AIM: To describe the radiological findings in primary liver lymphoma, which is a rare entity, presenting usually as a localized liver mass.MATERIALS AND METHODS: We reviewed retrospectively the imaging findings at presentation, of patients in whom a diagnosis of primary liver lymphoma was finally made histologically, The study period covered a 10-year period between January 1990 and December 1999, There were seven patients, all men, with a mean age of 49.6 years. Each patient presented with hepatobiliary disease without peripheral adenopathy, Imaging prior to diagnosis included ultrasonography (seven patients), computed tomography (seven patients) and magnetic resonance imaging (MRI) (two patients). Appearances during and after aggressive chemotherapy were reviewed.RESULTS: Imaging appearances were of either single or multiple Liver lesions simulating Liver metastases, On ultrasound all foci of primary hepatic lymphoma (PHL) were hypoechoic relative to normal liver. Computed tomography (CT) showed hypoattenuating lesions in all cases, and two cases showed rim enhancement following contrast administration. The MRI appearances were variable, and no pathognomonic feature of PHL was identified, so that histology was required in all patients to establish the diagnosis.CONCLUSIONS: This paper demonstrates the spectrum of findings encountered on various imaging modalities in PHL, We conclude that although PHL is a rare condition, it should always be considered in the differential diagnosis of liver metastases when no primary tumour is apparent. (C) 2001 The Royal College of Radiologists.

Digital subtraction is a simple, effective and relatively cheap technique which can aid in the interpretation of magnetic resonance imaging of the breast.

The authors conducted research to determine the structural relationships of the craniomandibular articulation that resulted when a mandibular reference position was established. A noninvasive clinical method was used to identify and record centric maxillomandibular relation in normal subjects and a suitable reference position in subjects with derangements of the craniomandibular articulation. The reference positions were checked for repeatability. Magnetic resonance imaging was used to determine the intraarticular relationships resulting from application of the clinical techniques. The normal subjects conformed well to the 1987 "Glossary of Prosthodontic Terms" definition, with the mandible close to first-tooth contact. In subjects with deranged articulations, the condyle was always in an abnormal relationship on the affected side in the reference position, and there were many intersubject variations.

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.

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.

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.

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.

This study investigates the potential of in vivo 31 P 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.

We describe a case of an infant with complete congenital absence of the extraocular muscles, noted at surgery and confirmed by multiplane MR, which found no evidence of extraocular muscle tissue. This almost certainly represents an extreme form of bilateral congenital fibrosis syndrome.

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.

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.

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.

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.

We report a case of moyamoya disease in a young adult female, in whom the initial clinical and radiological features were considered to be compatible with multiple sclerosis. The subsequent development of cerebral infarction led to the typical moyamoya features being found on carotid angiography. Magnetic resonance imaging (MRI) features of dilated collateral arteries were then recognized, and the initial MRI findings considered to represent demyelination were reinterpreted as areas of infarction. Although rare, moyamoya disease should be considered in the differential diagnosis in young patients presenting with symptoms and signs suggestive of multiple sclerosis. The diagnosis may be suggested by typical MRI findings.

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.

This study reviews prospectively a series of 29 patients who were examined by magnetic resonance imaging (MRI) and discography for degenerative disc disease. All had persistent low-back pain and non-diagnostic initial investigations, including plain films, myelography and/or computed tomography (CT). The imaging characteristics for degenerative disc disease correlated in 65 out of 73 intervertebral levels. All symptomatic discs were degenerate on both MRI and discography. Features of degenerative disc disease on MRI were assessed retrospectively, with a view to identifying the symptomatic level as defined by discography. MRI could not reliably detect this level, particularly in those with multi-level degenerative disc disease. Positive reproduction of symptoms at discography was the criteria used for surgery. All 12 patients in this group had posterior spinal fusion performed. Nine improved and three were unchanged. Of the ancillary features associated with disc degeneration, only a bulging annulus fibrosis proved to be of any value on MRI. Nonetheless, MRI should be used as the primary investigation in this patient group as it can lead to a marked reduction in the number of disc levels requiring injection.

Magnetic resonance (MR) imaging of the breast is currently of limited value because of lack of specificity. Enhanced MR imaging with gadolinium diethylenetriaminepentaacetic acid (DTPA) has been shown to be helpful in the further characterization of breast tissue. This prospective study attempted to differentiate benign and malignant breast disease with a dynamic enhancement technique. Bolus injection of Gd-DTPA and a short MR imaging time were used to examine 18 patients with a palpable breast mass. Construction of enhancement profiles helped effectively differentiate benign and malignant lesion (P less than .001). Dynamic MR imaging shows promise for the further characterization of breast tissue and, particularly, identification of breast carcinoma.

We report a case of moyamoya disease in a young adult female, in whom the initial clinical and radiological features were considered to be compatible with multiple sclerosis. The subsequent development of cerebral infarction led to the typical moyamoya features being found on carotid angiography. Magnetic resonance imaging (MRI) features of dilated collateral arteries were then recognized, and the initial MRI findings considered to represent demyelination were reinterpreted as areas of infarction. Although rare, moyamoya disease should be considered in the differential diagnosis in young patients presenting with symptoms and signs suggestive of multiple sclerosis. The diagnosis may be suggested by typical MRI findings.