Peter J. MacMahon
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Previous Organizations / Institutes
The organizations / institutes from the scholar's other articles in the past ten years
Research Subjects
Peter J. MacMahon has a total of 118 co-authors. Here are the top co-authors by number of shared publications:
- Danielle Byrne
Division of Neuroradiology, Vancouver General Hospital, Vancouver, British Columbia, Canada
4 shared publications - Eoin C. Kavanagh
Department of Radiology, Mater Misericordiae University Hospital, Dublin, Ireland
3 shared publications - Gavin Sugrue
Department of Radiology, Mater Misericordiae University Hospital, Dublin 7, Ireland.
3 shared publications - Brian Gibney
Mater Misericordiae University Hospital , Dublin, Dublin , Ireland
2 shared publications - Brian Murray
Neurology (B.M.), Mater Misericordiae University Hospital, Dublin, Ireland
2 shared publications - Cillian McNamara
From the Departments of Radiology (C.M., G.S., P.J.M.).
2 shared publications
Latest Publications
- Open Access
- 21 November 2025
- Published by Elsevier in Radiology Case Reports
- Vol. 21 (2) , 704-709
Transient lateral patellar dislocation resulting in osteochondral lesion of the lateral femoral condyle: a case series of findings on cone beam CT
- 21 November 2025
- Published by Elsevier in Radiology Case Reports
- Vol. 21 (2) , 704-709
Open AccessTransient lateral patellar dislocation resulting in osteochondral lesion of the lateral femoral condyle: a case series of findings on cone beam CT
- 21 September 2025
- Published by Springer Nature
- p. 139-148
Lesion-Aware CT-to-MRI Synthesis Using a Mask-Informed Diffusion with Adaptive-Weighted Loss (MIDAS)
- 21 September 2025
- Published by Springer Nature
- p. 139-148
Lesion-Aware CT-to-MRI Synthesis Using a Mask-Informed Diffusion with Adaptive-Weighted Loss (MIDAS)
- 25 July 2024
- Published by American Society of Neuroradiology (ASNR) in American Journal of Neuroradiology
- Vol. 45 (9) , 1370-1377
An Optimized CT Protocol for Detecting Suspected Cauda Equina Syndrome: A Comparative Analysis with MRI
BACKGROUND AND PURPOSE: Lumbar disc herniation, potentially leading to nerve root compression and cauda equina syndrome, is typically evaluated using MR imaging. However, the limited availability of MR imaging outside regular hours in certain health care systems poses considerable challenges. This purpose of this study was to prospectively evaluate the diagnostic accuracy of an optimized CT lumbar spine protocol as a potential alternative to MR imaging in assessing suspected neural compression. MATERIALS AND METHODS: Patients presenting to the emergency department with suspected cauda equina syndrome or acute radicular symptoms secondary to lumbar disc herniation referred for MR imaging were prospectively enrolled for an additional CT optimized to assess spinal stenosis. An expert radiologist, blinded to clinical data, graded canal stenosis at each lumbar level on CT. The same grading process was applied to MR imaging after a 4-week interval to maintain blinding. RESULTS: Fifty-nine individuals were included in the final analysis. In 22 (39%) cases, no significant stenosis was identified. In a further 22 (37%) cases, disc pathology was identified that was managed conservatively. Thirteen (22%) individuals proceeded to urgent surgical decompression. In 1 (2%) instance, an alternative diagnosis was identified. Compared with MR imaging, the sensitivity, specificity, and positive and negative predictive values for CT in detecting disc pathology in patients presenting with symptoms suggestive of acute neural compression were 97% (95% CI, 82%–99%), 97% (95% CI, 83%–99%), 97% (95% CI, 92%–99%), and 97% (95% CI, 83%–99%), respectively. CT accurately identified all cases requiring urgent decompression. CONCLUSIONS: CT accurately predicted MR imaging findings in patients with suspected cauda equina and nerve root compression, demonstrating its utility as an adjunct tool for patient triage in emergency settings with limited MR imaging access. This protocol could enhance the allocation of emergency resources by appropriately selecting patients for emergent MR imaging.
