Applicability and accuracy of pretest probability calculations implemented in the NICE clinical guideline for decision making about imaging in patients with chest pain of recent onset.

OBJECTIVES: To analyse the implementation, applicability and accuracy of the pretest probability calculation provided by NICE clinical guideline 95 for decision making about imaging in patients with chest pain of recent onset. METHODS: The definitions for pretest probability calculation in the original Duke clinical score and the NICE guideline were compared. We also calculated the agreement and disagreement in pretest probability and the resulting imaging and management groups based on individual patient data from the Collaborative Meta-Analysis of Cardiac CT (CoMe-CCT). RESULTS: 4,673 individual patient data from the CoMe-CCT Consortium were analysed. Major differences in definitions in the Duke clinical score and NICE guideline were found for the predictors age and number of risk factors. Pretest probability calculation using guideline criteria was only possible for 30.8 % (1,439/4,673) of patients despite availability of all required data due to ambiguity in guideline definitions for risk factors and age groups. Agreement regarding patient management groups was found in only 70 % (366/523) of patients in whom pretest probability calculation was possible according to both models. CONCLUSIONS: Our results suggest that pretest probability calculation for clinical decision making about cardiac imaging as implemented in the NICE clinical guideline for patients has relevant limitations. KEY POINTS: • Duke clinical score is not implemented correctly in NICE guideline 95. • Pretest probability assessment in NICE guideline 95 is impossible for most patients. • Improved clinical decision making requires accurate pretest probability calculation. • These refinements are essential for appropriate use of cardiac CT.

Correction to: Applicability and accuracy of pretest probability calculations implemented in the NICE clinical guideline for decision making about imaging in patients with chest pain of recent onset.

The original version of this article, published on 19 March 2018, unfortunately contained a mistake. The following correction has therefore been made in the original: The names of the authors Philipp A. Kaufmann, Ronny Ralf Buechel and Bernhard A. Herzog were presented incorrectly.

The feasibility of transpedicular screw fixation of the subaxial cervical spine in the Arab population: a computed tomography-based morphometric study.

BACKGROUND: Transpedicular screw fixation of the cervical spine provides excellent biomechanical stability. The feasibility of inserting a 3.5-mm screw in the pedicle requires a minimum pedicle diameter of 4.5 mm. This diameter allows at least 0.5 mm bony bridge medially and laterally in order to avoid pedicle violation which can result in neurovascular complications. We aim to evaluate the feasibility of this technique in Arab people since no data are available about this population. MATERIALS AND METHODS: This cross-sectional study involved a retrospective review of computed tomography scans of normal cervical spines of 99 Arab adults. Ten morphometric measurements were obtained. Data were analyzed using a p value of ≤0.05 as the cut-off level of statistical significance. RESULTS: Our sample included 63 (63.6 %) males and 36 (36.4 %) females, with a mean age of 35.5 ± 16.5 years. The morphometric parameters of C3-C7 spine pedicles were larger in males than in females. The outer pedicle width (OPW) was <4.5 mm in >25 % of all subjects at C3-C6 vertebrae. Statistically significant differences in the OPW between males and females were noted at C3 (p = 0.032) and C6 (p = 0.004). CONCLUSIONS: Inserting pedicle screws in the subaxial cervical spine is feasible among the majority of Arab people. LEVEL OF EVIDENCE: Level 3.

Combined ciprofloxacin and amikacin prophylaxis in the prevention of septicemia after transrectal ultrasound guided biopsy of the prostate.

