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) of the questionnaire to predict an AHI ≥ 15 was 58.8%, 77.6%, 82.9%, and 50.6%, respectively. The area under the receiving operator characteristic (ROC) curve for moderate-to-severe OSA was 0.682. When used to predict an AHI ≥ 30, the sensitivity of the questionnaire increased to 76.9% with a small drop in specificity to 72.7%. The corresponding NPV, PPV, and area under the ROC curve of the questionnaire to predict severe OSA were 96.3%, 25.3%, and 0.748, respectively. CONCLUSIONS The Berlin questionnaire may have utility in the general population setting as a screening tool for OSA in view of its good sensitivity and high NPV in ruling out severe OSA.
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Affiliation(s)
- Adeline Tan
- Department of Respiratory Medicine, Ng Teng Fong General Hospital, Jurong Health Services, Singapore
| | - Jason D C Yin
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System
| | - Linda W L Tan
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System
| | - Rob M van Dam
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System.,Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore and National University Health System
| | - Yan Yi Cheung
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore and National University Health System.,Department of Cardiology, National University Heart Centre, Singapore
| | - Chi-Hang Lee
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore and National University Health System.,Department of Cardiology, National University Heart Centre, Singapore
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Cheung YY, Tai BC, Loo G, Khoo SM, Cheong YP, Barbe F, Lee CH. OBSTRUCTIVE SLEEP APNEA AND CORONARY RISK IN HEALTH SCREENING CLINIC. J Am Coll Cardiol 2017. [DOI: 10.1016/s0735-1097(17)35186-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Tan A, Yin JDC, Tan LWL, van Dam RM, Cheung YY, Lee CH. Predicting obstructive sleep apnea using the STOP-Bang questionnaire in the general population. Sleep Med 2016; 27-28:66-71. [PMID: 27938922 DOI: 10.1016/j.sleep.2016.06.034] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Revised: 05/26/2016] [Accepted: 06/12/2016] [Indexed: 10/20/2022]
Abstract
OBJECTIVE The STOP-Bang questionnaire was developed as a quick and simple screening tool for obstructive sleep apnea (OSA) in preoperative clinics. We aimed to evaluate the validity of the STOP-Bang questionnaire to predict moderate-to-severe and severe OSA in the general population. METHODS A sample of 242 subjects selected from a population-based cohort in Singapore completed home-based sleep testing with a type 3 monitor. Subjects were asked to complete the STOP questionnaire while body mass index (BMI), age, neck circumference, and sex were recorded. A score of ≥3 on the questionnaire indicated high risk of OSA. RESULTS A total of 68 subjects (28.1%) and 26 subjects (10.7%) had an apnea-hypopnea index (AHI) of ≥15 and ≥30 events per hour, respectively. Of the subjects, 89 (36.8%) were classified as high risk based on the questionnaire. The sensitivity of a STOP-Bang score of ≥3 was 66.2% to detect AHI ≥15 and 69.2% to detect AHI ≥30. The specificities were 74.7% and 67.1%, respectively. The negative predictive values were 85% for moderate-to-severe OSA and 94.8% for severe OSA. The corresponding positive predictive values were 50.6% and 20.2%, respectively. Using BMI cutoffs of 30 and 27.5 for Asians compared to the original cutoff of 35 did not improve the questionnaire performance significantly. CONCLUSION The STOP-Bang questionnaire can be used as a screening tool in the general population in view of its moderate sensitivity and high negative predictive value for subjects with moderate-to-severe and severe OSA. The cutoff of BMI >35 can be used in Asians, as lower BMI cutoffs did not improve questionnaire performance.
