Validation of T2- and diffusion-weighted magnetic resonance imaging for mapping intra-prostatic tumour prior to focal boost dose-escalation using intensity-modulated radiotherapy (IMRT)

BACKGROUND AND PURPOSE

To assess the diagnostic accuracy and inter-observer agreement of T2-weighted (T2W) and diffusion-weighted (DW) magnetic resonance imaging (MRI) for mapping intra-prostatic tumour lesions (IPLs) for the purpose of focal dose-escalation in prostate cancer radiotherapy.

MATERIALS AND METHODS

Twenty-six men selected for radical treatment with radiotherapy were recruited prospectively and underwent pre-treatment T2W+DW-MRI and 5 mm spaced transperineal template-guided mapping prostate biopsies (TTMPB). A 'traffic-light' system was used to score both data sets. Radiologically suspicious lesions measuring ≥0.5 cm3 were classified as red; suspicious lesions 0.2-0.5 cm3 or larger lesions equivocal for tumour were classified as amber. The histopathology assessment combined pathological grade and tumour length on biopsy (red = ≥4 mm primary Gleason grade 4/5 or ≥6 mm primary Gleason grade 3). Two radiologists assessed the MRI data and inter-observer agreement was measured with Cohens' Kappa co-efficient.

RESULTS

Twenty-five of 26 men had red image-defined IPLs by both readers, 24 had red pathology-defined lesions. There was a good correlation between lesions ≥0.5 cm3 classified "red" on imaging and "red" histopathology in biopsies (Reader 1: r = 0.61, p < 0.0001, Reader 2: r = 0.44, p = 0.03). Diagnostic accuracy for both readers for red image-defined lesions was sensitivity 85-86%, specificity 93-98%, positive predictive value (PPV) 79-92% and negative predictive value (NPV) 96%. Inter-observer agreement was good (Cohen's Kappa 0.61).

CONCLUSIONS

MRI is accurate for mapping clinically significant prostate cancer; diffusion-restricted lesions ≥0.5 cm3 can be confidently identified for radiation dose boosting.

MRI measurement of residual cervical length after radical trachelectomy for cervical cancer and the risk of adverse pregnancy outcomes: a blinded imaging analysis

OBJECTIVE

To determine the association between the residual cervix measured on postoperative MRI after radical vaginal trachelectomy (RVT) and adverse obstetrical outcomes.

DESIGN

Observational study.

SETTING

Referral Cancer centre.

POPULATION

Women who conceived after RVT for cervical cancer at the Royal Marsden Hospital, London, between 1995 and 2015.

METHODS

Postoperative MRI scans were analysed by three researchers. The agreement between researchers was assessed by Pearson's correlation coefficient and Bland-Altman plot. Patients were divided into two groups (<10 and ≥10 mm residual cervix) for the analysis of adverse obstetrical outcomes.

MAIN OUTCOME MEASURES

Late miscarriage, premature delivery, premature rupture of membranes (PROM) and chorioamnionitis.

RESULTS

Thirty-one MRI scans were available; 29 of these women had a pregnancy that progressed beyond the first trimester. There was a strong reproducibility of the measurement of residual cervix (P < 0.001). Nineteen women (65.5%) had <10 mm residual cervix and 10 (34.5%) had ≥10 mm. Among women with <10 mm residual cervix, seven (36.8%) experienced PROM and ten (66.7%) had a preterm birth; No women with ≥10 mm residual cervix had PROM and two (22.2%) had a preterm birth (P = 0.028 and P = 0.035, respectively). Overall, there were nine (16.7%) first-trimester miscarriages, six (11.1%) late fetal losses, 12 (31.6%) preterm births and 36 (66.7%) live births. After a mean follow up of 78.1 months, 36 women were disease-free and one woman had died.

CONCLUSIONS

MRI measurements of the residual cervix are reproducible between observers. The incidence of PROM and premature delivery is higher when the residual cervix after RVT is <10 mm.

TWEETABLE ABSTRACT

The risk of prematurity after RVT can be predicted from measurements of residual cervical length on postoperative MRI scan.

Investigating the relationship between virtual cystoscopy image quality and CT slice thickness

OBJECTIVE

To investigate the effect of reconstruction slice thickness on image quality at CT virtual cystoscopy (VC).

