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PubMed2004

Persistent renal cortical scintigram defects in children 2 years after urinary tract infection.

BACKGROUND: Renal cortical scintigraphic studies challenge the role of vesicoureteric reflux in renal scar development, emphasizing instead the part played by acute pyelonephritis. OBJECTIVE: To determine the prevalence of renal cortical defects in a child cohort 2 years after the child's first diagnosed urinary tract infection and to analyze the relationship of these defects with acute illness variables, primary vesicoureteric reflux and recurrent infections. MATERIALS AND METHODS: In a prospective cohort study, 193 children younger than 5 years with their first proven urinary tract infection underwent renal sonography, voiding cystourethrogram, and renal cortical scintigraphy within 15 days of diagnosis. Two years later, 150 of the 193 children, or 77.7%, had a further renal cortical scintigram, including 75, or 86.2%, of the 87 children who had acute scintigraphic defects. The relationship of cortical defects to age, gender, pre-treatment symptom duration, hospitalization, presence and grade of vesicoureteric reflux, and recurrent urinary tract infections was evaluated. RESULTS: Overall, 20 of the 150 (13.3%; 95% confidence interval (CI) 8.3, 19.8) children had persistent defects 2 years after infection. This included 20 of 75 (26.7%; 95% CI 17.1, 38.1) with initially abnormal scintigrams. No new defects were detected. Although acute defects were more common in the young, those with persistent defects were older (median ages 16.4 vs. 6.8 months, P=0.004) than those with transient abnormalities. After adjustment for age, persistent defects were no longer associated with gender and were not predicted by acute illness variables, primary vesicoureteric reflux or recurrent infections. CONCLUSIONS: Renal cortical scintigraphic defects persisted in approximately one-quarter of young children after their first proven urinary tract infection. The associated clinical features, however, failed to predict scar formation. It is possible that some of the scintigraphic defects preceded the infection by arising from either previously undiagnosed acute pyelonephritis or from underlying congenital dysplasia. The etiology of scars may be best addressed by determining whether prevention of urinary tract infections from birth avoids post-natal scar acquisition or extension.

Chi-Square Distribution↗

PubMed2006

Glenoid defect associated with anterior shoulder instability: results of open Bankart repair.

The purpose of the study was to analyse the clinical results of an open Bankart repair for anterior instability in patients with a glenoid defect and those without a glenoid defect, and to identify factors related to the glenoid defect associated with anterior instability. The prospective study involved 20 patients with a glenoid defect (glenoid defect group) and 20 patients without a glenoid defect (control group) who were enrolled after an open Bankart repair. The average age of each group at the time of surgery was 28 and 23 years respectively. The average follow-up periods were 48 and 55 months. There were no significant differences in subjective pain and stability between the two groups. But the final Rowe score decreased significantly as the size of the glenoid defect increased. Redislocation or subluxation was seen in three patients in the glenoid defect group. The open Bankart procedure restored stability and improved shoulder functions in the patients with a glenoid defect associated with anterior instability, even though the glenoid defect group experienced a significant loss in the range of external rotation with the arm at the side, and the final outcome of the surgery depended upon the size of a glenoid defect. This was a therapeutic, level III case-control study.

Adolescent↗

PubMed2002

Fecal incontinence in females with a past history of vaginal delivery: significance of anal sphincter defects detected by ultrasound.

PURPOSE: The aim of this study was to determine the significance of anal sphincter defects detected by ultrasonography, in a population of fecal incontinent parous females without previous anoperineal surgery. METHODS: From 100 consecutive incontinent patients, 61 females with at least one previous vaginal delivery and no past anoperineal surgery were studied. The severity of fecal incontinence was assessed by the Cleveland Clinic questionnaire score. Lesions of the internal or external anal sphincters, and the radial size of these defects were assessed by ultrasonography. Anal vector manometry was performed to measure anal pressures at rest and during voluntary squeeze, and the anal asymmetry index. RESULTS: Twenty-three had a normal sphincter (38 percent), and 38 (62 percent) had a defect detected by ultrasonography: 20 isolated defects of the external sphincter and 18 combined defects of the internal and external sphincters. Combined defects were significantly larger. The radial size of the defects was positively correlated with the severity of clinical symptoms. Anal pressure asymmetry index was significantly increased in the group with combined defects compared with the two other groups. An index of 25 percent or greater had a very high (100 percent) negative predictive value for the presence of a defect larger than 90 degrees. CONCLUSIONS: This study confirms the high prevalence of anal sphincter defects detected by ultrasonography in a population of incontinent parous females without previous proctologic surgery. The clinical symptoms are related to the size of these defects. Anal vector manometry may be a useful tool to confirm the relation between echographic anal sphincter lesions and fecal incontinence.

