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Biomedical subjects

H E Fjøsne

Publications and source records attributed to H E Fjøsne.

14 recordsLinked to original sources
PubMed2004

Laparoscopic navigation pointer for three-dimensional image-guided surgery.

BACKGROUND: The main drawback with the laparoscopic approach is that the surgeon is unable to palpate vessels, tumors, and organs during surgery. Furthermore, the laparoscope provides only surface view of organs. There is a need for more advanced visualizations that can enhance the view to include information below the surface of the organs for planning of the procedure and for control and guidance during treatment. METHODS: We propose three-dimensional (3D) navigation technology based on preoperatively acquired magnetic resonance or computed tomography data used in combination with a laparoscopic navigation pointer (LNP). The LNP has an attached position tracker that allows the surgeon to control the display of images interactively before and during surgery. This study evaluated the patient registration accuracy, the feasibility of image-based navigation and, qualitatively, the navigation precision in the retroperitoneum during laparoscopic surgery. RESULTS: This technology was used during the treatment of six patients (involving adrenalectomies and a neuroma protruding into the pelvis). An average patient registration accuracy of 6.90 mm was achieved. The precision during navigation in the retroperitoneum was, in some cases, better than the patient registration accuracy suggested. The technology helped the surgeons to understand better the anatomy and to locate blood vessels. CONCLUSIONS: In the reported cases, the LNP was a useful tool for image guidance in laparoscopic surgery, both for planning the surgical approach in detail and for guidance. The authors believe that adominal 3D image guidance using an LNP has a large potential for improving laparoscopic surgery, especially when vessels and anatomic relations may be difficult to identify using only a laparoscope. Accordingly, they believe this new technology could increase safety and make it easier for the surgeon to perform successful laparoscopic surgery.

Adenoma↗
PubMed2003

Abnormal chromosome 8 copy number in cytological smears from breast carcinomas detected by means of fluorescence in situ hybridization (FISH).

Numerical change in chromosome 8 is an acquired abnormality associated with high clinical stage and may be involved in the conversion of carcinoma in situ in the breast to invasive carcinoma. Fine needle aspiration smears from 53 cases of breast carcinoma were hybridized with centromeric probes for chromosome 8 and the X chromosome. Thirty-eight cases revealed chromosome 8 copy gain. Of the 45 grade II and III tumours, 28 showed polysomy (>3 signals) and six showed trisomy. Of the eight grade I tumours, four were trisomic, none were polysomic. There were only two cases of chromosome 8 copy loss (one each of grade I and III). X chromosome polysomy was also a frequent finding although the signal counts were similar to those for chromosome 8 in only a few cases. Chromosome 8 polysomy occurs frequently in breast carcinoma and high copy number (>3) is associated with high malignancy grade.

Aneuploidy↗
PubMed2000

Axillary lymph node metastases in breast cancer: preoperative detection with dynamic contrast-enhanced MRI.

Metastatic involvement of axillary lymph nodes is one of the most important prognostic variables in breast cancer. The aim of our work was to study the value of dynamic contrast-enhanced MR imaging in revealing axillary lymph node metastases from breast cancer. A total of 65 patients with invasive breast cancer treated with axillary lymph node dissection were preoperatively evaluated by MRI. T1-weighted dynamic contrast-enhanced 3D images were acquired using a coil covering the breast and the axilla. The dynamic contrast enhancement, size, and morphology of the axillary lymph nodes were registered. Histopathological examination revealed axillary lymph node metastases in 24 patients. When using a signal intensity increase in the lymph nodes of >100% during the first postcontrast image as a threshold for malignancy, 57 of 65 patients were correctly classified (sensitivity 83%, specificity 90%, accuracy 88%). These results were not improved when lymph node size and morphology were used as additional criteria. Axillary lymph nodes can be evaluated as a part of an MR-mammography study without substantial increase in examination time, and provide the surgeon with knowledge about the localization of possible metastatic lymph nodes.

