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Biomedical subjects

Ara Kassarjian

Publications and source records attributed to Ara Kassarjian.

17 recordsLinked to original sources
PubMed2006

Distal clavicular osteolysis: MR evidence for subchondral fracture.

PURPOSE: To investigate the association between distal clavicular osteolysis and subchondral fractures of the distal clavicle at MRI. MATERIALS AND METHODS: This study was approved by the hospital human research committee, which waived the need for informed consent. Three radiologists retrospectively analyzed 36 shoulder MR examinations in 36 patients with imaging findings of distal clavicular osteolysis. The presence of a subchondral fracture of the distal clavicle, abnormalities of the acromioclavicular joint, rotator cuff tears and labral tears were assessed by MRI. These cases were then compared with 36 age-matched controls. RESULTS: At MRI, 31 of 36 patients (86%) had a subchondral line within the distal clavicular edema, consistent with a subchondral fracture. Of the 36 patients, 32 (89%) had fluid in the acromioclavicular joint, while 27 of 36 patients (75%) had cysts or erosions in the distal clavicle. There were 13 patients (36%) with associated labral tears, while eight patients (22%) had partial-thickness rotator cuff tears. In the control group one of 36 (3%) had a subchondral line (P<0.05), while ten of 36 (28%) had rotator cuff tears and 13 of 36 (36%) had labral tears. These latter two were not statistically significant between the groups. CONCLUSION: A distal clavicular subchondral fracture is a common finding in patients with imaging evidence of distal clavicular osteolysis. These subchondral fractures may be responsible for the propensity of findings occurring on the clavicular side of the acromioclavicular joint.

Adult↗
PubMed2006

Incidence and MR imaging features of fractures of the anterior process of calcaneus in a consecutive patient population with ankle and foot symptoms.

OBJECTIVE: To determine the incidence, appearances and associated injuries of fractures affecting the anterior process of calcaneus from a general population with foot and ankle symptoms. DESIGN AND PATIENTS: A retrospective review of foot and ankle MR imaging procedures was performed for detection of cases with a fracture affecting the anterior process of calcaneus over a four year period. Radiographs, MR imaging studies, radiology reports, medical records, and operative notes were reviewed. Imaging analysis included fracture pattern, displacement, associated fractures, and presence of tendon and ligamentous injuries. RESULTS: The incidence of anterior process of calcaneus fracture on MR imaging was 0.5% (14/2577). Fractures were more common in female subjects (71%, 10/14). Fracture orientation was predominantly vertical (93%, 13/14). No comminuted fractures were seen and only three fractures were displaced. Three of the eight MR imaging evident fractures of anterior process of calcaneus were seen on radiographs. Associated fractures of the talus (n=5), navicular bone (n=3), cuboid (n=2), and calcaneal body (n=1) were noted. Associated injuries to the anterior talofibular ligament (n=3) and tears of the peroneus brevis (n=3) and peroneus longus (n=1) tendons were present. All fractures were treated non-operatively. Two patients had subtalar joint steroid injection for symptomatic relief. CONCLUSIONS: Fractures of the anterior process of the calcaneus are uncommon in MR examinations of a general population of patients with foot and ankle symptoms. Although anterior process of calcaneus fractures are rare, there was a moderately high incidence of associated bone and soft-tissue injuries.

Adolescent↗
PubMed2006

MR imaging of the rotator cuff.

MR imaging is the optimal method for evaluating suspected rotator cuff pathology. Current techniques of fast spin-echo imaging without and with fat suppression allow accurate identification and characterization of tendinous and myotendinous abnormalities of the rotator cuff. Impingement disorders, tendon degeneration, instability,and trauma comprise the multifactorial nature of rotator cuff disease. This article addresses the role of MR imaging in evaluating the rotator cuff and the importance of MR imaging in identifying other lesions that may mimic rotator cuff pathology. A rationale for protocol design, including MR arthrography and the use of specialized positioning, such as abduction and external rotation (ABER), are discussed.

Humans↗
PubMed2006

Hip MR arthrography and femoroacetabular impingement.

