Canadian Association of Radiologists Practice Guidelines for Computed Tomography Colonography.

Colon cancer is the third most common malignancy in Canada. Computed tomography colonography (CTC) provides a creditable and validated option for colon screening and assessment of known pathology in patients for whom conventional colonoscopy is contraindicated or where patients self-select to use imaging as their primary modality for initial colonic assessment. This updated guideline aims to provide a toolkit for both experienced imagers (and technologists) and for those considering launching this examination in their practice. There is guidance for reporting, optimal exam preparation, tips for problem solving to attain high quality examinations in challenging scenarios as well as suggestions for ongoing maintenance of competence. We also provide insight into the role of artificial intelligence and the utility of CTC in tumour staging of colorectal cancer. The appendices provide more detailed guidance into bowel preparation and reporting templates as well as useful information on polyp stratification and management strategies. Reading this guideline should equip the reader with the knowledge base to perform colonography but also provide an unbiased overview of its role in colon screening compared with other screening options.

Diagnostic Performance and Interreader Agreement of the MRI Clear Cell Likelihood Score for Characterization of cT1a and cT1b Solid Renal Masses: An External Validation Study.

BACKGROUND. The clear cell likelihood score (ccLS) has been proposed for the noninvasive differentiation of clear cell renal cell carcinoma (ccRCC) from other renal neoplasms on multiparametric MRI (mpMRI), though further external validation remains needed. OBJECTIVE. The purpose of our study was to evaluate the diagnostic performance and interreader agreement of the ccLS version 2.0 (v2.0) for characterizing solid renal masses as ccRCC. METHODS. This retrospective study included 102 patients (67 men, 35 women; mean age, 56.9 ± 12.8 [SD] years) who underwent mpMRI between January 2013 and February 2018, showing a total of 108 (≥ 25% enhancing tissue) solid renal masses measuring 7 cm or smaller (83 cT1a [≤ 4 cm] and 25 cT1b [> 4 cm and ≤ 7 cm]), all with a histologic diagnosis. Three abdominal radiologists independently reviewed the MRI examinations using ccLS v2.0. Median reader sensitivity, specificity, and accuracy were computed for predicting ccRCC by ccLS of 4 or greater, and individual reader AUCs were derived. The percentage of masses that were ccRCC was calculated, stratified by ccLS. Interobserver agreement was assessed by the Fleiss kappa statistic. RESULTS. The sample included 45 ccRCCs (34 cT1a, 11 cT1b), 30 papillary renal cell carcinomas (RCCs), 13 chromophobe RCCs, 14 oncocytomas, and six fat-poor angiomyolipomas. Median reader sensitivity, specificity, and accuracy for predicting ccRCC by ccLS of 4 or greater were 85%, 82%, and 83% among cT1a masses and 82%, 100%, and 92% among cT1b masses. The three readers' AUCs for predicting ccRCC by ccLS for cT1a masses were 0.90, 0.84, and 0.89 and for cT1b masses were 0.99, 0.97, and 0.92. Across readers, the percentage of masses that were ccRCC among cT1a masses was 0%, 0%, 20%, 68%, and 93% for ccLS of 1, 2, 3, 4, and 5, respectively; among cT1b masses, the percentage of masses that were ccRCC was 0%, 0%, 32%, 90%, and 100% for ccLS of 1, 2, 3, 4, and 5, respectively. Interobserver agreement among cT1a and cT1b masses for ccLS of 4 or greater was 0.82 and 0.83 and for ccLS of 1-5 overall was 0.65 and 0.62, respectively. CONCLUSION. This study provides external validation of the ccLS, finding overall high measures of diagnostic performance and interreader agreement. CLINICAL IMPACT. The ccLS provides a standardized approach to the noninvasive diagnosis of ccRCC by MRI.

US LI-RADS Visualization Score: Interobserver Variability and Association With Cause of Liver Disease, Sex, and Body Mass Index.

