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Biomedical subjects

A D Vellet

Publications and source records attributed to A D Vellet.

At least 19 recordsLinked to original sources
PubMed1992

Sciatic neuropathy associated with persistent sciatic artery.

Persistent sciatic artery is a congenital vascular anomaly of the arterial supply to the lower extremity. Thrombosis, distal embolization, aneurysmal dilatation, and rupture of this vessel with compression of the sciatic nerve have been recorded. Although rare in occurrence, complications of persistent sciatic artery should be included in the differential diagnosis of sciatic neuropathy. We present a case of an acute sciatic neuropathy secondary to pseudoaneurysm formation of a persistent sciatic artery. We demonstrate the diagnostic usefulness of magnetic resonance imaging.

Adult↗
PubMed1992

Adenocarcinoma of the pancreatic ducts: comparative evaluation with CT and MR imaging at 1.5 T.

A prospective comparison of computed tomography (CT) and magnetic resonance (MR) imaging at 1.5 T was performed in 50 patients with the suspected diagnosis of pancreatic carcinoma. CT scans were obtained before and after administration of contrast material in 41 of 50 patients (82%); 34 of 41 postcontrast scans (83%) were obtained with dynamic CT. MR images were interpreted without knowledge of the results of CT, ultrasound, cholangiography, or endoscopic retrograde cholangiopancreatography in 48 patients (96%). Surgical correlation of findings at CT and MR imaging was performed in 24 patients (48%) at laparotomy and in two patients (4%) at autopsy. On T1-weighted MR images, relatively diminished signal intensity of tumor compared with that of the adjacent pancreas was a consistent finding. MR imaging proved superior to CT in identification of pancreatic carcinoma (particularly in smaller intrapancreatic tumors), peripancreatic extension, vascular and portal vein invasion, and duodenal invasion. These results suggest that MR imaging of the pancreas is superior in many instances to CT in preoperative evaluation of pancreatic carcinoma.

Adenocarcinoma↗
PubMed1992

Real-time sonography in ocular trauma.

Real-time sonography was evaluated retrospectively in 71 consecutive patients with ocular trauma. A total of 51 vitreous hemorrhages, 20 hemorrhages in the anterior chamber, 22 retinal detachments, seven choroidal detachments, five foreign bodies, and 12 dislocated lenses were identified sonographically. In 10 instances (three choroidal detachments, six retinal detachments, and one lens dislocation), these sonographic findings were not apparent on clinical examination. One hemorrhage of the anterior chamber was missed on sonography. Both sonography and clinical examination failed to visualize one retinal detachment. The results of this study show that real-time sonography is valuable in the assessment of ocular trauma and supplements clinical examination with valuable information.

Adult↗
PubMed1992

CT findings in patients with small-bowel transplants.

Orthotopic small-bowel transplantation procedures are being performed increasingly often worldwide. CT plays an important role in both the preoperative assessment and the postoperative care of these patients. This pictorial essay serves to acquaint radiologists with the CT findings related to small-bowel transplantation.

Abscess↗
PubMed1992

Magnetic resonance imaging of reconstructed knee ligaments.

Reconstruction of knee ligaments is now a common orthopedic procedure. Patients are frequently referred for magnetic resonance imaging (MRI) after later reinjury, and the ability to recognize normal reconstructed knee ligaments is therefore becoming increasingly important. This pictorial essay demonstrates various reconstructions of the cruciate and the collateral ligaments, as well as several abnormalities of these ligaments.

Anterior Cruciate Ligament↗
PubMed1992

Ultrasonographic findings in the anterior segment of the eye obtained with a nondedicated unit.

Many abnormalities of the anterior segment of the eye can be detected by ultrasonography (US), and associated anomalies of the posterior segment that are difficult to detect clinically may also be demonstrated by this modality. A total of 48 patients with ultrasonographically detectable abnormalities in the anterior segment were examined with real-time high-resolution US; 51 abnormalities were demonstrated. The most common problems were cataract (19 cases), intraocular lens implant (10), dislocated lens (9) and tumour (8). In addition, 23 abnormalities of the posterior segment of the eye were found. Six of the lesions in the posterior segment were obscured by those in the anterior segment and could be detected only by US.

Adult↗
PubMed1992

Subchondral bone infractions in acute ligamentous knee injuries demonstrated on bone scintigraphy and magnetic resonance imaging.

Bone scintigraphy is used to detect radiographically silent fractures. Magnetic resonance imaging (MRI) is currently used to screen knee injuries for cartilage and ligament damage. MRI also delineates bone marrow and fractures. We investigated the bone scintigraphic findings in patients who had subchondral bone injuries demonstrated on MRI. Thirteen patients underwent MRI, three-phase bone scintigraphy with SPECT, and arthroscopic surgery after sustaining acute traumatic hemarthrosis of a knee. They all had clinically unsuspected subchondral bone injuries demonstrated on MRI with normal radiographs and normal overlying articular cartilage at arthroscopy, consistent with occult fractures. All showed focal bone repair on scintigraphy. Two of the 13 patients showed additional bone injuries only on bone scan. Two other patients scintigraphically showed focal bone repair at the medial femoral condyle due to avulsion of the medial collateral ligament. SPECT was easier to interpret than multi-view planar imaging. Bone scintigraphy confirms subchondral fractures demonstrated on MRI but also demonstrates ligament avulsion injuries and additional more subtle bone injuries.