Hip pain is a common complaint among athletes of all ages. Advances in imaging and treatment are changing the paradigm of evaluation and management of hip pain. The role of abnormal femoral and acetabular morphology and lesions of the acetabular labrum and cartilage is increasingly recognized as being crucial in the development of degenerative change. In addition, femoroacetabular impingement is increasingly recognized as an etiologic factor in hip pain. This article discusses techniques of hip magnetic resonance (MR) arthrography, normal anatomy seen at hip MR arthrography, common intra-articular pathologies in patients with hip pain, and imaging findings of femoroacetabular impingement.

Acetabulum↗
PubMed2006

The accuracy of computed tomography for the diagnosis of tibial nonunion.

BACKGROUND: When a patient is seen with a possible tibial nonunion and equivocal findings on plain radiographs, the surgeon may choose to obtain a computed tomography scan to better delineate the bone anatomy. However, the sensitivity and specificity of computed tomography in this setting is not known. We investigated the accuracy of computed tomography for detecting nonunion in this clinical situation. METHODS: Thirty-five patients with equivocal findings on plain radiographs underwent computed tomography scanning. The patients were first seen at an average of 9.7 months after the injury and had undergone a mean of 2.6 prior operations. A so-called gold standard of union or nonunion was determined by either surgical findings (for twenty-five patients who were operatively treated) or six months of clinical observation (for ten patients who had nonoperative treatment). Computed tomography scans were assessed by two radiologists and one orthopaedic surgeon who were blinded to the clinical outcome. RESULTS: Computed tomography scans displayed very good diagnostic accuracy. Intraobserver agreement was high (intraclass correlation coefficient = 0.89), the sensitivity for detecting nonunion was 100%, and the overall accuracy was 89.9%. Computed tomography was limited by a low specificity of 62%, as three patients who were diagnosed as having tibial nonunion with computed tomography underwent surgery and were found to have a healed fracture. CONCLUSIONS: Computed tomography displays very good accuracy in the evaluation of tibial fracture-healing. However, it is limited by low specificity and may sometimes misrepresent a healed fracture as a nonunion. Surgeons must be aware of this pitfall in order to accurately determine which patients need surgical intervention.

Adult↗
PubMed2005

Triad of MR arthrographic findings in patients with cam-type femoroacetabular impingement.

PURPOSE: To retrospectively analyze magnetic resonance (MR) arthrographic findings in patients with clinical cam-type femoroacetabular impingement. MATERIALS AND METHODS: This study was approved by the institutional review board, and informed consent was waived. Study was compliant with the Health Insurance Portability and Accountability Act. Forty-two MR arthrograms obtained in 40 patients with clinical femoroacetabular impingement were analyzed retrospectively by two radiologists. Quantitative analysis by using alpha angle measurement was performed to assess anterosuperior femoral head-neck morphology. Presence of labral tears, articular cartilage lesions, paralabral cysts, os acetabuli, and synovial herniation pits was recorded. Presence of the typical triad of anterosuperior labral tear, anterosuperior cartilage lesion, and abnormal alpha angle was recorded. Surgical comparison was available for 11 patients. RESULTS: At imaging, in 40 patients (22 male, 18 female) with a mean age of 36.5 years, 39 of 42 hips (93%) had an abnormal alpha angle, with a mean angle of 69.7 degrees ; 40 of 42 (95%) had an anterosuperior cartilage abnormality; and 42 of 42 (100%) had an anterosuperior labral tear. Thirty-seven of 42 hips (88%) had the triad. Six had paralabral cysts, 17 had an os acetabuli, and two had synovial herniation pits. Surgical comparison for 11 hips led to confirmation of all labral and cartilage abnormalities seen at imaging. CONCLUSION: MR arthrography demonstrated a triad of abnormal head-neck morphology, anterosuperior cartilage abnormality, and anterosuperior labral abnormality in 37 of 42 patients with cam-type femoroacetabular impingement.

Acetabulum↗
PubMed2005

Synovial inflammatory processes in the hand.

