Whole-body magnetic resonance imaging in myxoid liposarcoma: A useful adjunct for the detection of extra-pulmonary metastatic disease.

Myxoid liposarcomas (MLS) are a subgroup of soft-tissue sarcomas which have a propensity for extra-pulmonary metastases. Conventional radiological staging of soft-tissue sarcomas consists of chest radiographs (CXR) and thoracic computed tomography (CT) for possible chest metastases, supplemented by magnetic resonance imaging (MRI) for local disease. The optimal radiological modality to detect extra-pulmonary metastases for systemic staging has not been proven. We reviewed the efficacy of Whole-Body MRI (WBMRI) for this purpose. 33 WBMRI and simultaneous CT scans were performed in 28 patients suffering from MLS between 2007 and 2015. 38 metastases were identified in seven patients via WBMRI. Osseous lesions predominated (spine, pelvis, chest-wall and long bones), followed by soft-tissue and abdominal lesions. Of the 29 soft-tissue or osseous metastases that were within the field-of-view of the simultaneous CT scans, five soft-tissue and zero osseous metastases were identified using CT. Metastatic disease was detected in three patients solely using WBMRI, which directly influenced their management. WBMRI is a useful adjunct in the detection of extra-pulmonary metastatic disease, which directly alters patient management. WBMRI has demonstrated an ability to identify more sites of metastatic disease compared to CT. WBMRI should be used in two situations. Firstly, at diagnosis where ablative treatment will be required e.g. amputation, when the diagnosis of occult metastasis would change treatment planning. Secondly, at diagnosis of relapse to confirm if it is a solitary site of relapse prior to consideration of metastectomy.

Predictors of the outcome of surgical treatment in acromegaly and the value of the mean growth hormone day curve in assessing postoperative disease activity.

Acromegaly is associated with increased morbidity and mortality unless serum GH levels are persistently less than 5 mU/L ( approximately 2 ng/mL) after treatment. Transsphenoidal surgical resection is the best available treatment for restoring GH to such "safe" levels; however, criteria for the assessment of the response to treatment are not uniform. To determine the clinically most useful method of assessing disease activity postoperatively and identify predictors of a favorable response to surgical treatment, we have analyzed 67 patients with acromegaly who underwent transsphenoidal surgery between 1993 and 1998. We used three different definitions of a satisfactory or safe response: 1) a postoperative mean GH less than 5 mU/L obtained from averaging five serum GH values obtained throughout one day; 2) a random single GH less than 5 mU/L; or 3) a serum insulin-like growth factor I (IGF-I) level within the normal range. Relying on a single GH measurement alone, 9 of the 23 patients with a single postoperative mean GH level less than 5 mU/L obtained at least one GH value of more than 5 mU/L (false positive rate, 28%) and 8 of the patients with a postoperative mean GH value of more than 5 mU/L obtained a single GH value of less than 5 mU/L (false negative rate, 15%). Postoperatively, a significant increase in the fluctuation of random GH values around the mean was observed in patients who were rendered safe (coefficient of variation, from 26 +/- 2% to 53 +/- 6%; P < 0.001) compared with patients with persistence of inadequately controlled disease. However, 13% (3 of 23) of patients with mean postoperative GH levels of less than 5 mU/L had elevated serum IGF-I levels postoperatively, and 17% (8 of 44) of patients with mean serum GH levels more than 5 mU/L had postoperative IGF-I levels within the normal range. There was no difference in the rate of agreement between mean GH less than 5 mU/L and normalization of IGF-I in relation to the interval since operation when IGF-I levels were measured. Preoperative tumor size and pretreatment mean GH levels were the major determinants of the outcome of surgery, as patients who were rendered safe had significantly lower preoperative mean GH levels than patients who were not cured (median, 31 mU/L vs. 78.5 mU/L, P < 0.01). IGF-I levels were weakly correlated with tumor size and could not be used to predict the patients who would be rendered safe. Preoperative PRL levels were higher in patients who failed to achieve a surgical satisfactory outcome [498 mU/L (187-857) vs. 196 mU/L (136-315), P < 0.01]. In summary, although single random GH values and IGF-I values are both significantly correlated with mean GH levels, they should not be used as an alternative to averaging several GH values to assess disease activity, because of the pulsatile nature of GH secretion and the multiple factors that may influence serum IGF-I. Because significant discrepancies occur, particularly postoperatively, mean GH levels remain the more reliable indicator of surgical outcome and disease activity. As there is considerably more evidence relating long-term prognosis to serum GH levels than to IGF-I and discrepancies occur between GH levels and IGF-I, we suggest that mean serum GH levels and single IGF-I levels, measured early in the postoperative period, are currently the best biochemical guide to the adequacy of surgery and, hence, the need for further treatment.

