Biomedical subjects

A Laorr

Publications and source records attributed to A Laorr.

12 recordsLinked to original sources

PubMed1998

The absent bow tie sign in bucket-handle tears of the menisci in the knee.

OBJECTIVE: Bucket-handle tears of the menisci are one of the most frequently missed diagnoses in MR examinations of the knee. This article describes the "absent bow tie sign," which can be used to identify bucket-handle tears on routine MR examinations of the knee. MATERIALS AND METHODS: The arthroscopic surgical reports (n = 350) from a single orthopedic surgeon's practice during a 24-month period were examined for patients who had a diagnosis of bucket-handle tear and who underwent MR imaging before surgery (n = 32). The MR examinations were retrospectively evaluated for the presence of a bow tie sign. The bow tie sign was considered normal when two sagittal images showed the body segment (a bow tie appearance). The bow tie sign was considered abnormal, consistent with a bucket-handle tear, when only one or no body segment was seen (the absent bow tie sign). Coronal images were evaluated for a truncated meniscus. Also, each MR examination was scrutinized for a displaced fragment and a double posterior cruciate ligament (PCL) sign. RESULTS: Thirty-three bucket-handle tears were found at arthroscopy in 32 patients. One patient had tears of the medial and lateral menisci. The absent bow tie sign was seen in 32 of the 33 cases (sensitivity, 97%) and correlated with the medial or lateral meniscus that was reported torn at arthroscopy. The single false-negative result occurred in a patient with a nondisplaced bucket-handle tear. The findings in 31 contralateral normal menisci were all negative for an absent bow tie sign (specificity, 100%). A displaced fragment was found in 30 (94%) of 32 cases. The coronal images showed a truncated meniscus in 21 (64%) of 33 cases. A double PCL sign was seen in 10 (30%) of 33 cases. CONCLUSION: The absent bow tie sign is an easily applied finding that can be used with good sensitivity to diagnose bucket-handle tears of the menisci on MR imaging. This sign has a higher accuracy rate than other findings common with bucket-handle tears, such as displaced fragments, a truncated appearance of the meniscus on coronal images, and the double PCL sign.

Adult↗

PubMed1996

Skeletal coccidioidomycosis: imaging findings in 19 patients.

OBJECTIVE: The objective of this study was to describe the distribution and radiologic appearance of skeletal coccidioidomycosis in 19 documented cases. DESIGN AND PATIENTS: Medical records of 19 patients (17 men, 2 women; age range 17-62 years, mean age 34 years) with clinically confirmed skeletal coccidioidomycosis were retrospectively reviewed. The patients were studied with plain radiography (n = 19), skeletal scintigraphy (n = 6), computed tomography (CT) (n = 5), and magnetic resonance imaging (MRI) (n = 1). RESULTS: Multiple lesions were seen in 11 of 19 patients (58%). Of a total of 46 lesions, 27 (59%) were described as punched-out lytic, 10 (22%) as permeative/destructive, and 9 (17%) as involving a joint and/or disk space. Lesions were identified in almost every bone (with the exception of the facial bones, ulna, carpus, and fibula) and were most commonly found in the axial skeleton (20 of 46; 43%). CONCLUSION: Skeletal coccidioidomycosis is frequently multicentric and may involve almost any bone. The axial skeleton is the most common site of involvement. Lesions are usually well demarcated but may present with an ill-defined border and permeative type of bone destruction, especially in the spine. Joint involvement is not uncommon. Plain radiographs are effective in the initial evaluation of bones and joints, scintigraphic studies can identify disseminated disease, and CT and MRI are effective in determining soft tissue involvement and spinal abnormalities.

Adolescent↗

PubMed1996

Semimembranosus-tibial collateral ligament bursitis: MR imaging findings.