METHODS

Pelvic CT examinations in bladder cancer patients were reconstructed at different slice thicknesses (0.6-5 mm) and intervals, and resulting VC images assessed. Quality indicators were ridging, holes, floaters and dimpling artefacts, tumour definition, and an overall score, ranked 1 (best) to 7 (worst). CT number and standard deviation (SD) for bladder contents and bladder wall were recorded. The mean SD was used as a measure of noise, and the contrast-to-noise ratio (CNR) was calculated as the CT number difference between them divided by the average image noise. The mean CNR across the three levels was used for analysis. Each qualitative image quality measure was compared with CT number, noise and CNR measurements.

RESULTS

Dimpling artefacts increased with thinner slice reconstruction and correlated with increased noise, often resulting in poor tumour definition. The best overall image quality score was seen for VC images reconstructed at 1.2 mm slice thickness, probably because of the competing effects of spatial resolution and CNR.

CONCLUSION

A slice thickness reconstruction <1.2 mm does not provide for better image quality at VC owing to the presence of increased noise.

Incidental pelvic lesions in the oncology patient

The identification of an incidental (i.e. unexpected and asymptomatic) lesion can create a dilemma for the clinician and radiologist. The incidental abnormality may represent metastatic disease, a second primary malignancy or a benign lesion. The diagnosis and management of such incidental findings will depend in part on the clinical setting, the pathology and stage of underlying primary malignancy and the imaging features of the incidental abnormality. This article reviews the diagnosis and management of incidental pelvic lesions in the oncology patient.

Assessment of colorectal hepatic metastases by quantitative T2 relaxation time

AIM

To determine the T(2) relaxation time of colorectal hepatic metastases and changes in T(2) relaxation times following chemotherapy.

MATERIALS AND METHODS

42 patients with 96 hepatic colorectal metastases underwent baseline MRI. Axial T(1), T(2) and multi-echo GRASE sequences were acquired. ROIs were drawn on T(2) relaxation maps, obtained from GRASE images, encompassing metastasis and normal liver to record T(2) relaxation time values. In 11 patients with 28 metastases, MRI was repeated using same protocol at 6 weeks following chemotherapy. The median pre-treatment T(2) values of metastases and normal liver were compared using the Mann-Whitney test. The pre- and post-treatment median T(2) values of metastases were compared using the Wilcoxon-Rank test for responding (n=16) and non-responding (n=12) lesions defined by RECIST criteria. The change in T(2) values (ΔT(2)) were compared and correlated with percentage change in lesion size.

RESULTS

There was no difference in the pre-treatment median T(2) of metastases between responding (67.3±8.6) and non-responding metastases (71.4±16.5). At the end of chemotherapy, there was a decrease in the median T(2) of responding lesions (61.6±12.6) p=0.83, and increase in non-responding lesions (76.2±18.4) p=0.03, but these were not significantly different from the pre-treatment values. There was no significant difference in ΔT(2) of responding and non-responding lesions (p=0.18) and no correlation was seen between size change and ΔT(2) (coefficient=0.3).

CONCLUSION

T(2) relaxation time does not appear to predict response of colorectal liver metastasis to chemotherapy.

Fusion of high b-value diffusion-weighted and T2-weighted MR images improves identification of lymph nodes in the pelvis

Accurate identification of lymph nodes facilitates nodal assessment by size, morphological or MR lymphographic criteria. We compared the MR detection of lymph nodes in patients with pelvic cancers using T2-weighted imaging, and fusion of diffusion-weighted imaging (DWI) and T2-weighted imaging. Twenty patients with pelvic tumours underwent 5-mm axial T2-weighted and DWI (b-values 0-750 s/mm(2)) on a 1.5T system. Fusion images of b = 750 s/mm(2) diffusion-weighted MR and T2-weighted images were created. Two radiologists evaluated in consensus the T2-weighted images and fusion images independently. For each image set, the location and diameter of pelvic nodes were recorded, and nodal visibility was scored using a 4-point scale (0-3). Nodal visualisation was compared using Relative to an Identified Distribution (RIDIT) analysis. The mean RIDIT score describes the probability that a randomly selected node will be better visualised relative to the other image set. One hundred fourteen pelvic nodes (mean 5.9 mm; 2-10 mm) were identified on T2-weighted images and 161 nodes (mean 4.3 mm; 2-10 mm) on fusion images. Using fusion images, 47 additional nodes were detected compared with T2-weighted images alone (eight external iliac, 24 inguinal, 12 obturator, two peri-rectal, one presacral). Nodes detected only on fusion images were 2-9 mm (mean 3.7 mm). Nodal visualisation was better using fusion images compared with T2-weighted images (mean RIDIT score 0.689 vs 0.302). Fusion of diffusion-weighted MR with T2-weighted images improves identification of pelvic lymph nodes compared with T2-weighted images alone. The improved nodal identification may aid treatment planning and further nodal characterisation.