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Affiliation(s)
- Adeline Tan
- Department of Respiratory Medicine, Ng Teng Fong General Hospital, Jurong Health Services, Singapore.
| | - Jason D C Yin
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore
| | - Linda W L Tan
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore
| | - Rob M van Dam
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore; Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Yan Yi Cheung
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Department of Cardiology, National University Heart Centre, Singapore
| | - Chi-Hang Lee
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Department of Cardiology, National University Heart Centre, Singapore
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Tan A, Cheung YY, Yin J, Lim WY, Tan LWL, Lee CH. Prevalence of sleep-disordered breathing in a multiethnic Asian population in Singapore: A community-based study. Respirology 2016; 21:943-50. [PMID: 26929251 DOI: 10.1111/resp.12747] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Revised: 12/13/2015] [Accepted: 12/15/2015] [Indexed: 10/22/2022]
Abstract
BACKGROUND AND OBJECTIVE Limited data exist on the prevalence variation in sleep-disordered breathing (SDB) across different Asian ethnicities. This population study aimed to estimate the prevalence of SDB in Singapore, a multiethnic nation, and to quantify the prevalence variation among Chinese, Malays and Indians. METHODS The Singapore Health Study 2012 was a cross-sectional population study conducted on adults aged 21-79 years. Among 2329 participants who completed baseline examination, a sample of 242 subjects completed home-based sleep testing with an Embletta device (type 3 monitor). Moderate-to-severe SDB, defined as an apnoea-hypopnoea index (AHI) of ≥15 events/h, was used to estimate prevalence. RESULTS The weighted estimates of the population prevalence of moderate-to-severe SDB and sleep apnoea syndrome were 30.5% and 18.1%, respectively. Of subjects with AHI ≥15, 91.0% were previously undiagnosed. Moderate-to-severe SDB prevalence varied across the Chinese (32.1%), Malays (33.8%) and Indians (16.5%). The mean body mass index (BMI) was lowest in Chinese (23.3 kg/m(2) ) and highest among Malays (26.0 kg/m(2) ) and Indians (25.4 kg/m(2) ). Compared with Chinese, Indians had lower odds of moderate-to-severe SDB after adjustment for age, sex and BMI (odds ratio 0.82, 95% CI: 0.70-0.96, P = 0.02). CONCLUSION Sleep-disordered breathing is prevalent but mostly undiagnosed among Asians in Singapore. There was a lower prevalence of SDB among Indians compared with Chinese that remained after adjustment for age, sex and BMI. Strategies are needed to optimize diagnosis and recognize ethnic differences in SDB prevalence.
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Affiliation(s)
- Adeline Tan
- Department of Respiratory Medicine, Ng Teng Fong General Hospital, Jurong Health Services, Singapore, 609606
| | - Yan Yi Cheung
- Department of Cardiology, National University Heart Centre, Singapore.,Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Jason Yin
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore
| | - Wei-Yen Lim
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore
| | - Linda W L Tan
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore
| | - Chi-Hang Lee
- Department of Cardiology, National University Heart Centre, Singapore.,Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
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Ho PL, Cheung YY, Wang Y, Lo WU, Lai ELY, Chow KH, Cheng VCC. Characterization of carbapenem-resistant Escherichia coli and Klebsiella pneumoniae from a healthcare region in Hong Kong. Eur J Clin Microbiol Infect Dis 2016; 35:379-85. [PMID: 26740321 DOI: 10.1007/s10096-015-2550-3] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Accepted: 12/07/2015] [Indexed: 12/21/2022]
Abstract
Carbapenem-resistant Enterobacteriaceae represents a major public health issue. This study investigated the clonality and resistance mechanisms of 92 carbapenem-resistant E. coli (n = 21) and K. pneumoniae (n = 71) isolates collected consecutively from clinical specimens and patients at high risk of carriage between 2010 and 2012 in a healthcare region in Hong Kong. Combined disk tests (CDTs) and the Carba NP test were used for phenotypic detection of carbapenemases. PCR assays were used to detect carbapenemase genes. All isolates were intermediate or resistant to at least one carbapenem. Nine (9.8 %) isolates were genotypic carbapenemase producers and included six K. pneumoniae (one ST1306/bla IMP-4, one ST889/bla IMP-4, two ST11/bla KPC-2, one ST258/bla KPC-2, one ST483/bla NDM-1) and three E. coli (one ST131/bla IMP-4, two ST744/ bla NDM-1) isolates. All nine isolates carrying carbapenemase genes could be detected by the CDTs and the Carba NP test. PCR identified bla CTX-M and bla AmpC alone or in combination in 77.8 % (7/9) and 96.4 % (80/83) of the carbapenemase-producers and non-producers, respectively. Porin loss was detected in 22.2 % (2/9) and 59.0 % (49/83) of the carbapenemase-producers and non-producers, respectively. Overall, the E. coli clones were diverse (14 different STs), but 36.6 % (26/71) of the K. pneumoniae isolates belonged to ST11. In conclusion, the prevalence of carbapenemases among carbapenem-nonsusceptible E. coli and K. pneumoniae remained low in Hong Kong. Porin loss combined with AmpC and/or CTX-M type ESBL was the major mechanism of carbapenem resistance in the study population.
