International Journal of Surgery Case Reports, 2022
Introduction and importance Although foreign bodies are a rare cause of gastrointestinal tract pe... more Introduction and importance Although foreign bodies are a rare cause of gastrointestinal tract perforation, they may serve as a nidus for hepatic abscess. Abdominal pain is the most common presenting symptom. We present a case of an ingested pen causing duodenal perforation and hepatic abscess several months after initially presenting with a pericardial effusion. Case presentation A 59-year-old female living in an intensive tertiary mental health facility was noted to have an incidental pericardial effusion during work-up for hyponatremia. Seven months later, she developed a new fever and was noted to have interval increase in the pericardial effusion size. This prompted further investigation which finally revealed that an ingested pen had perforated through the first part of the duodenum and caused an abscess in the left lobe of the liver. The pericardial effusion was presumed secondary to local inflammation. Upon discovery of the abscess, the patient underwent successful operative management including abscess drainage, foreign body extraction, and duodenal repair. Clinical discussion Reports of hepatic abscess from foreign body causing duodenal perforation are rare, with bone fragments and toothpicks the most common foreign bodies implicated. There is one other previously reported case of an ingested pen. Abdominal pain is present in up to 85% of cases, but fever may be the only presenting symptom. Conclusion Foreign body migration causing a hepatic abscess may present non-specifically with unexplained fever or even pericardial effusion. Psychiatric comorbidities may contribute to delays in diagnosis due to difficulties recalling the episode of ingestion.
Disease presented to the Emergency Department with abdominal discomfort localized to the left upp... more Disease presented to the Emergency Department with abdominal discomfort localized to the left upper quadrant (LUQ). The discomfort was described as an aching pain of 8/10 severity, periodically radiating to the back. The pain had been present 23 days before ...
Objectives: Overdiagnosis is arguably the greatest challenge in the management of men with prosta... more Objectives: Overdiagnosis is arguably the greatest challenge in the management of men with prostate cancer. Multi-parametric (mp)-MRI prior to prostate biopsy may have a role in ruling-in and ruling-out clinically significant disease. Patients and Methods: 114 consecutive men at risk of prostate cancer with previous biopsy underwent mp-MRI prior to transrectal ultrasound (TRUS)-guided biopsies. Standard systematic biopsies were carried out with targeting to suspicious areas. Results: 59.6% had cancer detected by TRUS-guided biopsy. Mean age was 63.6 years (SD 9.0). If men had not been biopsied because of a negative mp-MRI, 21% (24/114) with no cancer and 5% (6/114) with clinically insignificant cancer could have avoided a biopsy. However, 4% (4/114) would have been advised to defer a biopsy that demonstrated the presence of clinically significant cancer. Conclusion: mp-MRI may have a role in ruling-in and ruling-out clinically significant prostate cancer in men at risk prior to biopsy.
Canadian Urological Association journal = Journal de l'Association des urologues du Canada, Jan 6, 2018
The natural history of prostatic lesions identified on multiparametric magnetic resonance imaging... more The natural history of prostatic lesions identified on multiparametric magnetic resonance imaging (mpMRI) is largely unknown. We aimed to describe changes observed over time on serial MRI. All patients with ≥2 MRI studies between 2008 and 2015 at our institution were identified. MRI progression was defined as an increase in Prostate Imaging Reporting and Data System (PI-RADS; version 2) or size of existing lesions, or the appearance of a new lesion PIRADS ≥4. Patients on active surveillance (AS) were analyzed for correlation of MRI progression to biopsy reclassification. A total of 83 patients (54 on AS and 29 for diagnostic purposes) underwent serial MRI, with a mean interval of 1.9 years between scans. At baseline, 115 lesions (66 index, 49 non-index) were identified. Index lesions were more likely than non-index lesions to increase in size ≥2 mm (36.2 vs. 7.3 %; p=0.002). Overall progression was more likely to be seen among the index cohort (34.8 vs. 7.6%; p<0.001). New lesion...