PURPOSE: A steady increase in the incidence of septicemia after prostate biopsy in our unit between 2001 and 2005 prompted us to review our prophylactic antibiotic regimen. We compared the incidence of septicemia in patients undergoing prostate biopsy between 2001 and 2005 when only oral ciprofloxacin was used prophylactically (group 1) to the incidence among patients undergoing biopsy between 2006 and 2010 when a single dose of intravenous amikacin was added to ciprofloxacin (group 2). MATERIALS AND METHODS: In group 1 the 300 patients were given 500 mg oral ciprofloxacin twice daily 1 day before and for 2 days after the biopsy while in group 2 the 897 patients, in addition to the ciprofloxacin previously mentioned, received 500 mg intravenous amikacin 30 minutes before the biopsy. Patients admitted to the hospital with septicemia after prostate biopsy had urine and blood culture and sensitivity tests. The number of patients in whom septicemia developed in each group after prostate biopsy and the microorganisms isolated from the urine and blood of such patients were compared using the chi-square test. RESULTS: Septicemia was seen in 24 of 300 (8%) and 15 of 897 (1.7%) patients in groups 1 and 2, respectively (p <0.001). In group 1 the rate of septicemia after prostate biopsy was 2.1% and 13% in 2001 and 2005, respectively (p <0.001). In group 2 the rate of septicemia was 1.5% in 2006 and 1.6% in 2010 (p <0.25). Escherichia coli resistant to quinolones was responsible for 33 of 39 (84.6%) septicemic cases. CONCLUSIONS: The addition of amikacin to ciprofloxacin prophylaxis significantly reduces the incidence of septicemia after prostate biopsy.

Association of femoral intercondylar notch morphology, width index and the risk of anterior cruciate ligament injury.

PURPOSE: To determine the relationship between femoral notch morphology, femoral notch width index and anterior cruciate ligament tears using magnetic resonance imaging of the knee. METHODS: This retrospective study was conducted on 560 patients who had magnetic resonance imaging (MRI) examinations of the knee between February 2010 and June 2011. Two morphological changes were investigated: the shape of the femoral notch and its width index. The femoral notch shape was classified into one of three types: Type A, which is a narrow (Stenotic) notch that appears narrowed from the base to the midsection as well as at the apex; Type U, in which the midsection does not taper, allowing for a wider contour to the notch than Type A; and Type W, which has the characteristics of Type U but with two apparent apices. The femoral notch width index was calculated as a ratio of central notch width and transcondylar or intercondylar width; values of 0.270 or more were considered as normal and values of 0.269 or less were considered as below normal. These measurements were correlated with the presence or absence of anterior cruciate ligament (ACL) tears. RESULTS: Of 560 patients, there were 280 cases of ACL tear. Of the 560 patients, 240 had a Type A femoral notch shape and 320 had a Type U or W femoral notch shape. Of those with Type A, 73 % (176 patients) had ACL tears, and of those with Type U or W, 32 % (104 patients) had ACL tears. Statistical analysis showed that the Type A notch correlated with ACL injury (p value < 0.0001). The femoral notch width index was low in 37 % (88 subjects) with Type A notch compared with 27.5 % (88 subjects) with Type U or W notches. Of the 280 subjects with ACL tear, only 17 % (48 patients) had a reduced femoral notch index. CONCLUSION: This study showed that the Type A femoral notch appears to be a risk factor for ACL injury, whereas a reduced notch index has no significant correlation to ACL injury. LEVEL OF EVIDENCE: III.

Significance of Virchow-Robin spaces in patients newly diagnosed with multiple sclerosis: a case-control study in an Arab population.

OBJECTIVE: To assess the frequency and extent of dilatation of Virchow-Robin (VR) spaces at three levels of the brain in patients of Arab ethnicity in Kuwait recently diagnosed with multiple sclerosis (MS) and compare the results with age- and gender-matched controls. METHODS: The magnetic resonance imaging (MRI) scans performed within 3 months of the clinical diagnosis of 80 patients recently diagnosed with active MS were compared to those of 80 age- and gender-matched controls with headache but without any neurological deficits for the frequency and size of VR spaces. MRI was done with noncontrast axial and coronal T(1)W FSE, axial T(2)W FSE, axial T(2)W FLAIR and sagittal FLAIR sequences followed by postcontrast axial and coronal T(1)W sequences. The frequency of VR spaces in MS patients and controls at midbrain, lenticulostriate vessels and supraventricular levels was analyzed using a two-tailed McNemar test. RESULTS: There was no difference in the frequency of VR spaces at the levels of the midbrain, lenticulostriate vessels and supraventricular white matter between MS patients and controls. In the supraventricular region, however, there were 91 dilated VR spaces in 26 (32%) of the MS patients while in the control group, there were 8 dilated VR spaces in 6 (7.5%) patients and the difference was statistically significant (p < 0.0001). CONCLUSION: The data showed that dilated VR spaces in the supraventricular region could potentially be used as a marker for MS and as a prognostic tool. However, further studies with a larger population are needed to further evaluate and confirm this observation.

