PubMed Health⌕ Search

Biomedical subjects

J Zeiss

Publications and source records attributed to J Zeiss.

At least 19 recordsLinked to original sources
PubMed1996

Iron-based second-sphere contrast agents for magnetic resonance imaging: development of a model system and evaluation of iron (III) tris (tironate) complex in rats.

RATIONALE AND OBJECTIVES: Iron(III) complexes have been developed as magnetic resonance (MR) contrast agents based on the use of ligands capable of providing coordinative saturation at iron and allowing the second-sphere hydrogen bonding of water molecules. METHODS: Studies of solution-phase binding of a probe ion to a diamagnetic metal catecholate complex and molecular orbital calculations were performed. R1 values were determined. Toxicity studies of iron(III) tris(tironate) were conducted with rats. Excretion studies were performed by analysis of urine samples. MR measurements were made. RESULTS: Second-sphere coordination of a probe ion to a metal catecholate complex occurred in solution. Molecular orbital calculations suggested flexibility in design. Iron(III) tris (catecholate) complexes were shown to have high R1 values. Images of the kidneys and liver showed dose-dependent enhancement in T1-weighted images. The onset of toxicity was at approximately 0.30 mmol/kg. Urine analysis indicated essentially complete clearance (0.1-0.2 mmol/kg) within 24-48 hours. CONCLUSION: Interactions between water molecules and basic sites within a paramagnetic metal-ligand complex allow for application of suitable complexes as T1 agents.

1,2-Dihydroxybenzene-3,5-Disulfonic Acid Disodium ↗
PubMed1995

Current status of percutaneous vascular procedures.

The current nonsurgical therapeutic options for patients with peripheral vascular disease are rapidly expanding. No longer is conservative management the only alternative for patients with significantly symptomatic but noncritical limb ischemia. Certainly for vascular disease above the inguinal ligament interventional procedures especially with adjunctive stent placement have excellent success and long term patency. Femoropopliteal vascular disease of relatively limited nature also is well-treated with interventional procedures. Infrapopliteal vascular disease treated with a surgical venous bypass appears to have superior results than intervention. However, for poor surgical risk patients or in patients without the necessary venous conduit, limb salvage is still good with a percutaneous approach. Renal artery stenosis appears now to be well treated with interventional techniques. Early data with up to one year follow-up shows that even ostial stenoses respond well when vascular stents are utilized. Extending the life of failing hemodialysis grafts is another area where interventional techniques are of benefit. In the future, more extensive vascular disease and other vascular disease entities such as cerebrovascular disease and abdominal aortic aneurysm may be successfully treated by a percutaneous approach.

Angioplasty, Balloon, Coronary↗
PubMed1995

A 45-year-old woman with right shoulder pain.

The following case is presented to illustrate the roentgenographic and clinical findings of a condition of interest to the orthopedic surgeon. Initial history, physical findings, and roentgenographic examinations are found on the first page. The final clinical and roentgenographic differential diagnoses are presented on the following pages.

Diagnosis, Differential↗
PubMed1993

Case report 802: Ewing's tumor of the proximal phalanx of the third finger with radiographic progression documented over a 6-year-period.

In summary, a case of Ewing's tumor of the proximal phalanx of the long finger of the right hand was presented. This case is unusual because of its location as well as the unusually long clinical course before the correct diagnosis was made. The major point to be stressed is that Ewing's tumor may initially present with a "benign" appearance mimicking a bone cyst [17] or angioma [12]. Timely follow-up of so-called benign lesions, particularly when recurrent swelling occurs, would help in avoiding prolonged delays in diagnosis.

Bone Neoplasms↗
PubMed1992

Marginal fractures of the lateral malleolus in association with other fractures in the ankle region.

Eight cases of avulsion-type fracture of the distal fibula associated with fracture of the calcaneus, talus, or ankle region were identified. This avulsion fracture can be identified on routine radiographs as well as on CT scans of the ankle and is pathognomonic of rupture of the superior peroneal retinaculum with or without peroneal tendon displacement. Recognition of this avulsion fracture, with subsequent proper management of the underlying peroneal tendon pathology by immobilization or surgery, may prevent future tendon dysfunction. It may also alter the treatment of other associated injuries.