- 25 July 2024
- Published by American Society of Neuroradiology (ASNR) in American Journal of Neuroradiology
- Vol. 45 (9) , 1370-1377
An Optimized CT Protocol for Detecting Suspected Cauda Equina Syndrome: A Comparative Analysis with MRI
BACKGROUND AND PURPOSE: Lumbar disc herniation, potentially leading to nerve root compression and cauda equina syndrome, is typically evaluated using MR imaging. However, the limited availability of MR imaging outside regular hours in certain health care systems poses considerable challenges. This purpose of this study was to prospectively evaluate the diagnostic accuracy of an optimized CT lumbar spine protocol as a potential alternative to MR imaging in assessing suspected neural compression. MATERIALS AND METHODS: Patients presenting to the emergency department with suspected cauda equina syndrome or acute radicular symptoms secondary to lumbar disc herniation referred for MR imaging were prospectively enrolled for an additional CT optimized to assess spinal stenosis. An expert radiologist, blinded to clinical data, graded canal stenosis at each lumbar level on CT. The same grading process was applied to MR imaging after a 4-week interval to maintain blinding. RESULTS: Fifty-nine individuals were included in the final analysis. In 22 (39%) cases, no significant stenosis was identified. In a further 22 (37%) cases, disc pathology was identified that was managed conservatively. Thirteen (22%) individuals proceeded to urgent surgical decompression. In 1 (2%) instance, an alternative diagnosis was identified. Compared with MR imaging, the sensitivity, specificity, and positive and negative predictive values for CT in detecting disc pathology in patients presenting with symptoms suggestive of acute neural compression were 97% (95% CI, 82%–99%), 97% (95% CI, 83%–99%), 97% (95% CI, 92%–99%), and 97% (95% CI, 83%–99%), respectively. CT accurately identified all cases requiring urgent decompression. CONCLUSIONS: CT accurately predicted MR imaging findings in patients with suspected cauda equina and nerve root compression, demonstrating its utility as an adjunct tool for patient triage in emergency settings with limited MR imaging access. This protocol could enhance the allocation of emergency resources by appropriately selecting patients for emergent MR imaging.
- 8 July 2022
- Published by Oxford University Press (OUP) in British Journal of Radiology
- Vol. 94 (1126) , 20201333
Nomenclature for groin pain in athletes
Currently, there is much variation in the terminology used to describe groin pain in athletes. Several groups have attempted to reach consensus on nomenclature in this area. This article outlines the current status of groin pain nomenclature for the radiologist, highlighting inherent heterogeneity, recent attempts to reach a consensus, the need for a radiological consensus and why imprecise terminology should be avoided when reporting.
- 8 July 2022
- Published by Oxford University Press (OUP) in British Journal of Radiology
- Vol. 94 (1126) , 20201333
Nomenclature for groin pain in athletes
Currently, there is much variation in the terminology used to describe groin pain in athletes. Several groups have attempted to reach consensus on nomenclature in this area. This article outlines the current status of groin pain nomenclature for the radiologist, highlighting inherent heterogeneity, recent attempts to reach a consensus, the need for a radiological consensus and why imprecise terminology should be avoided when reporting.
- Open Access
- 19 April 2022
- Published by MDPI AG in Healthcare
- Vol. 10 (5) , 755
A Two-Stage De-Identification Process for Privacy-Preserving Medical Image Analysis
Identification and re-identification are two major security and privacy threats to medical imaging data. De-identification in DICOM medical data is essential to preserve the privacy of patients’ Personally Identifiable Information (PII) and requires a systematic approach. However, there is a lack of sufficient detail regarding the de-identification process of DICOM attributes, for example, what needs to be considered before removing a DICOM attribute. In this paper, we first highlight and review the key challenges in the medical image data de-identification process. In this paper, we develop a two-stage de-identification process for CT scan images available in DICOM file format. In the first stage of the de-identification process, the patient’s PII—including name, date of birth, etc., are removed at the hospital facility using the export process available in their Picture Archiving and Communication System (PACS). The second stage employs the proposed DICOM de-identification tool for an exhaustive attribute-level investigation to further de-identify and ensure that all PII has been removed. Finally, we provide a roadmap for future considerations to build a semi-automated or automated tool for the DICOM datasets de-identification.
- 19 April 2022
- Published by MDPI AG in Healthcare
- Vol. 10 (5) , 755
Open AccessA Two-Stage De-Identification Process for Privacy-Preserving Medical Image Analysis
Identification and re-identification are two major security and privacy threats to medical imaging data. De-identification in DICOM medical data is essential to preserve the privacy of patients’ Personally Identifiable Information (PII) and requires a systematic approach. However, there is a lack of sufficient detail regarding the de-identification process of DICOM attributes, for example, what needs to be considered before removing a DICOM attribute. In this paper, we first highlight and review the key challenges in the medical image data de-identification process. In this paper, we develop a two-stage de-identification process for CT scan images available in DICOM file format. In the first stage of the de-identification process, the patient’s PII—including name, date of birth, etc., are removed at the hospital facility using the export process available in their Picture Archiving and Communication System (PACS). The second stage employs the proposed DICOM de-identification tool for an exhaustive attribute-level investigation to further de-identify and ensure that all PII has been removed. Finally, we provide a roadmap for future considerations to build a semi-automated or automated tool for the DICOM datasets de-identification.
