Biomedical subjects

J Scheidler

Publications and source records attributed to J Scheidler.

46 records · Page 3Linked to original sources

PubMed1994

[MR tomography in staging of carcinomas of the uterus].

Magnetic resonance imaging (MRI) has proven to be a suitable imaging modality for the evaluation of uterine neoplasms. In contrast to computed tomography and ultrasound, MRI allows multiplanar observer-independent imaging of the whole female pelvis with high tissue-specific contrast. This article reviews the advantages and limitations of MRI in the staging of endometrial and cervical carcinoma, focusing on MRI with reference to other imaging modalities. New technical developments are discussed and an imaging approach for these tumor types is suggested.

Cervix Uteri↗

PubMed1994

Diagnosis of osteomyelitis. Accuracy and limitations of antigranulocyte antibody imaging compared to three-phase bone scan.

Thirty-seven patients with suspected osteomyelitis in conjunction with diabetic gangrene (N = 14, group 1), arthroplasty (N = 8, group 2), and various diseases (N = 15, group 3) were examined. Three-phase bone scans, followed by granulocyte imaging using I-123 labeled anti-NCA 95 monoclonal antibodies, were performed to evaluate and compare the diagnostic accuracy of both procedures. Final diagnosis was established histologically, bacteriologically, or by both methods either through the clinical course or by long-term follow-up in patients in group 1. Osteomyelitis was proven in 17 out of the 37 patients. Bone and antigranulocyte imaging demonstrated positive results in all patients with osteomyelitis (sensitivity 100% for each method). No signs of skeletal infection were found in 20 patients. Fifteen of these patients had no antigranulocyte antibody accumulation, resulting in 75% specificity. Ten patients without infection had normal three-phase bone imaging results (specificity 50%). Antigranulocyte imaging results were negative in 6 out of 10 patients without osteomyelitis in groups 2 and 3 whose bone imaging results were questionable. However, because of identical bone and granulocyte imaging results, no increase of diagnostic accuracy could be obtained by additional granulocyte imaging in patients with diabetic gangrene. Final diagnoses of false-positive antigranulocyte studies were aseptic osteonecrosis (N = 2), loosening of prostheses, gouty arthritis, and pain after arthrolysis. In summary, antigranulocyte antibody imaging offered high sensitivity and acceptable specificity for the diagnosis of osteomyelitis. Diagnostic accuracy can be improved through the adjuvant use of antigranulocyte imaging for patients with suspected osteomyelitis, especially when radiographic and scintigraphic results are questionable or unreliable.

Adult↗

PubMed1994

[Ct-portography in diffuse liver steatosis. Potential for a false-negative assessment].

CT portography is the most sensitive technique currently available for the preoperative diagnosis of liver metastases. We report on a patient with liver steatosis in whom ultrasound examination revealed two liver metastases in the follow up after resection of a papillary carcinoma. The liver metastases could be clearly identified both on plain CT and on enhanced CT with dynamic bolus contrast medium injection. Because of the small difference in attenuation values between liver parenchyma and metastases the two liver metastases had not been recognized on CT portography. When severe and diffuse liver steatosis is present CT portography may fail to detect metastases or small hepatocellular carcinoma.

Adult↗

PubMed1992

Immunoimaging of choroidal melanoma: assessment of its diagnostic accuracy and limitations in 101 cases.

Immunoscintigraphy (IS) was performed on 101 patients with space occupying intraocular lesions including choroidal melanomas (85), choroidal naevi (11), non-melanoma metastases (three), and other melanoma simulating lesions (two). Scintigraphic images with conventional and emission computer tomography techniques were obtained after the intravenous injection of 99mTc-labelled F(ab')2 fragments of monoclonal antibody (MoAb) 225.28S directed against the high molecular weight-melanoma associated antigen (HMW-MAA). Immunohistochemistry was performed on sections of four out of 10 melanoma-containing eyes to confirm MoAb binding. IS demonstrated positive scans in 66 out of 85 choroidal melanomas, offering a sensitivity of 78%. Sensitivity was dependent on the lesion size. True negative results were obtained in 15 out of 16 non-melanoma lesions (specificity 94%). False positive antibody accumulation was found in one patient with a post-traumatic subretinal haemorrhage. Immunohistochemistry demonstrated positive MoAb 225.28S binding in all melanoma sections. In summary IS offered substantial sensitivity and specificity in the differentiation of intraocular lesions, particularly choroidal melanomas, naevi, and metastases. In combination with other diagnostic procedures such as ultrasound echography and fluorescein angiography IS proved to be a valuable method in the diagnosis of choroidal melanoma.

