Canadian Association of Radiologists Journal

To explore resource utilization through evaluation of computed tomography (CT) imaging trends in the emergency department by examining common indications/outcomes for imaging in this setting.

A retrospective analysis of clinical indications/outcomes for all CT imaging in 3 emergency departments over a 1-year period was conducted. Scans were divided by body part and the most common indications for each type of scan were determined. Clinical outcomes from each study were extracted from final interpretations by the reporting radiologist.

A total of 4556 CT scans were performed in the emergency department over a 1-year period. A total of 3.6% of all-comers to our emergency departments underwent CT scan as part of their investigation. There were 2107 head CTs (46%), 1296 (28%) abdominal CTs, 468 (10%) CTs of the chest, 408 (9%) CTs of the neck/spine, and 101 (2%) extremity CTs performed. The most common clinical indication for performing a CT head was focal neurological defect comprising 1534 (73%) of all CT heads. Twenty-four percent of abdominal CTs were for investigation of right lower quadrant pain, followed by flank pain (19%). Chest pain and shortness of breath were the most common indications for CTs of the chest (315 [75%]) with 10% of these examinations for this indication positive for pulmonary embolism. Trauma was the most common indication for neck CTs (296 [73%]) and extremities (70 [69%]). Nil acute was the most common final interpretation in all categories (79% CT heads, 75% neck CTs, 38% abdominal CTs, 43% chest CTs).

Nil acute was the most common diagnosis; however, serious clinical outcomes were identified 40% of the time. Cross-sectional imaging remains an integral tool for triage and diagnosis in this environment as the cost of missing a diagnosis in this setting has a great impact on patient care.

The concept of “advanced polyps” is well accepted and is defined as polyps ≥10 mm and/or those having a villous component and/or demonstrating areas of dysplasia. Of these parameters, computed tomography colonography (CTC) can only document size. The accepted management of CTC-detected “advanced polyps” is to recommend excision if feasible, whereas the management of “intermediate” (6–9 mm) polyps is more controversial, and interval surveillance may be acceptable. Therefore, distinction between 6-9 mm and ≥10 mm is important.

Datasets containing 26 polyps originally reported as between 8-12 mm in diameter were reviewed independently by 4 CTC-accredited radiologists. Observers tabulated the largest measurement for each polyp on axial, coronal, sagittal, and endoluminal views at lung-window settings. These measurements were also compared to those determined by the computer-aided detection (CAD) software.

The interobserver reliability intra-class correlation coefficient (ICC) for sagittal projection was 0.80 (“excellent” category of Hosmer and Lemeshow [2004]), 0.71 for axial (“acceptable”), 0.69 for coronal, and 0.41 for endoluminal (“unacceptable”). The largest of sagittal/axial/coronal measurement gave the best reliability with the smallest variance (ICC = 0.80; 95% CI 0.67–0.89). For 8 of 26 polyps, at least one radiologist's measurement placed the polyp in a different category compared to a colleague. For the majority of the polyps, the CAD significantly overestimated the readings compared to the largest of the manual measurements with an average difference of 1.6 mm (P < .0001 for sagittal/axial/coronal). This resulted in 33% of polyps falling into a different category—10% were lower and 23% were higher (P < .034).

It is apparent that around the cutoff point of 10 mm between “advanced” and “intermediate” polyps, interobserver performance is variable.

To determine the incidence of malignancy, follow-up ultrasound (US), and repeat fine needle aspiration (FNA) in thyroid nodules that have been previously biopsied as benign.

This is a retrospective, descriptive study of benign thyroid nodules evaluated by US between 2010-2011. We determined the frequency of follow-up ultrasounds and FNAs, mean years of follow-up, interval between follow-up US, change in nodule size, reasons for repeat FNA (rFNA), frequency of thyroidectomy, and thyroid malignancy during 5 years of follow-up.

A total of 733 benign thyroid nodules were reviewed in 615 patients. Mean years of US follow-up was 3.47 ± 1.65 years; 275 (37.5%) had no follow-up US; 109 (14.9%) had 1 follow-up US; 93 (12.7%) had 2 follow-up US; and 256 (34.9%) had 3 or more follow-up US. Assessment of thyroid nodule size showed that 215 (28.8%) nodules decreased in size, 145 (19.4%) increased in size by less than 50%, and 91 (12.1%) increased in size by more than 50%. Of the 733 nodules, 17 nodules (2.3%) underwent thyroidectomy for which the pathology result of 9 (1.2%) showed malignancy, and 65 (8.9%) thyroid nodules underwent rFNA. When applying the 2015 recommendations for repeat FNA, 35% were done unnecessarily.

In our sample of initially benign thyroid nodules, only 9 patients (1.2%) had pathology-proven malignancy after a mean follow-up of 3.5 years. Over 30% of patients had more than 3 rUSs. Decreased interval and frequency of rUS should be considered in future guidelines for thyroid management.

Thyroid ultrasound has been widely used to determine which nodules need further investigation. The goal of this study is to determine if using an ultrasonographic features checklist based on 2015 American Thyroid Association (ATA) guidelines can improve reporting and decrease unnecessary further testing.