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Affiliation(s)
- P L Ho
- Department of Microbiology, Queen Mary Hospital, University of Hong Kong, Pokfulam Road, Pokfulam, Hong Kong, SAR, People's Republic of China.
| | - Y Y Cheung
- Department of Microbiology, Queen Mary Hospital, University of Hong Kong, Pokfulam Road, Pokfulam, Hong Kong, SAR, People's Republic of China
| | - Y Wang
- Department of Microbiology, Queen Mary Hospital, University of Hong Kong, Pokfulam Road, Pokfulam, Hong Kong, SAR, People's Republic of China
| | - W U Lo
- Department of Microbiology, Queen Mary Hospital, University of Hong Kong, Pokfulam Road, Pokfulam, Hong Kong, SAR, People's Republic of China
| | - E L Y Lai
- Department of Microbiology, Queen Mary Hospital, University of Hong Kong, Pokfulam Road, Pokfulam, Hong Kong, SAR, People's Republic of China
| | - K H Chow
- Department of Microbiology, Queen Mary Hospital, University of Hong Kong, Pokfulam Road, Pokfulam, Hong Kong, SAR, People's Republic of China
| | - V C C Cheng
- Department of Microbiology, Queen Mary Hospital, University of Hong Kong, Pokfulam Road, Pokfulam, Hong Kong, SAR, People's Republic of China
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Cheung YY, Chen KC, Chen H, Seng EK, Chu JJH. Antiviral activity of lanatoside C against dengue virus infection. Antiviral Res 2014; 111:93-9. [PMID: 25251726 DOI: 10.1016/j.antiviral.2014.09.007] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Revised: 08/07/2014] [Accepted: 09/13/2014] [Indexed: 10/24/2022]
Abstract
Dengue infection poses a serious threat globally due to its recent rapid spread and rise in incidence. Currently, there is no approved vaccine or effective antiviral drug for dengue virus infection. In response to the urgent need for the development of an effective antiviral for dengue virus, the US Drug Collection library was screened in this study to identify compounds with anti-dengue activities. Lanatoside C, an FDA approved cardiac glycoside was identified as a candidate anti-dengue compound. Our data revealed that lanatoside C has an IC50 of 0.19μM for dengue virus infection in HuH-7 cells. Dose-dependent reduction in dengue viral RNA and viral proteins synthesis were also observed upon treatment with increasing concentrations of lanatoside C. Time of addition study indicated that lanatoside C inhibits the early processes of the dengue virus replication cycle. Furthermore, lanatoside C can effectively inhibit all four serotypes of dengue virus, flavivirus Kunjin, alphavirus Chikungunya and Sindbis virus as well as the human enterovirus 71. These findings suggest that lanatoside C possesses broad spectrum antiviral activity against several groups of positive-sense RNA viruses.
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Affiliation(s)
- Yan Yi Cheung
- Laboratory of Molecular RNA Virology and Antiviral Strategies, Department of Microbiology, Yong Loo Lin School of Medicine, National University Health System, 5 Science Drive 2, National University of Singapore, Singapore 117597, Singapore
| | - Karen Caiyun Chen
- Laboratory of Molecular RNA Virology and Antiviral Strategies, Department of Microbiology, Yong Loo Lin School of Medicine, National University Health System, 5 Science Drive 2, National University of Singapore, Singapore 117597, Singapore
| | - Huixin Chen
- Laboratory of Molecular RNA Virology and Antiviral Strategies, Department of Microbiology, Yong Loo Lin School of Medicine, National University Health System, 5 Science Drive 2, National University of Singapore, Singapore 117597, Singapore
| | - Eng Khuan Seng
- School of Chemical & Life Sciences, 180 Ang Mo Kio Ave 8, Nanyang Polytechnic, Singapore 569830, Singapore
| | - Justin Jang Hann Chu
- Laboratory of Molecular RNA Virology and Antiviral Strategies, Department of Microbiology, Yong Loo Lin School of Medicine, National University Health System, 5 Science Drive 2, National University of Singapore, Singapore 117597, Singapore.
