Distribution of lymph nodes in men with prostatic adenocarcinoma and lymphadenopathy at presentation: a retrospective radiological review and implications for prostate and pelvis radiotherapy

AIMS

To describe the distribution of enlarged lymph nodes by nodal group found radiologically in patients presenting with adenocarcinoma of the prostate. This will help to define which nodal groups should be treated during the pelvic radiotherapy of patients with less advanced disease.

MATERIALS AND METHODS

The scans of 55 men presenting with prostate cancer and metastases to lymph nodes only were reviewed. Lymph nodes of 8 mm or more in size were considered to be enlarged.

RESULTS

The medial external iliac (obturator) nodes were most commonly enlarged (75% of patients) followed by nodes in the para-aortic region (26%) and anterior internal iliac region (24%). Para-aortic lymph-node enlargement was uncommon in the absence of pelvic lymphadenopathy. Midline pre-sacral lymph-node enlargement was not observed. Incidence of enlarged lymph nodes in the lateral external iliac group was 18%, an area which may not be routinely included during radiotherapy.

CONCLUSION

There is a case for studying further the role of including lateral external iliac lymph nodes in the pelvic radiotherapy volume, as there may be an appreciable risk of lymph-node spread to this area.

Routine computerized tomography scanning, groin ultrasound with or without fine needle aspiration cytology in the surgical management of primary squamous cell carcinoma of the vulva

We set out to study whether computerized tomography (CT) scanning of the vulva and the groin and groin ultrasound scanning (USS) alone or with fine needle aspiration cytology (FNAC) (USS/FNAC) influenced or could influence the surgical management of primary squamous cell carcinoma of the vulva (SCCaV). Forty-four patients underwent surgery for primary SCCaV following radiologic imaging by one or more modalities. Patient details included the clinical assessment of the carcinoma, radiologic findings, the operation performed, and whether the decision regarding the type and extent of surgery for the vulval carcinoma and, in particular, for the groin node dissection was or could be influenced by the radiologic findings. The age range was 38-87 years, with a median of 74 years. A total of 75 groin dissections were performed. Twenty-five of the 44 patients (56.8%) did not have groin node metastasis, 14 had unilateral metastasis (31.8%), and 5 (11.4%) had bilateral metastasis. All cases with histologically proven nodal status were analyzed to compare the preoperative imaging status with the histology. The calculated sensitivity, specificity, negative predictive value, and positive predictive value for CT were 58%, 75%, 75%, and 58%, for USS alone-87%, 69%, 94%, and 48%, and for USS-guided FNAC-80%, 100%, 93%, and 100%, respectively. There was no patient in whom surgical planning for the vulval carcinoma or the groin nodes was or could be altered by the CT findings. The data do not support the routine use of CT scanning in patients with primary SCCaV, either in assessment of the primary vulval carcinoma or in detecting groin nodal metastases. For the groin nodes, USS/FNAC is superior to CT in assessing disease status. In contrast to CT, USS/FNAC may have a useful clinical role in the management of the groin nodes in vulval carcinoma.

Imaging functional adrenal disorders

Technological developments in cross-sectional imaging have revolutionized the localization and characterization of functioning adrenal pathology. With effective use of modern imaging, the diagnosis of the cause and nature of functioning adrenal pathology can be reached speedily, accurately and efficiently in the majority of patients. We review the appearance of primary and secondary adrenal pathology, evaluate the diagnostic performance of imaging modalities, highlight newer technical developments, and propose a rational use of these tests in identifying functioning adrenal disease.

The role of magnetic resonance imaging and ultrasound in patients with adnexal masses

AIMS

To evaluate the accuracy of ultrasonography (US) and magnetic resonance imaging (MRI) in characterizing adnexal masses, and to determine which patients may benefit from MRI.

METHODS

We prospectively studied 72 women (mean age 53 years, range 19 to 86 years) with clinically suspected adnexal masses. A single experienced sonographer performed transabdominal and transvaginal greyscale spectral and colour Doppler examinations. MRI was carried out on a 1.5T system using T1, T2 and fat-suppressed T1-weighted sequences before and after intravenous injection of gadolinium. The adnexal masses were categorized as benign or malignant without knowledge of clinical details, according to the imaging features which were compared with the surgical and pathological findings.