AJR. American journal of roentgenology, Jan 8, 2017
The purpose of this article is to review the general principles, technique, and clinical applicat... more The purpose of this article is to review the general principles, technique, and clinical applications of contrast-enhanced ultrasound of the liver. Proper technique and optimization of contrast-enhanced ultrasound require a balance between maintaining the integrity of the microbubble contrast agent and preserving the ultrasound signal. Established and emerging applications in the liver include diagnosis of focal lesions, aiding ultrasound-guided intervention, monitoring of therapy, and aiding surgical management.
AJR. American journal of roentgenology, Jan 5, 2017
Neurocutaneous syndromes are a heterogeneous group of multisystemic disorders. We review the mult... more Neurocutaneous syndromes are a heterogeneous group of multisystemic disorders. We review the multimodality imaging findings in the disorders with a propensity for intraabdominal disease. We highlight more recently recognized disease patterns and discuss imaging surveillance optimization. Knowledge of varied intraabdominal phenotypic expressions can increase diagnostic rates. Limitation of radiation dose must be considered in screening this tumor-prone population. Early detection of neoplastic findings is critical for morbidity and mortality reduction.
Canadian Association of Radiologists journal = Journal l'Association canadienne des radiologistes, 2017
Magnetic resonance imaging (MRI) has a well-established role as a highly specific and accurate mo... more Magnetic resonance imaging (MRI) has a well-established role as a highly specific and accurate modality for characterizing benign and malignant focal liver lesions. In particular, contrast-enhanced MRI using hepatocyte-specific contrast agents (HSCAs) improves lesion detection and characterization compared to other imaging modalities and MRI techniques. In this pictorial review, the mechanism of action of gadolinium-based MRI contrast agents, with a focus on HSCAs, is described. The clinical indications, protocols, and emerging uses of the 2 commercially available combined contrast agents available in the United States, gadoxetate disodium and gadobenate dimeglumine, are discussed. The MRI features of these agents are compared with examples of focal hepatic masses, many of which have been obtained within the same patient therefore allowing direct lesion comparison. Finally, the pitfalls in the use of combined contrast agents in liver MRI are highlighted.
To determine whether multiparametric magnetic resonance imaging (MRI) of the prostate (mpMRI) com... more To determine whether multiparametric magnetic resonance imaging (MRI) of the prostate (mpMRI) combined with MRI fusion technology during transrectal ultrasound-guided biopsy can enhance the detection of significant disease in patients with apparent low-risk prostate cancer on active surveillance (AS). We reviewed the charts of 603 patients on AS for localized prostate cancer between January 2006 and September 2013. mpMRI before repeat transrectal ultrasound-guided biopsy was obtained in 111 patients, of whom 69 underwent subsequent fusion biopsy (39 true and 30 cognitive) in addition to standard template biopsy. The results of fusion biopsy were compared with the standard biopsy. The primary endpoint was termination of AS. mpMRI detected 118 suspicious lesions in 70 patients (63%). Of these, 42 patients (60%) had lesions with Prostate imaging, reporting, and data system (PIRADS) score 3, and 28 patients (40%) had PIRADS score 4 or 5 lesions. AS was terminated in 27 (24.3%) of the 11...
Canadian Association of Radiologists Journal, 2013
The purpose of this pictorial review is to illustrate the various imaging findings of extrapulmon... more The purpose of this pictorial review is to illustrate the various imaging findings of extrapulmonary tuberculosis. Manifestations of cardiac, central nervous system, head and neck, musculoskeletal, abdominal, genitourinary, and breast tuberculosis will be discussed. Extrapulmonary tuberculosis presents a difficult diagnostic challenge for the radiologist and requires a high index of suspicion, particularly in high-risk populations.