Ossification of ligamentum flavum in Middle East Arabs: a hospital-based study.

OBJECTIVE: To investigate the frequency of ossification of the ligamentum flavum (OLF) in the spine among the Arab population in Kuwait using magnetic resonance imaging (MRI) surveillance of the whole spine. SUBJECTS AND METHODS: A consecutive series of 102 patients with low back pain were recruited from the outpatient clinic of Mubarak Al-Kabeer Hospital, Kuwait. MRI of the whole spine in the sagittal plane was obtained in at least two sequences (T(1) and T(2)). The OLF was defined as low signal intensity thickening of the ligament in both T(1) and T(2) sequences on the posterior margin of the spinal canal, causing indentation of the theca with or without cord compression. RESULTS: Of the 102 cases, 19 (18.6%) patients had OLF. Of the 19 positive cases, 12 (63.2%) were present at a single level, and 7 (36.8%) at multiple levels. A total of 26 OLF segments were identified in the following anatomical distribution: cervical: 15 (57.7%); upper thoracic (T1-T4): 1 (3.8%); mid thoracic (T5-T8): 4 (15.4%); lower thoracic (T9-T12): 4 (15.4%), and lumbar region: 2 (7.7%). Of the 19 OLF patients, 2 (10.5%) had tandem ossification of the posterior longitudinal ligament in the cervical spine and were symptomatic. CONCLUSIONS: The frequency of OLF appears to be high among this hospital-based cohort of the Arab population. OLF should be kept in mind if a patient presents with radiculopathy, particularly in the cervical region, for which surgical intervention is contemplated.

Radiologic features of granulomatous mastitis.

Granulomatous mastitis (GM) is a recognized, but an uncommon cause of breast mass. Awareness of this condition is important, because it can clinically as well as radiologically mimic breast carcinoma. In this study, we present the imaging features of a series of 10 cases with proved diagnosis of granulomatous mastitis with emphasis on magnetic resonance (MR) findings. All those patients who were histologically proven to have GM of the breast were analyzed. Their files were reviewed and data recorded for demographic, clinical presentation and imaging appearances. The imaging features of the lesions by mammography, ultrasound, and magnetic resonance imaging were analyzed. Of the 305 patients who were surgically treated, 10 (3%) cases proved to have GM. All the patients were females with age ranging from 27 to 53 years (average 38 years and median age 36 years). Guided core biopsy was performed in all cases for confirmation of diagnosis followed by either excision biopsy (in five cases) or lumpectomy (in five cases). The final histopathologic results were chronic granulomatous inflammation consistent with tuberculosis in four cases and GM with acute inflammation, but unknown etiology in four cases and GM due to duct ectasia in two cases. GM, a rare breast condition, should be considered in the differential diagnosis of patients with a breast mass associated with inflammatory change. Routine breast imaging with US, MG, or MRI, the condition from malignant lesions and biopsy, still remains the only method of definite diagnosis.

Fat-saturated post gadolinium T1 imaging of the brain in multiple sclerosis.

BACKGROUND: Magnetic resonance imaging (MRI) is of vital importance in the diagnosis and follow-up of patients with multiple sclerosis (MS). Imaging sequences better demonstrating enhancing lesions can help in detecting active MS plaques. PURPOSE: To evaluate the role of fat-saturated gadolinium-enhanced T1-weighted (T1W) images of the brain in MS and to assess the benefit of performing this additional sequence in the detection of enhancing lesions. MATERIAL AND METHODS: In a prospective study over a six-month period, 70 consecutive patients with clinically diagnosed MS were enrolled. These constituted 14 male and 56 female patients between the ages of 21 and 44 years. All the patients underwent brain MRIs on a 1.5 Tesla Magnet. Gadolinium-enhanced T1 images with and without fat saturation were compared and results were recorded and analyzed using a conspicuity score and McNemar test. RESULTS: There were a total of 157 lesions detected in 70 patients on post-contrast T1W fat-saturated images compared with 139 lesions seen on the post-contrast T1W fast spin-echo (FSE) images. This was because 18 of the lesions (11.5%) were only seen on the fat-saturated images. In addition, 15 lesions were more conspicuous on the fat saturation sequence (9.5%). The total conspicuity score obtained, including all the lesions, was 2.24 +/-0.60 (SD). Using the two-tailed McNemar test for quantitative analysis, the P value obtained was <0.0001. CONCLUSION: T1W fat-saturated gadolinium-enhanced images show better lesion enhancement than T1W images without fat saturation.