RESULTS

For characterizing lesions as malignant, the sensitivity, specificity and accuracy of MRI were 96.6%, 83.7% and 88.9%, respectively, and of US were 100%, 39.5% and 63.9%, respectively. MRI was more specific (p<0.05) than US. Both MRI and US correctly diagnosed 17 (24%) cases with benign and 28 (39%) cases with malignant masses. MRI correctly diagnosed 19 (26%) cases with benign lesion(s), which on US were thought to be malignant. The age, menopausal status and CA-125 levels in these women made benign disease likely, but US features were suggestive of malignancy (large masses and solid-cystic lesions with nodules).

CONCLUSION

MRI is more specific and accurate than US and Doppler assessment for characterizing adnexal masses. Women who clinically have a relatively low risk of malignancy but who have complex sonographic features may benefit from MRI.

Diagnostic performance of CT versus MR in detecting aldosterone-producing adenoma in primary hyperaldosteronism (Conn's syndrome)

The aim of the present study is to compare the diagnostic performance of CT and MR imaging in detecting aldosterone-producing adenoma and to compare the interobserver variability in the detection of an aldosterone-producing adenoma on CT and MR. A retrospective study of 34 patients with primary hyperaldosteronism was performed. A total of 17 cases of aldosterone-producing adenoma and 17 cases of bilateral adrenal hyperplasia were included. The final diagnosis of an adenoma was made by surgery with histological confirmation, whereas that of bilateral adrenal hyperplasia was made on adrenal venous sampling or a good biochemical and clinical response following medical treatment alone and in the absence of a unilateral radiological abnormality. The CT (n=30) and MR (n=24) scans were reviewed independently by two radiologists experienced in adrenal imaging, who were unaware of the cause of the primary hyperaldosteronism. The diagnostic performances of both observers in detecting an aldosterone-producing adenoma on CT and MR imaging were compared. The 16 adenomatous nodules that were detected on imaging ranged from 1 to 4.75 cm in diameter. The calculated sensitivity and specificity for detecting aldosterone-producing adenoma were 87 and 93% for one observer and 85 and 82% for the other observer on CT, and 83 and 83% for one observer and 92 and 92% for the other observer on MR, respectively. Receptor operating characteristics curve analysis showed similar performances of both observers in detecting an aldosterone-producing adenoma on CT and MR imaging. There was good interobserver agreement on CT (k=0.71) and on MR (k=0.67). We have demonstrated comparable diagnostic performance and good interobserver agreement on CT and MR imaging for the detection of aldosterone-producing adenoma.

Computed tomography assessment of fat distribution in male and female patients with Cushing's syndrome

OBJECTIVE

Our aims were to describe the abdominal fat distribution in male patients with Cushing's syndrome (CS) on computerised tomography (CT), to compare our findings with non-cushingoid patients, to validate previous reports of increased visceral fat in female patients with CS and to identify any correlations between fat distribution and biochemical findings.

DESIGN

Retrospective and observational.

PATIENTS

Appropriate CT scans were identified in 31 patients (seven male) with active CS.

MEASUREMENTS

Total, visceral and subcutaneous fat areas were obtained. The percentage of visceral fat and the visceral to subcutaneous fat ratio (V:S ratio) were calculated. Biochemical data were recorded. Control data of fat distribution were obtained from the literature.

RESULTS

There was a significant increase in the V:S ratio in male patients with CS when compared with non-cushingoid controls (1.175+/-0.59 vs 0.77+/-0.39, 95% confidence interval (CI) 0.0817-0.728). There was a significant increase in the V:S ratio in female patients with CS (0.845+/-0.53 vs 0.38+/-0.19, 95% CI 0.269-0.661). There was no difference in the V:S ratio between male and female patients with CS (1.175+/-0.59 vs 0.845+/-0.53, 95% CI -0.144-0.804). No significant correlations between fat distribution and glucose levels, circulating cortisol, ACTH or lipids were found.

CONCLUSIONS

Our data demonstrate an increase in visceral fat distribution in both male and female patients with CS, with the abolition of the normal male to female difference in visceral fat. Increased visceral fat may increase the risk of the metabolic syndrome in this group of patients.