To document the existing radiology services available to emergency physicians in hospitals across... more To document the existing radiology services available to emergency physicians in hospitals across Canada and to preview future trends and needs. Questionnaires (n = 130) regarding the type, availability and satisfaction with radiology services were distributed to radiologists and emergency physicians at 65 hospitals across Canada. Fifty-three (41%) questionnaires were returned, and 45 (35%) completed questionnaires from 35 hospitals were used for analysis (24 from radiologists and 21 from emergency physicians). Plain radiographs were available in all hospitals at all times. Ultrasonography, intravenous pyleograms and computed tomography (CT) were available in all departments during normal working hours; after hours, CT was unavailable in 1 hospital and ultrasonography was unavailable in 2. Focused assessment with sonography for trauma (FAST) was routinely performed for blunt abdominal trauma in 6 centres, and 10 centres had teleradiology services. Regarding the quality of emergency service, 7 of 45 responded &amp;amp;quot;poor,&amp;amp;quot; 4 &amp;amp;quot;average,&amp;amp;quot; 14 &amp;amp;quot;good,&amp;amp;quot; and 17 of 45 rated service &amp;amp;quot;excellent.&amp;amp;quot; Interestingly, most radiologists answered &amp;amp;quot;good&amp;amp;quot; or &amp;amp;quot;excellent,&amp;amp;quot; and most of the &amp;amp;quot;poor&amp;amp;quot; responses came from emergency physicians. Regarding staff coverage after 5 pm, 34 hospitals provided CT services, 20 had ultrasonography staff available, and there was radiology nursing coverage in 14 hospitals. Clinical details on requisitions were generally rated &amp;amp;quot;adequate&amp;amp;quot; or &amp;amp;quot;poor.&amp;amp;quot; Although most radiograph reports were available within 48 hours, some took longer. Hot-seat reporting was available in 11 centres. During normal working hours, radiologists were the first to read films in 5 of 35 hospitals. After hours, emergency physicians were the first to read films in all hospitals, but only 14 hospitals indicated they were &amp;amp;quot;formally&amp;amp;quot; trained to do so. This survey documents the strengths and weaknesses of the radiology services available to emergency physicians. The perceptions of emergency physicians and radiologists of the adequacy those services differ significantly.
In many patients, the diagnosis of SBO can often be made by a combination of clinical history, ph... more In many patients, the diagnosis of SBO can often be made by a combination of clinical history, physical examination and plain radiographs. However, in many cases, the diagnosis of SBO may be difficult. Abdominal radiographs are limited in their ability to diagnose SBO and, more particularly, to identify a specific underlying cause. Although barium studies, ultrasonography and magnetic resonance imaging may all play a role in the evaluation of SBO, CT should be the examination of choice for most patients when the diagnosis and underlying cause of SBO is unclear. It may help differentiate pseudo-obstruction from true obstruction, and a specific underlying cause can often be determined. Signs of closed-loop obstruction, strangulation, perforation or infarction may be detected and allow for more timely and appropriate surgical management. We advocate the use of CT in any patient with SBO where the cause or diagnosis is unclear. We have attempted to demonstrate a range of clinical cases ...
Annals of hepatology: official journal of the Mexican Association of Hepatology
Acoustic Radiation Force Impulse Imaging (ARFI) is a novel non invasive technique studying the lo... more Acoustic Radiation Force Impulse Imaging (ARFI) is a novel non invasive technique studying the localized mechanical properties of tissue by utilising short, high intensity acoustic pulses (shear wave pulses) to assess the mechanical response (tissue displacement), providing a measure of tissue elasticity. The aim of this study is to investigate the feasibility of ARFI imaging as a non-invasive method for the assessment of liver fibrosis compared to liver biopsy scores. A prospective blind comparison study of ARFI elastography (Virtual Touch Imaging., ACUSON S2000 Ultrasound Unit, Siemens, Mountain View CA) in a consecutive series of patients who underwent liver biopsy for assessment of fibrosis in chronic liver disease. ARFI shear-wave propagation velocity was measured in meters per second. Mean ARFI velocities were compared with both Batts-Ludwig (F0 to F4) and Modified Ishak scores (F0 to F4) for fibrosis in liver biopsy findings. Twenty-one patients with chronic liver disease (He...