PURPOSE: The purpose of this paper is to describe the MR imaging characteristics of semimembranosus-tibial collateral ligament (SMTCL) bursitis. MATERIALS AND METHODS: Fifteen patients (37-68 years old) with medial joint pain and presumed internal derangements of the knee underwent MR imaging. Fluid collections around the SMTCL were found prospectively in five patients. Our retrospective evaluation of recent MR imaging cases that had been previously diagnosed as pes anserinus bursitis revealed 10 additional cases with similar findings. RESULTS: We believe that SMTCL bursitis clinically explained the patients' medial pain in all cases diagnosed prospectively. We gave the additional cases the same diagnosis presumptively. CONCLUSIONS: SMTCL bursitis has a characteristic MR imaging appearance of fluid draped over the semimembranosus tendon in the shape of an inverted U. This entity can clinically mimic internal derangement of the knee, typically causing pain more superior and posterior to that of pes anserinus bursitis. MR imaging is useful in diagnosing SMTCL bursitis and avoiding unnecessary knee arthroscopy.

Adult↗

PubMed1995

Traumatic hip dislocation: early MRI findings.

PURPOSE: Objective of this study was to present the spectrum of early magnetic resonance imaging (MRI) findings following traumatic dislocation of the femoral head, and to identify any associated injuries that may have therapeutic or prognostic significance and be better delineated by MRI than by conventional radiography. PATIENTS AND METHODS: Prospective MRI of both hips was formed on 18 patients (14 male, 4 female; age range 14-54 years; average age 30.5 years) within 5 weeks of a traumatic femoral head dislocation. The interval between the time of injury and the time of injury and the imaging studies ranged from 2 to 35 days (average 13.2 days). Posterior dislocation was present in 14 patients and anterior dislocation in 4 patients. In the majority of cases, we performed axial T1, coronal T1, and coronal T2* (MPGR) sequences. Images were retrospectively evaluated by consensus of three radiologists for possible abnormalities of the bone and cartilage, joint space, and soft tissues. Because all patients were treated with closed reduction, surgical correlation was not obtained. RESULTS: All patients had a joint effusion or hemarthrosis. Of the 14 patients with posterior dislocation, isolated femoral head contusions (trabecular microfractures) were identified in 6 patients. Four patients had small femoral head fractures, and one had an osteochondral defect. Acetabular lip fractures were seen in six patients, and one patient had a labral tear. Four patients had intra-articular loose bodies and one had ligamentum teres entrapment. Twelve patients had iliofemoral ligament injury. All patients had muscle injury involving the gluteal region and medical fascial compartment, and 13 patients had anterior fascial compartment muscle injury. Seven patients with posterior dislocation had posterior fascial compartment injury. Of the four patients with anterior dislocation, two had bony contusion, two had cortical infraction, one had a labral tear, and all four had an iliofemoral ligament injury. All four patients in this group had muscle injury of the gluteal region and of the anterior and medial fascial compartments. CONCLUSIONS: MRI can effectively identify and quantify the muscle injury and joint effusion that invariably accompany traumatic hip dislocations. It is also useful for demonstrating trabecular bone contusion (trabecular injury) and iliofemoral ligament injury, which occur commonly with acute hip dislocation.

Acetabulum↗

PubMed1995

Carpal scaphoid: radiographic pattern of dislocation.

Plain radiographs help establish the diagnosis and pattern of dislocation of the carpal scaphoid. Isolated dislocations can be treated with closed reduction, but dislocations in conjunction with axial carpal disruption must be treated with open reduction to fix the unstable radial half of the carpus to the stable ulnar half. Two case reports illustrate each type of carpal scaphoid dislocation.

Adult↗

PubMed1995

Lipoma arborescens of the shoulder: magnetic resonance imaging findings.

Lipoma arborescens is a rare intra-articular lesion that typically affects the knee. This condition represents villous lipomatous proliferation of the synovial membrane. The magnetic resonance imaging findings are diagnostic and include a frond-like, fatty synovial mass and associated joint effusion. The authors describe a 90-year-old woman with lipoma arborescens of the shoulder. To the authors' knowledge, lipoma arborescens has not previously been reported in this joint.

Aged↗

PubMed1994

Negative bone scintigraphy with diffuse osteoblastic breast carcinoma metastases.

A patient with diffuse osteoblastic metastases from invasive lobular carcinoma of the breast is presented in whom radionuclide bone scan was negative for skeletal lesions. Skeletal metastases were documented by plain radiography, CT, MRI, and bone marrow biopsy. This case report points to the value of plain-film, CT, and MRI findings in situations of high clinical suspicion of metastatic disease despite a normal scintigraphy.