Adult↗

PubMed2006

The risk of birth defects in multiple births: a population-based study.

OBJECTIVES: To determine if multiple births have higher risks of birth defects compared to singletons and to identify types of birth defects that occur more frequently in multiple births, controlling for seven sociodemographic and health-related variables. METHODS: A retrospective cohort study was conducted of all resident live births in Florida during 1996-2000 using data from a population-based surveillance system. Birth defects were defined as in the 9th edition of the International Classification of Diseases-Clinical Modification (ICD-9-CM) code for the 42 reportable categories in the Centers for Disease Control and Prevention (CDC) Birth Defects Registry list and eight major birth defects classifications. Relative risks (RR) before and after adjusting for control variables and 95% confidence intervals (95% CI) were calculated. The control variables included mother's race, age, previous adverse pregnancy experience, education, Medicaid participation during pregnancy, infant's sex and number of siblings. RESULTS: This study included 972,694 live births (27,727 multiple births and 944,967 singletons). Birth defects prevalence per 10,000 live births was 358.50 for multiple births and 250.54 for singletons. After adjusting for control variables, multiple births had a 46% increased risk of birth defects compared to singletons. Higher risks were found in 23 of 40 birth defects for multiple births. Five highest adjusted relative risks for birth defects among multiple births were: anencephalus, biliary atresia, hydrocephalus without spina bifida, pulmonary valve atresia and stenosis, and bladder exstrophy. Increased risks were also found in 6 out of 8 major birth defects classifications. CONCLUSIONS: Multiple births have increased risks of birth defects compared to singletons.

Adult↗

PubMed1985

The persistent defect on exercise thallium imaging and its fate after myocardial revascularization: does it represent scar or ischemia?

Persistent defects on serial thallium scans are commonly thought to represent fibrosis or scar. However, such a pattern may also represent severe ischemia. To better understand persistent defects, exercise thallium and resting gated blood pool scans were reviewed in 52 patients pre and post coronary angioplasty for single-vessel left anterior descending (LAD) coronary artery disease, and the fate of persistent defects after successful revascularization was determined. Persistent and transient defects were defined from the average scores of three observers. Ten patients with 16 myocardial segments with persistent defects were compared to another 11 patients with 20 myocardial segments with transient defects. After angioplasty (PTCA), 75% of the regions that had persistent defects and 85% of the regions that had transient defects were normal by visual assessment. In the persistent defect group, only regional wall motion on the resting gated blood pool scan pre PTCA helped to distinguish those segments that would or would not revert to normal. We conclude that regions of persistent defect on thallium scan often revert to normal after PTCA (75%), suggesting that persistent defects may represent hypoperfusion of viable myocardium, and should not preclude consideration of an intervention.

Adult↗

PubMed1994

Prevalence of right ventricular perfusion defects after inferior myocardial infarction assessed by low-level exercise with technetium 99m sestamibi tomographic myocardial imaging.