- 1 September 2021
- Published by Radiological Society of North America (RSNA) in Radiology
- Vol. 300 (3) , E339-E341
Radiology and the Climate Crisis: Opportunities and Challenges—Radiology In Training
Radiology trainees have an important role to play in advancing more sustainable and environmentally conscious radiology practices through research, education, and local advocacy.
- 1 September 2021
- Published by Radiological Society of North America (RSNA) in Radiology
- Vol. 300 (3) , E339-E341
Radiology and the Climate Crisis: Opportunities and Challenges—Radiology In Training
Radiology trainees have an important role to play in advancing more sustainable and environmentally conscious radiology practices through research, education, and local advocacy.
- 1 May 2021
- Published by Elsevier in Radiography
- Vol. 27 (2) , 389-397
Evaluation of optimised 3D turbo spin echo and gradient echo MR pulse sequences of the knee at 3T and 1.5T
- 1 May 2021
- Published by Elsevier in Radiography
- Vol. 27 (2) , 389-397
Evaluation of optimised 3D turbo spin echo and gradient echo MR pulse sequences of the knee at 3T and 1.5T
- 1 January 2021
- Published by Elsevier in European Journal of Radiology
- Vol. 134, 109414
Structured reporting in portable chest radiographs: An essential tool in the diagnosis of COVID-19
- 1 January 2021
- Published by Elsevier in European Journal of Radiology
- Vol. 134, 109414
Structured reporting in portable chest radiographs: An essential tool in the diagnosis of COVID-19
- 1 July 2020
- Published by Radiological Society of North America (RSNA) in RadioGraphics
- Vol. 40 (4) , 1198
Cone-beam CT for Diagnosis of Avulsion Injuries of the Hand and Wrist
- 1 July 2020
- Published by Radiological Society of North America (RSNA) in RadioGraphics
- Vol. 40 (4) , 1198
Cone-beam CT for Diagnosis of Avulsion Injuries of the Hand and Wrist
- 1 June 2020
- Published by Springer Nature in Emergency Radiology
- Vol. 27 (3) , 293-301
Assessment of RAdiopaque Patient IDentification Stickers (RAPIDS) for patient-scan correlation in a mass casualty incident
Purpose To qualitatively assess the legibility of radiopaque patient identification stickers and their effect on image quality. These stickers are intended for use as a part of a patient registration and identification pack utilized in a mass casualty incident (MCI), to prevent errors in correlating patients with their diagnostic imaging and reports. Methods Four different prototype designs of stickers with radiopaque identification numbers which are legible on radiographs and CT were created. These were affixed to head and thorax phantoms and scanned using standard imaging protocols. Images were reviewed qualitatively for legibility and the presence of image degradation due to the radiopaque sticker materials using Likert scales by four radiologists and four emergency physicians. Results All four prototypes were confidently legible on forehead, shoulder and sternum on CT on topogram and reconstructed images. Sticker positioning over the temple resulted in unreliable legibility on topogram. All prototypes were confidently legible on shoulder and sternum on CT and radiographs. Significant image degradation was reported on radiographs with sticker position over the sternum. The preferred anatomic position was the forehead. Conclusion In a mass casualty incident, radiopaque patient identification stickers affixed to injured patients may help to ensure confidence in the correlation between patients and their imaging. Tested prototypes were found to be easily legible without substantial degradation of image quality. Preferred anatomical position and construction material was established. Consideration should be given to addition of such radiographic identity aides to MCI patient registration packs.
- 1 June 2020
- Published by Springer Nature in Emergency Radiology
- Vol. 27 (3) , 293-301
Assessment of RAdiopaque Patient IDentification Stickers (RAPIDS) for patient-scan correlation in a mass casualty incident
Purpose To qualitatively assess the legibility of radiopaque patient identification stickers and their effect on image quality. These stickers are intended for use as a part of a patient registration and identification pack utilized in a mass casualty incident (MCI), to prevent errors in correlating patients with their diagnostic imaging and reports. Methods Four different prototype designs of stickers with radiopaque identification numbers which are legible on radiographs and CT were created. These were affixed to head and thorax phantoms and scanned using standard imaging protocols. Images were reviewed qualitatively for legibility and the presence of image degradation due to the radiopaque sticker materials using Likert scales by four radiologists and four emergency physicians. Results All four prototypes were confidently legible on forehead, shoulder and sternum on CT on topogram and reconstructed images. Sticker positioning over the temple resulted in unreliable legibility on topogram. All prototypes were confidently legible on shoulder and sternum on CT and radiographs. Significant image degradation was reported on radiographs with sticker position over the sternum. The preferred anatomic position was the forehead. Conclusion In a mass casualty incident, radiopaque patient identification stickers affixed to injured patients may help to ensure confidence in the correlation between patients and their imaging. Tested prototypes were found to be easily legible without substantial degradation of image quality. Preferred anatomical position and construction material was established. Consideration should be given to addition of such radiographic identity aides to MCI patient registration packs.