International Journal of Surgery Case Reports, 2022
Introduction and importance Although foreign bodies are a rare cause of gastrointestinal tract pe... more Introduction and importance Although foreign bodies are a rare cause of gastrointestinal tract perforation, they may serve as a nidus for hepatic abscess. Abdominal pain is the most common presenting symptom. We present a case of an ingested pen causing duodenal perforation and hepatic abscess several months after initially presenting with a pericardial effusion. Case presentation A 59-year-old female living in an intensive tertiary mental health facility was noted to have an incidental pericardial effusion during work-up for hyponatremia. Seven months later, she developed a new fever and was noted to have interval increase in the pericardial effusion size. This prompted further investigation which finally revealed that an ingested pen had perforated through the first part of the duodenum and caused an abscess in the left lobe of the liver. The pericardial effusion was presumed secondary to local inflammation. Upon discovery of the abscess, the patient underwent successful operative management including abscess drainage, foreign body extraction, and duodenal repair. Clinical discussion Reports of hepatic abscess from foreign body causing duodenal perforation are rare, with bone fragments and toothpicks the most common foreign bodies implicated. There is one other previously reported case of an ingested pen. Abdominal pain is present in up to 85% of cases, but fever may be the only presenting symptom. Conclusion Foreign body migration causing a hepatic abscess may present non-specifically with unexplained fever or even pericardial effusion. Psychiatric comorbidities may contribute to delays in diagnosis due to difficulties recalling the episode of ingestion.
Disease presented to the Emergency Department with abdominal discomfort localized to the left upp... more Disease presented to the Emergency Department with abdominal discomfort localized to the left upper quadrant (LUQ). The discomfort was described as an aching pain of 8/10 severity, periodically radiating to the back. The pain had been present 23 days before ...
Objectives: Overdiagnosis is arguably the greatest challenge in the management of men with prosta... more Objectives: Overdiagnosis is arguably the greatest challenge in the management of men with prostate cancer. Multi-parametric (mp)-MRI prior to prostate biopsy may have a role in ruling-in and ruling-out clinically significant disease. Patients and Methods: 114 consecutive men at risk of prostate cancer with previous biopsy underwent mp-MRI prior to transrectal ultrasound (TRUS)-guided biopsies. Standard systematic biopsies were carried out with targeting to suspicious areas. Results: 59.6% had cancer detected by TRUS-guided biopsy. Mean age was 63.6 years (SD 9.0). If men had not been biopsied because of a negative mp-MRI, 21% (24/114) with no cancer and 5% (6/114) with clinically insignificant cancer could have avoided a biopsy. However, 4% (4/114) would have been advised to defer a biopsy that demonstrated the presence of clinically significant cancer. Conclusion: mp-MRI may have a role in ruling-in and ruling-out clinically significant prostate cancer in men at risk prior to biopsy.
Canadian Urological Association journal = Journal de l'Association des urologues du Canada, Jan 6, 2018
The natural history of prostatic lesions identified on multiparametric magnetic resonance imaging... more The natural history of prostatic lesions identified on multiparametric magnetic resonance imaging (mpMRI) is largely unknown. We aimed to describe changes observed over time on serial MRI. All patients with ≥2 MRI studies between 2008 and 2015 at our institution were identified. MRI progression was defined as an increase in Prostate Imaging Reporting and Data System (PI-RADS; version 2) or size of existing lesions, or the appearance of a new lesion PIRADS ≥4. Patients on active surveillance (AS) were analyzed for correlation of MRI progression to biopsy reclassification. A total of 83 patients (54 on AS and 29 for diagnostic purposes) underwent serial MRI, with a mean interval of 1.9 years between scans. At baseline, 115 lesions (66 index, 49 non-index) were identified. Index lesions were more likely than non-index lesions to increase in size ≥2 mm (36.2 vs. 7.3 %; p=0.002). Overall progression was more likely to be seen among the index cohort (34.8 vs. 7.6%; p<0.001). New lesion...