Percutaneous coblation nucleoplasty in patients with contained lumbar disc prolapse: 1 year follow-up in a prospective case series.

BACKGROUND: Nucleoplasty appears a successful minimally-invasive treatment for symptomatic contained disc herniation (protrusion). The purpose of this prospective study was to assess the effectiveness of nucleoplasty for alleviating pain and dysfunction in our patients. METHOD: All patients who presented with established low back and/or leg pain of at least 3 months' duration were clinically followed for 1 year following the nucleoplasty procedure. Self-reported grading of pain using the Visual Analogue Scale (VAS) and the Roland Morris Disability Questionnaire (RMDQ), and subjective global rating of overall satisfaction were recorded and analysed. RESULTS: Eighty-three patients, aged between 20 and 65 years who were treated with nucleoplasty were included in the study. No complications were noted. At the 12-month-follow-up, the median VAS and RMDQ scores were significantly reduced in the patients who were considered successful (VAS by 6-7 points, RMDQ by 8 points) compared to the patients who were considered failed showing much less reduction. (P = 0.000 in both cases; Mann-Whitney U test.) There was no significant difference in the baseline VAS and RMDQ scores in the two groups. Patients who were considered to have failed the procedure tended to be older. Multi-level disc decompression did not appear to be a risk factor for failure. CONCLUSIONS: This disc decompression procedure was a safe and effective treatment option for carefully selected patients affected by low back and leg pain due to contained disc herniation.

Accuracy of 64-multidetector-row computed tomography in the diagnosis of coronary artery disease.

OBJECTIVES: The aim of this prospective study was to assess the accuracy of 64-multidetector-row computed tomography coronary angiography (CTA) in the diagnosis of coronary artery disease (CAD). PATIENTS AND METHODS: Ninety-two patients suspected of having CAD underwent CTA using a 64-slice CT scanner before a scheduled, conventional coronary angiogram (CCA). Blinded assessment of CTA to detect CAD was performed. The accuracy of CTA in detecting significant stenoses (> or =50%) was compared to CCA. Data analysis was performed on 73 patients because the scans were nondiagnostic in 5 patients and 14 refused to undergo coronary angiography. RESULTS: The CTAs of 21 of these 73 patients were considered as normal; 19 were confirmed on CCA. For the remaining 52 diagnosed as abnormal, 51 were confirmed on CCA. For patient-based analysis, CTA had a sensitivity of 95%, a specificity of 96%, a positive predictive value of 98% and a negative predictive value of 90%. For the whole vessel, the sensitivity of CTA was 60-100%, for all vessels and the specificity was 82-100%. Pooled sensitivity was 92% and pooled specificity was 98%. For the segments, the sensitivity of CTA was 64% or above for all vessels except for the distal left anterior descending artery (40%), mid circumflex artery (50%) and posterior descending artery (60%); the pooled sensitivity was 79%. The specificity for the segments was 82-100% for all vessels and pooled specificity was 94%. CONCLUSION: The sensitivity and specificity for patient-based analysis and for the main coronary vessels were high whereas for the segments, the sensitivity was moderately good, but the specificity was high, confirming that a negative CTA is useful to rule out significant CAD. A coordinated classification system between radiologists and cardiologists is required to eliminate errors in segment classification.

Relative contribution of digital rectal examination and transrectal ultrasonography in interpreting serum prostate-specific antigen values for screening prostate cancer in Arab men.

