Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where J. O’Brien is active.

Publication


Featured researches published by J. O’Brien.


European Radiology | 2007

Imaging of Budd-Chiari syndrome

O. Buckley; J. O’Brien; Aisling Snow; H. Stunell; I. Lyburn; Peter L. Munk; William C. Torreggiani

Budd-Chiari syndrome occurs when venous outflow from the liver is obstructed. The obstruction may occur at any point from the hepatic venules to the left atrium. The syndrome most often occurs in patients with underlying thrombotic disorders such as polycythemia rubra vera, paroxysmal nocturnal hemoglobinuria and pregnancy. It may also occur secondary to a variety of tumours, chronic inflammatory diseases and infections. Imaging plays an important role both in establishing the diagnosis of Budd-Chiari syndrome as well as evaluating for underlying causes and complications such as portal hypertension. In this review article, we discuss the role of modern imaging in the evaluation of Budd-Chiari syndrome.


Journal of Medical Imaging and Radiation Oncology | 2008

Imaging of horseshoe kidneys and their complications

J. O’Brien; O. Buckley; Orla Doody; E. Ward; Thara Persaud; William C. Torreggiani

Horseshoe kidney is the most common renal fusion anomaly and the patients are prone to a variety of complications, such as stone disease, pelviureteric junction (PUJ) obstruction, trauma, infections and tumours. As result of the abnormal anatomy of a horseshoe kidney, imaging and treatment pathways vary substantially from the normal kidney. In this review, we describe the role of modern imaging in depicting horseshoe kidneys and their complications, in tandem with the role the interventional radiologist plays in treating these patients.


Journal of Medical Imaging and Radiation Oncology | 2008

Imaging of adenomyomatosis of the gall bladder.

H Stunell; O. Buckley; T Geoghegan; J. O’Brien; E. Ward; William C. Torreggiani

Adenomyomatosis is a relatively common abnormality of the gall bladder, with a reported incidence of between 2.8 and 5%. Although mainly confined to the adult study group, a number of cases have been reported in the paediatric study group. It is characterized pathologically by excessive proliferation of the surface epithelium and hypertrophy of the muscularis propria of the gall bladder wall, with invagination of the mucosa into the thickened muscularis forming the so‐called ‘Rokitansky–Aschoff’ sinuses. The condition is usually asymptomatic and is often diagnosed as an incidental finding on abdominal imaging. The radiological diagnosis is largely dependent on the visualization of the characteristic Rokitansky–Aschoff sinuses. As the condition is usually asymptomatic, the importance of making a correct diagnosis is to prevent misinterpretation of other gall bladder conditions such as gall bladder cancer, leading to incorrect treatment. In the past, oral cholecystography was the main imaging method used to make this diagnosis. In most institutions, oral cholecystography is no longer carried out, and the diagnosis is now more commonly seen on cross‐sectional imaging. In this review article, we describe the manifestations of adenomyomatosis on the various imaging methods, with an emphasis on more modern techniques such as magnetic resonance cholangiopancreatography. A brief section on oral cholecystography to aid readers familiar with this technique in understanding the comparable imaging features on more modern imaging techniques is included.


European Journal of Radiology | 2011

Magnetic resonance imaging features of asymptomatic bipartite patella.

J. O’Brien; C. Murphy; Darragh Halpenny; G. McNeill; William C. Torreggiani

OBJECTIVE The purpose of our study was to describe the magnetic resonance imaging (MRI) features of bipartite patella in asymptomatic patients. MATERIALS AND METHODS The study was prospective in type and performed following institutional ethical committees approval. In total, 25 subjects were recruited into the study and informed consent obtained in each case. The local radiology database was utilised in conjunction with a clinical questionnaire to identify patients who had asymptomatic bipartite patella. Any patient with a history of trauma or symptomatic disease was excluded from the study. MRI imaging was performed in each case on a 1.5 T system using a dedicated knee coil and a standardised knee protocol. The images obtained were then analysed by two musculoskeletal radiologists in consensus. RESULTS Of the 25 subjects, there were 8 females and 17 males. The mean age was 34.6 years. All but one of the bipartite fragments were located on the superolateral aspect of the patella. In 23 cases, one fragment was identified. The average transverse diameter of the fragment was 12.8 mm. The average distance between the fragment and the adjacent patella in the axial plane was 1.46 mm. In addition, the cartilage overlying the patella and accessory fragment was intact in all cases. The average thickness of the patella cartilage at its border to the fragment was 2.4mm with an average ratio of the cartilage thickness of the fragment as compared with the cartilage thickness of the patella of 0.72. There was no evidence of high signal or bone marrow oedema on fluid sensitive sequences within either the patella or the fragment in any of the patients. Fluid was identified in the cleft between the patella and the fragment in the majority of cases. CONCLUSIONS Asymptomatic bipartite patella is characterised by intact but thinned cartilage along the border between the patella and the fragment, fluid between the cleft and a lack of any bone marrow oedema or high signal within the patella or its fragment.