AJR. American journal of roentgenology, Jan 8, 2017
The purpose of this article is to review the general principles, technique, and clinical applicat... more The purpose of this article is to review the general principles, technique, and clinical applications of contrast-enhanced ultrasound of the liver. Proper technique and optimization of contrast-enhanced ultrasound require a balance between maintaining the integrity of the microbubble contrast agent and preserving the ultrasound signal. Established and emerging applications in the liver include diagnosis of focal lesions, aiding ultrasound-guided intervention, monitoring of therapy, and aiding surgical management.
AJR. American journal of roentgenology, Jan 5, 2017
Neurocutaneous syndromes are a heterogeneous group of multisystemic disorders. We review the mult... more Neurocutaneous syndromes are a heterogeneous group of multisystemic disorders. We review the multimodality imaging findings in the disorders with a propensity for intraabdominal disease. We highlight more recently recognized disease patterns and discuss imaging surveillance optimization. Knowledge of varied intraabdominal phenotypic expressions can increase diagnostic rates. Limitation of radiation dose must be considered in screening this tumor-prone population. Early detection of neoplastic findings is critical for morbidity and mortality reduction.
Canadian Association of Radiologists journal = Journal l'Association canadienne des radiologistes, 2017
Magnetic resonance imaging (MRI) has a well-established role as a highly specific and accurate mo... more Magnetic resonance imaging (MRI) has a well-established role as a highly specific and accurate modality for characterizing benign and malignant focal liver lesions. In particular, contrast-enhanced MRI using hepatocyte-specific contrast agents (HSCAs) improves lesion detection and characterization compared to other imaging modalities and MRI techniques. In this pictorial review, the mechanism of action of gadolinium-based MRI contrast agents, with a focus on HSCAs, is described. The clinical indications, protocols, and emerging uses of the 2 commercially available combined contrast agents available in the United States, gadoxetate disodium and gadobenate dimeglumine, are discussed. The MRI features of these agents are compared with examples of focal hepatic masses, many of which have been obtained within the same patient therefore allowing direct lesion comparison. Finally, the pitfalls in the use of combined contrast agents in liver MRI are highlighted.
To determine whether multiparametric magnetic resonance imaging (MRI) of the prostate (mpMRI) com... more To determine whether multiparametric magnetic resonance imaging (MRI) of the prostate (mpMRI) combined with MRI fusion technology during transrectal ultrasound-guided biopsy can enhance the detection of significant disease in patients with apparent low-risk prostate cancer on active surveillance (AS). We reviewed the charts of 603 patients on AS for localized prostate cancer between January 2006 and September 2013. mpMRI before repeat transrectal ultrasound-guided biopsy was obtained in 111 patients, of whom 69 underwent subsequent fusion biopsy (39 true and 30 cognitive) in addition to standard template biopsy. The results of fusion biopsy were compared with the standard biopsy. The primary endpoint was termination of AS. mpMRI detected 118 suspicious lesions in 70 patients (63%). Of these, 42 patients (60%) had lesions with Prostate imaging, reporting, and data system (PIRADS) score 3, and 28 patients (40%) had PIRADS score 4 or 5 lesions. AS was terminated in 27 (24.3%) of the 11...
Canadian Association of Radiologists Journal, 2013
The purpose of this pictorial review is to illustrate the various imaging findings of extrapulmon... more The purpose of this pictorial review is to illustrate the various imaging findings of extrapulmonary tuberculosis. Manifestations of cardiac, central nervous system, head and neck, musculoskeletal, abdominal, genitourinary, and breast tuberculosis will be discussed. Extrapulmonary tuberculosis presents a difficult diagnostic challenge for the radiologist and requires a high index of suspicion, particularly in high-risk populations.