OBJECTIVES: To evaluate the interobserver agreement between radiologists using the Ultrasound Liver Reporting And Data System (US LI-RADS) visualization score and assess association between visualization score and cause of liver disease, sex, and body mass index (BMI). METHODS: This retrospective, single institution, cross-sectional study evaluated 237 consecutive hepatocellular carcinoma surveillance US examinations between March 4, 2017 and September 4, 2017. Five abdominal radiologists independently assigned a US LI-RADS visualization score (A, no or minimal limitations; B, moderate limitations; C, severe limitations). Interobserver agreement was assessed with a weighted Kappa statistic. Association between US visualization score (A vs B or C) and cause of liver disease, sex, and BMI (< or ≥ 25 kg/m2) was evaluated using univariate and multivariate analyses. RESULTS: The average weighted Kappa statistic for all raters was 0.51. A score of either B or C was assigned by the majority of radiologists in 148/237 cases and was significantly associated with cause of liver disease (P = 0.014) and elevated BMI (P < 0.001). Subjects with viral liver disease were 3.32 times (95% CI: 1.44-8.38) more likely to have a score of A than those with non-alcoholic steatohepatitis (P = 0.007). The adjusted odds ratio of visualization score A was 0.249 (95% CI: 0.13-0.48) among those whose BMI was ≥25 kg/m2 vs. BMI < 25 kg/m2. CONCLUSION: Interobserver agreement between radiologists using US LI-RADS score was moderate. The majority of US examinations were scored as having moderate or severe limitations, and this was significantly associated with non-alcoholic steatohepatitis and increased BMI.

Insulinoma presenting as hypoglycemia during lactose tolerance testing: a case report.

BACKGROUND: Insulinoma is a rare functioning pancreatic endocrine tumor, typically presenting as a sporadic solitary lesion causing hypoglycemia. While these tumors can lead to marked autonomic and neuroglycopenic symptoms, the diagnosis is often delayed. CASE PRESENTATION: We present a case of a 60-year-old Caucasian man presenting with a 1-year history of progressive episodic confusion and an unexpected finding of symptomatic hypoglycemia during a lactose tolerance test. Further inquiry revealed an 8-year history of more subtle episodic neuroglycopenic symptoms preceding his presentation. After additional biochemical testing suggested a diagnosis of insulinoma, abdominal imaging was performed and revealed a 1.2-cm tumor in the tail of the pancreas. Following laparoscopic resection of the tumor, the patient had complete resolution of his symptoms and maintained normal glucose levels. CONCLUSIONS: The clinical presentation of functioning pancreatic neuroendocrine tumors can be subtle and nonspecific. As such, clinicians should remain vigilant for insulinoma when symptomatic hypoglycemia is present. To our knowledge, this is the first report of an insulinoma found after hypoglycemia was detected during lactose tolerance testing.

Comparison of Objective Image Quality Metrics to Expert Radiologists' Scoring of Diagnostic Quality of MR Images.

Image quality metrics (IQMs) such as root mean square error (RMSE) and structural similarity index (SSIM) are commonly used in the evaluation and optimization of accelerated magnetic resonance imaging (MRI) acquisition and reconstruction strategies. However, it is unknown how well these indices relate to a radiologist's perception of diagnostic image quality. In this study, we compare the image quality scores of five radiologists with the RMSE, SSIM, and other potentially useful IQMs: peak signal to noise ratio (PSNR) multi-scale SSIM (MSSSIM), information-weighted SSIM (IWSSIM), gradient magnitude similarity deviation (GMSD), feature similarity index (FSIM), high dynamic range visible difference predictor (HDRVDP), noise quality metric (NQM), and visual information fidelity (VIF). The comparison uses a database of MR images of the brain and abdomen that have been retrospectively degraded by noise, blurring, undersampling, motion, and wavelet compression for a total of 414 degraded images. A total of 1017 subjective scores were assigned by five radiologists. IQM performance was measured via the Spearman rank order correlation coefficient (SROCC) and statistically significant differences in the residuals of the IQM scores and radiologists' scores were tested. When considering SROCC calculated from combining scores from all radiologists across all image types, RMSE and SSIM had lower SROCC than six of the other IQMs included in the study (VIF, FSIM, NQM, GMSD, IWSSIM, and HDRVDP). In no case did SSIM have a higher SROCC or significantly smaller residuals than RMSE. These results should be considered when choosing an IQM in future imaging studies.

