Differential Diagnosis of Colonic Strictures: Pictorial Review With Illustrations from Computed Tomography Colonography.

Strictures of the colon can lead to significant morbidity requiring surgical management. The etiology of strictures is broad and generally categorized as benign, malignant, or pseudostrictures. Computed tomography (CT) is a crucial imaging modality in the assessment and characterization of colonic pathologies but colonoscopy remains the diagnostic gold standard. However, in the setting of incomplete colonoscopy due to strictures, the imaging features of CT will be relied on. This review will focus on the CT features of different colon pathologies leading to strictures and will be illustrated with images from 10 years of experience with CT colonography at our institutions from 2002-2012 (Hotel Dieu Hospital, Queen's University and Mount Sinai Hospital, University of Toronto).

The assessment of anemia from attenuation values of cranial venous drainage on unenhanced computed tomography of the head.

OBJECTIVE: To determine if prediction of anemia is possible from quantitative analyses of unenhanced cranial computed tomography (CT) images. METHODS: A retrospective chart review revealed 101 patients who had hemoglobin and hematocrit levels obtained within 24 hours of an unenhanced cranial CT. Regions of interest were the place on the torcular Herophili (confluence of sinuses) and the left and right transverse sinuses. Attenuation values were correlated with hemoglobin and hematocrit to investigate any possible relationship. RESULTS: Hemoglobin levels were correlated with torcular and transverse sinus attenuation levels. For every 10 Hounsfield unit (HU) increase in torcular attenuation, hemoglobin levels increased by 16.3 g/L (P < .001). When subgroup analysis was performed, by sex, for every 10 HU increase in torcular attenuation, hemoglobin levels increased by 22.6 g/L (P < .001) in men and 8.96 g/L (P < .05) in women. CONCLUSION: The attenuation values for venous drainage on unenhanced cranial CT constitute a practical adjunct in the assessment of anemia. Given the number of individuals undergoing CT without blood work, this rapid assessment technique for anemia is a convenient means for narrowing possible diagnoses.

Posterior fossa measurements in patients with and without Chiari I malformation.

PURPOSE: To determine if there is a correlation between cerebellar tonsillar descent in patients with and without Chiari I malformation and three skull morphometric measurements: clivus length, anteroposterior diameter of the foramen magnum, and Boogard's angle. METHODS: Cerebellar tonsillar descent, clivus length, anteroposterior diameter of the foramen magnum, and Boogard's angle were measured in mid-sagittal T1-weighted magnetic resonance images of 188 patients. The study included 81 patients with Chiari I malformations (CMI). Without identifiable pathology, 107 patients served as a comparison group. Two-sample t-tests were used to assess for significance. A Pearson correlation matrix was constructed to assess the strength of linear dependence between measured parameters for the study population. RESULTS: A negative correlation was found between tonsillar herniation and clivus length (r = -0.30, P < 0.001), while a positive correlation was found between tonsillar herniation and foramen magnum size (r = 0.15, P = 0.0431), and Boogard's angle (r = 0.23, P = 0.0014). Clivus length was shorter (P = 0.0009) in CMI patients (4.02 cm ± 0.45) than comparison patients (4.23 cm ± 0.42). In addition, the anteroposterior diameter of the foramen magnum was wider (P = 0.0412) (3.74 cm ± 0.40 compared to 3.63 ± 0.30) and Boogard's angle was larger (P = 0.0079) (123.58 degrees ± 8.27 compared to 120.62 degrees ± 6.79) with CMI. CONCLUSION: A greater degree of cerebellar tonsillar herniation is associated with a shorter clivus length, a wider anteroposterior diameter of foramen magnum, and a wider Boogard's angle.

Delayed recovery in patients with whiplash-associated disorders.

BACKGROUND: Prognosis of whiplash injury has been found to be related to a number of sociodemographic, treatment and clinical factors. In the current study, we attempt to identify several novel prognostic factors for delayed recovery in whiplash-associated disorders (WADs), using a validated and reliable measure of recovery. PATIENTS AND METHODS: Retrospective review of a large database of a national network of physiotherapy and rehabilitation service providers in Canada yielded 5581 individuals injured in motor vehicle collisions. Cases were grouped into 3 cohorts based on time lapsed between injury date and initial presentation. Acute (n=3075), early chronic (n=958) and chronic (n=1548) patient cohorts were compared regarding treatment outcome and relative distribution of 29 prognostic factors. Outcome was defined by a minimally important clinical change (10%) on a previously validated disability questionnaire between initial and discharge rehabilitation visits. RESULTS: Analysis demonstrated positive outcomes to be proportionally fewer in the chronic cohort (52.1%) relative to the early chronic (61.4%), which was in turn lower than the acute cohort (72.3%). Furthermore, individuals presenting with chronic pain were more likely to: (1) be female; (2) present with lower limb pain or nonorganic signs; (3) have returned to work; (4) have retained a lawyer; or (5) have undergone previous spinal surgery, and were less likely to: (1) present with neck or midback pain; (2) live in Ontario or Nova Scotia; or (3) have modified duties upon return to work. Acute, early chronic and chronic cohorts were also found to differ in the distribution of several other prognostic factors at initial clinical visit. CONCLUSIONS: Recovery in whiplash-associated disorder appears to be multifactorial with both medical and non-injury related factors influencing outcome. Further characterisation of these factors may prove invaluable in guiding future clinical treatment and referral practices.