Stage 0 mucinous adenocarcinoma in situ of the urachus.

Adenocarcinomas of the urinary bladder are rare (1-5% of bladder tumours) and of notoriously poor prognosis. About one third of such tumours arise in urachal remnants related to the bladder. This is believed to be the first report of in situ change in the urachal remnant. The patient presented with mucusuria and computed tomography showed a typical urachal cyst. After excision the cyst was found to contain mucinous adenomatous epithelium but without invasion of the basal lamina. Pathological stage is the best prognostic indicator in urachal tumours. Prompt investigation and management of mucusuria may allow the diagnosis of urachal tumours in this preinvasive stage.

Rationale for a national multi-centre study of magnetic resonance imaging screening in women at genetic risk of breast cancer.

In 1994, the UK National Health Service identified as a research priority that magnetic resonance imaging (MRI) should be assessed as a screening tool for young, pre-menopausal women who are at a high genetic risk of developing breast cancer. In 1997 a national multicentre study was established to compare MRI with X-ray mammography as a method for screening for breast cancer in this group of women. This paper reviews the relevant literature and describes the rationale that led to the setting up of this study.

Protocol for a national multi-centre study of magnetic resonance imaging screening in women at genetic risk of breast cancer.

The protocol of the national multicentre study of Magnetic Resonance Imaging (MRI) as a method of screening for breast cancer in women at genetic risk is described. The sensitivity and specificity of contrast-enhanced MRI will be compared with two-view X-ray mammography in a comparative trial. Approximately 500 women below the age of 50 at high genetic risk of breast cancer will be recruited per year for 3 years, with annual MRI and X-ray examination continuing for up to 5 years. A symptomatic cohort will be measured in the initial phase of the study to ensure consistent reporting between centres. The MRI examination will comprise an initial high-sensitivity screening measurement, followed by a high-specificity measurement in equivocal cases. Retrospective analysis will identify the most specific indicators of malignancy. Sensitivity and specificity, together with diagnostic performance, diagnostic impact and therapeutic impact will be assessed with reference to pathology, follow-up and changes in diagnostic certainty and therapeutic decisions. The psychological impact of screening in this high-risk group will be ascertained.

Quantitative magnetic resonance imaging of vertebral bodies: a T1 and T2 study.

Multiple point T1 and T2 values of 424 vertebral bodies were measured and analysed. The influence of several factors including age, sex, location in the spine and status of neighbouring discs on the measured relaxation times were evaluated. The results indicate limitations in the region of interest approach. Vertebral bodies of different age, sex and location in the spine could not be distinguished. For heterogeneous tissues a more advanced form of image analysis appears to be essential. Diurnal factors resulting from the stress of normal ambulatory activity caused increased variation in vertebral body relaxation time values.

Magnetic resonance imaging screening in women at genetic risk of breast cancer: imaging and analysis protocol for the UK multicentre study. UK MRI Breast Screening Study Advisory Group.

The imaging and analysis protocol of the UK multicentre study of magnetic resonance imaging (MRI) as a method of screening for breast cancer in women at genetic risk is described. The study will compare the sensitivity and specificity of contrast-enhanced MRI with two-view x-ray mammography. Approximately 500 women below the age of 50 at high genetic risk of breast cancer will be recruited per year for three years, with annual MRI and x-ray mammography continuing for up to 5 years. A symptomatic cohort will be measured in the first year to ensure consistent reporting between centres. The MRI examination comprises a high-sensitivity three-dimensional contrast-enhanced assessment, followed by a high-specificity contrast-enhanced study in equivocal cases. Multiparametric analysis will encompass morphological assessment, the kinetics of contrast agent uptake and determination of quantitative pharmacokinetic parameters. Retrospective analysis will identify the most specific indicators of malignancy. Sensitivity and specificity, together with diagnostic performance, diagnostic impact and therapeutic impact will be assessed with reference to pathology, follow-up and changes in diagnostic certainty and therapeutic decisions. Mammography, lesion localisation, pathology and cytology will be performed in accordance with the UK NHS Breast Screening Programme quality assurance standards. Similar standards of quality assurance will be applied for MR measurements and evaluation.

