Canadian Association of Radiologists Journal

To assess the percentage, type, and location of radiology fellowships chosen by graduating Canadian residents between 2009 and 2011.

A short e-mail questionnaire was sent to the radiology program directors at all 16 institutions in Canada that provide English or French residency. The responses were collected between December 6, 2010, and May 20, 2011.

A 75% response rate was observed for the survey: 76%–79% residents were enrolled in radiology fellowship training. In 2009–2010, 72%–73% of residents remained in Canada. This dropped to 51% in 2011. In 2009–2010, 22%–23% of residents chose U.S.-based radiology training. This rose to 49% in 2011. Europe was chosen by 0%–4% of residents: all of whom were French-speaking residents, and all programs were in France. Relatively consistent percentages of radiology residents choose abdominal (19%–30%), cardiac (4%–7%), musculoskeletal (12%–20%), and pediatrics (2%–5%) from year to year. Greater variability was noted in chest (2%–9%), women's imaging (0%–14%), intervention radiology (6%–18%), and neuroradiology (2%–18%). Radiology fellowships in split subspecialties, which were available at a small number of institutions, were chosen by 8%–9% of the residents.

Nearly 4 of 5 residents choose radiology fellowship training. In 2011, there was a 2-fold increase in the number of residents who chose training in the United States. This may be a 1-year outlier but should be observed. A wide range of fellowships were chosen, with consistent numbers in some core fellowships and variability in others year to year. Limited exploration of the rationale for, or employability value of, radiology fellowship choices has been done in Canada. Nearly 1 of 10 residents chose split radiology fellowships, an option limited by availability at few centers. The value of expanding this option is worthy of investigation.

Chondromalacia patellae is a common cause of anterior knee pain in young patients and can be detected noninvasively with magnetic resonance imaging (MRI). The purpose of our study was to evaluate the correlation between subcutaneous fat thickness around the knee joint on axial MRIs as a surrogate marker of obesity, with the presence or absence of chondromalacia patellae.

A retrospective review was conducted of knee MRIs in 170 patients who satisfied the inclusion criteria. Imaging was performed over a 12-month period on a 1.5T MRI system with a dedicated extremity coil. Two radiologists experienced in musculoskeletal imaging assessed each examination in consensus for the presence or absence of chondromalacia patellae and graded positive studies from 0 (absent) to 3 (full cartilage thickness defect). Measurement of subcutaneous knee fat thickness was obtained on the medial aspect of the knee.

MRI findings of chondromalacia patellae were present in 33 patients (19.4%), of which, there were 11 grade 1 lesions (33.3%), 9 grade 2 lesions (27.3%), and 13 grade 3 lesions (39.4%). The mean subcutaneous knee fat thickness was significantly higher in the chondromalacia patellae group for all grades compared with the normal group (P < .001), and there was a significant correlation between subcutaneous knee fat thickness and grades of chondromalacia patellae (R = 0.48 [95% confidence interval, 0.38-0.68]; P < .001). Female patients had thicker subcutaneous knee fat and more severe grades of chondromalacia patellae.

Subcutaneous knee fat thickness as a surrogate marker of obesity was positively associated with the presence and severity of chondromalacia patellae on MRI.

It is important for physicians to be aware of the radiation doses as well as the risks associated with diagnostic imaging procedures that they are ordering.

A survey was administered to patients, medical students, and referring physicians from a number of specialties to determine background knowledge regarding radiation exposure and risk associated with commonly ordered medical imaging tests.

A total of 127 patients, 32 referring physicians, and 30 medical students completed the survey. The majority of patients (92%) were not informed of the radiation risks associated with tests that they were scheduled to receive and had false perceptions about the use of radiation and its associated risks. Physicians and medical students had misconceptions about the use of ionizing radiation in a number of radiologic examinations; for example, 25% and 43% of physicians and medical students, respectively, were unaware that interventional procedures used ionizing radiation, and 28% of physicians were unaware that mammography used ionizing radiation. Computed tomographies and barium studies were thought to be associated with the least ionizing radiation among physicians.