Nontuberculous mycobacterial breast implant infections.

BACKGROUND: For reasons that are unclear, the incidence of nontuberculous mycobacterial disease is increasing worldwide. Periprosthetic nontuberculous mycobacterial infections following augmentation mammaplasty and breast reconstruction have been reported previously in the form of case reports. METHODS: This retrospective case series examines periprosthetic nontuberculous mycobacterial infections in two western Canadian cities (Edmonton, Alberta, and Vancouver, British Columbia) over a 10-year time period. RESULTS: Ten patients were identified, four of whom had bilateral infections. The most common isolate was Mycobacterium fortuitum. Clinical features were similar to nonmycobacterial periprosthetic infections. The median time to onset of symptoms was 4.5 weeks and the median time to culture an organism was 5.4 weeks. The median duration of antibiotic therapy was 22 weeks. Patients required a mean of three additional operations after diagnosis. Nine patients underwent explantation of the involved implant(s). Reimplantation was performed in six patients a median of 11.5 months after explantation. All cases of reimplantation were successful. CONCLUSIONS: Experience with this postoperative complication is limited, as nontuberculous mycobacteria represent a minority of the pathogens responsible for periprosthetic infections. In the absence of specific features with which to identify patients at risk, the surgeon must be aware of the possibility of this infection. To achieve earlier diagnosis, the clinician should have a high index of suspicion in a patient with delayed onset of symptoms, negative preliminary cultures, and a periprosthetic infection that fails to resolve following a course of conventional antimicrobial treatment. With appropriate treatment, nontuberculous mycobacterial periprosthetic infections can be managed successfully.

Prognostic factors associated with minimal improvement following acute whiplash-associated disorders.

STUDY DESIGN: Retrospective clinical cohort study. OBJECTIVE: To identify the prognostic factors associated with a poor response to treatment in the early stages of a whiplash-associated disorder (WAD). SUMMARY OF BACKGROUND DATA: Several demographic and clinical factors related to recovery following acute WADs have been identified. However, few longitudinal studies have investigated a multivariable model of recovery that includes socio-demographic, treatment, clinical, and nonclinical factors. METHODS: A study cohort of 2,185 patients with acute or subacute WADs presenting to 48 rehabilitation clinics in 6 Canadian provinces were investigated for factors associated with failure to demonstrate a minimally important clinical change (10%) in the Canadian Back Institute Questionnaire (CBIQ) score between the initial and discharge rehabilitation visits. RESULTS: Multivariable analysis revealed eight prognostic factors associated with a negative outcome: 1) older age, 2) female gender, 3) increasing lag time between injury date and presentation for treatment, 4) initial pain location, 5) province of injury, 6) higher initial pain intensity, 7) lawyer involvement, and 8) at work at entry to the clinic. The effect of lawyer involvement was stronger for patients with less intense pain on initial visit (odds ratio = 2.97; 95% confidence interval, 1.77-4.99). Similarly, the effect of work status was stronger for patients with less intense pain on initial visit (odds ratio = 2.02; 95% confidence interval, 1.18-3.46). CONCLUSIONS: Researchers and clinicians should be aware of the potential for non-injury-related factors to delay recovery, and be aware of the interaction between the initial intensity of a patient's pain and other covariates when confirming these results.

The impact of non-injury-related factors on disability secondary to whiplash associated disorder type II: a retrospective file review.

BACKGROUND: There is evidence to suggest that Whiplash Associated Disorders (WADs) are influenced by physical trauma and psychosocial factors, as well as by medicolegal and compensation systems. OBJECTIVE: To investigate the impact of noninjury related variables on self-reported disability at initial assessment among patients presenting with WAD type II injuries. DESIGN AND SETTING: We reviewed a total of 1101 consecutive files of patients presenting to a single chiropractor's office in British Columbia, Canada. We included those who met the inclusion criteria. We extracted demographic variables and noninjury related information from 33 eligible patient files. We calculated correlations between variables and created a multivariable linear regression model to evaluate their relative associations with Neck Disability Index (NDI) scores on presentation. RESULTS: Higher NDI scores on initial assessment correlated with female sex (r = 0.40, P =.02), a greater number of subsequent treatments (r = 0.44, P =.01), a higher number of providers seen before presentation (r = 0.40, P =.02), and most strongly with the involvement of a lawyer (r = 0.73, P <.01). A multivariable linear regression model found that only female sex (P =.03) and the involvement of a lawyer (P =.01) remained significantly associated with higher NDI scores on presentation (adjusted R2 = 0.68 for the model). Female sex was associated with a 10-point increase in NDI scores on presentation (beta coefficient = 10.5; 95% confidence interval [CI] 2.8-18.2), and involvement of a lawyer was associated with a 15-point increase in NDI scores on presentation (beta coefficient = 14.9; 95% CI 5.0-24.7). CONCLUSION: Our analysis of WAD type II patients in receipt of compensation found that higher self-reported disability on initial assessment was associated with female sex and in particular by retaining a lawyer. Large prospective studies are needed to establish the validity of these findings.