Adult↗
PubMed1992

The radiologic diagnosis of autopsy-proven ventilator-associated pneumonia.

An abnormal chest roentgenogram is essential for the diagnosis of ventilator-associated pneumonia. The diagnostic accuracy of various roentgenographic signs of pneumonia has not been assessed previously in the portable anteroposterior roentgenograms obtained in ventilated patients. Seven roentgenographic signs (air bronchograms, alveolar infiltrates, silhouette sign, cavities, fissure abutment, atelectasis, and asymmetric infiltrates superimposed on diffuse bilateral infiltrates) were evaluated for their accuracy in predicting pneumonia alone, in combination with other signs, or in combination with clinical parameters. The last roentgenogram prior to autopsy of 69 ventilated patients was interpreted by three reviewers and the above signs were correlated with autopsy evidence of pneumonia. Pneumonia was present in 24 (35 percent) of the 69 autopsies. No roentgenographic sign had a diagnostic efficiency of greater than 68 percent. By stepwise logistic regression, the presence of air bronchograms was the only roentgenographic sign that correlated with pneumonia in the total group, correctly predicting 64 percent of pneumonias. In patients without adult respiratory distress syndrome (ARDS), the presence of air bronchograms or alveolar infiltrates correlated with pneumonia, while in patients with ARDS, no roentgenographic sign and only the clinical parameter of purulent sputum correlated with pneumonia. Only a minority (7/22) of worsening alveolar infiltrates in all groups were due to pneumonia and were often confused with ARDS. Alveolar hemorrhage occurred with a surprising frequency (38 percent of autopsies), including 13/45 (29 percent) patients without pneumonia. Alveolar hemorrhage was associated with 29 percent of multiple air bronchograms and 30 percent of bilateral alveolar infiltrates in patients without pneumonia. We conclude that in intubated patients with diffuse bilateral roentgenographic infiltrates, no roentgenographic sign correlates well with pneumonia. No clinical parameter added to the accuracy of either an alveolar infiltrate or an air bronchogram in patients without diffuse infiltrates. Pulmonary hemorrhage and/or infarction are frequent autopsy findings in intubated patients and may be confused radiologically with pneumonia.

Autopsy↗
PubMed1992

The ulnar tunnel at the wrist (Guyon's canal): normal MR anatomy and variants.

The ulnar tunnel (Guyon's canal) is a fibroosseous tunnel along the anteromedial portion of the wrist that contains the ulnar nerve and artery. As with the adjacent carpal tunnel, its main clinical significance is that it may cause nerve compression. The purpose of this study was to determine whether the anatomy of this area could be depicted in sufficient detail by MR imaging for MR to be useful in the evaluation of patients with ulnar neuropathy. MR studies of 36 wrists of volunteers were reviewed with attention to the size and shape of the canal, its anatomic boundaries, the presence of anomalous muscles, the size and bifurcation of the ulnar nerve, and the presence of a fibrous or muscular arch overlying the deep motor branch of the ulnar nerve. T1-weighted transverse MR images of 3-mm-thick sections were obtained by using either an extremity coil or dedicated wrist coil. Excellent anatomic delineation was achieved. The boundaries and shape of the canal varied from proximal to distal, but no statistical differences were present in the mean cross-sectional area of the canal. Anomalous muscles were present in the canal in nine (25%) of 36 wrists; six (67%) of the nine were bilateral. The ulnar nerve had a mean diameter of 3 mm and bifurcated an average distance of 12 mm from the proximal margin of the pisiform bone. Delineation of the fibromuscular arch at the origin of the flexor digiti minimi brevis muscle was limited by imager resolution, but 50% were judged to be fibrous and 50% to be muscular. Our results show that MR images depict the ulnar tunnel in excellent detail. Since those structures associated with ulnar neuropathy are clearly delineated by MR, the procedure should be useful in the evaluation of patients suspected of having ulnar nerve compression within the tunnel.

Adolescent↗
PubMed1992

MR imaging of the quadriceps tendon: normal layered configuration and its importance in cases of tendon rupture.