Epithelioid angiomyolipoma: imaging appearances

Epithelioid angiomyolipoma is a recently described rare variant of renal angiomyolipoma. It can occur in patients with or without tuberous sclerosis, and may potentially be malignant. We report the imaging findings from two cases of epithelioid angiomyolipoma: the first in a patient with tuberous sclerosis complex, arising in a horse-shoe kidney and growing into the inferior vena cava and right atrium; the second in a 62-year-old hypertensive man.

Comparison of whole-body MRI and bone scintigraphy in the detection of bone metastases in renal cancer

This study aims to compare the sensitivity of whole-body MRI with bone scintigraphy in the detection of bone metastases in patients with renal cancer. A prospective study was carried out in 47 patients with renal cancer (mean age 62 years, range 29-79 years). All patients had assessment of the skeleton with whole-body bone scintigraphy (with technetium-99m methylene diphosphonate) and whole-body MRI (coronal T(1) weighted and short tau inversion recovery sequences). The number and sites of bony metastases were assessed on each imaging investigation independently. Sites of extra-osseous metastasis on MRI were also noted. The imaging findings were correlated with other imaging modalities and follow-up. 15 patients (32%) had bone metastases at 34 different sites. Both scintigraphy and MRI were highly specific (94% and 97%, respectively), but the sensitivity of MRI (94%) was superior (p = 0.007) to that of scintigraphy (62%). MRI identified more metastases in the spine and appendicular skeleton, whereas scintigraphy showed more lesions in the skull/facial and thoracic bones. MRI identified extra-osseous metastases in 33 patients (70%), these were mainly lung and retroperitoneal in site. Whole-body MRI is a more sensitive method for detection of bone metastases in renal cancer than bone scintigraphy, and also allows the assessment of soft-tissue disease.

MRI appearances of borderline ovarian tumours

This review was performed to describe the range of magnetic resonance imaging (MRI) appearances of borderline ovarian tumours. The MRI findings in 26 patients with 31 borderline ovarian tumours (mean age: 40.1 years, range: 14-85 years) were retrospectively reviewed. For each tumour, site, size, MRI characteristics, and enhancement following gadolinium administration were recorded. There were 20 serous and 11 mucinous borderline ovarian subtypes. Nine of 26 patients demonstrated bilateral disease on MRI; synchronous contralateral ovarian disease included three benign, five serous borderline, and one serous invasive tumour. A history of a metachronous mucinous borderline tumour was identified in one patient. MRI appearances were classified into four morphological categories: group 1 (6/31, 19%), unilocular cysts; group 2 (6/31, 19%), minimally septate cysts with papillary projections; group 3 (14/31, 45%), markedly septate lesions with plaque-like excrescences; and group 4 (5/31, 16%), predominantly solid with exophytic papillary projections, all of serous subtype. There was a significant difference in mean volume between serous (841.5 cm(3)) and mucinous (6358.2 cm(3)) subtypes (p=0.009). All tumours demonstrated at least one MRI feature suggestive of malignancy. The present review demonstrates the variable MRI appearances of borderline ovarian tumours along with imaging features suggestive of tumour subtype. In patients in whom the clinical features are suggestive of a borderline ovarian tumour (young age and normal or minimally elevated CA125), the ability to predict a borderline disease using morphological features observed on MRI would be extremely helpful in surgical planning, with the potential to offer fertility or ovary-preserving surgery. Future studies are required to further this aim.

Does magnetic resonance imaging of the spine have a role in the staging of prostate cancer?

AIMS

Magnetic resonance imaging (MRI) is an effective method for evaluating the spine in patients with a high risk of metastatic disease. The aim of this study was to compare MRI spine with radionuclide bone scan in detecting spinal metastases for staging prostate cancer patients.

MATERIALS AND METHODS

A cohort of 99 patients with locally advanced prostate cancer at high risk of skeletal metastasis (prostate-specific antigen>10 ng/ml, composite Gleason score>or=8) or equivocal findings on bone scan were included in the retrospective study, and their MRI spine and bone scans were analysed.