BACKGROUND: This study was conducted to determine the utility of digital rectal examination (DRE), transrectal ultrasonography (TRUS) and serum prostate-specific antigen (PSA) in the diagnosis of prostate cancer in men in Arabia, an are of the world with a relatively low incidence of this disease. PATIENTS AND METHODS: 329 patients suspected of having prostate cancer on account of raised serum PSA level (>4 ng/ml), DRE or TRUS findings, underwent TRUS-guided prostate biopsy. Raised PSA individually as well as combined, or a lesion suspicious of carcinoma on DRE or TRUS was recorded as PSA(+), DRE(+) or TRUS(+), respectively. The contribution of DRE, TRUS and serum PSA to the diagnosis of prostate cancer was analysed. RESULTS: Of the 329 patients who had prostate biopsies 109 cases (33.1%) had PCa. Of these 109 patients 56 (51%) had DRE(+), 77 (42%) had TRUS(+) and 49 (66%) had both DRE(+) and TRUS(+). Statistical analysis revealed that DRE(+) tripled the probability for cancer. PSA over a range of 10-50 ng/mL demonstrated an increasing cancer probability ranging from 2 to 3 fold. TRUS(+) was only significantly associated with cancer risk if PSA was elevated. The presence of all three factors increased the cancer probability by 6 to 7 fold. CONCLUSION: TRUS findings are dependent on PSA for interpretation while DRE(+) with elevated PSA makes PCa more likely.

Gold nanoparticle and graphene oxide incorporated strontium crosslinked alginate/carboxymethyl cellulose composites for o-nitroaniline reduction and Suzuki-Miyaura cross-coupling reactions.

Self-organized strontium ion crosslinked alginate/carboxymethyl cellulose composite materials with gold nanoparticles (Au-NPs) and graphene oxide (GO) were effectively fabricated using dissipative convective procedures followed by the freeze-drying method. Composite gels were characterized by using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy with Energy dispersive X-ray analysis (SEM-EDAX) and transmission electron microscopy (TEM) analysis. Moreover, thermal, mechanical and rheological properties were also performed to identify their strength and stability. The results revealed that Sr/Alg/CMC/Au and Sr/Alg/CMC/GO/Au composites showed remarkably porous structures with ordered capillaries; rheologically gel-like structures with high mechanical strength. Moreover, composites were tested for the reduction of o-nitroaniline and Suzuki-Miyaura cross-coupling reaction. The Sr/Alg/CMC/GO/Au composite competently reduced the o-nitroaniline within 2min (k=4.86×10-2s-1) with recyclability up to 7 consecutive cycles and also displayed 98% isolated yield (TOF value is 4900h-1) for Suzuki-Miyaura cross-coupling reaction with 6cycles recyclability. This approach of using nanoparticles incorporated composite systems as reusable catalysts opens a door of new materials for various catalytic applications.

Electrochemical determination of an anti-hyperlipidimic drug pitavastatin at electrochemical sensor based on electrochemically pre-treated polymer film modified GCE.

An electrochemically pretreated silver macroporous (Ag MP) multiwalled carbon nanotube modified glassy carbon electrode (PAN-Ag MP-MWCNT-GCE) was fabricated for the selective determination of an anti-hyperlipidimic drug, pitavastatin (PST). The fabricated electrochemical sensor was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The fabricated electrode was employed in quantifying and determining PST through differential pulse adsorptive stripping voltammetry (DPAdSV) and CV. The electrode fabrication proceeded with remarkable sensitivity to the determination of PST. The effect of various optimized parameters such as pH, scan rate (ν), accumulation time (tacc), accumulation potential (Uacc) and loading volumes of Ag MP-MWCNT suspension were investigated to evaluate the performance of synthesized electrochemical sensor and to propose a simple, accurate, rapid and economical procedure for the quantification of PST in pharmaceutical formulations and biological fluids. A linear response of PST concentration in the range 2.0×10-7-1.6×10-6 M with low detection (LOD) and quantification (LOQ) limits of 9.66±0.04 nM and 32.25±0.07 nM, respectively, were obtained under these optimized conditions.

Is fasting a necessary preparation for abdominal ultrasound?

OBJECTIVE: To study the effect of fasting on the technical success of abdominal ultrasound examination. METHODS: In a randomized, prospective study, 150 patients for abdominal ultrasound were divided into two groups of 75 patients each with instructions to fast for six hours or have normal breakfast respectively. RESULT: The technical success of the abdominal ultrasound performed by radiologists blinded to the instruction did not differ significantly between the groups. CONCLUSION: It appears that routine fasting before abdominal ultrasound is not necessary.