OBJECTIVE: The quadriceps tendon is a multilayered structure with separate layers arising from different muscle groups. We examined this layered configuration on MR images to determine if it is relevant in the evaluation of the traumatized quadriceps tendon. MATERIALS AND METHODS: Sagittal and axial T1-weighted MR images of 52 knees with normal tendons were reviewed to determine the number and the muscle origins of these layers. Five knees with traumatized quadriceps tendons were imaged with T1 and T2 weighting to determine the relationship between the layered configuration and the injury. RESULTS: All the normal quadriceps tendons had a laminated appearance with either four (6%), three (56%), or two (30%) layers. In 8%, the laminations were barely perceptible. The site of origin of each layer was consistent, and each favored a given muscle. The superficial layer originated from the posterior fascia of the rectus femoris muscle, and the deep layer originated from the anterior fascia of the midline vastus intermedius muscle. The middle layer(s) arose from the deep fascia separating the vastus medialis and the vastus lateralis muscles from the vastus intermedius muscle. When only two layers were present, the middle layer merged with the superficial and deep layers. In the injured tendon, complete rupture produced transection of all the layers. Incomplete ruptures were seen as focal discontinuities of individual layers; other layers remained intact. CONCLUSION: The existence of a layered configuration of the quadriceps tendon is significant in the MR examination of partial ruptures. It can help not only in detecting and localizing injuries but also in determining appropriate treatment based on the number or thickness of injured layers.

Female↗
PubMed1992

Internal fixation of radial neck fracture in a fracture dislocation of the elbow. A case report.

A 27-year-old manual laborer presented with dislocation of the right elbow, complete separation of the radial head at the neck level, and avulsion of the coronoid process. Closed reduction of the elbow resulted in ulnohumeral instability. As an alternative to silastic implant, the radial head was reduced, internally fixed, and used as a spacer to restore elbow stability. The radial head fracture healed with no sequelae. At two years follow-up examination, the patient had a stable elbow with nearly full range of motion.

Adult↗
PubMed1992

Titanium hip implants for improved magnetic resonance and computed tomography examinations.

The value of magnetic resonance imaging (MRI) for assessment of the hip has been demonstrated, particularly in cases of avascular necrosis. Magnetic resonance imaging can be used to provide anatomic evaluation of the femoral head, acetabulum, hip joint, joint fluid, and the surrounding structures. MR examinations of two patients with hip fractures fixed with stainless steel hip implants were compared with nine patients with hip fractures fixed with titanium hip implants, one of which showed avascular necrosis of the femoral head. The titanium implants resulted in less MRI artifacts, allowing for improved depiction of the femoral head and surrounding soft tissue. For this reason titanium fixation devices are recommended as a substitute for stainless steel in the hip joint region in a patient who may need future MR examination.

Bone Nails↗
PubMed1991

Radiological evaluation of peroneal tendon pathology associated with calcaneal fractures.

Review of MRI, CT, and radiographic views of 21 intraarticular calcaneal fractures revealed eight cases of peroneal tendon subluxation or dislocation. Routine radiographs were nondiagnostic for the soft tissue injury in five of these eight patients. The anatomic relationships between the tendons, retinaculum, and fibular groove could typically be identified easily on MRI or CT scan. In this combined injury, recognition of the peroneal tendon subluxation or dislocation and its proper management may reduce subsequent tendon dysfunction; it may also alter the calcaneal fracture management.

Adult↗
PubMed1991

Magnetic resonance imaging of the calcaneus: normal anatomy and application in calcaneal fractures.

Images obtained from normal volunteers demonstrate highly detailed anatomy of the soft tissue and bony structures near the calcaneus and subtalar joint. Cortical bone, marrow, articular cartilage, ligaments, tendons, muscles, fibrous tissue, vascular bundles, and nerves can be identified. However, images obtained of acute calcaneal fractures were found to offer unsatisfactory depiction of bony anatomy. The presence of small fragments was obscured by a change in normal marrow signal by contusion, hemorrhage, and edema, and by the inability of magnetic resonance (MR) to image small pieces of cortical bone. Only in rare instances might MR be helpful in the acute setting when the location or displacement of tendons cannot be clearly ascertained with computed tomography (CT). MR may prove more useful in the long-term follow-up of healed fractures with persistent pain. In this setting it might be used in the diagnosis of complications such as residual or recurrent tendon displacement, tenosynovitis, heel fat integrity, and tarsal tunnel evaluation. However, this paper did not directly compare the efficacy of MR with that of CT in the long term. Therefore, the degree to which MR may eventually supplement or supplant CT is unclear and further study is required before the use of MR can be recommended in the routine clinical follow-up of calcaneal fractures.

