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Biomedical subjects

J P Stack

Publications and source records attributed to J P Stack.

At least 19 recordsLinked to original sources
PubMed1995

The relationship of minor physical anomalies and other putative indices of developmental disturbance in schizophrenia to abnormalities of cerebral structure on magnetic resonance imaging.

Minor physical anomalies, together with obstetric complications, family history, and handedness status, were assessed to explore putative neurodevelopmental disturbance(s) in patients with schizophrenia whose cerebral structure had been examined previously by magnetic resonance imaging. Minor physical anomalies were related to negative symptoms in males and to premorbid intellectual function in females, but not to ventricular volume; however, three patients with evident neurodevelopmental anomalies of the ventricular system showed prominent minor physical anomalies. In exploratory analyses, obstetric complications were associated with left ventricular asymmetry, and a positive family history with inverse profiles of asymmetry in males vs. females; non-right-handedness was associated with increased ventricular volume in males but with poorer premorbid intellectual function in females. This nexus of relationships and their gender specificities suggest early dysmorphogenesis in schizophrenia that is related to sexual dimorphism.

Abnormalities, Multiple↗
PubMed1995

Basal ganglia T2 relaxation times in schizophrenia: a quantitative magnetic resonance imaging study in relation to tardive dyskinesia.

Transverse, or spin-spin, relaxation times (T2) from magnetic resonance images of basal ganglia structures were compared between control subjects and patients with schizophrenia, who were subdivided on the basis of the presence or absence of tardive dyskinesia. As a group, schizophrenic patients showed evidence of somewhat more prolonged T2 relaxation times in the right putamen and globus pallidus than did control subjects; there were no significant correlations between hemispheric T2 values and corresponding volumes of the lateral ventricles. Overall, there was little difference in T2 values between patients with and without tardive dyskinesia. These data extend the range of evidence for basal ganglia dysfunction in schizophrenia, but they do not support earlier reports of prominent T2 changes associated with tardive dyskinesia.

Adult↗
PubMed1995

Digital subtraction in Gd-DTPA enhanced imaging of the breast.

PURPOSE: This study examines the role of digital subtraction magnetic resonance imaging (MRI) of the breast in the interpretation of the morphology and characteristics of breast disease. METHODS: Thirty-one patients with an abnormal mammogram or clinically palpable abnormality underwent MRI of the breast prior to surgical excision of the lesion. FLASH 3-D images of the breast were acquired before and after IV contrast injection of Gd-DTPA. Digital subtraction was performed on selected images. The images were independently assessed by two radiologists experienced in both mammography and MRI. RESULTS: Accurate diagnosis was possible in 29 out of 31 patients using the subtraction technique compared to 23 cases using the pre-subtraction images alone. The actual extent of disease and multicentricity were also better appreciated on the subtracted image. Subtraction also provided better identification of tumour recurrence in the post-operative and post-radiotherapy breast. Chest wall and lymph node involvement were more easily appreciated on the subtraction images. CONCLUSION: Digital subtraction is a simple, effective and relatively cheap technique which can aid in the interpretation of magnetic resonance imaging of the breast.

Adult↗
PubMed1995

Tardive dyskinesia in schizophrenia. Relationship to minor physical anomalies, frontal lobe dysfunction and cerebral structure on magnetic resonance imaging.

BACKGROUND: It was hypothesised that schizophrenic patients with tardive dyskinesia show an excess of neurodevelopmental disturbance, particularly minor physical anomalies, in association with cognitive dysfunction and abnormalities of cerebral structure. METHOD: Forty-seven out-patients with a DSM-III diagnosis of schizophrenia were examined for tardive dyskinesia using the Abnormal Involuntary Movement Scale; they were examined also for minor physical anomalies and neuropsychological test performance. Cortical atrophy, signal hyperintensities and lateral ventricular volume were determined on magnetic resonance imaging. RESULTS: Patients with and without tardive dyskinesia could not be distinguished by age, gender distribution or a number of clinical measures; however, patients with tardive dyskinesia sorted fewer categories on the Wisconsin Card Sorting Test (P = 0.04). Cerebral structure in patients with and without tardive dyskinesia could not be distinguished on magnetic resonance imaging but those with dyskinesia, all of whom showed involvement of the orofacial region, showed more evident minor physical anomalies of the head relative to those of the periphery (P = 0.02). CONCLUSIONS: Tardive orofacial dyskinesia in schizophrenia appears to be associated particularly with poorer frontal lobe function, while predominance of craniofacial dysmorphogenesis may constitute a vulnerability factor that is related to the early origins of the disease process.