CT features in abdominal tuberculosis: 20 years experience.

BACKGROUND: Abdominal tuberculosis (TB) is endemic in the developing world and is reemerging in the West. Since computed tomography (CT) has the ability to demonstrate changes in the peritonium, mesentry, lymphnodes, bowel and solid organs and is being increasingly used for primary evaluation of abdominal conditions, it is important to be familiar with the CT features of the disease. METHODS: CT findings were retrospectively analysed in 49 patients with proved abdominal TB. Patients with genitourinary TB and with AIDS/HIV were not included in the study. RESULTS: Peritoneal involvement was the most common feature (77.5%) with ascites (wet peritonitis) seen in more than half the cases (55.2%). The rest showed peritoneal, mesenteric or omental thickening or mass formation but no ascites (dry peritonitis). Other findings included lymphadenopathy (46.9% mainly of diffuse nature, bowel wall thickening (38%) and solid organ involvement (20.4%). CONCLUSIONS: CT reliably demonstrates the entire range of findings which need interpretation in the light of clinical and laboratory data.

Papillary thyroid carcinoma and its variants in fine needle aspiration smears. A cytomorphologic study with special reference to tall cell variant.

OBJECTIVE: To study the fine needle aspiration (FNA) cytologic features of papillary thyroid carcinoma (PTC) with special reference to its tall cell variant (TCV), which is the most aggressive of the variants. STUDY DESIGN: Fifty-four PTC cases were classified into variants, and the frequency of well-known morphologic criteria was determined. Four parameters were quantitatively analyzed based on a study of 200 consecutive neoplastic follicular cells: shape of cells, color of cytoplasm, intranuclear cytoplasmic inclusion (INCI) and nuclear grooves. RESULTS: The PTC cases included 6 TCV (> or = 30% tall cells), 8 cases with a significant tall cell component (sig. TCC) having 10-29% tall cells, 17 usual variant (UV), 17 follicular variant (FV) and 6 miscellaneous variants. TCV differed significantly from UV and FV in having a higher tall cell count, higher count of cells with reddish cytoplasm and INCI, and higher frequency of cases with lymphocytic infiltration. PTC (with significant tall cell component [TCC]) differed significantly from TCV with regard to tall cell count and lymphocytic infiltration, from UV with respect to tall cell count and monolayered sheets, and from FV with respect to tall cells, INCI, grooved nuclei, acinar formation, fire-flare appearance and giant cells. CONCLUSION: TCV was cytologically distinct from other variants. The biologic behavior of PTC cases with significant TCC, which morphologically seem to be a group intermediate between TCV on the one hand and UV and FV on the other, however, needs to be carefully monitored.

Spinal tuberculosis: CT and MRI feature.

BACKGROUND: Spinal tuberculosis (TB) is perhaps the most clinically important extrapulmonary form of the disease. Early recognition is therefore necessary to minimize residual spinal deformity and/or permanent neurological deficit. We defined the CT and MRI image morphology of spinal TB and correlated the imaging features of these two modalities. METHODS: CT (29 patients) and MRI (11 patients) images were retrospectively analyzed in 30 patients with proved spinal TB. CT and MRI findings were compared in cases with both imaging tests (10 cases). The parameters assessed were the type and extent of bone and soft tissue involvement. RESULTS: The majority of the 30 patients were males (n=18) in the 30-49 year age group (43%). The most common clinical presentation was backache (73.3%) followed by fever (63.3%) and malaise (36.6%). The lumbar spine was the commonest site of the disease (43.3%) followed by the thoracic region (36.6%). A fragmentary type of bone destruction was the most frequent CT feature of the disease (48.2%) followed by the lytic type (24.1%). Intervertebral disc destruction (72%) and paravertebral mass/abscess (65.5%) were other features. Of the 11 patients who had an MRI, contiguous vertebral disease with disc destruction was seen in 10 cases. In 4 patients, there was distant vertebral disease in addition to the disease at the symptomatic site. CONCLUSIONS: MRI offers excellent visualization of the bone and soft tissue components of spinal tuberculosis and helps to identify disease at distant asymptomatic sites. CT is useful in assessing bone destruction, but is less accurate in defining the epidural extension of the disease and therefore its effect on neural structures. MR imaging clearly demonstrated the extent of soft tissue disease and its effect on the theca/cord and foramen in cases with doubtful CT findings.