To assess the prevalence of right ventricular perfusion defects after a recent inferior wall myocardial infarction, 33 patients were studied 6 to 14 days after infarction with low-level exercise testing and technetium 99m (99mTc) sestamibi (SPECT) imaging. Twenty-two control subjects with a < 5% likelihood of coronary artery disease undergoing exercise 99mTc sestamibi imaging were also studied. For each image the right ventricle was computer isolated from reconstructed transverse cardiac slices, followed by reorientation into oblique slices. Both right and left ventricular images were visually assessed for defects. A quantitative method of defect detection was also applied to the right ventricle. For the right ventricle, 100% of the stress images and 96% of the rest images were adequate for interpretation. Right ventricular stress perfusion defects were identified in 10 (30%) of 33 patients with recent inferior infarction, with 50% completely or partially normalizing on rest images, consistent with ischemia. Of 14 patients with left ventricular inferoseptal defects, eight (57%) had right ventricular defects compared with 2 (11%) of 19 without inferoseptal defects (p < 0.005). We concluded that the right ventricle can be adequately assessed for perfusion defects by means of exercise with 99mTc sestamibi SPECT imaging. Defects of the right ventricle after inferior myocardial infarction occur frequently, and many have evidence of ischemia. Right ventricular perfusion defects are closely associated with left ventricular inferoseptal defects.

Case-Control Studies↗

PubMed1995

Limb defects after chorionic villus sampling.

OBJECTIVE: To clarify the association between limb defects and chorionic villus sampling (CVS). METHODS: Questionnaires were sent to 165 major obstetric units in Taiwan to survey the incidence of limb defects with and without CVS exposure during 1991. Limb defects with CVS exposure from September 1990 to June 1992 were also surveyed. The spectrum of limb defects in CVS-exposed and general populations were compared by the Poisson test. RESULTS: The incidence of limb defects in the surveyed general population in 1991 was 0.032% and that with CVS exposure was 0.294%, a statistically significant difference (P < .001). The incidence of severe limb defects in the general population was 0.0026% and that with CVS exposure was 0.22%, also statistically significant (P < .001). Twenty-nine cases of limb defects after CVS were reported from September 1990 until June 1992: 19 cases with transverse limb reduction, two with mid-palm reduction, seven with adactyly or hypodactyly, and one with syndactyly. Four cases also had oromandibular-limb hypogenesis syndrome. CONCLUSIONS: The incidence of limb defects, especially the severe types, was increased after CVS. The spectrum of limb defects with CVS exposure was more severe than the limb defects seen in the general population and showed a specific pattern ranging from hypodactyly, adactyly, and transverse limb reduction, to oromandibular-limb hypogenesis. A correlation between the severity of limb defects and the timing of CVS was suggested.

Abnormalities, Multiple↗

PubMed2005

In vitro fertilization is associated with an increase in major birth defects.

OBJECTIVE: To determine the risk of major birth defects in cohorts of children conceived through IVF or through IUI as compared with naturally conceived children. DESIGN: Retrospective cohort study. SETTING: Academic medical center. PATIENT(S): Children conceived by IVF or IUI at the University of Iowa from 1989 through 2002, compared with a matched cohort of naturally conceived children. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Outcome data were obtained from Iowa state birth and fetal death certificates and from the Iowa Birth Defects Registry. RESULT(S): Ninety of 1,462 IVF-conceived children (6.2%) and 17 of 343 IUI-conceived children (5.0%) had a major birth defect, compared with 369 of 8,422 naturally conceived children (4.4%). The adjusted odds ratio of a major birth defect in all IVF-conceived children was 1.30 (95% confidence interval [CI] 1.00-1.67) and 1.11 (95% CI 0.67-1.84) for IUI-conceived children. The birth defect rate was increased after IVF when the analysis was limited to term singletons. Cardiovascular and musculoskeletal defects and known birth defect syndromes were increased after IVF. Among IVF-conceived children, there was no difference in birth defect rates after intracytoplasmic sperm injection (ICSI) or after transfer of cryopreserved embryos. CONCLUSION(S): Infants conceived through IVF have a slightly higher rate of major birth defects. More birth defects are noted among children born to infertile couples treated with IUI, although this difference is not statistically significant. Larger studies of infants conceived by infertile couples after all types of infertility treatment are needed to definitively determine whether the increased risk of birth defects is secondary to problems inherent in the infertile couple and/or factors associated with some aspect of the treatment.

Abnormalities, Multiple↗

PubMed2005

Repair of osteochondral defects with hyaluronan- and polyester-based scaffolds.