Percutaneous native renal biopsy adequacy: a successful interdepartmental quality improvement activity.

BACKGROUND: An adequate renal biopsy is essential for diagnosis and treatment of medical renal disease. OBJECTIVE: We evaluated two initiatives to improve adequacy of renal biopsy samples at our centre. DESIGN: Retrospective determination of renal biopsy adequacy. SETTING: Queen Elizabeth II Health Sciences Centre. PATIENTS: Patients undergoing medical renal biopsies. MEASUREMENTS: Renal biopsy adequacy. METHODS: The first initiative was to restrict the performance of biopsies to a smaller group of radiologists and to include a comment on biopsy adequacy in every pathology report. The second initiative was to introduce on-site adequacy assessment by a medical laboratory technologist. Native renal and allograft biopsy adequacies were calculated for three periods: 1) baseline, October 2005 to September 2006; 2) after implementation of the first initiative, January 2007 to September 2011; and 3) after implementation of the second initiative, October 2011 to September 2012. A subset of native renal biopsies was examined to determine if there was a relationship between adequacy and number of passes. RESULTS: The percentages of adequate native renal biopsies during the first, second, and third periods were 31%, 72% and 90%, respectively. This represents a significant increase (40%, p < 0.0001) in adequacy following the first initiative, and another significant increase (18%, p = 0.0003) following the second initiative. The percentages of adequate renal allograft biopsies during the first, second, and third periods were 75%, 56% and 69%, respectively. These changes in adequacy were not statistically significant. In the subset of native renal biopsies examined, a biopsy comprising more than three cores was not associated with increase in adequacy. LIMITATIONS: The most important limitation is the lack of generally accepted and applied adequacy criteria limiting generalizability of our findings. CONCLUSIONS: Restricting the performance of biopsies to subspecialist operators, including an adequacy statement in the renal biopsy report and on-site adequacy assessment were effective in significantly improving native renal biopsy adequacy. This improvement appeared unrelated to an increase in the number of passes taken with a biopsy needle. Neither initiative improved the low adequacy of allograft biopsies.