Adult↗
PubMed2000

Breast lesions: evaluation with dynamic contrast-enhanced T1-weighted MR imaging and with T2*-weighted first-pass perfusion MR imaging.

PURPOSE: To evaluate the diagnostic value of an imaging protocol that combines dynamic contrast-enhanced T1-weighted magnetic resonance (MR) imaging and T2*-weighted first-pass perfusion imaging in patients with breast tumors and to determine if T2*-weighted imaging can provide additional diagnostic information to that obtained with T1-weighted imaging. MATERIALS AND METHODS: One hundred thirty patients with breast tumors underwent MR imaging with dynamic contrast-enhanced T1-weighted imaging of the entire breast, which was followed immediately with single-section, T2*-weighted imaging of the tumor. RESULTS: With T2*-weighted perfusion imaging, 57 of 72 carcinomas but only four of 58 benign lesions had a signal intensity loss of 20% or more during the first pass, for a sensitivity of 79% and a specificity of 93%. With dynamic contrast-enhanced T1-weighted imaging, 64 carcinomas and 19 benign lesions showed a signal intensity increase of 90% or more in the first image obtained after the administration of contrast material, for a sensitivity of 89% and a specificity of 67%. CONCLUSION: T2*-weighted first-pass perfusion imaging can help differentiate between benign and malignant breast lesions with a high level of specificity. The combination of T1-weighted and T2*-weighted imaging is feasible in a single patient examination and may improve breast MR imaging.

Adult↗
PubMed1999

Characterization of neoplastic and normal human breast tissues with in vivo (1)H MR spectroscopy.

The purpose of this study was to evaluate whether the detection of choline-containing compounds in in vivo (1)H magnetic resonance spectroscopy (MRS) of breast lesions is specific for carcinomas, whether a choline peak in in vivo (1)H MRS can be detected under physiological conditions of increased metabolism in breast parenchyma, and whether analysis of lipid signals can differentiate between various breast lesions and tissues. Forty patients and volunteers were examined with in vivo (1)H MR spectroscopy. Three spectra with identical localization but increasing echo times were obtained. Choline-containing compounds were detected in 9 of 11 carcinomas and in 2 of 11 benign lesions. A choline signal was also detected in five of seven volunteers who were breast-feeding at the time of examination, demonstrating that choline compounds can be detected by in vivo (1)H MRS in breast tissue under physiological conditions. Analysis of lipid signals did not contribute to differentiation between various breast lesions and tissues. J. Magn. Reson. Imaging 1999;10:159-164.

Adult↗
PubMed1999

Differentiating benign and malignant breast lesions with T2*-weighted first pass perfusion imaging.

PURPOSE: Invasive breast carcinomas and fibroadenomas are often difficult to differentiate in dynamic contrast-enhanced T1-weighted MR imaging of the breast, because both tumors can enhance strongly after contrast injection. The purpose of this study was to evaluate whether the addition of T2*-weighted first pass perfusion imaging can increase the differentiation of malignant from benign lesions. MATERIAL AND METHODS: Nine patients with invasive carcinomas and 10 patients with contrast enhancing fibroadenomas were examined by a dynamic contrast-enhanced T1-weighted 3D sequence immediately followed by a single slice T2*-weighted first pass perfusion sequence positioned in the contrast-enhancing lesion. RESULTS: The carcinomas and the fibroadenomas were impossible to differentiate based on the contrast enhancement characteristics in the T1-weighted sequence. The signal loss in the T2*-weighted perfusion sequence was significantly stronger in the carcinomas than in the fibroadenomas (p = 0.0004). CONCLUSION: Addition of a T2*-weighted first pass perfusion sequence with a high temporal resolution can probably increase the differentiation of fibroadenomas from invasive carcinomas in contrast-enhanced MR imaging of the breast.