OBJECTIVE: The natural repair of osteochondral defects can be enhanced with biocompatible, biodegradable materials that support the repair process. It is our hypothesis that hyaluronan-based scaffolds are superior to synthetic scaffolds because they provide biological cues. We tested this thesis by comparing two hyaluronan-based scaffolds [auto cross-linked polysaccharide polymer (ACP) and HYAFF-11] to polyester-based scaffolds [poly(DL-lactic-co-glycolic acid) (PLGA) and poly(L-lactic acid) (PLLA)] with similar pore size, porosity and degradation times. DESIGN: Fifty-four rabbits received bilateral osteochondral defects. One defect received a hyaluronan-based scaffold and the contralateral defect received the corresponding polyester-based scaffold. Rabbits were euthanized 4, 12 and 20 weeks after surgery and the condyles dissected and processed for histology. RESULTS: Only ACP-treated defects presented bone at the base of the defect at 4 weeks. At 12 weeks, only defects treated with rapidly dissolving implants (ACP and PLGA) presented bone reconstitution consistently, while bone was present in only one third of those treated with slowly dissolving scaffolds (HYAFF-11 and PLLA). After 20 weeks, the articular surface of PLGA-treated defects presented fibrillation more frequently than in ACP-treated defects. The surface of defects treated with slowly dissolving scaffolds presented more cracks and fissures. CONCLUSIONS: The degradation rate of the scaffolds is critical for the repair process. Slowly dissolving scaffolds sustain thicker cartilage at the surface but, it frequently presents cracks and discontinuities. These scaffolds also delay bone formation at the base of the defects. Hyaluronan-based scaffolds appear to allow faster cell infiltration leading to faster tissue formation. The degradation of ACP leads to rapid bone formation while the slow degradation of HYAFF-11 prolongs the presence of cartilage and delays endochondral bone formation.

Animals↗

PubMed2005

Diagnostic ability of optical coherence tomography with a normative database to detect localized retinal nerve fiber layer defects.

PURPOSE: To evaluate the diagnostic ability of third-generation optical coherence tomography (Stratus OCT) with a normative database to detect localized retinal nerve fiber layer (RNFL) defects. DESIGN: Cross-sectional study. PARTICIPANTS: One eye of each of 55 subjects (43 normal-tension glaucoma and 12 primary open-angle glaucoma subjects) with localized, wedge-shaped RNFL defects by red-free RNFL photographs and corresponding visual field defects (mean deviation, -6.77+/-3.54; range, -1.25 to -9.20 dB). METHODS: The segments of the borderline and outside normal limits in the RNFL thickness profile of OCT were considered to be significant RNFL defects by OCT and by comparison with their corresponding red-free RNFL photographs. The angular locations and widths of RNFL defects by OCT were compared with those of RNFL defects by red-free RNFL photographs. MAIN OUTCOME MEASURES: Sensitivity and specificity of OCT with a normative database to detect the localized RNFL defects. RESULTS: The mean age of the patients was 57.9+/-10.6 years (range, 25-78 years). The overall sensitivity and specificity of the OCT with a normative database for detecting localized RNFL defects were 85.9% and 97.4%, respectively. The OCT with a normative database showed good diagnostic agreement with red-free RNFL photographs (overall kappa value = 0.79). The angular locations and widths of RNFL defects by OCT were highly correlated with those of RNFL defects by red-free RNFL photographs (Pearson correlation coefficient [r] = 0.996 and 0.725, respectively). CONCLUSIONS: The OCT with a normative database can detect localized RNFL defects with moderate sensitivity and high specificity, and shows good diagnostic agreement with red-free RNFL photographs.

Adult↗

PubMed2005

Genetic sperm defects.

Genetic sperm defects are specific sperm defects, which have been shown to have a genetic mode of transmission. Such genetic linkage, either direct or indirect, has been associated with a number of sperm defects in different species, with this number increasing with improved diagnostic capabilities. A number of sperm defects, which have proven or suspected genetic modes of transmission are discussed herein, with particular emphasis on cattle. These include: 1. Acrosome defects (knobbed, ruffled and incomplete); 2. Head defects (abnormal condensation, decapitated, round head, rolled head, nuclear crest); 3. Midpiece abnormalities ("Dag" defect, "corkscrew" defect, "pseudo-droplet" defect); 4. Tail defects ("tail stump" defect, primary ciliary dyskinesia).