Hepatic steatosis in Cushing's syndrome: a radiological assessment using computed tomography

OBJECTIVE

Hepatic steatosis may occur in association with insulin resistance and obesity, two features commonly seen in Cushing's syndrome (CS). The aim of this report is to assess the prevalence of hepatic steatosis in patients with active CS using computed tomography (CT) and to identify any associations between hepatic steatosis, endocrine and biochemical variables and body fat distribution.

PATIENTS AND MEASUREMENTS

We identified 50 patients with active CS in whom appropriate CT was available to allow measurement of liver and spleen attenuation. In 26 patients, abdominal fat measurements were also available. Serum markers of CS and liver function tests were recorded.

RESULTS

Ten of 50 patients had a liver-to-spleen CT attenuation ratio (L/S) of less than 1, indicating hepatic steatosis. There was a significant negative correlation between both liver attenuation and L/S ratio with total abdominal fat area, visceral fat area, the percentage of visceral fat and the visceral to subcutaneous fat ratio; the strongest negative correlation was found between visceral fat area and L/S ratio (r=-0.638, P<0.001, n=26). L/S ratio positively correlated with alkaline phosphatase levels (r=+0.423, P=0.044, n=23) but with no other serum marker of CS activity or liver enzyme.

CONCLUSIONS

We have demonstrated hepatic steatosis on CT in 20% of patients with active CS. The presence of hepatic steatosis was significantly correlated with total abdominal fat area and visceral fat area.

CT of primary hyperaldosteronism (Conn's syndrome): the value of measuring the adrenal gland

OBJECTIVE

The objectives of our study of patients with primary hyperaldosteronism (Conn's syndrome) were to determine whether the adrenal glands are larger in patients with bilateral adrenal hyperplasia than in those with aldosterone-producing adenomas or in healthy control subjects; and whether a CT criterion based on adrenal gland size can be developed to positively diagnose bilateral adrenal hyperplasia.

MATERIALS AND METHODS

A retrospective study of CT scans of 28 patients with primary hyperaldosteronism was performed. The means of two observers' measurements of adrenal gland size were recorded and compared with published normal values. In addition, a radiologist experienced in adrenal imaging and unaware of the cause of the primary hyperaldosteronism diagnosed either bilateral adrenal hyperplasia or aldosterone-producing adenoma by visual inspection.

RESULTS

The adrenal glands in patients with bilateral adrenal hyperplasia were significantly (p < 0.05) larger than those in patients with aldosterone-producing adenoma or in healthy control subjects. A sensitivity of 100% was achieved when a mean limb width of greater than 3 mm was used to diagnose bilateral adrenal hyperplasia, and a specificity of 100% was achieved when the mean limb width was 5 mm or greater. Receiver operating characteristic curve analysis showed that the overall performance of the radiologist and the mean adrenal limb width in detecting bilateral adrenal hyperplasia were equivalent.

CONCLUSION

In patients with primary hyperaldosteronism, adrenal limb measurements on CT can aid in differentiating bilateral adrenal hyperplasia from aldosterone-producing adenoma because the adrenal glands in bilateral adrenal hyperplasia are larger.

MR imaging of uterine sarcomas

OBJECTIVE

The MR imaging appearances of uterine sarcomas are not well described in the literature. We describe the MR imaging features of uterine sarcomas.

MATERIALS AND METHODS

MR images from all patients with histologically proven uterine sarcomas scanned between 1993 and 2000 were reviewed. Tumor size, its relationship to the uterus, signal characteristics, and enhancement pattern after IV injection of gadolinium were noted.

RESULTS

Twenty-five scans from 22 patients were reviewed. Findings from the scans included 11 leiomyosarcomas, five mixed müllerian tumors, two rhabdosarcomas, and four endometrial stromal sarcomas. Two patterns of disease were observed, including a characteristic large heterogenous pelvic mass (n = 17) and an endometrial mass indistinguishable from endometrial carcinoma (n = 8). On T2-weighted images, the large masses were characteristically of low or intermediate background signal intensity with pockets of very high T2 signal. The areas of high T2 signal corresponded to cystic necrosis in the tumor. Pockets of high T1-weighted signal corresponded to hemorrhage. Gadolinium enhancement was present in the solid components of all tumors. This pattern was observed in all recurrent sarcomas. Some correlation was shown between the histologic subtypes and the MR imaging appearances.

CONCLUSION

Uterine sarcomas show two patterns on MR imaging. The most common presentation is a large heterogenous mass. However, sarcomas can mimic endometrial carcinoma.