CONTEXTE: L'importance que joue la biopsie percutanée dans le diagnostic et le traitement des maladies rénales est un fait bien connu. Un spécimen adéquat est nécessaire pour une interprétation correcte des résultats. La surveillance de la qualité de biopsie reste une pratique importante de contrôle de la qualité. OBJECTIF DE L'ÉTUDE: Deux initiatives visant une meilleure qualité des échantillons rénaux pour la biopsie ont été évaluées à notre centre. TYPE D'ÉTUDE: Détermination rétrospective de la qualité de la biopsie rénale. CONTEXTE: Le Queen Elizabeth II Health Sciences Centre. PATIENTS: Patients subissant des biopsies rénales. MESURES: Qualité de la biopsie rénale. MÉTHODES: La première initiative visait à restreindre la réalisation des biopsies à un petit groupe de radiologues et d'ajouter un commentaire sur la qualité de la biopsie dans chaque rapport de pathologie. La deuxième initiative visait à implanter l'évaluation de cette qualité sur place, par l'intermédiaire d'un technicien de laboratoire médical. La qualité des biopsies de reins natifs et d'allogreffes ont été calculées en trois temps : 1) mesure de référence: d'octobre 2005 à septembre 2006; 2) après l'implantation de la première initiative, de janvier 2007 à septembre 2011; 3) après l'implémentation de la deuxième initiative, d'octobre 2011 à septembre 2012. Un sous-ensemble de biopsies effectuées sur des reins natifs a été examiné afin de déterminer s'il existait un lien entre la qualité et le nombre de ponctions. RÉSULTATS: Les pourcentages d'une qualité adéquate des biopsies de reins natifs des trois phases étaient de 31%, 72% et 90%, respectivement. On remarque des hausses de la qualité des biopsies importantes après la première initiative (40%, p < 0,0001) et après la deuxième (18%, p = 0,0003). Les pourcentages d'une qualité adéquate des biopsies d'allogreffes rénales des trois étapes étaient de 75%, 56% et 69%, respectivement; ces changements n'étaient pas statistiquement significatifs. Dans le sous-ensemble des biopsies de reins natifs, celles de plus de trois échantillons n'étaient pas associées avec une hausse de la qualité. LIMITES DE L'ÉTUDE: Parmi les limites de l'étude, on compte les données lacunaires concernant : les complications postopératoires; l'analyse détaillée des caractéristiques des radiologistes avant et après la première intervention; certaines données permettant de mesurer l'effet de la deuxième intervention indépendamment de son lien avec la première intervention; un consensus sur les critères de la qualité des biopsies de reins natifs et d'allogreffes rénales à des fins de comparaisons entre les différentes institutions, et qui s'est répercuté sur la généralisabilité de nos résultats (provenant d'un seul centre) à d'autres établissements. Le manque de puissance statistique a limité la possibilité de détecter certaines différences entre les sous-groupes. CONCLUSIONS: La restriction de la réalisation des biopsies par une sous-spécialité, l'ajout d'un commentaire sur la qualité de la biopsie rénale dans le rapport, et l'évaluation sur place de la qualité ont eu l'effet d'améliorer de façon significative la proportion de biopsies rénales natives avec une qualité adéquate. Cette amélioration ne semble pas liée à une hausse du nombre de ponctions faites avec une aiguille à biopsie. Aucune des initiatives n'a amélioré la basse qualité des biopsies d'allogreffes.

Surgical therapy of a large pancreatic solid-pseudopapillary neoplasm during pregnancy.

Solid-pseudopapillary neoplasms (SPNs) of the exocrine pancreas are rare, accounting for only 2% of pancreatic tumours. These tumours predominantly affect women during the second and third decades of life. They frequently present with vague symptoms and can pose a diagnostic challenge. Surgical resection remains the treatment of choice that can cure up to 95% of patients when negative resection margins are obtained. SPNs diagnosed during pregnancy are exceptional and with profound implications on the mother and fetus. The authors present a case of an asymptomatic SPN in a 24-year-old woman diagnosed at 14 weeks of gestation on a routine prenatal ultrasound. Distal pancreatectomy, splenectomy and cholecystectomy were successfully performed at 18 weeks of gestation. A healthy full-term male child was born 5 months following surgery without complications.

Live liver donors' risk thresholds: risking a life to save a life.

BACKGROUND: There is still some controversy regarding the ethical issues involved in live donor liver transplantation (LDLT) and there is uncertainty on the range of perioperative morbidity and mortality risks that donors will consider acceptable. METHODS: This study analysed donors' inclinations towards LDLT using decision analysis techniques based on the probability trade-off (PTO) method. Adult individuals with an emotional or biological relationship with a patient affected by end-stage liver disease were enrolled. Of 122 potential candidates, 100 were included in this study. RESULTS: The vast majority of participants (93%) supported LDLT. The most important factor influencing participants' decisions was their wish to improve the recipient's chance of living a longer life. Participants chose to become donors if the recipient was required to wait longer than a mean ± standard deviation (SD) of 6 ± 5 months for a cadaveric graft, if the mean ± SD probability of survival was at least 46 ± 30% at 1 month and at least 36 ± 29% at 1 year, and if the recipient's life could be prolonged for a mean ± SD of at least 11 ± 22 months. CONCLUSIONS: Potential donors were risk takers and were willing to donate when given the opportunity. They accepted significant risks, especially if they had a close emotional relationship with the recipient.