Quantitative tissue characterisation in pancreatic disease using magnetic resonance imaging.

Twenty-nine patients, 27 of whom had either inflammatory disease of the pancreas or pancreatic tumour, were studied by magnetic resonance imaging (MRI) and computed tomography (CT). Six healthy volunteers were studied by MRI alone. The pancreatic T1 and T2 relaxation times were calculated using a multipoint iterative method with data from seven total saturation recovery and six spin echo sequences. Magnetic resonance imaging can demonstrate the normal pancreas and a variety of pathological processes greater than 1-2 cm in size, but with less spatial resolution than CT. The relaxation-time results indicated no significant discrimination between chronic pancreatitis and pancreatic tumour. A significant elevation in the relaxation times was observed, however, in those patients with calcific chronic pancreatitis compared with the non-calcific chronic pancreatitic group and normal controls, suggesting a different pathophysiology for the two subgroups of chronic pancreatitis. The active phase of acute pancreatitis was associated with significantly elevated relaxation times, which returned to normal levels during the resolved phase of the disease. Associated extrapancreatic fluid collections were characterised by their very long relaxation times. The problems associated with spatial resolution, respiratory motion and lack of quantitative tissue characterisation suggest that MRI of the pancreas, using present methods, is unlikely to contribute to the overall management of patients with exocrine pancreatic disease.

Detection of coronary artery bypass graft patency as assessed by magnetic resonance imaging.

In a study of 22 patients with 60 coronary artery bypass grafts, magnetic resonance imaging (MRI) correctly assessed graft patency or occlusion in 90% of cases when compared with selective coronary graft angiography and computed tomography. It is concluded that MRI can detect a normally functioning coronary artery bypass graft and could be used as a non-invasive technique to assess graft patency in patients presenting with post-operative angina.

A method for the clinical measurement of relaxation times in magnetic resonance imaging.

A method for the determination of relaxation times in clinical magnetic resonance images is described. Three components are measured: the spin-lattice (T1) and spin-spin (T2) relaxation times and the proton density (M infinity). These components are separated in the algorithm to give increased tissue discrimination. Multiple data points are used to minimise error and increase reproducibility. Errors that arise in imaging data because of the short sequence repetition periods are considered and a technique for their reduction described. Clinical results obtained using the method are reviewed. These results demonstrate the clinical utility of the technique.

Quantitative magnetic resonance imaging in rectal carcinoma.

T1 and T2 relaxation times have been calculated in 30 patients with rectal carcinoma and seven patients with a fibrotic pelvic mass. The relaxation times were calculated using a multipoint iterative method with data from seven total saturation recovery and six spin-echo sequences. The results show that the calculated T1 relaxation value is a useful discriminant between carcinoma and pelvic fibrosis and should improve the detection of early tumour recurrence.

MR imaging of the intervertebral disc: a quantitative study.

The T1 and T2 relaxation times and the proton density of the nucleus pulposus have been measured in 107 normal and 18 surgically proven degenerate intervertebral discs. Data from total saturation recovery and spin echo sequences have been utilised in a robust multi-point method and relaxation times and proton density calculated. The results show that both the T1 and T2 values of the normal nucleus pulposus decrease with age. There was no significant correlation between proton density and age in normal discs. At all ages there was a highly significant difference between the T1 values of normal and degenerate discs. With T2 a highly significant difference in the younger age groups reduced to no distinction in the seventh decade. The observed change in the T1 and T2 values of the nucleus is in agreement with the reduction of water content known to occur with age. Our results indicate that quantitative MR imaging may assist in the diagnosis of intervertebral disc degeneration.

Magnetic resonance imaging of acoustic neuromas: the role of gadolinium-DTPA.