Adult↗
PubMed1996

Inherited breast carcinoma--prospective findings in 1,194 women at risk.

According to preset criteria, 1,194 women at risk for inherited breast carcinoma were selected and subjected to examination. Six hundred and three women were examined once, 591 were followed for a mean of 1.8 years. Twenty infiltrating cancers (median age 49 years) and 16 precancers (median age 44 years) were found, demonstrating that breast carcinoma continued to occur in the selected families as expected under the hypothesis of dominant inheritance. At first round, 14 (1.2%) infiltrating carcinomas and a total of 22 (1.8%) cancers or precancers were found. Incidence rates of 0.58% pr. year for infiltrating cancers, and 1.04% pr. year for cancer or precancer were calculated. This confirms the tentative conclusions that were drawn in our previous report. These are the first prospective reports documenting how to delineate a high risk group for premenopausal breast cancer, and how to diagnose cancer at an early stage. All but two affected women had cancer without lymph node metastasis. Although a longer observation time is needed, we cautiously conclude that the results are in keeping with our aim of providing safety for those at risk. Clinical use of predictive genetic testing may be implemented within these families.

Adult↗
PubMed1994

1H NMR spectroscopic characterization of perchloric acid extracts from breast carcinomas and non-involved breast tissue.

High-resolution 1H NMR spectra were obtained from perchloric acid extracts of breast tumor specimens and adjacent non-involved tissue. Two-dimensional shift-correlated and homonuclear J-resolved spectroscopy were used to identify coupled resonances in the spectra. Chemical shifts, multiplicities and spin-spin coupling constants of several non-resolved resonances in the one-dimensional spectra could be determined by the two-dimensional methods. Several differences in the metabolite content of the two types of extracts were established. The spectra of extracts from non-involved tissue were dominated by signals from glucose and other carbohydrates, while most of the tumors had very low or no detectable levels of glucose. High concentrations of lactate, taurine and succinate, an increase of the phosphocholine level, and a very low phosphocreatine level were characteristic findings in the 1H spectra of tumor extracts. The variation in the level of myo-inositol follows the variation in glucose for the two types of tissue. Scyllo-inositol was for the first time observed in the NMR spectra from breast tissue. Uridine 5'-diphospho-N-acetylglucosamine and uridine 5'-diphospho-N-acetylgalactosamine have been identified and there is an increased level of these two hexoses in the tumor tissue. These results provide insight into breast tumor metabolism, by simultaneously detecting a large number of metabolites and demonstrate the potential for using 1H NMR spectroscopy for studying different metabolic pathways in breast tumors. At the same time they provide useful information for interpretation of in vivo 1H NMR spectra of breast tumors.

Breast↗
PubMed1986

Comparison of oral ftorafur and intravenous 5-fluorouracil in patients with advanced cancer of the stomach, colon or rectum.

In this prospective randomized study the effect of oral Ftorafur was compared with that of intravenous 5-fluorouracil in patients with advanced adenocarcinoma of the stomach, colon or rectum. Forty-five patients were evaluable. The overall response rates were 26.9% in the 5-fluorouracil group, 26.7% in the Ftorafur group. The median duration of response was 6 months in both groups. Survival in the 5-fluorouracil group was slightly better than in the Ftorafur group, but the difference was not statistically significant. The myelosuppressive effect of 5-fluorouracil was significantly stronger than that of Ftorafur. Gastrointestinal side effects were more pronounced in the Ftorafur group, but the difference was not statistically significant.

Actuarial Analysis↗
PubMed1986

Bioassay of gastrin, using the totally isolated, vascularly perfused rat stomach. A biomodel sensitive to gastrin in physiological concentrations.