Pathophysiology, epidemiology, classification and treatment options for polycystic liver diseases.

Polycystic liver diseases (PLD) represent a group of genetic disorders in which cysts occur in the liver (autosomal dominant polycystic liver disease) or in combination with cysts in the kidneys (autosomal dominant polycystic kidney disease). Regardless of the genetic mutations, the natural history of these disorders is alike. The natural history of PLD is characterized by a continuous increase in the volume and the number of cysts. Both genders are affected; however, women have a higher prevalence. Most patients with PLD are asymptomatic and can be managed conservatively. Severe symptoms can affect 20% of patients who develop massive hepatomegaly with compression of the surrounding organs. Rrarely, patients with PLD suffer from acute complications caused by the torsion of hepatic cysts, intraluminal cystic hemorrhage and infections. The most common methods for the diagnosis of PLD are cross sectional imaging studies. Abdominal ultrasound and computerized tomography are the two most frequently used investigations. Magnetic resonance imaging is more sensitive and specific, and it is a valuable test for patients with intravenous contrast allergies or renal dysfunction. Different treatment modalities are available to physicians caring for these patients. Medical treatment has been ineffective. Percutaneous sclerotherapy, trans-arterial embolization, cyst fenestration, hepatic resection and liver transplantation are indicated to specific groups of patients and have to be tailored according to the extent of disease. This review outlines the current knowledge of the pathophysiology, clinical course, diagnosis and treatment strategies of PLD.

Biliary stent therapy for dominant strictures in patients affected by primary sclerosing cholangitis.

The diagnosis and the treatment of dominant strictures (DS) in patients with primary sclerosing cholangitis (PSC) is challenging and the scientific literature on the subject is quite limited. Only level II and level III evidence is available to guide physicians managing patients with DS and PSC. For the diagnosis, intraductal endoscopic ultrasound is the most sensitive (64%) and specific (95%) test. However, the majority of cases require a combination of several different diagnostic tests, as there is no single investigation that can rule out malignancy in this group of patients. For the treatment, serial endoscopic or percutaneous dilatations provide 1- and 3-year biliary duct patency in 80 and 60% of patients, respectively. Dilatation and stenting are the most common interventions, although the optimal duration of treatment has still not been clearly defined. Bile duct resection and/or bilioenteric bypass are currently indicated only for patients with preserved liver function. For all other patients, benign DS can be treated with endoscopic dilatation with short-term stenting. This approach is effective and safe and does not increase the risk of malignant transformation or complications for liver transplant candidates. During the last decade, the use of self-expandable metallic stents for benign diseases has become an innovative option. The aim of this article is to review the diagnostic and therapeutic strategies for patients affected by PSC and DS with specific emphasis on the outcomes of patients treated with temporary stents.

Histological percutaneous diagnosis of stage IV microcystic serous cystadenocarcinoma of the pancreas.

Malignant serous cystic neoplasms (SCN) of the pancreas are exceptionally rare, and only a few cases have been reported. As a result, SCN have been unanimously classified as benign tumours. Contrary to this conviction, in 1989, George et al published the very first case of a patient found to have a malignant pancreatic SCN. Up to the time of the submission of this paper, 27 cases of serous cystoadenocarcinomas have been published. In all the previously published cases of malignant SCN, the correct diagnosis was made postoperatively or at the time of autopsy. The authors present a case of a 68-year-old patient who was incidentally found to have a large liver mass on transthoracic echocardiogram ordered for suspected coronary artery insufficiency. Subsequent investigations revealed an additional large mass in the pancreas and percutaneous biopsies of both lesions revealed histological features consistent with malignant SCN metastasised to the left hepatic lobe.

A rare grade III symptomatic Tsunoda class III left lobe hepatolithiasis in a North American woman.