The numerous synovial articulations and tendon sheaths of the hand afford it a central role in the diagnosis and management of inflammatory arthropathies. Inflammation may be idiopathic, infectious, post-traumatic, or secondary to deposition diseases. In most cases, synovial inflammation represents the primal event in the onset of destructive arthropathies. We review the imaging features of acute and chronic synovitis in the hand. Magnetic resonance imaging is very sensitive to the earliest changes of synovitis and provides a modality for early detection of disease. Additionally, once a diagnosis is established, magnetic resonance imaging has an emerging role in rapid assessment of response to therapy. Positron emission tomography and ultrasound also show promise in the evaluation and treatment of inflammatory arthropathies. Although highly sensitive to the presence of inflammation these more advanced imaging techniques often lack specificity. Therefore, the radiographic evaluation of the pattern of bone destruction remains critical to distinguishing among the different synovial inflammatory processes.

Arthritis↗
PubMed2005

MR imaging of sports-related groin pain.

With increasing participation in professional and recreational athletics, activity-limiting pelvic and groin pain presents a growing challenge for patients and health care providers. The causes of musculoskeletal-related groin pain among athletes are diverse, with considerable overlap in history and physical examination findings. Pubalgia is a clinical diagnosis invoked when no more specific cause ofa patient's symptoms can be determined on history and physical examination. In many cases, dedicated MR imaging of the hip and pelvis can provide a prompt and specific diagnosis, which allows for early treatment and return to participation.

Athletic Injuries↗
PubMed2005

Imaging of the overhead throwing athlete.

Knowledge of overhead throwing biomechanics is crucial to understand specific injuries encountered in throwing athletes on diagnostic imaging. Most specific injuries of overhead throwing athletes occur at the shoulder and elbow. Throwing athletes are susceptible to rotator cuff tears from tensile overload and external and internal impingement. The labrum is also commonly degenerated or torn secondary to overuse syndrome, internal impingement, and microtrauma. The elbow is typically injured secondary to excessive valgus forces during throwing. The ulnar collateral ligament, ulnar nerve, and common flexor tendon origin are all at increased risk of injury. Capitellar osteochondral injuries and loose intra-articular bodies are also frequent. Knowledge of injury pathophysiology is crucial to understanding the treatment rationale in throwing athletes.

Athletic Injuries↗
PubMed2005

Intramuscular rotator cuff cysts: association with tendon tears on MRI and arthroscopy.

OBJECTIVE: This study was designed to explore the relationship between intramuscular cysts and rotator cuff tendon tears. CONCLUSION: Intramuscular cysts are strongly associated with rotator cuff tendon tears. Identification of such a cyst should prompt a search for a rotator cuff tear. Findings on MR arthrography and surgery suggest that a delaminating component of the rotator cuff tear may lead to the development of these cysts and may explain the occasional discrepancy between location of tears and location of cysts.

Arthroscopy↗
PubMed2004

Infantile hepatic hemangiomas: clinical and imaging findings and their correlation with therapy.

OBJECTIVE: This study was undertaken to determine different imaging patterns in infantile hepatic hemangiomas and to explore the relationship between clinical presentations, imaging findings, and response to therapy. MATERIALS AND METHODS: The imaging studies and clinical records of all patients with infantile hepatic hemangiomas from two tertiary children's hospitals were reviewed. Univariate and multivariate stepwise logistic regression techniques were used to determine whether clinical presentation and imaging variables differentiated the type of treatment required. RESULTS: Typical hemangiomas appeared as focal or multifocal T2-hyperintense spheres with centripetal contrast enhancement and dilated feeding and draining vessels. Three atypical patterns included focal mass lesions with central varix with or without direct shunts, focal mass with central necrosis or thrombosis, and massive hemangiomatous involvement of the liver with abdominal vascular compression. In general, patients with focal lesions without high flow needed no treatment, and those with central varix and direct shunts developed severe high-output cardiac failure that responded quickly to embolization. The pattern of massive replacement of liver was associated with hypothyroidism, abdominal compartment syndrome, and a high mortality rate. Multivariate analysis of 55 patients indicated that congestive heart failure was the only independent predictor of treatment (p = 0.005). The presence of a shunt was the only independent factor associated with embolization or surgery (p = 0.002). CONCLUSION: Although the imaging features of infantile hepatic hemangiomas vary to some extent, MRI features are typical in most patients and certain imaging findings are predictive of the clinical course. MRI is the technique of choice in diagnosing infantile hepatic masses.