In this retrospective study, ultrasonographic images of all nodules biopsied at our institution in 2014 and 2015 were reviewed by radiologists blinded to fine needle aspiration (FNA) biopsy result using a checklist. The checklist was prepared based on 2015 ATA guidelines. The ultrasonographic characteristics of thyroid nodules were compared with the result of biopsy to determine positive predictive value (PPV), negative predictive value (NPV), sensitivity, and specificity for predicting malignancy. Radiologists also made an overall recommendation on need for FNA.

A total of 425 thyroid nodule ultrasound scans were reviewed by radiologists. Biopsy results of 31 nodules were malignant and 394 were non-malignant. Malignant nodules showed higher frequency of solid composition, hypoechoechogenicity, and cervical lymph node involvement compared to benign nodules. Solid nodule composition had the highest PPV (13%) and NPV (94.7%). Extra-thyroid extension had the highest specificity (90.1%). Lesion vascularity had the highest sensitivity (83.8%), followed by hypoechogenicity (65.6%). Overall, the checklist had a positive predictive value of 9%, negative predictive value of 97.5%, sensitivity of 96.8%, and specificity of 11.14%. Radiologists determined that 10% of the nodules were very low-risk and did not require FNA.

Using a checklist based on 2015 ATA guideline thyroid nodule ultrasonographic features is a sensitive tool with high NPV to predict benign thyroid nodule, thereby preventing unnecessary FNAs.

3-D printing is an increasingly widespread technology that allows physical models to be constructed based on cross-sectional medical imaging data. We sought to develop a pipeline for production of 3-dimensional (3-D) models for presurgical planning and assess the value of these models for surgeons and patients.

In this institutional review board–approved, single-center case series, participating surgeons identified cases for 3-D model printing, and after obtaining patient consent, a 3-D model was produced for each of the 7 participating patients based on preoperative cross-sectional imaging. Each model was given to the surgeon to use during the surgical consent discussion and preoperative planning. Patients and surgeons completed questionnaires evaluating the quality and usefulness of the models.

The 3-D models improved surgeon confidence in their operative approach, influencing the choice of operative approach in the majority of cases. Patients and surgeons reported that the model improved patient comprehension of the surgery during the consent discussion, including risks and benefits of the surgery. Model production time was as little as 4 days, and the average per-model cost was $350.

3-D printed models are useful presurgical tools from both surgeon and patient perspectives. Development of local hospital-based 3-D printing capabilities enables model production with rapid turnaround and modest cost, representing a value-added service for radiologists to offer their surgical colleagues.

To assess the applicability of magnetic resonance imaging (MRI) to complement ultrasound in the diagnosis of fetal urinary tract anomalies.

This was a retrospective cohort study that included 41 women between 19 weeks and 37 weeks and 6 days of gestation carrying fetuses with malformations of the urinary tract which were initially diagnosed by ultrasound and then referred for MRI. In all cases, the diagnosis was confirmed after birth either through imaging or autopsy. A surface coil was positioned over the abdomen and T2-weighted sequences were obtained in the axial, coronal, and sagittal planes; T1 in at least one plane; and three-dimensional (3-D) TRUFI in fetuses with dilatation of the urinary tract.

Mean gestational age at the time of MRI examination was 28.21 weeks. The rapid T2 sequences allowed all the anomalies of the fetal urinary tract to be assessed, whereas 3-D TRUFI sequencing proved very useful in evaluating anomalies involving dilatation of the urinary tract. The signs of pulmonary hypoplasia characterized by hypointense signal in the T2-weighted sequences were identified in 13 of the 41 fetuses.

MRI confirmed and added information to the ultrasound regarding fetal urinary tract anomalies, as well as information related to the other associated malformations, their progress in the prenatal period, and possible postnatal prognosis.

In suspected spondylodiscitis and vertebral osteomyelitis, computed tomography (CT)-guided biopsies are often performed to determine a causative organism and guide antimicrobial therapy. The aim of this study is to determine the diagnostic culture yield of CT-guided biopsies performed in cases of suspected spinal infections.

A literature search of PubMed and MEDLINE up to April 2017 was performed for keywords “CT guided vertebral biopsy infection,” “CT-guided spine biopsy infection,” “CT guided spine biopsy yield,” and “CT guided vertebral biopsy yield.” Inclusion criteria primarily consisted of studies exclusively using CT-guided biopsies in cases of suspected infectious lesions only. After study selection, published articles were analysed to determine diagnostic culture yield. Descriptive statistics were applied.

220 search results were screened; 11 met our inclusion criteria and were reviewed. In total, 647 biopsies of suspected infectious spinal lesions were performed. Positive cultures were obtained in 241 cases. Upon excluding one paper's skewed results, the net pooled results culture yield was 33%. Several cultures grew multiple organisms, leading to a total of 244 species identified. Most common isolated organisms include Staphylococcus aureus (n = 83), coagulase-negative Staphylococcus (n = 45), and Mycobacteria (n = 38).

The diagnostic culture yield of CT-guided biopsies in cases of suspected spinal infection is 33%. In the majority of cases, a causative organism is not identified. This suggests that improvements can be made in biopsy technique and specimen transfer to optimize culture yield and increase the clinical value of the procedure.