To document the existing radiology services available to emergency physicians in hospitals across... more To document the existing radiology services available to emergency physicians in hospitals across Canada and to preview future trends and needs. Questionnaires (n = 130) regarding the type, availability and satisfaction with radiology services were distributed to radiologists and emergency physicians at 65 hospitals across Canada. Fifty-three (41%) questionnaires were returned, and 45 (35%) completed questionnaires from 35 hospitals were used for analysis (24 from radiologists and 21 from emergency physicians). Plain radiographs were available in all hospitals at all times. Ultrasonography, intravenous pyleograms and computed tomography (CT) were available in all departments during normal working hours; after hours, CT was unavailable in 1 hospital and ultrasonography was unavailable in 2. Focused assessment with sonography for trauma (FAST) was routinely performed for blunt abdominal trauma in 6 centres, and 10 centres had teleradiology services. Regarding the quality of emergency service, 7 of 45 responded &amp;amp;quot;poor,&amp;amp;quot; 4 &amp;amp;quot;average,&amp;amp;quot; 14 &amp;amp;quot;good,&amp;amp;quot; and 17 of 45 rated service &amp;amp;quot;excellent.&amp;amp;quot; Interestingly, most radiologists answered &amp;amp;quot;good&amp;amp;quot; or &amp;amp;quot;excellent,&amp;amp;quot; and most of the &amp;amp;quot;poor&amp;amp;quot; responses came from emergency physicians. Regarding staff coverage after 5 pm, 34 hospitals provided CT services, 20 had ultrasonography staff available, and there was radiology nursing coverage in 14 hospitals. Clinical details on requisitions were generally rated &amp;amp;quot;adequate&amp;amp;quot; or &amp;amp;quot;poor.&amp;amp;quot; Although most radiograph reports were available within 48 hours, some took longer. Hot-seat reporting was available in 11 centres. During normal working hours, radiologists were the first to read films in 5 of 35 hospitals. After hours, emergency physicians were the first to read films in all hospitals, but only 14 hospitals indicated they were &amp;amp;quot;formally&amp;amp;quot; trained to do so. This survey documents the strengths and weaknesses of the radiology services available to emergency physicians. The perceptions of emergency physicians and radiologists of the adequacy those services differ significantly.
In many patients, the diagnosis of SBO can often be made by a combination of clinical history, ph... more In many patients, the diagnosis of SBO can often be made by a combination of clinical history, physical examination and plain radiographs. However, in many cases, the diagnosis of SBO may be difficult. Abdominal radiographs are limited in their ability to diagnose SBO and, more particularly, to identify a specific underlying cause. Although barium studies, ultrasonography and magnetic resonance imaging may all play a role in the evaluation of SBO, CT should be the examination of choice for most patients when the diagnosis and underlying cause of SBO is unclear. It may help differentiate pseudo-obstruction from true obstruction, and a specific underlying cause can often be determined. Signs of closed-loop obstruction, strangulation, perforation or infarction may be detected and allow for more timely and appropriate surgical management. We advocate the use of CT in any patient with SBO where the cause or diagnosis is unclear. We have attempted to demonstrate a range of clinical cases ...
Annals of hepatology: official journal of the Mexican Association of Hepatology
Acoustic Radiation Force Impulse Imaging (ARFI) is a novel non invasive technique studying the lo... more Acoustic Radiation Force Impulse Imaging (ARFI) is a novel non invasive technique studying the localized mechanical properties of tissue by utilising short, high intensity acoustic pulses (shear wave pulses) to assess the mechanical response (tissue displacement), providing a measure of tissue elasticity. The aim of this study is to investigate the feasibility of ARFI imaging as a non-invasive method for the assessment of liver fibrosis compared to liver biopsy scores. A prospective blind comparison study of ARFI elastography (Virtual Touch Imaging., ACUSON S2000 Ultrasound Unit, Siemens, Mountain View CA) in a consecutive series of patients who underwent liver biopsy for assessment of fibrosis in chronic liver disease. ARFI shear-wave propagation velocity was measured in meters per second. Mean ARFI velocities were compared with both Batts-Ludwig (F0 to F4) and Modified Ishak scores (F0 to F4) for fibrosis in liver biopsy findings. Twenty-one patients with chronic liver disease (He...
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Papers by Alison Harris