Choroid↗

PubMedDate not supplied

MRI of pelvic masses: efficacy of the rectal superparamagnetic contrast agent Ferumoxsil.

The purpose of this study was to determine the potential value of rectally administered Ferumoxsil for pelvic MRI. Twenty patients with suspected rectosigmoid and ovarian tumors were prospectively examined before and after rectal administration of 300 to 600 ml of the superparamagnetic contrast agent Ferumoxsil. Imaging parameters (1.5-T system, phased-array coil, transverse T1-weighted spin echo (SE) and T2-weighted turbo-SE sequences, 6-mm slice thickness, 350-mm field of view [FOV], 512 x 512 matrix) were kept constant. Images were evaluated for tumor presence, lymphadenopathy, bowel involvement, and peritoneal implants. Precontrast and postcontrast studies were rated for bowel delineation, lesion/organ-to-bowel differentiation, presence of artifacts, and confidence of diagnosis. Delineation of rectum and sigmoid colon (P < .001) as well as separation of bowel and vagina, uterus/adnexa, dome of the urinary bladder, lymph nodes, and vessels improved significantly (P < .01) on both T1-weighted and T2-weighted postcontrast sequences. The rectal contrast agent did not increase the level of artifacts. Changes in diagnosis in 7 of 20 patients were mainly due to identification of colorectal tumors or bowel involvement on postcontrast images. The readers' diagnostic confidence was significantly higher on contrast-enhanced than on unenhanced studies (93 +/- 6.4% vs 68 +/- 25.2%). Rectal application of Ferumoxsil improves lesion/organ-to-bowel delineation and overall diagnostic confidence in pelvic MRI.

Administration, Rectal↗

PubMedDate not supplied

Computed tomography in pneumatosis intestinalis: differential diagnosis and therapeutic consequences.

Case reports of five patients with pneumatosis intestinalis diagnosed by computed tomography (CT) are presented. Etiology, differential diagnoses, and clinical consequences arising from CT imaging are discussed. In four of the patients, pneumatosis was found to be secondary to gastric ulcer, colon carcinoma, metastasis in the mesentery, and trauma-induced mesenteric ischemia. In one patient, the etiology remained elusive. Using CT, both the extent and the distribution pattern of pneumatosis could be depicted, allowing for differentiation of primary and secondary forms and assessment of prognosis. Evaluation with a lung window is a pre-requisite for reliable diagnosis of pneumatosis with CT. The presence of gas in the mesenteric or portal venous system in mesenteric ischemia is indicative of an unfavorable prognosis.

Aged↗

PubMedDate not supplied

Postoperative MRI in patients undergoing interstitial laser coagulation thermotherapy of benign prostatic hyperplasia.

OBJECTIVE: We conducted MRI of the effects of laser-induced thermal therapy (LITT) in benign prostatic hyperplasia (BPH). MATERIALS AND METHODS: Eighteen patients (average age 64 years) were examined with MRI 24-48 h before and after LITT of BPH. Sagittal and axial T2-weighted FSE MR images were evaluated for signs of coagulation necrosis in the prostate gland and the presence of intra- and extraprostatic edema. RESULTS: Coagulation areas showed as a hypointense central core with a hyperintense rim. Intraprostatic edema led to a volume increase of 18-108% both in the central and in the total gland. Periprostatic edema was severe in preprostatic and prevesical tissue as well as lateral to the prostate, moderate in the presacral space, and mild perirectally and dorsal to the prostate. Follow-up examinations 2 weeks to 6 months after LITT in five patients showed decrease of coagulation necrosis volume, prostate size, and edema. CONCLUSION: MRI appears to be a reliable method to monitor LITT effects in patients with BPH.