Adult↗
PubMed1994

1H-magnetic resonance spectroscopy of the left temporal and frontal lobes in schizophrenia: clinical, neurodevelopmental, and cognitive correlates.

Twenty eight schizophrenic patients and 20 normal volunteers underwent proton magnetic resonance spectroscopy (MRS) on the left temporal and frontal lobe regions. Male patients showed a significant reduction in frontal but not temporal n-acetylaspartate (an intraneuronally distributed metabolite) in comparison with either male controls or female patients; frontal choline was raised in male patients relative to these groups. Putative neurodevelopmental indices, including obstetric complications, family history of schizophrenia, and minor physical anomalies, proved unrelated to MRS resonances. However, multiple aspects of memory function in patients were related to temporal but not frontal creatine, a pattern that was not apparent among controls. These MRS findings complement some previous structural MRI studies and much clinical and epidemiological evidence of important gender differences in schizophrenia. The findings also suggest that memory dysfunction in patients with schizophrenia may be associated with a particular pattern of temporal lobe metabolism on MRS.

Adult↗
PubMed1994

Case report: magnetic resonance demonstration of haemorrhagic acoustic neuroma.

A 70-year-old patient with a history suggestive of acoustic neuroma developed sudden neurological symptoms. CT showed an enhancing mass in the left cerebello-pontine angle thought to be a meningioma. Magnetic resonance (MR) with gadolinium enhancement demonstrated appearances consistent with a haemorrhagic acoustic neuroma, a diagnosis confirmed at surgery. The literature regarding haemorrhagic intracerebral tumours and MR appearances of acoustic neuroma is reviewed.

Aged↗
PubMed1994

Screening for breast cancer in Ireland: the Eccles Breast Screening Programme.

The Eccles Breast Screening Programme is a population-based screening programme for breast cancer, based at the Mater Misericordiae Hospital, Dublin. It began in 1989 simultaneously with similar programmes in Belgium, France, Greece, Portugal and Spain. The objectives of the Eccles Programme are: (i) to evaluate the impact of mammographic screening on morbidity and mortality from breast cancer in Irish women; and (ii) to address the feasibility and potential value of a national breast cancer screening programme. The specific group targeted for screening is women born in 1925 to 1940 inclusive, in a defined geographical area comprising north Dublin City and County, and Counties Cavan and Monaghan. The areas combined comprise 16% of the country's population; just over 29,000 women were invited for screening. An analysis of the demographic and socioeconomic features of the target population reveals that it represents the total population remarkably well. Participants were invited from a population register to attend one of two screening units. Follow-up treatment for those with abnormalities takes place predominantly at the Mater Hospital where the facilities of the Departments of Pathology, Surgery and Oncology have been made available to the programme. Almost 18,000 women had a mammogram in the first round of screening, an overall response rate of 62%. A total of 129 cancers were detected, a prevalence of breast cancer of 7.2 per 1,000. Of those, 15 (11.6%) were entirely intraduct, and an additional 7 (5.4%) had minimal invasion. This is considerably higher than the proportion of intraduct cancers seen in referral practice populations.

Aged↗
PubMed1994

Digital subtraction in contrast-enhanced MR imaging of the postoperative lumbar spine.

OBJECTIVE: The objective of this study was to evaluate the routine use of digital image subtraction as an adjunct to standard MR sequences in patients with failed lumbar spine surgery. MATERIALS AND METHODS: Unenhanced and contrast-enhanced T1-weighted MR images of 112 consecutive patients with failed back surgery were reviewed, and corresponding axial images at the level of previous surgery were digitally subtracted by using standard software. The technique was successful in 96 patients and was abandoned in 16 owing to patient motion. Two radiologists independently assessed the subtracted images for areas of enhancement not seen on T1-weighted images, and suggested a diagnosis based on a combination of the findings on standard and subtracted images. This diagnosis was compared with the original MR diagnosis, and surgical findings were sought in cases of conflict. RESULTS: Enhancement was best seen on the subtracted images in muscle fascial planes (100%), anterior epidural fibrosis (55%), spinal canal fat (31%), posterior epidural fibrosis (27%), types I and II marrow change (24%), and facet joints (17%). Subtraction improved the homogeneity of contrast enhancement, thereby improving the visualization of nerve roots lying in scar tissue (16%), and better defined the extent of epidural fibrosis, particularly when the fibrosis was contiguous with fat. The subtracted image increased diagnostic confidence in 25% of cases, but altered final diagnosis in only two patients. CONCLUSION: Although digital subtraction revealed areas of enhancement not seen on standard spin-echo MR images, it rarely altered final diagnosis and does not appear to be useful for routine imaging of patients with failed lumbar spine surgery. It might, however, be useful for increasing diagnostic confidence or as a problem-solving technique in selected patients.