MRI of pancreatic neuroendocrine tumours

Neuroendocrine tumours of the pancreas are rare and are frequently difficult to demonstrate. Several imaging modalities have been used to demonstrate these tumours, but recent reports have suggested that MRI may have an important role in their localization. We review the spectrum of MRI appearances of pancreatic neuroendocrine tumours.

The effect of decreasing mAs on image quality and patient dose in sinus CT

The aim of this study was to determine the effect of reducing mAs on the diagnostic quality of images and the radiation dose to the orbits in patients undergoing sinus CT. We studied 40 consecutive patients undergoing paranasal sinus CT for inflammatory disease prior to functional endoscopic sinus surgery (FESS). Four groups of 10 patients were scanned at 200 mAs, 150 mAs, 100 mAs and 50 mAs, respectively. Orbital radiation dose was measured using thermoluminescent dosemeters. Images were reviewed independently by two observers who were unaware of the mAs setting used. Image quality was evaluated using a semi-quantitative scoring system for six anatomical structures. The osteomeatal complex, uncinate process, infundibulum, frontal recess, middle turbinate and optic nerve were assessed as: clearly demonstrated (2 points); demonstrated but not clearly visualized (1 point); or not seen (0 points). No significant difference was shown between any of the four groups in terms of image quality according to the scoring system used in this study. Mean radiation dose to the orbit was reduced by 77%, from 13.5 mGy at 200 mAs to 3.1 mGy at 50 mAs (p<0.05). CT of the sinuses can be performed in patients prior to FESS at greatly reduced mAs without loss of diagnostic quality of the images. This is important in reducing the radiation dose to the lens.

CT assessment of tumour response to treatment: comparison of linear, cross-sectional and volumetric measures of tumour size

Changes in cross-sectional area are currently used to assess tumour response to treatment. The aims of this study were to validate a helical CT technique for volume determination using a series of phantoms and to compare tumour responses indicated by one-, two- and three-dimensional measures of tumour size change in patients treated for germ cell cancer or lymphoma. All studies were performed on an IGE HiSpeed Advantage helical CT scanner with an Advantage Windows workstation. Phantom volumes were calculated using volume reconstruction software and compared with reference volumes determined by water displacement. 20 lymph node masses were studied on serial CT scans in 16 patients treated with chemotherapy for germ cell cancer or lymphoma. For each lesion the maximum diameter, maximum cross-sectional area and volume were determined before and after treatment. Tumour response was assessed using the standard World Health Organisation criteria (i.e. changes in cross-sectional area) and the newly proposed unidimensional response evaluation criteria in solid tumour (RECIST). The CT volume measurement error was 1.0-5.1% for regularly shaped phantoms larger than 35 cm3. In the assessment of treatment response there was 90% agreement between one-dimensional (1D) and two-dimensional (2D) measurements and 100% agreement between 2D and three-dimensional (3D) measurements. CT volume measurements are accurate and reproducible, particularly for larger structures. Assessment of tumour response using 1D, 2D and 3D measures had limited influence on the classification of treatment response. However, the impact of CT assessment of tumour response using 1D, 2D and 3D measurements on clinical decisions and patient outcome remains to be determined.

The pathology of median neuropathy in acromegaly

BACKGROUND

Median neuropathy is commonly associated with acromegaly, although its pathology is uncertain.

OBJECTIVE

To study the pathology of median neuropathy in acromegaly by using magnetic resonance imaging (MRI).

DESIGN

Case series.

SETTINGS

Outpatient clinic and MRI unit.

PATIENTS

Nine patients with acromegaly, four of whom had clinical symptoms of neuropathy.

MEASUREMENTS

At presentation and 6 months after treatment, median nerve size, its signal intensity, and the volume of the carpal tunnel contents were measured.

RESULTS

At presentation, patients with symptoms of neuropathy had increased nerve size and signal intensity compared with asymptomatic patients, but the two groups did not differ in volume of carpal tunnel contents. These measures improved with treatment of acromegaly in symptomatic patients; asymptomatic patients experienced no change or worsening.

CONCLUSION

The predominant pathology of median neuropathy in acromegaly seems to be increased edema of the median nerve within the carpal tunnel rather than extrinsic compression from increased volume of the carpal tunnel contents.