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Abstract
The total synthesis of asteriscanolide (1) has been achieved by taking advantage on an intermolecular Pauson-Khand cycloaddition and a ring-closing metathesis as key bond-forming transformations. The approach incorporates the cyclooctane stereogenic center prior to ring formation. Interestingly, the ring-closing metathesis generates a new eight-membered ring with an "in-out" intrabridgehead relationship.
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Affiliation(s)
- M E Krafft
- Department of Chemistry, Florida State University, Tallahassee, Florida 32306-4390, USA.
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Abstract
PURPOSE To determine the magnetic resonance (MR) imaging features that characterize tear of the peroneus longus tendon at the midfoot. MATERIALS AND METHODS Medical records and MR images in nine patients with a tear of the middle segment of the peroneus longus tendon were retrospectively reviewed. All nine patients had undergone routine ankle MR imaging; three had undergone additional oblique coronal MR imaging. Surgical proof of a tear was available for three patients. RESULTS Partial tear was present in four patients, and complete tear was present in five. Partial tears were characterized by heterogeneous signal intensity and thickening of the tendon. Complete tears were characterized by discontinuity of the tendon. Additional findings included fluid in the tendon sheath (n = 6), marrow edema of the lateral calcaneal wall (n = 3), enlarged peroneal tubercle (n = 3), and tear of the peroneus brevis tendon (n = 2). The extent of the tear was better assessed with oblique coronal MR images. CONCLUSION The characteristic MR imaging appearance of complete or partial tear of the middle portion of the peroneus longus tendon includes foci of increased signal intensity in the distal tendon, morphologic alterations, and/or discontinuity of tendon. Bone marrow edema along the lateral calcaneal wall may be suggestive of the diagnosis. Additional oblique coronal midfoot MR images may help in assessment of the extent of the tear.
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Affiliation(s)
- J Rademaker
- Department of Radiology, Charite, Virchow Hospital Campus, Humboldt University of Berlin, Germany
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Abstract
OBJECTIVE The flexor digitorum accessorius longus muscle (FDAL), an anomalous muscle about the ankle, has recently been implicated in tarsal tunnel syndrome. The purpose of this study is to document the prevalence of the FDAL, its MR appearance and its relation to the neurovascular bundle in the tarsal tunnel. DESIGN AND PATIENTS The prevalence of the FDAL was determined from 100 ankle MR examinations in asymptomatic individuals. The appearance of the FDAL was summarized from 20 examples of FDAL: six gathered from the asymptomatic group and 14 acquired from a group of randomly collected cases of patients with ankle complaints. RESULTS The prevalence of the FDAL was 6%, calculated from the group of 100 asymptomatic individuals. Possessing a dominant fleshy component in the tarsal tunnel, the FDAL accompanies the posterior neurovascular bundle as it descends the ankle. CONCLUSION The FDAL is encountered in 6% of asymptomatic individuals. Its prominent fleshy component in the tarsal tunnel and its close proximity to the posterior tibial neurovascular bundle readily differentiate the FDAL from other medial anomalous muscles on MR imaging.
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Affiliation(s)
- Y Y Cheung
- Radiology Department, St. Vincent's Hospital, New York, NY 10011, USA
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Abstract
PURPOSE To determine the prevalence of the peroneus quartus (PQ) muscle, to demonstrate the morphology of this accessory muscle on magnetic resonance (MR) images, and to reassess the reported association of the PQ muscle with a hypertrophic peroneal tubercle. MATERIALS AND METHODS A retrospective review was performed of 136 consecutive ankle MR imaging studies. The origins, insertions, and variations in size of the muscle and the dimensions of the peroneal tubercle and retrotrochlear eminence were recorded. RESULTS The prevalence of the PQ muscle was 10% (14 of 136 cases). The accessory muscle and tendon unit descended medial and posterior to the peroneal tendons. The site of insertion was variable and included the calcaneus, peroneus longus tendon, peroneus brevis tendon; and cuboid bone. The calcaneus was the insertion site in 11 cases. The accessory tendon attached to the retrotrochlear eminence of the calcaneus. In the group with the PQ muscle, the retrotrochlear eminence was significantly taller (P < .01) than in the group without the PQ muscle. CONCLUSION Contrary to previous reports, the peroneocalcaneal variant of the PQ muscle appears to insert in the retrotrochlear eminence of the calcaneus rather than the peroneal tubercle. The presence of the PQ muscle is associated with a prominent retrotrochlear eminence but not with an enlarged peroneal tubercle.