A bioassay sensitive to gastrin (G 1-17) in physiological concentrations and suitable for testing of biological activity of minor amounts of radioiodinated gastrin is reported. G 1-17 was iodinated by a gentle Iodo-gen method and purified to high specific activity (1900 Ci/mmol). Totally isolated vascularly perfused rat stomachs were prepared and stimulated by graded amounts of G 1-17. Gastrin 'dose'-dependently increased the acid output from 5.7 +/- 1.0 mueq/40 min (basal) to a maximum of 58.8 +/- 10.0 mueq/40 min at a concentration of 520 pmol/l in the vascular perfusate. The lowest G 1-17 concentration that significantly increased the acid output from the basal value was 65 pmol/l, corresponding to a dose of 17.5 ng/stomach-hour. 125I-G 1-17 also increased the acid output significantly at this threshold dose. The amount of lactic acid enzymatically determined in the luminal perfusate was negligible, indicating a true parietal cell stimulation. Accordingly, a very sensitive bioassay for gastrin, suitable for testing of biological activity of G 1-17 and 125I-G, is described. Significant acid responses were obtained with physiological concentrations of gastrin, requiring less than 100 ng of hormone and labelled hormone, respectively, to show biological activity.

Animals↗
PubMed1986

Palliative intubation in malignant stricture of the oesophagus and cardia.

One-hundred patients treated with oesophageal intubation for stricture-forming inoperable oesophago-gastric malignancies during the years 1972 to 1983 were analyzed. Fifteen tubes were endoscopically positioned, the rest by thoracotomy or laparotomy. Seven patients died from causes related to the intubation, the causes of death being perforation (2), mediastinitis (3) or aortic erosion (2). Mean survival-time was three months (range one day to 14 months). Nineteen of the most deteriorated patients died within two weeks. Eighty-seven percent of the patients experienced relief of dysphagia. Thus the intended palliation was satisfactory and the results therefore support oesophageal intubation as an alternative to be considered in the treatment of malignancies of the oesophagus and cardia. However, deteriorated patients with extremely short life expectancy might not benefit from the procedure.

Adult↗
PubMedDate not supplied

Comparative signal intensity measurements in dynamic gadolinium-enhanced MR mammography.

Increases in signal intensity enhancement were measured in defined regions of interest (ROIs) to allow distinction between malignant and benign tumors with dynamic gadolinium-enhanced magnetic resonance (MR) mammography. Twenty patients with palpable breast lesions (15 malignant, five benign) underwent MR mammography. The dynamic gradient-echo sequence was performed with intravenous bolus injection of gadopentetate dimeglumine and consisted of 25 images with a time resolution of 30 seconds. Contrast enhancement was calculated by comparing user-defined ROIs on pre- and postcontrast images. An increase in signal intensity of 70% or more on the 1-minute postcontrast image was used as the criterion of malignancy. MR mammographic results correlated with histopathologic findings in all patients when the defined ROI was in the most enhancing part of the tumor. For the ROI in areas of submaximal enhancement or when the ROI surrounded the whole lesion, only five and nine tumors, respectively, fulfilled the malignancy criterion. All malignant tumors showed large variations in signal intensity enhancement that depended on the position of the ROI in the tumor. Dynamic, gadolinium-enhanced MR mammography allows distinction of benign from malignant breast tumors when the selected ROI is in the most enhancing part of the lesion.

Breast↗
PubMedDate not supplied

In vivo 1H MRS of normal breast and breast tumors using a dedicated double breast coil.

Image-guided localized proton MR spectroscopy (MRS) of normal breasts and breast tumors (ductal and undifferentiated carcinomas) was performed using a dedicated double breast coil. In vivo 1H MR spectra from 10 normal volunteers showed signals from water and lipids only, even in breasts with small contribution of fatty breast tissue. In the spectra from 6 of the 12 examined patients, an intense signal assigned to choline compounds was detected. The signal was also detected at lower levels in the remaining patients. This study shows that in vivo 1H MRI/MRS examinations of breast tumors can be performed within an examination time of 45 to 60 minutes. Signals from breast tumor metabolites may be detected using in vivo 1H MRS.

Adult↗