Chi-Square Distribution↗
PubMed2003

Magnetic resonance imaging of the hip: sports-related injuries.

Normal hip disorders do not account for a large proportion of exercise-related injuries, but they can pose a clinical dilemma because symptoms tend to be nonspecific. Conventional radiographs may demonstrate some causes of hip pain, such as stress fractures and degenerative joint disease. Magnetic resonance imaging (MRI) of the hip has proven valuable in the diagnosis of radiographically occult osseous abnormalities and periarticular soft-tissue disorders such as stress fractures, avulsion injuries, musculotendinous abnormalities, and bursitis. Conventional MRI has been less useful in the evaluation of intra-articular lesions, including acetabular labral tears, intra-articular loose bodies, and cartilage lesions. Visualization of intra-articular structures and their abnormalities can be improved by injection of diluted gadolinium, which distends the capsule and leaks into labral tears. This article focuses on the use of conventional radiography and MRI in recreational and professional athletes with painful hip joints. Where possible, MRI is compared with other diagnostic modalities such as bone scan and computed tomography.

Adolescent↗
PubMed2002

Reimaging in pediatric neurotrauma: factors associated with progression of intracranial injury.

PURPOSE: The purpose of this study was to characterize the radiologic changes that are seen in the first 24 to 48 hours after head injury and to correlate those changes with clinical findings, to determine which children are at greatest risk for progression of their neurologic injury. METHODS: The authors identified 104 children (less-than-or-equal17 years of age) who had a second computed tomography (CT) scan of the head within 24 to 48 hours of admission. CT scans were evaluated systematically in a blinded fashion. Mechanism of injury, findings on physical examination, therapeutic measures, and changes in management were recorded from hospital medical records. The 50 children whose second CT scan showed progression of injury were compared with the 54 patients whose intracranial injuries were unchanged or improved on their second CT. RESULTS: Twenty-six percent of patients (13 of 50) with radiographic progression of injury had an admission Glasgow coma score of 15. Progression of injury was more common, however, in patients with lower Glasgow coma scores, averaging 9 on admission and 10 at the time of the second CT. Progression of injury also was more common if the initial head CT showed 3 or more intracranial injuries, mass effect, intraventricular hemorrhage, or an epidural hematoma. CONCLUSIONS: Children with an intracranial injury identified on their initial head CT scan should undergo a second scan 24 hours after injury, especially if the initial CT shows 3 or more intracranial injuries, mass effect, intraventricular hemorrhage, or an epidural hematoma. .

Adolescent↗
PubMed2002

Angiographic classification of hepatic hemangiomas in infants.

PURPOSE: To review the angiograms in patients with hepatic hemangiomas referred to two North American children's hospitals to determine the variability in angiographic findings and to propose a classification system that is based on these findings. MATERIALS AND METHODS: Angiograms obtained in 15 infants with a diagnosis of hepatic hemangioma who were examined at or referred to two tertiary pediatric hospitals in North America from 1981 through 2000 were reviewed. The angiographic findings were then used to classify hemangiomas into types on the basis of a number of features, including high-flow nodules, early filling of veins, and the type of direct shunt present. Clinical data, including age at presentation, presence of cardiac insufficiency, and treatment, were also recorded. RESULTS: Lesions were classified into five types on the basis of angiographic findings. In three of 15 patients, angiograms demonstrated the classic appearance of hepatic hemangiomas, with early filling of abnormal vascular channels, stagnation of contrast material, and no evidence of a direct shunt (type 1). In four patients, images showed high-flow nodules without direct shunts (type 2). In eight patients, direct shunts were demonstrated: arteriovenous shunts (type 3) in one, portovenous shunts (type 4) in three, and both arteriovenous and portovenous shunts (type 5) in four. CONCLUSION: Hepatic hemangioma in infants is a heterogeneous lesion with variable angioarchitecture and a spectrum of angiographic findings.

Angiography↗