Radiological and clinicopathological features of orbital xanthogranuloma

BACKGROUND

Orbital xanthogranuloma, a diagnosis confirmed histologically, occurs rarely in adults and children. With its characteristic macroscopic appearance the adult form may be associated with a spectrum of biochemical and haematological abnormalities including lymphoproliferative malignancies.

METHOD

The clinicopathological features and imaging appearances on computed tomography and magnetic resonance imaging of this condition are described in eight adults and a child.

RESULTS

Radiological evidence of proptosis was present in seven patients. In all nine patients an abnormal infiltrative soft tissue mass was seen, with increased fat in six cases. All patients had associated enlargement of extraocular muscles suggestive of infiltration and five had lacrimal gland involvement. Encasement of the optic nerve, bone destruction, and intracranial extension was present only in the child with juvenile xanthogranuloma. Haematological and/or biochemical abnormalities were detected in seven patients and seven patients had other systemic diseases which were considered to have an immune basis. One patient subsequently developed non-Hodgkin's lymphoma.

CONCLUSION

The investigation and management of orbital xanthogranulomas requires a multidisciplinary approach even though the diagnosis may be suspected clinically. Imaging delineates the extent of disease and involvement of local structures and may influence the differential diagnosis. The juvenile form may be more locally aggressive, causing bone destruction with consequent intracranial extension.

Primary hyperaldosteronism (Conn syndrome): MR imaging findings

PURPOSE

To describe the magnetic resonance (MR) imaging features of the adrenal glands in primary hyperaldosteronism and assess MR imaging in the detection and characterization of aldosterone-producing adenoma (APA).

MATERIALS AND METHODS

The authors retrospectively reviewed the cases of 20 patients (13 female and seven male patients; age range, 14-67 years; median age, 46 years) with primary hyperaldosteronism who underwent 1.5-T MR imaging between 1995 and 1998. All patients underwent transverse T1- and T2-weighted imaging, and chemical shift imaging was performed in 17 patients. Imaging results were correlated with findings at biochemical testing, venous sampling, or surgery.

RESULTS

Among the 20 patients, 10 (50%) had APA and 10 (50%) bilateral adrenal hyperplasia (BAH). In the detection of APA, MR imaging had a sensitivity of 70%, specificity of 100%, and accuracy of 85%. APAs (mean size, 20 x 16 mm) were iso- or hypointense relative to the liver on T1-weighted images and slightly hyperintense on T2-weighted images. With chemical shift imaging, the signal intensity decreased on the out-of-phase images in six of seven (86%) patients with APA and in eight of nine (89%) patients with BAH.

CONCLUSION

MR imaging has a high specificity in the detection of APA. As with nonhyperfunctioning adenoma, APA and BAH show evidence of intracellular lipid at chemical shift imaging.

Adrenal enlargement and failure of suppression of circulating cortisol by dexamethasone in patients with malignancy

The aim of this study was to further elucidate the activity of the hypothalamo-pituitary-adrenal (HPA) axis in patients with malignancy and to correlate this with the size of the adrenal glands. Fourteen patients with a variety of malignancies were studied prior to receiving cytotoxic chemotherapy. During routine staging computerized tomographic (CT) scans, the size of the body, medial and lateral limbs of the adrenal glands were measured and compared with those of a normal group of patients studied previously. Measurements of 09:00 h serum cortisol and plasma adrenocorticotropic hormone (ACTH) levels were made before and after the administration of dexamethasone (0.5 mg 6-hourly for 48 h) in addition to the peak cortisol response to i.v corticotropin releasing hormone (CRH). Overall, patients with malignancy had significantly larger adrenal glands than patients without malignancy; those with non-haematological malignancies had larger glands than patients with haematological malignancies. Following dexamethasone to suppress circulating cortisol levels, nine patients (64%) demonstrated abnormal resistance with cortisol levels > 50 nmol l(-1): mean value 294 nmol l(-1) (range 67-1147). Those patients who failed to suppress after dexamethasone had significantly larger adrenal glands than those that did suppress and tended to have non-haematological malignancies. ACTH levels were undetectable or low in three patients in whom it was measured and who did not suppress with dexamethasone. Following CRH, the cortisol levels were highest (823 and 853 nmol l(-1)) in two of these patients. Malignancy is associated with diffuse enlargement of the adrenal glands and resistance to dexamethasone-induced suppression of the HPA axis, which is not due to ectopic ACTH secretion. This disturbance of the normal control of the HPA axis is unexplained and its functional significance remains uncertain.