Acrosome↗

PubMed2000

Treatment of persistent corneal epithelial defect with extended wear of a fluid-ventilated gas-permeable scleral contact lens.

PURPOSE: To report treatment of persistent corneal epithelial defects unresponsive to other therapies by extended wear of a fluid-ventilated gas-permeable scleral contact lens. METHODS: In this retrospective study, 14 eyes of 13 consecutive patients referred for the treatment of persistent corneal epithelial defects that failed to heal with conventional therapies or developed epithelial defects after penetrating keratoplasty for persistent corneal epithelial defects were fitted with an extended-wear gas-permeable scleral lens. These included seven eyes of six patients with Stevens-Johnson syndrome and seven eyes of seven patients who did not have Stevens-Johnson syndrome. Twelve eyes had undergone recent penetrating keratoplasty. All 14 eyes were fitted with a gas-permeable scleral contact lens designed to avoid the intrusion of air bubbles under its optic. An antibiotic and corticosteroid were added to the lens fluid reservoir or instilled before each lens insertion in 12 of 14 eyes. The lenses were worn continuously except for brief periods of removal for purposes of cleaning, replacement of the lens fluid reservoir, and examination and photography of the cornea. RESULTS: Five of the seven persistent corneal epithelial defects associated with Stevens-Johnson syndrome healed. The persistent corneal epithelial defects of four of these eyes re-epithelialized within 7 days, and a fifth healed in 27 days of gas-permeable scleral lens extended wear. A sixth persistent corneal epithelial defect that failed to heal initially re-epithelialized after a subsequent penetrating keratoplasty and gas-permeable scleral lens extended wear. The seventh eye healed after 3 days of gas-permeable scleral lens extended wear, but the persistent corneal epithelial defect subsequently recurred. Three of seven non-Stevens-Johnson syndrome persistent corneal epithelial defects re-epithelialized within 36 hours, 6 days, and 36 days, respectively. Of the six (six of 14) persistent corneal epithelial defects that failed to heal with a gas-permeable scleral lens extended wear, one subsequently healed after multiple amniotic membrane grafts. Microbial keratitis occurred in four eyes (four of 14) and graft failure in one eye, all of which required repeat penetrating keratoplasty. CONCLUSION: Extended wear of an appropriately designed gas-permeable scleral contact lens was effective in promoting the healing of persistent corneal epithelial defects in some eyes that failed to heal after other therapeutic measures. Re-epithelialization appears to be aided by a combination of oxygenation, moisture, and protection of the fragile epithelium afforded by the scleral lens. However, microbial keratitis represents a significant risk.

Adolescent↗

PubMed2002

Molecular dynamics simulation of the evolution of hydrophobic defects in one monolayer of a phosphatidylcholine bilayer: relevance for membrane fusion mechanisms.

The spontaneous formation of the phospholipid bilayer underlies the permeability barrier function of the biological membrane. Tears or defects that expose water to the acyl chains are spontaneously healed by lipid lateral diffusion. However, mechanical barriers, e.g., protein aggregates held in place, could sustain hydrophobic defects. Such defects have been postulated to occur in processes such as membrane fusion. This gives rise to a new question in bilayer structure: What do the lipids do in the absence of lipid lateral diffusion to minimize the free energy of a hydrophobic defect? As a first step to understand this rather fundamental question about bilayer structure, we performed molecular dynamic simulations of up to 10 ns of a planar bilayer from which lipids have been deleted randomly from one monolayer. In one set of simulations, approximately one-half of the lipids in the defect monolayer were restrained to form a mechanical barrier. In the second set, lipids were free to diffuse around. The question was simply whether the defects caused by removing a lipid would aggregate together, forming a large hydrophobic cavity, or whether the membrane would adjust in another way. When there are no mechanical barriers, the lipids in the defect monolayer simply spread out and thin with little effect on the other intact monolayer. In the presence of a mechanical barrier, the behavior of the lipids depends on the size of the defect. When 3 of 64 lipids are removed, the remaining lipids adjust the lower one-half of their chains, but the headgroup structure changes little and the intact monolayer is unaffected. When 6 to 12 lipids are removed, the defect monolayer thins, lipid disorder increases, and lipids from the intact monolayer move toward the defect monolayer. Whereas this is a highly simplified model of a fusion site, this engagement of the intact monolayer into the fusion defect is strikingly consistent with recent results for influenza hemagglutinin mediated fusion.