Individual patient data meta-analysis for the clinical assessment of coronary computed tomography angiography: protocol of the Collaborative Meta-Analysis of Cardiac CT (CoMe-CCT).

BACKGROUND: Coronary computed tomography angiography has become the foremost noninvasive imaging modality of the coronary arteries and is used as an alternative to the reference standard, conventional coronary angiography, for direct visualization and detection of coronary artery stenoses in patients with suspected coronary artery disease. Nevertheless, there is considerable debate regarding the optimal target population to maximize clinical performance and patient benefit. The most obvious indication for noninvasive coronary computed tomography angiography in patients with suspected coronary artery disease would be to reliably exclude significant stenosis and, thus, avoid unnecessary invasive conventional coronary angiography. To do this, a test should have, at clinically appropriate pretest likelihoods, minimal false-negative outcomes resulting in a high negative predictive value. However, little is known about the influence of patient characteristics on the clinical predictive values of coronary computed tomography angiography. Previous regular systematic reviews and meta-analyses had to rely on limited summary patient cohort data offered by primary studies. Performing an individual patient data meta-analysis will enable a much more detailed and powerful analysis and thus increase representativeness and generalizability of the results. The individual patient data meta-analysis is registered with the PROSPERO database (CoMe-CCT, CRD42012002780). METHODS/DESIGN: The analysis will include individual patient data from published and unpublished prospective diagnostic accuracy studies comparing coronary computed tomography angiography with conventional coronary angiography. These studies will be identified performing a systematic search in several electronic databases. Corresponding authors will be contacted and asked to provide obligatory and additional data. Risk factors, previous test results and symptoms of individual patients will be used to estimate the pretest likelihood of coronary artery disease. A bivariate random-effects model will be used to calculate pooled mean negative and positive predictive values as well as sensitivity and specificity. The primary outcome of interest will be positive and negative predictive values of coronary computed tomography angiography for the presence of coronary artery disease as a function of pretest likelihood of coronary artery disease, analyzed by meta-regression. As a secondary endpoint, factors that may influence the diagnostic performance and clinical value of computed tomography, such as heart rate and body mass index of patients, number of detector rows, and administration of beta blockade and nitroglycerin, will be investigated by integrating them as further covariates into the bivariate random-effects model. DISCUSSION: This collaborative individual patient data meta-analysis should provide answers to the pivotal question of which patients benefit most from noninvasive coronary computed tomography angiography and thus help to adequately select the right patients for this test.

Magnetic resonance imaging of the lumbar spine in young arabs with low back pain.

STUDY DESIGN: A prospective study. PURPOSE: To Investigate the prevalence of magnetic resonance imaging (MRI) changes of the lumbar spine in low back pain (LBP) and the associated risk factors in young Arab population. OVERVIEW OF LITERATURE: Studies on the prevalence of MRI findings and their relationship with LBP have been conducted; these have occurred in adult populations in developed countries. The prevalence of MRI changes in the young Arab population with LBP is not known. METHODS: Two hundred and fourteen patients of Arab origin in the 16 to 29 year age group with LBP symptoms underwent MRI examinations. The prevalence of MRI changes in the lumbar spine and associated risk factors were determined and compared to age, race, and gender-matched controls. RESULTS: A majority (64%) of the patients with LBP (138 out of 214) were found to have MRI evidence of degenerative disc disease (DD) compared to 10% (22 out of 214) in the control group. The majority (61%) of patients had multiple level disease, most commonly involving the lowest 2 disc levels. Reduced signal of the disc followed by disc bulge was the most common MRI features seen in the symptomatic subjects. Obesity correlated with MRI prevalence of abnormalities, while activity demonstrated a positive trend. CONCLUSIONS: The MRI prevalence of DD among the young Arab patients with LBP is high when compared to other reports in literature. Obesity correlated with MRI prevalence of abnormalities while activity demonstrated a positive trend.