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Affiliation(s)
- Y Y Cheung
- Department of Radiology, St Vincent's Hospital, New York, NY 10011, USA
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Abstract
OBJECTIVE Our objective is to describe the characteristic MR imaging features of longitudinal tears of the peroneus brevis tendon and to describe pathologic conditions and normal variants that are associated with these tears which may require surgical intervention at the time of primary tendon repair. MATERIALS AND METHODS We retrospectively reviewed 10 MR images of asymptomatic volunteers and 31 MR images of 27 patients with evidence of longitudinal splits of the peroneus brevis tendon. Seven of these cases were surgically proven. In addition, we assessed five pathologic conditions and normal variants: lateral collateral ligamentous tears; injuries to the superior peroneal retinaculum; low-lying muscle belly of the peroneus brevis tendon; peroneus quartus muscle; and convex, flat, or irregular retromalleolar groove. RESULTS In the patient's group, we saw longitudinal splits as clefts and an irregularity of the contour of the peroneus brevis tendon with (71%) and without (29%) signal changes on proton density-weighted and T2-weighted MR imaging sequences. Divisions of the split tendon assumed a characteristic C-shaped configuration that partly enveloped the peroneus longus tendon. Fifteen cases revealed other pathologic conditions and normal variants known to be associated with or to predispose to tears of the peroneus brevis tendon. These include ankle ligamentous tears (n = 3); abnormal superior peroneal retinaculum (n = 4); low-lying muscle belly of the peroneus brevis tendon (n = 1); peroneus quartus muscle (n = 2); and convex, flat, or irregular retromalleolar groove (n = 15). MR imaging revealed tears in all patients with surgical proof (n = 7). CONCLUSION MR imaging is a useful technique for revealing longitudinal tears of the peroneus brevis tendon as well as showing anatomic and pathologic factors associated with or predisposed to tears.
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Affiliation(s)
- Z S Rosenberg
- Department of Radiology, Hospital for Joint Diseases Orthopaedic Institute, New York, NY 10003, USA
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Rosenberg ZS, Cheung YY, Beltran J, Sheskier S, Leong M, Jahss M. Posterior intermalleolar ligament of the ankle: normal anatomy and MR imaging features. AJR Am J Roentgenol 1995; 165:387-90. [PMID: 7618563 DOI: 10.2214/ajr.165.2.7618563] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
OBJECTIVE The purposes of this study were to delineate the normal anatomy and MR imaging features of the posterior intermalleolar ligament--a normal ligamentous variant of the posterior portion of the ankle--and to identify normal anatomic characteristics that may account for the role of the ligament in the development of posterior impingement syndrome. MATERIALS AND METHODS The prevalence, size, and shape of the posterior intermalleolar ligament were documented in 36 cadaveric ankles and in 97 MR studies of the ankle in patients with and without symptoms. RESULTS The posterior intermalleolar ligament was identified in 20 (56%) of the 36 cadaveric feet. It was 1-8 mm wide, and its diameter (anterior to posterior) was 5-8 mm. The ligament often resembled a meniscus, and in one case its anterior lip herniated into the ankle joint. The posterior intermalleolar ligament was detected in 18 (19%) of the 97 MR studies of the ankle. It was visualized on coronal T1- or T2-weighted images as a distinct, hypointense band traversing between the posterior talofibular ligament and the inferior transverse ligament. CONCLUSION The posterior intermalleolar ligament is a normal variant of the posterior ligaments of the ankle and is present in a significant number of persons. It is best seen on coronal T1- and T2-weighted MR images. Its meniscuslike shape and occasional extension into the ankle joint may account for the development of posterior impingement syndrome in susceptible persons.