There is a need for educating the public, medical students, and referring physicians about radiation exposure and associated risk so that (1) patients receiving multiple medical imaging tests are aware of the radiation that they are receiving and (2) physicians and future physicians will make informed decisions when ordering such tests to limit the amount of radiation that patients receive and to promote informed consent among patients.

The left ventricle (LV) is routinely assessed with cardiac magnetic resonance imaging (MRI) by using short-axis orientation; it remains unclear whether the right ventricle (RV) can also be adequately assessed in this orientation or whether dedicated axial orientation is required. We used phase-contrast (PC) flow measurements in the main pulmonary artery (MPA) and the ascending aorta (Aorta) as nonvolumetric standard of reference and compared RV and LV volumes in short-axis and axial orientations.

A retrospective analysis identified 30 patients with cardiac MRI data sets. Patients underwent MRI (1.5 T or 3 T), with retrospectively gated cine steady-state free-precession in axial and short-axis orientations. PC flow analyses of MPA and Aorta were used as the reference measure of RV and LV output.

There was a high linear correlation between MPA-PC flow and RV–stroke volume (SV) short axis (r = 0.9) and RV-SV axial (r = 0.9). Bland-Altman analysis revealed a mean offset of 1.4 mL for RV axial and −2.3 mL for RV–short-axis vs MPA-PC flow. There was a high linear correlation between Aorta-PC flow and LV-SV short-axis (r = 0.9) and LV-SV axial (r = 0.9). Bland-Altman analysis revealed a mean offset of 4.8 m for LV short axis and 7.0 mL for LV axial vs Aorta-PC flow. There was no significant difference (P = .6) between short-axis–LV SV and short-axis–RV SV.

No significant impact of the slice acquisition orientation for determination of RV and LV stroke volumes was found. Therefore, cardiac magnetic resonance workflow does not need to be extended by an axial data set for patients without complex cardiac disease for assessment of biventricular function and volumes.

The rate of unsatisfactory samples from ultrasound-guided fine-needle aspirations of thyroid nodules varies widely in the literature. We aimed to evaluate our thyroid ultrasound-guided fine-needle aspiration biopsy technique in the absence of on-site microscopic examination by a pathologist; determine factors that affect the adequacy rate, such as the number of needle passes and needle size; compare our results with the literature; and establish an optimal technique.

We performed a retrospective review of cytopathology reports from 252 consecutive thyroid ultrasound-guided fine-needle aspiration biopsies performed by a radiologist between 2005 and 2010 in our hospital's radiology department. Sample adequacy, the number of needle passes, and needle size were determined. There was an on-site cytologist who prepared slides immediately after fine-needle aspiration but no on-site microscopic assessment of sample adequacy to guide the number of needle passes that should be performed. Cytopathology biopsy reports were classified as either unsatisfactory or satisfactory samples for diagnosis; the latter consisted of benign, malignant, and undetermined diagnoses.

Seventy-seven biopsies were performed with 1 needle pass, 124 with 2 needle passes, and 51 with 3 needle passes. The rates of unsatisfactory biopsies were 33.8%, 23.4% (odds ratio [OR] 0.599 [95% confidence interval {CI}, 0.319-1.123]; P = .110), and 13.7% (OR 0.312 [95% CI, 0.124-0.788]; P = .014), respectively.

In a hospital in which there is no on-site pathologist, a 3-pass method increases the specimen satisfactory rate by 20% compared with 1 pass, achieves similar rates to the literature, and provides a basis for further improvement of our practice.

In a previous publication, it was revealed that a disturbingly high incidence of adult fingers were seen on pediatric intensive care unit radiographs, an example of inappropriate occupational exposure to diagnostic radiation. The present study examined adult fingers seen on neonatal intensive care unit (NICU) radiographs to assess the frequency of this occupational radiation exposure. During this study, we encountered an unexpected issue. The inappropriately exposed fingers appeared on the raw images but were sometimes cropped during technologist image processing before being sent to the picture archiving and communication system (PACS) for interpretation. Our audit describes the frequency of cropping adult fingers from images before display on PACS, with the intent of unmasking this source of occupational radiation exposure, of which quality assurance personnel may not be aware.