Adult↗
PubMed1993

A technique for magnetic resonance imaging of the temporomandibular joint.

T1-weighted Magnetic Resonance Imaging (MRI) of 72 temporomandibular joints (TMJs) of symptomatic patients and normal subjects was performed after they had been clinically classified. The images were then interpreted by two radiologists, blinded to the clinical classification. The technique of imaging used a head coil for bilateral imaging, allowing a 3-position study in under 1 h. Correlation between MRI and clinical classification at the level of normal vs abnormal was achieved in 61/72 joints, giving a sensitivity of 79% and a specificity of 91% for MRI relative to the clinical assessment. True coronal images were of no added value. The addition of supplemental gradient-echo images was helpful in 12/15 joints. Osseous condylar abnormalities were present in 15 joints, all of which had otherwise identifiable disc abnormalities. Diminished condylar translation was a useful indirect sign of non-reducing disc displacement. We conclude that MRI is a very useful and reliable technique in TMJ imaging. The technique described is applicable to any MR unit, without the need for dedicated coils.

Adolescent↗
PubMed1993

Magnetic resonance imaging of schizophrenia-like psychoses associated with cerebral trauma: clinicopathological correlates.

Three patients with schizophrenia-like psychosis and two with schizoaffective-like psychosis who experienced cerebral trauma before the onset of their illness underwent clinical and magnetic resonance imaging evaluation. Each patient with a schizophrenia-like psychosis, but neither of those with a schizoaffective-like psychosis, showed abnormalities confined to or including the left temporal lobe. These observations complement recent findings in schizophrenia.

Adult↗
PubMed1992

31P MRS as an early prognostic indicator of patient response to chemotherapy.

In this study 31P spectral changes were closely monitored following the initial administration of cytotoxic drugs and related to five parameters of patient response. Pre- and postchemotherapy 31P MRS examinations were performed on 16 patients with large, malignant tumors. These included four tumor types: (i) lymphoma (n = 7), (ii) breast carcinoma (n = 4), (iii) musculoskeletal tumors (n = 4), and (iv) adenocarcinoma (n = 1). A mean of 5 spectra/patient (range 2-10) was performed following the initial chemotherapy. The spectral trends exhibited by 14 of 16 patients reached "points of maximum change," after which they began to revert toward prechemotherapy values. In 2 of 16 patients that did not respond to the initial chemotherapy regimen, no spectral trends were observed. The degree of change of certain spectral parameters, namely, decreases in PME, PME/PDE, PME/PCr, PME/NTP, PDE/PCr, and tumor pH, as well as increases in the ratios Pi/PME and Pi/PDE, were associated with good patient response and separated responders from nonresponders. Pi/PME appears the most promising for discriminating partial from complete responders.

Adult↗
PubMed1992

Tissue characterization and assessment of preoperative chemotherapeutic response in musculoskeletal tumors by in vivo 31P magnetic resonance spectroscopy.

This study investigates the potential of in vivo 31P magnetic resonance spectroscopy (MRS) to characterize musculoskeletal tumors and to determine preoperative levels of histological necrosis, which is an important clinical indicator of patient response. Pretherapy MRS was performed on 28 patients with large musculoskeletal tumors: 13 with osteosarcoma, 3 with chondrosarcoma, 5 with malignant fibrous histiocytoma, 1 with desmoid tumor, 1 with Ewing's, 2 with hemangioendothelioma, 1 with myxoid liposarcoma, 1 with synovial cell sarcoma, and 1 with rhabdomyosarcoma. Fifteen patients had follow-up MRS examinations after commencement of chemotherapy (mean of five/patient), eight of whom have now had surgery. Elevated levels of PMEs (P < 0.01), P(i) (P < 0.01), and PDEs (P < 0.02) as well as elevated tumor pH (P < 0.05) were observed in all patients. The synovial cell sarcoma was characterized by high levels of PMEs (> 20%) and low pH (pH 6.76). This contrasted with the spectra obtained from the malignant fibrous histiocytomas which had high levels of PDEs (17 +/- 5%). Reductions in PDE levels postchemotherapy were associated with a high degree of necrosis (> 90%) at surgery, while an increase in PDE levels was associated with a low level of histological necrosis. Likewise, reductions in the ratios PDE/NTP and PDE/PCr and an increase in P(i)/PDE were also associated with a high level of necrosis.