CT appearance of the adrenal glands in adrenocorticotrophic hormone-dependent Cushing's syndrome

OBJECTIVE

The purpose of this study was to describe the size and appearance of the adrenal glands on CT in patients with adrenocorticotrophic hormone (ACTH)-dependent Cushing's syndrome and to correlate gland dimensions with circulating cortisol and ACTH levels.

MATERIALS AND METHODS

We retrospectively analyzed clinical, biochemical, and imaging data for 53 patients referred for CT of the adrenals as part of an investigation for ACTH-dependent Cushing's syndrome at our institution between 1988 and 1997. Two observers, who were unaware of the endocrine data, measured the body and limb widths of the adrenal glands using an electronic cursor.

RESULTS

Of the 53 patients, 37 (70%) were shown to have enlarged adrenal glands on CT. The mean width of the adrenal limbs positively correlated with the circulating cortisol and ACTH levels. The adrenals were larger in patients with ectopic ACTH syndrome than in patients with Cushing's disease (p < .02). Ten patients (19%) had nodules that were 10 mm or greater in diameter.

CONCLUSION

The adrenal glands were often enlarged in patients with ACTH-dependent Cushing's syndrome, and the enlargement could be quantified on CT. However, having normalsized adrenals (observed in 30% the patients in our study) did not preclude such a diagnosis. We found that adrenal limb width positively correlates with ACTH and cortisol levels.

Computed tomography appearance of the thymus and anterior mediastinum in active Cushing's syndrome

Computed tomography (CT) evaluation of the thymus and anterior mediastinum is an important aspect of the investigation of patients with ACTH-dependent Cushing's syndrome in order to exclude an ACTH-secreting carcinoid tumor. We have reviewed the CT imaging of the thymus and anterior mediastinum in a series of 85 patients (55 females; median age 41, range 7-77 yr) with active Cushing's syndrome as there are few data on the range of appearances in hypercortisolemic states. One patient had a thymic carcinoid tumor (24 x 18 mm). Of the others, 28/84 (33%) patients showed thymic remnant tissue, consisting of either nodule(s) at least 5 mm diameter (n = 21, mean diameters 12.5 +/- 5 x 9.6 +/- 4 mm), or triangular bilobed glands (n = 7, mean thickness of the body, right and left limbs 25 +/- 7, 14 +/- 3, and 12 +/- 5 mm). Thymic involution appeared in 56/84 (67%) patients, ranging from small nodule(s) of less than 5mm diameter to linear soft tissue strands and complete fatty replacement. Patients with thymic remnant tissue were younger than those with thymic involution (P < 0.05). The thymic carcinoid tumor could be distinguished from remnant tissue on the basis of age and size. The presence of anterior mediastinal nodule(s) in hypercortisolemia need not imply the presence of a thymic carcinoid tumor, although in older patients this should arouse suspicion.

Orbital rhabdomyosarcoma--the radiological characteristics

We reviewed computed tomography (CT) studies in 30 patients with histologically confirmed orbital rhabdomyosarcoma. There were 17 male and 13 female patients, mean age 8.8 years (median age 7 years, age range 1 month to 51 years). The tumour occupied the intra and extraconal compartments in 14 (47%) cases; it was solely extraconal in 11 (37%) and intraconal in five (16%). Within the orbit the upper inner quadrant was the most common site, 20 (67%) of the tumours lying in this region. More than one quadrant was involved in 16 (53%) cases. The epicentre of the tumour was in the eyelids of three (10%) patients. At presentation the mean size of the mass was 25 x 17 mm in long and short axis diameters, respectively. The tumours were of soft tissue density with moderately well defined margins and an irregular shape. They showed mild to moderate contrast enhancement. Calcification was seen in one case. Changes in the adjacent bone were seen in at least 12 (40%) patients. Intracranial extension was present in one (3%) patient and invasion of the paranasal sinuses was also seen in one (3%) patient. The intraorbital structures were displaced or encased by the tumour mass. The globe was displaced and distorted but not invaded by the tumour. Magnetic resonance imaging (MRI) studies were also reviewed in five patients. On T1-weighted images the tumour gave a similar signal to muscle but on T2-weighted images it gave a higher signal.