European Radiology | 2007

A novel technique in selective venous sampling in the localization of parathyroid tumours utilizing a micro-wire and standardized catheter

O. Buckley; J. O’Brien; Orla Doody; William C. Torreggiani

Selective venous sampling (SVS) is a useful technique to localize a number of hormone-producing tumours, such as parathyroid tumours, when other imaging techniques are inconclusive. Typically, a 5 French selective single end-hole catheter and standard hydrophilic wire are utilized to access the required vessels and an attempt made to withdraw blood. However, most interventional radiologists are familiar with the difficulty and limited success in withdrawing venous blood through an end-hole catheter. We describe a simple, cheap and novel technique utilizing a micro-wire that we have developed in our interventional suite to overcome this common problem. Having reached the target site with the selective end-hole catheter, a Tuohy Borst adapter is attached to the catheter end. A 0.018-inch micro-wire is then inserted through the selective end-hole catheter such that the distal wire tip exits the distal catheter tip. The purpose of the micro-wire exiting the catheter is to both straighten the catheter tip to a position parallel to the vessel, allowing easier aspiration as well as physically preventing blockage of the catheter by the vein intimal wall collapse on suction. The 5-ml sample required for PTH assay is then successfully obtained via the Tuohy Borst adapter.


European Radiology | 2007

An unusual case of elevated liver enzymes (2006: 10b)

J. O’Brien; O. Buckley; P. L. Munk; William C. Torreggiani

HELLP syndrome is a form of severe pre-eclampsia with multisystem involvement. Laboratory markers include haemolysis (H), elevated liver enzymes (EL), and low platelets (LP). We present a patient to our institution with HELLP syndrome complicated by liver necrosis. The patient underwent urgent Caesarian section prior to transfer.


European Journal of Radiology | 2010

Comprehensive ultrasound assessment of complications post-liver transplantation

J. O’Brien; A.R. Buckley; R. Browne

Human liver transplantation for end-stage liver disease was first performed in 1963. Refinements in surgical technique and new immunosuppressive regimens have improved outcomes. Today, transplant patients have a 5-year survival rate of approximately 75%. Nevertheless, significant complications still occur. Ultrasonography (US), is the initial imaging modality of choice allowing bedside assessment for detection and follow-up of early and delayed graft complications, and facilitating interventional procedures. This review outlines the role of ultrasound in post-transplantation assessment.


European Radiology | 2008

An unusual cause of persistent headache: Chloroma (2008: 2b)

J. O’Brien; O. Buckley; C. Murphy; William C. Torreggiani

A chloroma (granulocytic sarcoma) is a rare tumour that is usually associated with leukaemia. The osseous skeleton is most commonly involved, and it confers a poorer prognosis for the underlying leukaemic disease. We present a case of a chloroma of the nasal sinuses that was the primary presentation of the patient’s underlying leukaemia.


Irish Journal of Medical Science | 2009

A case of back pain associated with neurology in a young man

J. O’Brien; E. Ward; Orla Doody; M. Ryan

BackgroundWe present the case of a 14-year-old with a 3-month history of back pain, who on presentation, was demonstrated to have neurological signs.MethodInvestigation with radiographs and subsequent magnetic resonance imaging was performed, which demonstrated an expansile lesion in the tenth thoracic vertebra with posterior extension causing spinal cord compression. This was treated with surgical resection and spinal cord decompression.ResultsDiagnosis of aneurysmal bone cyst was made following histopathological examination of the resected lesion.ConclusionBack pain in childhood is a significant and often sinister symptom, which requires careful evaluation.


European Radiology | 2007

Calvarial tuberculosis: an unusual presentation (2007: 8b)

J. O’Brien; O. Buckley; Thara Persaud; E. Colhoun

We describe a case of calvarial tuberculosis with an associated extra-dural collection. This presentation has rarely been reported in the literature and the magnetic resonance imaging features are not well documented.

Collaboration


Dive into the J. O’Brien's collaboration.

Top Co-Authors

Avatar

O. Buckley

Boston Children's Hospital

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

E. Ward

Boston Children's Hospital

View shared research outputs
Top Co-Authors

Avatar

Orla Doody

Boston Children's Hospital

View shared research outputs
Top Co-Authors

Avatar

C. Murphy

Boston Children's Hospital

View shared research outputs
Top Co-Authors

Avatar

Thara Persaud

Boston Children's Hospital

View shared research outputs
Top Co-Authors

Avatar

Aisling Snow

Boston Children's Hospital

View shared research outputs
Top Co-Authors

Avatar

Darragh Halpenny

Boston Children's Hospital

View shared research outputs
Top Co-Authors

Avatar

E. Colhoun

Boston Children's Hospital

View shared research outputs
Top Co-Authors

Avatar

G. McNeill

Boston Children's Hospital

View shared research outputs
Researchain Logo
Decentralizing Knowledge