Adult↗
PubMed1991

Magnetic resonance imaging in the assessment of rheumatoid arthritis--a comparison with plain film radiographs.

Conventional radiography lacks sensitivity in early rheumatoid disease. MRI with its advantages of soft tissue discrimination and multiplanar imaging facility might detect earlier disease. This study compares the MR images and conventional radiographs of 11 rheumatoid patients' wrists and carpi. In all cases, erosions were more extensive and numerous on the MR images compared to plain radiographs. MR is useful in detecting early aggressive disease and in monitoring the response to treatments.

Adult↗
PubMed1991

In vivo phosphorus-31 magnetic resonance spectroscopy of normal and pathological breast tissues.

In vivo phosphorus-31 magnetic resonance spectroscopy, at 1.5 T, in addition to magnetic resonance imaging and mammography, was performed on the breast tissue of 59 subjects, using a 40 mm or 80 mm surface coil for spectral localization. The patients were divided into three groups: Group 1, 46 control subjects; Group 2, nine patients with breast carcinoma; Group 3, four patients with benign breast disease. The relationship of age, menopausal status, breast size and pattern, use of contraceptive pill and history of breast disease to spectral characteristics of breast tissue was examined for the control group. In multivariate analysis, only menopausal status and age were found to be significantly related to tissue biochemistry. Pre-menopausal women had reduced phosphocreatine (PCr) (%) (p = 0.02), and increased phosphomonoesters (PMEs) and beta-nucleotide triphosphate (beta-NTP) (%) (p = 0.05), while the fat-to-water ratio was higher in older women (p = 0.02). No significant differences were identified between the control subjects and the patients with benign breast disease. When spectra from patients with breast carcinoma were compared with an age-matched volunteer group, alpha- and gamma-NTP (%) were found to be higher in the cancer tissue (p less than 0.01 and p = 0.01, respectively), while PCr (%) was reduced (p less than 0.01). The ratio beta-NTP:PCr was higher in the carcinoma group of patients (p less than 0.05). In vivo phosphorus-31 magnetic resonance spectroscopy is a non-invasive examination which may prove useful in the early differentiation of malignant breast disease from normal and benign conditions.

Aged↗
PubMed1991

Imaging of intramedullary tumour spread in osteosarcoma. A comparison of techniques.

The level of bone resection for osteosarcoma depends on the pre-operative evaluation of the extent of intramedullary tumour. We compared the accuracy of magnetic resonance imaging (MRI), computerised tomography (CT), and isotope bone scanning with the actual extent of the tumour in the resected specimens from 34 patients with primary osteosarcoma of a long bone. The extent of medullary tumour was defined accurately in 23 of 24 MRI scans (96%) and 24 of 32 CT scans (75%). A flexion contracture of a joint close to the tumour was an important cause for inaccurate measurements from both MRI and CT scans. Isotope bone scanning was inaccurate: its role is now confined to detecting skeletal metastases and skip lesions.

Adolescent↗
PubMed1990

A comparison of modern imaging modalities in osteonecrosis of the femoral head.

Eleven symptomatic and seven asymptomatic patients, considered to be at high risk of osteonecrosis of the hip, were studied using plain radiography, scintigraphy, computed tomography (CT) with multiplanar reconstruction (MPR), and magnetic resonance imaging (MRI), to determine the precise roles of the various imaging modalities in detecting and staging femoral head osteonecrosis, and to evaluate the incidence in an asymptomatic high-risk patient group. Osteonecrosis was best detected by MRI and was particularly useful for the diagnosis of early disease when other imaging modalities were negative. It is recommended that MRI be performed for the detection of early osteonecrosis, while CT/MPR be used for accurate staging and treatment planning in the established disease.

Adult↗