Ankle↗
PubMed1991

Percutaneous decompression for femoral neuropathy secondary to heparin-induced retroperitoneal hematoma: case report and review of the literature.

Retroperitoneal hematoma resulting in femoral nerve injury is a serious potential complication of systemic heparin anticoagulation. Review of the literature reveals lack of agreement with respect to conservative versus surgical management. The authors report the first case in which return of function was established by percutaneous decompression of a retroperitoneal hematoma in a patient who was not a candidate for immediate surgery. The favorable result suggests that percutaneous drainage may represent a reasonable alternative or first step in surgical treatment of this compression.

Adult↗
PubMed1991

Magnetic resonance imaging for ineffectual tarsal tunnel surgical treatment.

Tarsal tunnel syndrome (TTS) is an entrapment neuropathy caused by compression of the posterior tibial nerve beneath the ankle flexor retinaculum. Treatment of TTS consists of surgical release of the retinaculum. The failure rate is 10%-20%. Magnetic resonance (MR) imaging was used to evaluate a patient with an unsatisfactory response. MR imaging demonstrated incompleteness of the surgical release of the flexor retinaculum.

Calcaneus↗
PubMed1990

Carpal tunnel changes and median nerve compression during wrist flexion and extension seen by magnetic resonance imaging.

Magnetic resonance imaging was done on the wrists of 14 volunteer subjects with the wrists in the neutral position, then flexed and extended at 45 degrees. Computer enhanced cross-sectional areas were measured on each subject at the level of the hook of the hamate. In the neutral position the distance between confining structures around the median nerve is 2.0 +/- 0.2 mm in the anteroposterior direction, and the mean cross-sectional area of the carpal tunnel is 1.52 cm2. With the wrist in the extended position the distance available for the median nerve measures 2.2 +/- 0.4 mm and the cross-sectional area increases to 1.75 cm2. When the wrist is flexed, the distance available for the median nerve between the flexor tendons and transverse carpal ligament decreases to 1.1 +/- 0.4 mm, and the cross-sectional tunnel area decreases to 1.36 cm2. Flexion of the wrist and/or fingers both produces a palmar rearrangement of the flexor tendons creating potential compression of the median nerve. The nerve responds to these forces by becoming interposed in various positions between the superficial flexor tendons.

Adult↗
PubMed1990

Magnetic resonance imaging in the diagnosis of tarsal tunnel syndrome. Case report.

In a patient suspected of having tarsal tunnel syndrome by clinical and electrophysiological exam, magnetic resonance imaging (MRI) was performed in an attempt to define the cause. Transverse and sagittal T1 and T2 images were obtained which demonstrated tubular T2 enhancing masses felt to be abnormally dilated and tortuous veins with slow flow. The nerve was displaced posteriorly from its usual position. Surgery confirmed these findings and the retinaculum was released with good results. In certain cases, therefore, MRI can be of help in the tarsal tunnel although its overall role has yet to be defined.

Female↗
PubMed1990

Fatty liver change as a result of hepatic artery infusion chemotherapy.

Direct hepatic arterial infusion of floxuridine (FUDR) (Roche Laboratories, Division of Hoffman-LaRoche Inc., Nutley, NJ, U.S.A.) has been used extensively in the treatment of metastases of colorectal tumors to the liver. The effectiveness of infusion and tolerance of the chemotherapy has been improved utilizing a totally implantable infusion pump delivery system. However, unequal distribution of drug infusion may occur to different parts of the liver parenchyma as demonstrated by hepatic arterial infusion scintigraphy (HAPS). We present a case of such unequal perfusion in which fatty metamorphosis of the liver occurred in the overperfused liver segment after FUDR therapy. The liver parenchymal changes were followed by serial computerized tomography scans and proven by biopsy during a minilaparotomy. Serial HAPS examinations show redirection of subsequent infusion to the opposite liver lobe due to parenchymal damage and vascular sclerosis. The importance of uniform liver perfusion and a rare dose-related effect of FUDR on liver parenchyma are thereby demonstrated.

Colonic Neoplasms↗