Biophysical Phenomena↗

PubMed1999

Maternal factors associated with severity of birth defects.

OBJECTIVE: Due to inbreeding and nutritional factors, the Bedouin Arabs represent a high risk population for birth defects. The severity of birth defects is probably related to the time and extent of interference with embryogenesis. The present study was aimed at identifying factors associated with severity of birth defects, in pregnancies of Bedouin women examined at a third level ultrasound clinic. METHODS: The study population consisted of 295 Bedouin women who attended an ultrasound clinic at the Soroka Medical Center between 1990 and 1996. The case group included 188 women carrying fetuses with severe birth defects, defined as incompatible with life or which significantly interfere with normal living. For those defects the option of pregnancy termination was discussed. The comparison group consisted of 107 women whose fetuses were diagnosed with mild defects. RESULTS: Women carrying fetuses with severe birth defects had more pregnancies and more deliveries than women carrying fetuses with mild defects (P = 0.005, P = 0.04, respectively). The severity of defects was found to be unrelated to maternal age, consanguinity, residence, birth order, previously uncompleted pregnancies and birth defects in the family. CONCLUSIONS: Higher birth order was associated with severity of birth defects detected at the second trimester.

Arabs↗

PubMed1996

Limb defects and chorionic villus sampling: results from an international registry, 1992-94.

BACKGROUND: Several reports of limb defects occurring among infants exposed to chorionic villus sampling (CVS) during pregnancy resulted in concern about the safety of this procedure for prenatal diagnosis. To avoid publication bias and evaluate the true risk of limb defects in a CVS cohort, the World Health Organization initiated international registration of post-CVS limb defects in 1992. METHODS: From May, 1992, to May, 1994, 77 infants or fetuses with limb defects from 138 996 pregnancies having CVS were reported to the WHO CVS Registry. These cases were analysed by standardised methods-ie, exclusion of syndromes, inherited disorders, and defects occurring in previable fetuses. The included limb deficiencies were studied by pattern analysis. FINDINGS: Defects of the upper limbs were reported in 64.6%, of the lower limbs in 12.5%, and of both upper and lower limbs in 20.8% of cases. These figures are in agreement with the distribution of limb defects in several large population-based studies. Transverse limb defects occurred in 40.8% and longitudinal defects in 59.2%, compared with 42.7% and 57.3% in an unexposed population. INTERPRETATION: The analysis of this cohort did not show any differences from the background population in the overall frequency or pattern distribution of limb deficiencies. There was also no correlation between gestational age at CVS and severity of defects. Therefore these results do not indicate any increased risk of limb defects after CVS.

Arm↗

PubMed1998

Visual field defect after pars plana vitrectomy.

OBJECTIVE: This study aimed to report the occurrence of visual field defects after pars plana vitrectomy (PPV) for the treatment of each of the following conditions: macular hole (MH), subretinal neovascular membrane (SRNVM), and epiretinal membrane proliferation (EMP). This study also aimed to speculate on the pathogenic mechanisms for the observed field defects. DESIGN: Noncomparative case series. PARTICIPANTS: The study included 48 subjects (50 eyes). Twenty-one of the 50 eyes had stage III MH, 13 eyes had SRNVM, and 16 eyes had EMP. TESTING: Goldmann kinetic perimetry was performed postoperatively. MAIN OUTCOME MEASURE: Visual field defects. RESULTS: Nine (18%) of the 50 eyes had visual field defects. Four (19%) of the 21 eyes with MH and 5 (38%) of the 13 eyes with SRNVM had visual field defects. Of the 16 patients who had epiretinal membrane peeling, none had a visual field defect. An air-fluid exchange had been performed in all patients found to have a postvitrectomy field defect. The difference in rate of visual field defects in eyes that had air-fluid exchange (EMP group) was statistically significant (P < 0.05, chi-square). No significant correlation was found between visual field defect and preoperative intraocular pressure, postoperative intraocular pressure, patient's age, and iatrogenic detachment of the vitreous cortex. The field defects identified were altitudinal (2 eyes), baring of the blind spot (1 eye), inferotemporal (3 eyes), inferonasal (2 eyes), and superonasal (1 eye). CONCLUSIONS: Central and peripheral visual field defects may occur after PPV for the treatment of MHs or SRNVMs. Air-fluid exchange procedure was the common denominator in all of the patients found to have visual field deficit. The etiology is likely to be trauma to the optic nerve region during the air-fluid exchange procedure.