Adolescent↗
PubMed1992

Tuberculosis of the odontoid bone: a rare but treatable cause of quadriplegia.

Radiologic investigation plays an important role in the diagnosis and management of tuberculosis of the odontoid bone. Immediate confirmation of the condition by examination of tissue and surgery may save lives and reduce the morbidity rate substantially. When the clinical history is appropriate, a diagnosis of tuberculosis is strongly suggested by plain films of the cervical spine showing precervical swelling of the soft tissues, narrowing of the disk spaces and focal erosion of the bones and by computed tomography scans demonstrating details of the soft-tissue abnormality, focal bony erosion and sclerosis.

Adult↗
PubMed1992

Colour-flow Doppler imaging of a carotid-cavernous fistula.

The authors describe a case of carotid-cavernous fistula evaluated with both conventional carotid angiography and colour-flow Doppler ultrasonography. The findings in the colour-flow Doppler images correlated well with those from angiography; in addition, Doppler imaging supplied extra information about the direction and the velocity of flow. After embolization, colour-flow Doppler imaging demonstrated a marked decrease in the flow. The authors conclude that colour-flow Doppler imaging may be useful for noninvasively detecting and evaluating a carotid-cavernous fistula, as well as for monitoring the patient's progress after therapy.

Aged↗
PubMed1992

Peripancreatic fluid collections: vascular structures masquerading as pseudocysts.

Five patients with splanchnic arterial aneurysms and one patient with a tortuous splenic vessel presented with peripancreatic masses that exhibited an anechoic portion in real-time ultrasonography (US) images; the masses were incorrectly diagnosed as pseudocysts. In two patients a vascular abnormality was suspected, and colour-flow Doppler and pulsed Doppler US were performed; these techniques showed the presence of pseudoaneurysms. In the other four patients the possibility of a pseudoaneurysm was not entertained until further studies had been performed. These results emphasize the need for colour-duplex US evaluation of all peripancreatic fluid collections during the initial US examination to avoid the misinterpretation of an aneurysm or a pseudoaneurysm as a simple or complex fluid collection and to prevent the potential disaster of performing biopsy, surgery or other interventions.

Adult↗
PubMed1992

Current status of magnetic resonance imaging of the ankle and the hindfoot.

With the increasing use of magnetic resonance imaging (MRI) for examining the musculoskeletal system, numerous applications have been found in the evaluation of ankle and hindfoot problems. For example, MRI is ideal for assessing tendon disorders, which are common in this region. In addition, the technique allows accurate staging of osteochondral fractures, as well as both soft-tissue and bony neoplasms. Tarsal coalition can be readily evaluated and the type determined. Increasingly, arthritis and synovial abnormalities are coming under scrutiny with MRI; this is currently an area of avid interest. In this article the authors review the current status of MRI of the ankle and the hindfoot and illustrate a variety of these disorders.

Ankle Joint↗
PubMed1992

Current status of magnetic resonance imaging of the wrist.

Conventional imaging of the wrist has relied heavily on plain radiography, tomography, fluoroscopy and arthrography. More recently, computed tomography and magnetic resonance imaging (MRI) have been added to this armamentarium. In this article the authors review the normal anatomy of the wrist and demonstrate a variety of pathologic conditions that can be assessed with MRI, including avascular necrosis and tears of the intrinsic and the extrinsic ligaments and the triangular fibrocartilage. MRI of the wrist is still evolving rapidly, and its place in the work-up of wrist disorders is only now being defined.

Bone Diseases↗
PubMed1991

Occult posttraumatic osteochondral lesions of the knee: prevalence, classification, and short-term sequelae evaluated with MR imaging.

The prevalence, characterization, and classification of acute, post-traumatic, occult subcortical fractures of the knee, identified at magnetic resonance (MR) imaging, were evaluated prospectively in 120 consecutive patients first seen with acute posttraumatic hemarthrosis of the knee. Occult subcortical femoral and tibial fractures were identified in 72% of patients. A modified MR imaging classification is suggested based on a combination of the appearances of such lesions at MR imaging and their short-term osteochondral sequelae. Among 67% of a cohort of 21 patients first seen with what have been described as occult geographic subcortical fractures, osteochondral sequelae were seen at follow-up MR imaging 6-12 months later. The evidence from this study indicates that specific subcategories of occult subcortical knee fractures are associated with an inordinately high prevalence of osteochondral sequelae, especially significant cartilage damage.

Adult↗