Aged↗

PubMed1994

Proximal fetal cerebral ventricle: description of US technique and initial results.

PURPOSE: To establish adequacy and ease of visualization of the proximal ventricle, normal range of measurements of the proximal ventricle, and distance of the proximal choroid plexus from the lateral ventricular wall. MATERIALS AND METHODS: With use of an angled technique, ultrasound (US) evaluation of the proximal fetal ventricle was attempted in 439 fetuses during routine obstetric US examination. Ease of examination, additional time required, mean measurements, and standard deviation (SD) were calculated. RESULTS: Visualization and measurement of the proximal ventricle were performed without difficulty in 77% of cases and with difficulty in 19%, and were impossible in 4%. Average additional time required was 4.2 minutes. The upper limit of normal for the midportion of the proximal ventricle was 8 mm (mean + 2.5 SD). In no normal pregnancy was the proximal ventricle separated from the choroid plexus by greater than 3 mm. CONCLUSION: Visualization and measurement of the proximal fetal cerebral ventricle can be performed during routine obstetric US examination in little additional time and can be used to detect abnormalities that might otherwise be overlooked because of fetal position.

Cerebral Ventricles↗

PubMed1994

Distal lateral ventricular atrium: reevaluation of normal range.

PURPOSE: To reassess the mean size of the lateral cerebral ventricular atrium in the fetus. MATERIALS AND METHODS: Measurements were obtained from axial ultrasound (US) images of 500 fetuses by using the standard criteria, and they were reviewed for consistency. Eleven fetuses had ventricular atrial measurements of 10 mm or more, and they were also followed up. Postnatal evaluation consisted of US examinations of the head in three patients and clinical examination of all 11 patients. RESULTS: The mean size of the ventricular atrium was 6.6 mm with a standard deviation (SD) of 1.4 mm. However, the mean plus 2.5 SD would yield an upper normal limit of 10.1 mm. Findings at the postnatal examinations of the 11 fetuses with isolated lateral ventriculomegaly (three with measurements of 13 mm or less and eight with measurements at 10 mm) were normal. CONCLUSION: Use of 10 mm (mean from this study plus 2.5 SD) as the upper limit of normal for the ventricular atrial measurement should be continued. Measurements of 10 mm or above should prompt a careful search for associated fetal abnormalities and consideration of amniocentesis.

Brain Diseases↗

PubMed1994

Severe osteopenia in congenital erythropoietic porphyria.

Congenital erythropoietic porphyria is a rare disorder of porphyrin metabolism. The authors describe a 15-year-old boy in whom the radiologic manifestations of this disorder included the known features of osteopenia, acro-osteolysis, soft-tissue calcifications and widening of the diploic space, as well as the previously unreported findings of severe vertebral compression fractures, thoracic kyphosis, and "salt and pepper" skull.

Adolescent↗

PubMed1993

Parosteal lipoma with hyperostosis: report of two pathologically proven cases evaluated by magnetic resonance imaging.

The authors describe two cases of parosteal lipoma, an infrequent benign tumour, associated with hyperostosis. The first patient presented with a mass in the posterior neck, the other with one in the proximal forearm. Radiologic diagnosis was facilitated by magnetic resonance imaging (MRI). The MRI images showed the characteristic features of a parosteal lipoma, as well as hyperostotic areas that remained of low signal intensity in both T1-weighted and T2-weighted sequences. MRI is both sensitive and specific for diagnosing these lesions and provides excellent depiction of the anatomic features before surgery.

Adult↗

PubMed1993

Hand lipomas: detection and characterization by magnetic resonance imaging.

The initial clinical examination of two patients with a mass lesion of the palmar aspect of the hand failed to suggest the cause. Subsequently, the patients were examined with magnetic resonance imaging, which demonstrated that the lesions were lipomas. The scans revealed masses with smooth, lobulated margins and internal septations of low signal intensity; the masses exhibited high signal intensity in T1-weighted spin-echo images and intermediate signal intensity in T2-weighted images, features consistent with a lipoma.

Adult↗