Magnetic resonance imaging (MRI) was performed in 20 patients with evidence on computed tomography (CT) of 21 acoustic neuromas before and after intravenous administration (0.1-0.2 mmol/kg body weight) of gadolinium-diethylene-triamine-pentaacetic acid (Gd-DTPA). Multi-section spin-echo (SE) sequences of varying repetition (TR) and echo (TE) times were performed in the transverse and coronal planes with a section thickness of 10 mm. All acoustic neuromas displayed marked enhancement on the T1-weighted (short TR/TE) SE sequence post-Gd-DTPA. The intrameatal component was particularly well demonstrated compared with non-enhanced magnetic resonance (MR) images and contrast-enhanced CT. Identification of intrameatal tumour was difficult on T2-weighted SE images and one tumour was not identified on the T1-weighted SE sequence prior to Gd-DTPA. Four of five intrameatal tumours measuring less than 8 mm could only be demonstrated on CT by using CT air meatography. Extrameatal tumour extension was demonstrated on contrast-enhanced CT, although the assessment of brain-stem involvement and displacement was not as clearly seen as on coronal MR images. In two patients with large acoustic neuromas and a cyst, the true relationship of the cyst to the tumour could only be identified on the post-Gd-DTPA scan. Magnetic resonance imaging with gadolinium-DTPA is a relatively quick, safe, well tolerated and effective method for the diagnosis of acoustic neuroma.

Magnetic resonance imaging in macromelia and macrodactyly.

We report five cases presenting with soft tissue and bone overgrowth that demonstrate the ability of MRI to establish a diagnosis in the absence of specific clinical features. Disorders included macrodystrophia lipomatosa, angiolipomatosis, Klippel-Trenaunay-Weber syndrome, blue rubber bleb naevus syndrome and one case of segmental limited hypertrophy. The MRI appearances, and other radiological features of these conditions are discussed. MRI is recommended in all cases of macrodystrophy when the clinical features and plain film findings are indeterminate.

Magnetic resonance (MR) cine imaging of the human heart.

A novel approach has been developed for MR cine imaging of the human heart by a modified ECG-gated 2DFT method. A pulse sequence has been devised to minimise the effects of saturation which can be anticipated in sequences that require rapid pulsing. Five frames are produced at the same anatomical level at predetermined intervals during the cardiac cycle. The total time taken to achieve this data is 8 minutes. Additional frames can be interleaved by repeating the sequence with an ECG-gated delay. The anatomical sections, which can be in any orthogonal plane, are then displayed as a cine loop. Cine display in the coronal plane has been used to examine 10 volunteers and 12 patients. In addition to the morphological feature displayed in single slice ECG-gated imaging, areas of dyskinesia can be detected and subjective estimates have been made of left ventricular function.

Analysis of magnetic resonance images from normal and degenerate lumbar intervertebral discs.

Degenerate discs can be identified quantitatively by measurement of magnetic resonance (MR) relaxation times. MR images have been recorded from 16-year-old and 82-year-old cadaveric L3-4 discs at the highest resolution attainable with a Picker International MR Imaging System operating at 0.26 Tesla. By recording images with a series of spin-echo and/or saturation-recovery sequences of differing time intervals, the values for sample magnetization, M infinity, and the T1 and T2 relaxation times, have been calculated from each pixel in the MR image. The distribution of M infinity values shows the relative degrees of hydration in different regions of the disc while the corresponding T1 and T2 values are sensitive to the chemical environment of the water molecules. Images from cadaveric discs allowed the nucleus pulposus and annulus fibrosus to be distinguished clearly, and the laminated structure of the annulus could be seen. Loss of water from the nucleus during aging was demonstrated by a reduction and change in the distribution of the M infinity values for an 82-year-old disc, as compared with a 16-year-old disc. Values of T1 and T2 indicated a difference in the chemical environment of water molecules in the nucleus pulposus and annulus fibrosus; the extent of this difference was much greater for younger than for older discs. High-resolution MR images from discs of living subjects showed almost as much detail as those from experimental specimens, but in the latter, the laminated structure of the annulus was resolved.(ABSTRACT TRUNCATED AT 250 WORDS)

The influence of chemical shift artifact on magnetic resonance imaging of the ligamentum flavum at 0.5 tesla.