RESULTS

Ten patients were detected to have definite spinal metastasis by bone scan, whereas 12 patients had definite skeletal metastasis by MRI spine. Compared with the 'gold standard', derived from clinical and radiological follow-up, the sensitivities for radionuclide bone scan and that for MRI spine for detecting skeletal metastasis were 71.4 and 85.7%, respectively (P=0.023), whereas the specificities were 96.5 and 97.7%, respectively (P=0.95). Of the 34 individual metastatic lesions in the spine, 15 were concordantly positive on both scans, whereas five lesions were positive only by bone scan and 11 positive only by MRI. The addition of MRI spine in the staging for prostate cancer resulted in a change of stage and management plan in seven (7%) patients.

CONCLUSION

MRI spine has comparable specificity and slightly better sensitivity than bone scan to detect spinal metastasis from prostate cancer.

Distortion-correctedT2weighted MRI: a novel approach to prostate radiotherapy planning

The purpose of this study was to evaluate distortion-corrected MRI as a radiotherapy planning tool for prostate cancer and the resultant implications for dose sparing of organs at risk. 11 men who were to be treated with radical conformal radiotherapy for localized prostate cancer had an MRI scan under radiotherapy planning conditions, which was corrected for geometric distortion. Radiotherapy plans were created for planning target volumes derived from the MRI- and CT-defined prostate. Dose volume histograms were produced for the rectum, bladder and penile bulb. The mean volume of the prostate as defined on CT and MRI was 41 cm3 and 36 cm3, respectively (p = 0.009). The predicted percentage of the rectum treated to dose levels of 45-65 Gy was significantly lower for plans delineating the prostate with MRI than for those with CT. The rectal-sparing effect was confined to the lowermost 4 cm of the rectum (anal canal). There were no differences between the predicted doses to bladder or penile bulb (as defined using MRI) between plans. In conclusion, prostate radiotherapy planning based on distortion-corrected MRI is feasible and results in a smaller target volume than does CT. This leads to a lower predicted proportion of the rectum, in particular the lower rectum (anal canal), treated to a given dose than with CT.

Surveillance in testicular cancer: who, when, what and how?

Surveillance as a management strategy in stage 1 testicular germ cell tumour (GCT) is increasing in popularity due to the recognition of the long-term side effects of treatment. Imaging, in particular computed tomography (CT), plays a central part in the surveillance protocols. There is a tendency towards less frequent use of imaging as supported by recent trials in non-seminomatous GCT but further studies are needed with respect to the assessment of seminoma and to evaluate the role of magnetic resonance imaging (MRI) instead of abdominal CT.

Primary non-Hodgkin's lymphoma of the ovaries: imaging findings

Primary ovarian lymphoma is very rare. We report a case of primary ovarian Burkitt-type non-Hodgkin's lymphoma, describing the imaging appearance on ultrasound, CT and MRI, and review the literature.

Detection of occult spinal cord compression with magnetic resonance imaging of the spine

AIMS

Spinal cord compression (SCC) is the most significant complication due to skeletal metastasis from prostate cancer. The early detection of SCC is essential as the neurological status before treatment is the major determinant influencing outcome. The aim of this investigation was to determine the role of magnetic resonance imaging of the spine in detecting SCC or occult SCC in patients with metastatic prostate cancer with no functional neurological deficit (FND).

MATERIALS AND METHODS

A retrospective analysis of the clinical data of 150 consecutive patients with metastatic prostate cancer and no FND, who had MRI of the spine from January 2001 to May 2005, was carried out. 'Overt SCC' on MRI was defined as the involvement or compression of either the spinal cord or the cauda equina by an epidural or intramedullary mass lesion and 'occult SCC' as metastatic disease causing impingement, indentation or loss of definition of the thecal sac, which were considered together for statistical purposes as radiological spinal cord compromise (rSCC).

RESULTS

Twenty-four (16%) patients had overt SCC, whereas 17 (11.3%) patients had occult SCC. Seven patients had rSCC at multiple non-contiguous sites. The significant clinical determinants of rSCC on univariate analysis were extensive bone metastasis (P=0.005) and back pain (P=0.002). On multivariate analysis, both back pain (P=0.012) and extensive bone metastasis (P=0.047) significantly predicted for rSCC.

CONCLUSION

A significant proportion (27.3%) of patients with metastatic prostate cancer may harbour overt or occult SCC in the absence of FND. MRI of the spine for the early diagnosis of SCC may be considered useful in patients with extensive skeletal metastasis and back pain.