Aged↗

PubMedDate not supplied

Carpal tunnel syndrome: assessment by turbo spin echo, spin echo, and magnetization transfer imaging applied in a low-field MR system.

PURPOSE: The purpose of this work was to evaluate patients with carpal tunnel syndrome (CTS) using a low-field extremity MR system (E-MRI: 0.2 T). METHOD: Twenty-two patients with typical findings of CTS and 30 control persons were imaged on an E-MRI. Axial T2-weighted turbo SE (TSE), T1-weighted SE sequences, and 2D GRE magnetization transfer (MTC) sequences were compared. SE and MTC sequences were obtained before and after contrast agent administration (0.1 mmol/kg body wt of Gd-DTPA). Two readers evaluated typical MR findings of CTS independently. RESULTS: Patients with CTS demonstrated palmar bowing of the flexor retinaculum significantly more often. The normal or edematous median nerve was best identified on TSE and MTC scans (kappa = 0.59 and 0.8). The MTC sequences showed perineural enhancement significantly better than respective T1-weighted SE sequences but were rated second in comparison with T2-weighted TSE scans. CONCLUSION: At low-field strength, median nerve edema is best depicted on T2-weighted TSE sequences, whereas MTC sequences are most sensitive to perineural contrast enhancement.

Carpal Tunnel Syndrome↗

PubMedDate not supplied

Navigator echo-based respiratory gating for three-dimensional MR coronary angiography: reduction of scan time using a slice interpolation technique.

PURPOSE: The aim of the study was to compare a conventional respiratory-gated 3D MR coronary angiographic technique (conventional MRCA) with a respiratory-gated 3D MR coronary angiographic technique that includes a slice interpolation technique (slice interpolation MRCA). Both MRCA techniques were compared based on the quality of visualization of the coronary arteries and the diagnostic accuracy in identifying hemodynamically significant coronary artery stenoses. METHOD: Forty patients with known proximal coronary artery stenosis after conventional CA were examined on a 1.5 T scanner, that is, 20 patients with each sequence. A 6 point grading system (0 = worst quality, 5 = best quality) was used to evaluate and compare the image quality. The length and proximal diameter of the depicted coronary arteries were measured. Detection of coronary artery stenoses was compared with that obtained by conventional CA by two blinded readers. RESULTS: With the slice interpolation technique, the average scan time of the entire heart was reduced by approximately 40%. With use of conventional MRCA, 69% of all proximal and middle coronary artery segments were visualized with a sufficient image quality; with the slice interpolation technique, 79% of these segments were depicted adequately. For the assessment of stenoses, sensitivity was 71% and specificity was 53% for conventional MRCA and 72 and 60% for slice interpolation MRCA, respectively. These differences in sensitivity and specificity were statistically not significant. CONCLUSION: The application of a slice interpolation technique reduces the scan time, maintains a comparable sensitivity and specificity for the assessment of coronary artery stenoses, and increases the number of completely identified coronary artery segments compared with the conventional technique.

Aged↗

PubMedDate not supplied

The use of cold therapy after anterior cruciate ligament reconstruction. A prospective, randomized study and literature review.

We performed a randomized, prospective study to assess the effectiveness of postoperative cold therapy in patients who had anterior cruciate ligament reconstructions. Drain output, length of hospital stay, range of motion, and use of pain medication were all assessed. Patients were randomized into one of four groups after surgery. Group 1 patients had a cooling pad applied to the knee postoperatively and set at a temperature of 40 degrees to 50 degrees F, Group 2 had the cooling pad set at 70 degrees to 80 degrees F, Group 3 received ice packs, and Group 4 received no cold therapy of any kind. The skin temperatures in Groups 1 and 3 were significantly lower than the skin temperatures in Groups 2 and 4 (P < 0.001). The length of hospital stay, range of motion at discharge, use of oral and intramuscular pain medicine, and drain output were not significantly different between groups. No complications related to the type of cold therapy were seen in any group. Thus, both ice packs and cooling pads significantly decreased knee temperature, but we found no objective benefits in the early postoperative course due to this decrease in temperature.

Administration, Oral↗