A 44-year-old Caucasian woman without any identified predisposing factors, presented to her local emergency room with multiple episodes of recurrent ascending cholangitis. She underwent a laparoscopic cholecystectomy several years prior to her admission to the hospital for parenteral antibiotic therapy and she had no personal or family history of hypercholesterolaemia. Transferred to a tertiary hospital for surgical therapy, she underwent a left hepatic resection for a chronically infected left lobe hepatolithiasis (HL) conditioning atrophy of the parenchyma due to obstruction of the biliary tree by multiple large cholesterol stones. HL is a very rare condition in Western countries and its aetiology and predisposing factors are still unclear. We present her symptomatology, diagnostic and therapeutic management and discuss the epidemiology and risk factors of HL, that is, a common condition in South East Asia while exceptional in Caucasian patients who have not travelled in high-prevalence regions.

Liver abscess caused by toothpick and treated by laparoscopic left hepatic resection: case report and literature review.

Hepatic abscesses caused by ingested foreign bodies have been reported in the medical literature but represent very uncommon events. Extra-luminal migration of sawing needles and pins is the most common cause of perforation of the gastrointestinal tract associated with liver infections. Other non-metallic sharp objects such as animal bones and toothpicks have been described but are less frequent. The authors present a case of a 45-year-old woman who suffered from sepsis and a liver abscess because of the migration of a toothpick that lodged in the left hepatic lobe. Review of the literature on the pathogenesis and clinical management of liver abscesses caused by ingested foreign is presented.

Intra and extra-hepatic cystadenoma of the biliary duct. Review of literature and radiological and pathological characteristics of a very rare case.

Painless obstructive jaundice is often associated with a malignant disease of the common bile duct or head of the pancreas. The authors present a unique case of a 62-year-old woman affected by an intrahepatic cystadenoma that extended into the common biliary duct. To our knowledge no previous case reports have been published on similar cases. After undergoing an en-block hepatic and bile duct resection, this patient is doing well without signs of recurrent disease.

Do family physicians request ultrasound scans appropriately?

OBJECTIVE: To review family physicians' requests for abdominal, thyroid, pelvic, soft tissue, and carotid ultrasound (US) scans, and to determine whether 5% or more of these tests were not clearly indicated based on the clinical history provided. DESIGN: Analysis of 620 randomly chosen requests for US scans. SETTING: The Radiology Department at the Capital District Health Authority in Halifax, NS, between October 1, 2008, and June 30, 2009. PARTICIPANTS: Two radiologists and 2 family physicians with clinical expertise and familiarity with the Canadian Association of Radiologists' 2005 guidelines. MAIN OUTCOME MEASURES: Whether US requests were "indicated," "not clearly indicated," or "not legible" according to the Canadian Association of Radiologists' 2005 guidelines. Those that were illegible were discarded and replaced. Results More than 5% of requests for abdominal, thyroid, or carotid US scans were not clearly indicated. The percentages of requests for pelvic and soft tissue scans that were not clearly indicated were not significant. The reviewers found only 5 illegible request forms. Percentages of abdominal, thyroid, and carotid US scans not clearly indicated were 12.1%, 18.8%, and 25.2%, respectively. Reasons for inappropriate US requests included the following: wrong tests (3.2%), vague clinical questions (4.8%), and unfocused examinations (4.8%) for abdominal scans; wrong tests (3.2%), vague clinical questions (3.2%), unnecessary investigations (5.6%), and unnecessary follow-up examinations (5.6%) for thyroid scans; and unnecessary tests (10.5%), vague clinical questions (5.6%), and unnecessary tests for "dizziness" (10.5%) for carotid scans. CONCLUSION: More than 5% of the abdominal, thyroid, and carotid US scans requested by family physicians were not clearly indicated based on the clinical history provided. Common trends in requesting these examinations reinforce the need to improve guidelines for requesting scans and for managing many presenting complaints in family practice.