Differential diagnosis of adnexal masses: risk of malignancy index, ultrasonography, magnetic resonance imaging, and radioimmunoscintigraphy

A risk of malignancy index (RMI), based on menopausal status, ultrasound (US) findings, and serum CA125, has previously been described and validated in the primary evaluation of women with adnexal masses and is widely used in selective referral of women from local cancer units to specialized cancer centers. Additional imaging modalities could be useful for further characterization of adnexal masses in this group of women. A prospective cohort study was conducted of 196 women with an adnexal mass referred to a teaching hospital for diagnosis and management. Follow-up data was obtained for 180 women; 119 women had benign and 61 women malignant adnexal masses. The sensitivity and specificity of specialist US, magnetic resonance imaging (MRI), radioimmunoscintigraphy (RS), and the RMI were determined. We identified a subgroup of women with RMI values of 25-1000 where the value of further specialist imaging was evaluated. Sensitivity and specificity for specialist US were 100% and 57%, for MRI 92% and 86%, and for RS 76% and 87%, respectively. Analysis of 123 patients managed sequentially, using RMI cutoff values of > or =25 and <1000 and then US and MRI provided a sensitivity of 94% and a specificity of 90%. Using this RMI cutoff followed by specialist US and MRI, as opposed to the traditional RMI cutoff value of 250, can increase the proportion of patients with cancer appropriately referred in to a cancer center, with no change in the proportion of patients with benign disease being managed in a local unit.

The performance of magnetic resonance imaging in early cervical carcinoma: a long-term experience

We report our long-term experience of performance of magnetic resonance imaging (MRI) in localizing cervical tumor, assessing tumor size, staging, and lymph node infiltration in patients with early cervical cancer. MRI of 150 patients with early carcinoma between 1995-2005 was retrospectively reviewed. Tumor location, size, tumor distance from internal os, parametrial invasion, myometrial invasion, lymph node size, and location were documented. All patients underwent surgery, pelvic lymphadenectomy, and histological correlation of MRI findings. For staging, MRI and histopathology had kappa value of 0.89. For parametrial invasion, MRI had specificity, negative predictive value (NPV) of 97% and 100%, respectively. For tumor size, MRI and histology had mean difference of -0.9 mm with 95% limits of agreement between -12.6 to +13 mm. In tumors greater than 10 mm, mean difference was 0.3 mm and limits of agreement were -7.5 to +7.9 mm. For internal os involvement sensitivity, specificity, positive predictive value (PPV) and NPV were 90%, 98%, 86%, 98%. respectively. For myometrial invasion sensitivity, specificity, NPV, and PPV were 100%, 99%, 88%, 100%, respectively. Incidence of nodal metastases was 2.9%. On a per-patient basis, sensitivity, specificity for nodal involvement was 37% and 92% and on node-by-node basis, sensitivity and specificity of MRI was 27% and 99%, respectively. Our study confirms MRI is highly accurate in localizing cervical tumor, excluding parametrial invasion, confirming myometrial and internal os invasion. MRI is therefore useful in selecting patients for surgery and mandatory in patients for fertility-preserving surgery. Using accepted size criteria for nodal involvement, MRI is insensitive and currently will not avoid need for pelvic lymphadenectomy.

Evaluation of endometrial carcinoma on magnetic resonance imaging

Our aims were to assess diagnostic performance of T2-weighted (T2W) and dynamic gadolinium-enhanced T1-weighted (T1W) magnetic resonance imaging (MRI) in the preoperative assessment of myometrial and cervical invasion by endometrial carcinoma and to identify imaging features that predict nodal metastases. Two radiologists retrospectively reviewed MR images of 96 patients with endometrial carcinoma. Tumor size, depth of myometrial and cervical invasion, and nodal enlargement were recorded and then correlated with histology. The sensitivity, specificity, positive and negative predictive values (PPV and NPV) for the identification of any myometrial invasion (superficial or deep) were 0.94, 0.50, 0.93, 0.55 on T2W and 0.92, 0.50, 0.92, 0.50 on dynamic T1W, and for deep myometrial invasion were 0.84, 0.78, 0.65, 0.91 on T2W and 0.72, 0.88, 0.72, 0.88 on dynamic T1W. The sensitivity, specificity, PPV and NPV for any cervical invasion (endocervical or stromal) were 0.65, 0.87, 0.57, 0.90 on T2W and 0.50, 0.90, 0.46, 0.92 on dynamic T1W, and for cervical stromal involvement were 0.69, 0.95, 0.69, 0.95 on T2W and 0.50, 0.96, 0.57, 0.95 on dynamic T1W. Leiomyoma or adenomyosis were seen in 73% of misdiagnosed cases. Sensitivity and specificity for the detection of nodal metastases was 66% and 73%, respectively. Fifty percent of patients with cervical invasion on MRI had nodal metastases. In conclusion, MRI has a high sensitivity for detecting myometrial invasion and a high NPV for deep invasion. MRI has a high specificity and NPV for detecting cervical invasion. Dynamic enhancement did not improve diagnostic performance. MRI may allow accurate categorization of cases into low- or high-risk groups ensuring suitable extent of surgery and adjuvant therapy