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Affiliation(s)
- Z S Rosenberg
- Radiology Department, Hospital for Joint Diseases, New York, NY 10003, USA
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Abstract
PURPOSE To describe the pseudodefect of the distal humerus at the junction of the capitellum and lateral epicondyle, which may simulate an osteochondral lesion on axial and coronal magnetic resonance (MR) images. MATERIALS AND METHODS MR imaging studies of the elbow in 32 patients and 22 asymptomatic volunteers were retrospectively reviewed. Thirty-two human humeri were also examined for normal anatomy of the junction of the capitellum and distal humerus. RESULTS Twenty-two of the clinical MR examinations and 14 of the studies on volunteers revealed the presence of the pseudodefect. A groove at the junction and the overhanging lateral edges of the capitellum account for the appearance of this pseudolesion. CONCLUSION Familiarity with the characteristic appearance and location of this pseudodefect will prevent its misinterpretation as an osteochondral fracture of the distal humerus.
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Affiliation(s)
- Z S Rosenberg
- Department of Radiology, Hospital for Joint Diseases, New York, NY 10003
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Abstract
The authors retrospectively reviewed 15 magnetic resonance (MR) studies of elbows with radiographic evidence of nerve disorders. These 15 cases were selected from 55 MR studies of the elbow in patients referred for various complaints. MR images of the elbow of 10 healthy volunteers were also reviewed. Ulnar nerve disorders were seen in 11 cases. Three patients had median nerve disease, and one patient had a pathologic condition of the radial nerve. The following nerve abnormalities were detected: focal or diffuse nerve thickening, increased signal intensity on T2-weighted images, and course deviation due to either mass effect or spontaneous subluxation. Six of seven patients with nerve thickening, two of two patients with increased nerve signal intensity, and five of eight patients with nerve displacement complained of neurologic symptoms. Four of the patients underwent surgery; in each, surgical results confirmed the findings at MR. These results suggest that MR imaging has a potential role in the detection of nerve disorders at the elbow and in the guidance of treatment.
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Affiliation(s)
- Z S Rosenberg
- Department of Radiology, Hospital for Joint Diseases/Orthopaedic Institute, New York, NY 10003
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Rosenberg ZS, Kawelblum M, Cheung YY, Beltran J, Lehman WB, Grant AD. Osgood-Schlatter lesion: fracture or tendinitis? Scintigraphic, CT, and MR imaging features. Radiology 1992; 185:853-8. [PMID: 1438775 DOI: 10.1148/radiology.185.3.1438775] [Citation(s) in RCA: 102] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
To determine whether the Osgood-Schlatter lesion (OS) is produced by avulsion fracture or injury to the patellar tendon, all images obtained in 28 cases of OS in 20 patients (16 scintigrams, 34 computed tomographic [CT] scans, and 27 magnetic resonance [MR] images) were retrospectively analyzed. In 21 cases, imaging was performed before and after treatment; in 20 cases, relief from pain was complete at the time of repeat examination. In all patients (100%), abnormal size of the tendon, decreased attenuation, and increase in signal intensity were compatible with the CT and MR imaging appearance of tendinitis. Distended deep infrapatellar bursa was a frequent finding, particularly on MR studies. These abnormalities had partially disappeared at follow-up examination. An ossicle was seen in only nine of 28 cases (32%); in three of seven cases with follow-up, the ossicle remained nonunited to the tibial tuberosity on follow-up studies despite relief from symptoms. This implies that healing of fracture is not essential for relief from symptoms. These results strengthen the argument that in most cases of OS, insult to the tendon and associated soft tissues, rather than avulsion fracture, causes OS.
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Affiliation(s)
- Z S Rosenberg
- Department of Radiology, Hospital for Joint Diseases/Orthopaedic Institute, New York, NY 10003
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Zhang YN, Riby P, Cox AG, McLeod CW, Date AR, Cheung YY. On-line pre-concentration and determination of lead in potable water by flow injection atomic absorption spectrometry. Analyst 1988; 113:125-8. [PMID: 3358497 DOI: 10.1039/an9881300125] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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Abstract
A patient with disseminated cysticercosis involving orbit, tongue, parotid glands, epicardial fat, muscle, and subcutaneous tissues is presented. Magnetic resonance findings are described with emphasis on intraorbital and extracranial lesions.
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