STUDY DESIGN: Retrospective clinical magnetic resonance imaging study and prospective magnetic resonance imaging volunteer study of the appearance of the ligamentum flavum. OBJECTIVE: To demonstrate the effect of chemical shift artifact on the apparent thickness of the ligamentum flavum on axial magnetic resonance images. SUMMARY OF BACKGROUND DATA: The ligamentum flavum is a symmetric structure clearly seen on magnetic resonance images. Apparent unilateral thickening may be interpreted as indicating a pathologic process, and the influence of chemical shift artifact on the apparent thickness of the ligamentum flavum has not been emphasized. METHODS: Ligamenta flava thicknesses were measured from axial T1-weighted gradient echo magnetic resonance scans of 12 consecutive patients and various axial sequences in seven volunteers. RESULTS: The ligamentum flavum appeared consistently thicker on the lower side of the readout gradient field. This chemical shift effect could be manipulated by swapping phase and frequency or patient orientation in the magnet. CONCLUSIONS: Caution should be applied in attributing apparent asymmetry of the ligamenta flava to disease; the influence of chemical shift artifact should be considered.

Herniated intervertebral disc-associated periradicular fibrosis and vascular abnormalities occur without inflammatory cell infiltration.

STUDY DESIGN: Prospective histologic comparison of perineural tissues from patients requiring decompression surgery for herniated intervertebral disc with those from cadaveric controls. OBJECTIVES: To examine the significance of herniated intervertebral-disc-associated perineural vascular and fibrotic abnormalities with respect to back pain symptom generation. SUMMARY OF BACKGROUND DATA: Previous cadaveric studies have demonstrated perineural vascular congestion, dilatation, and thrombosis and perineural and intraneural fibrosis occurring in association with herniated intervertebral disc. It was suggested that these neural abnormalities were the result of ischemia, due to venous outflow obstruction, and also represented a possible cause of ongoing back pain symptoms. Criticisms of such a conclusion arose, however, because the possibility could not be excluded that these abnormalities were the result of postmortem artifact. METHODS: Histologic and immunohistochemical comparison of discal and peridiscal tissues removed from 11 patients with radiographically proven herniated intervertebral disc requiring decompressive surgery and from 6 fresh cadavers without history of back pain in life. RESULTS: Histology and immunohistochemistry of perineural and extraneural tissues from patients revealed vascular congestion, neovascularization, and endothelial abnormalities including luminal platelet adhesion, in association with reductions in von Willebrand factor levels, together with perivascular and perineural fibrosis. Elevated fibrogenic cytokine concentrations were also detected in patients' tissues. These changes occurred without evidence of inflammation and were absent in cadaveric control tissues. CONCLUSIONS: The vascular abnormalities detected in patients may represent an important etiopathologic factor predisposing to intraneural and perineural fibrosis, and hence to chronic pain symptoms, after disc herniation. It seems important to preserve the perineural microcirculation following disc herniation.

Investigation of children with suspected spinal dysraphism by magnetic resonance imaging.

Findings on Magnetic Resonance Imaging (MRI) of 52 children with suspected spinal dysraphism have been reviewed. In 24, no significant spinal abnormality was demonstrated. Seven patients had scoliosis or vertebral segmentation anomalies without demonstrable abnormality of the underlying soft tissues and one had an isolated subcutaneous haemangioma. In 20 children with spinal dysraphism, a low tethered cord was the most frequent finding, occurring in 80%. Other manifestations included myelo- or meningocoele (60%), syringomyelia (30%), lipoma (25%), congenital tumour (20%), diastematomyelia (15%) and thickened filum terminale (5%). The relationship between the clinical reason for requesting MRI and the scan results are discussed.

An unusual posterior cranial fossa tumour causing hearing loss.

Clivus meningioma is an uncommon tumour arising from the region of the synchrondrosis between the basal portions of the sphenoid and occipital bones. We report a case of a patient with a large meningioma of the clivus whose presenting symptom was auditory change. Alteration of hearing is a rare mode of presentation for such a tumour although it may present at a later stage in about 50 per cent of cases. The discrepancy between the size of the tumour and the paucity of physical findings, the value of a multiple test auditory screening strategy, and the surgical approach in this case are discussed.