Adult↗

PubMed2003

Magnetic resonance-detected subchondral bone marrow and cartilage defect characteristics associated with pain and X-ray-defined knee osteoarthritis.

OBJECTIVE: To assess whether the presence of subchondral bone marrow abnormalities (bone marrow edema (BME)) and cartilage defects, determined by magnetic resonance imaging (MRI), would explain the difference between painful osteoarthritis of the knee (OAK) compared with painless OAK or pain without OAK. METHOD: Four groups of women (30 per group), aged 35-55 years, were recruited from the southeast Michigan Osteoarthritis cohort (group 1: painful OAK; group 2: painless OAK; group 3: knee pain without OAK; and group 4: no OAK or knee pain). OAK was defined by a Kellgren-Lawrence score of 2 or greater, while pain was based on self-report. BME and cartilage defects were identified from MRI. RESULTS: BME lesions were identified in 56% of all knees. BME lesions were four times (95% CI=1.7, 8.7) more likely to occur in the painless OAK group as compared with the group with pain, but no OAK. BME lesions >1cm were more frequent (OR=5.0; 95% CI=1.4, 10.5) in the painful OAK group than all other groups. While the frequency of BME lesions was similar in the painless OAK and painful OAK groups, there were more lesions, >1cm, in the painful OAK group. About 75% of all knees had evidence of some cartilage defect, of which 35% were full-thickness defects. Full-thickness cartilage defects occurred frequently in painful OAK. One-third of knees with full-thickness defects and 47% of knees with cartilage defects involving bone had BME >1cm. Women with radiographic OA, full-thickness articular cartilage defects, and adjacent subchondral cortical bone defects were significantly more likely to have painful OAK than other groups (OR=3.2; 95% CI=1.3, 7.6). CONCLUSION: The finding on MRI of subchondral BME cannot satisfactorily explain the presence or absence of knee pain. However, women with BME and full-thickness articular cartilage defects accompanied by adjacent subchondral cortical bone defects were significantly more likely to have painful OAK than painless OAK.

Adult↗

PubMedDate not supplied

Enhanced accuracy of defect detection by myocardial single-photon emission computed tomography with attenuation correction with gadolinium 153 line sources: evaluation with a cardiac phantom.

BACKGROUND: Photon attenuation is a major cause of artifacts on single-photon emission tomographic imaging. METHODS AND RESULTS: To study a new method to perform photon attenuation correction (AC), we used a cardiac phantom filled with (99m)Tc and imaged it (1) without extrinsic attenuation or defects, (2) with extrinsic attenuation but without defects, (3) without extrinsic attenuation but with defects involving 10% of the myocardial volume and activity ranging from 0% to 75% of maximum, and (4) with both extrinsic attenuation and defects. Transmission and emission images acquired with a dual-head single-photon emission computed tomographic system with 153Gd line sources were processed by iterative maximum-likelihood-expectation-maximization and were evaluated both qualitatively and quantitatively. The small defects were readily identified both before and after AC. Mean count activity (percent of maximal activity) of the segments with overlying extrinsic attenuation but without defects was only 56% +/- 4% without AC but increased to 86% +/- 4% with AC (p < 0.0001). Without AC, the count activities in the defects with overlying extrinsic attenuation were lower than the actual defect activities, but AC resulted in better approximation of actual defect activities in all but the most severe (0% tracer activity) defects. CONCLUSION: This new AC method provided an improved estimation of actual myocardial count activity. Even small defects with mild reduction in tracer activity were still identifiable after AC.

Artifacts↗