Recurrent endometrial cancer: patterns of recurrent disease and assessment of prognosis

AIM

To evaluate patterns of disease and identify factors predicting outcome in patients presenting with recurrent endometrial adenocarcinoma following primary surgery.

MATERIALS AND METHODS

A retrospective review was performed of the imaging and clinical data in 86 patients (median age 66 years, range 42-88 years) presenting with recurrent endometrial adenocarcinoma following primary surgery.

RESULTS

Following primary surgery recurrent disease occurred within 2 years in 64% and within 3 years in 87%. Relapse was seen within lymph nodes in 41 (46%), the vagina in 36 (42%) the peritoneum in 24 (28%) and the lung in 21 (24%). Unusual sites of disease included spleen, pancreas, rectum, muscle and brain. Univariate survival analysis showed the factors significant for poor outcome were: multiple sites of disease, liver and splenic disease, haematogenous, peritoneal and nodal spread, poorly differentiated tumour, and early relapse. The presence of disease within the vagina, bladder or lung was not associated with poor prognosis. Multivariate analysis identified multiple sites of disease, liver and splenic metastases to be independent predictors of poor outcome.

CONCLUSION

The most frequently observed sites of relapse are: lymph nodes, vagina, peritoneum and lung. Significant predictors of poor outcome in recurrent disease are multiple sites of disease and liver and splenic metastases.

Imaging of testicular germ cell tumours

In testicular germ cell tumour (GCT), imaging plays a central role in assessment of tumour bulk, sites of metastases, monitoring response to therapy, surgical planning and accurate assessment of disease at relapse. The primary modality used for imaging patients with GCT is computed tomography (CT) but plain film radiography, ultrasound, magnetic resonance imaging (MRI) and positron emission tomography (PET) may all have roles to play. This article reviews the role of imaging of testicular germ cell tumours.

Imaging of endometrial adenocarcinoma

Endometrial cancer is the most common gynaecological malignancy and the incidence rising. Prognosis depends on age of patient, histological grade, depth of myometrial invasion and cervical invasion and lymph node metastases. Myometrial invasion and accurate cervical involvement cannot be predicted clinically. Pre-treatment knowledge of these criteria is advantageous in order to plan treatment. The clinical challenge is to effectively select patients at risk of relapse for more radical treatment whilst avoiding over treating low risk cases. This is important as endometrial cancer predominately occurs in postmenopausal women with co-morbidities. Modern imaging provides important tools in the accurate pre-treatment assessment of endometrial cancer and may optimize treatment planning. However, there is little consensus to date on imaging in the routine preoperative assessment of endometrial carcinoma and practice varies amongst many gynaecologists. Transvaginal ultrasound is often the initial imaging examination for women with uterine bleeding. However, once the diagnosis of endometrial cancer has been made, contrast-enhanced magnetic resonance imaging (MRI) provides the best assessment of the disease. The results of contrast-enhanced MRI may identify patients who need more aggressive therapy and referral to a cancer centre. In this article we review the role of imaging in the diagnosis and staging/preoperative assessment of endometrial carcinoma.

Advanced imaging applied to radiotherapy planning in head and neck cancer: a clinical review

Head and neck squamous cell carcinoma represents an ideal model to investigate the application of recent advances in medical imaging to radiotherapy planning. Tumours usually remain localized, and are potentially curable with local radiation. The steep radiation dose-response relationships support the strategies of radiation dose escalation to increase local control. Two-dimensional simulator-based planning and CT planning have significant drawbacks in terms of accurate target volume definition. MRI has enhanced soft tissue delineation, but has to be fused with CT to allow dose calculation. Functional imaging using dynamic contrast enhanced CT or MRI sequences may allow improved knowledge of tumour function. Positron emission tomography (PET) may allow further physiological information to be determined. This review summarizes the current techniques in clinical development in this area.

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.