At the x-ray workstation, the raw NICU source x-ray images were analysed for the visibility of adult fingers and then were compared with the final processed images sent to PACS by the x-ray technologist.

Of 230 radiographs audited, 30 (13%) contained fingers directly in the x-ray beam that remained visible on PACS, 22 (10%) contained fingers in the direct beam that were cropped before being sent to PACS for analysis, and 44 (19%) contained fingers in the coned area.

A significant number of adult fingers are being exposed to radiation during the acquisition of NICU radiographs. Cropping NICU radiographs before sending them to PACS can conceal a significant source of occupational radiation exposure.

The purpose of our study was to describe the salient magnetic resonance imaging (MRI) findings in primary intraspinal peripheral primitive neuroectodermal tumour (PNET).

A retrospective review of the clinical and MRI images of 7 pathologically proven cases of intraspinal peripheral PNETs was performed. The various parameters, such as vertebral level of involvement; tumour location, size, focality, and margin; signal intensity of the lesion; the presence of hemorrhage or calcification; any signal voids; assessment of the adjacent cord for cord compression; cord dilatation; the presence of paraspinal tissue mass; or vertebral or other bony changes, were analysed.

All 7 patients had lesions in the thoracolumbar region. Three patients had extradural lesions, 4 had intradural extramedullary lesions, and none had intramedullary lesions. Six lesions were well circumscribed. Only 1 patient had multifocal involvement. All lesions were of hypointense or isointense signal on T1-weighted imaging, whereas all but one were hyperintense on T2-weighted imaging. Lesions enhanced heterogeneously except 1 intradural extramedullary lesion, which enhanced homogeneously. A paraspinal mass was noticed in 2 patients. Vertebral collapse was present in 1 patients.

Intraspinal peripheral PNETs are rare spinal tumours. Although imaging characteristics are not specific, a focal circumscribed lesion in a young individual at the intramedullary, extramedullary intradural, or extradural spinal location that shows hypointense and hyperintense signal on T1- and T2-weighted images, respectively, requires PNET to be considered in the differentials.

Global absence of cerebral circulation is an important ancillary test for brain death when the diagnosis cannot be confirmed clinically. A number of imaging methods are available to assess cerebral circulation; however, new techniques are sought to improve on limitations of the current tests. Dynamic computed tomographic angiography (dCTA) is a novel technique that enables dynamic noninvasive imaging of cerebral blood flow.

We present the use of dCTA in 3 cases as a corroboratory tool to diagnose brain death. Analysis of our findings suggest that it is a reliable technique for demonstrating the lack of intracranial blood flow, with many advantages over other current methods.

A dCTA may be used to reliably demonstrate the lack of cerebral blood flow in patients with suspected brain death.

To determine the frequency of arm port catheter fracture and embolization related to the Cook Vital Port Mini Titanium.

A retrospective audit of our Cerner Radiology Information System was performed between June 1, 2006, and June 30, 2011, to determine the number of Cook arm venous ports implanted and the frequency of foreign body retrievals related to catheter fracture for these arm ports.

A total of 691 arm implantations of the Cook Vital Port during the 5-year time frame were analysed. Eleven of these patients (1.6%) required intravenous foreign body retrieval in the interventional radiology suite related to catheter fracture and embolization. Three of these fractured catheters were retrieved from the peripheral venous system upstream of the pulmonary circulation, whereas 8 embolized to the pulmonary arteries. All were successfully extracted with an intravenous snare by interventional radiology.

We discovered a 1.6% frequency of catheter fracture and embolization associated with arm implantation of the Cook Vital Port. All the catheters fractured at the vein entry site and did not detach from the port housing. The cause for catheter fracture and embolization is uncertain. Pulmonary embolization of the fractured catheters puts the patients at risk for possible further complications. No patients had ancillary complications related to catheter embolization or to catheter extraction procedures. Further investigation is required in an attempt to determine the circumstances that may result in catheter fracture and embolization related to this venous access device.