A multicentre assessment of prostate MRI quality and compliance with UK and international standards.

AIM: To assess prostate magnetic resonance imaging (MRI) image quality and compliance with technical standards between centres in the South West region of the UK. MATERIALS AND METHODS: Fifteen imaging sites in the region submitted seven consecutive anonymised MRI studies. These were assessed by two experienced radiologists in consensus. Overall, subjective image quality for T2-weighted imaging (T2W), diffusion weighted imaging (DWI), and dynamic contrast enhancement (DCE) was scored on a five-point Likert scale. Five additional quality parameters were also assessed visually, including image noise, motion, artefact, and distortion. The degree of compliance by each site with 21 published technical standards was also assessed. RESULTS: Ninety-four MRI examinations were reviewed from across all sites (mean 6.3 scans per site, range 5-7). Mean compliance with technical standards was 63% (range 38-86%). Forty-seven percent of sites did not perform DCE. One site used a 3 T scanner. The percentage of patients with overall quality scores of ≥3 (diagnostically acceptable) were 68% for T2W, 81% for DWI, and 60% for both T2W and DWI. Ninety-three percent of the 45 patients who underwent DCE had diagnostically acceptable studies. By scanner age, the percentage of patients with diagnostically acceptable T2W scores was 53% for scanners ≥7 years and 80% when <7 years (p=0.006). Comparing individual sites, the mean overall quality scores were 2.9 (range 2.2-4.2) for T2W, 3.2 (1.8-4.7) for DWI, and 3.4 (2.5-4.7) for DCE. CONCLUSION: There is wide variation in compliance with recognised technical standards and image quality across sites. If MRI is to replace biopsy in selected low-risk patients, improvements in image quality may be required.

Bone metastases from prostate, breast and multiple myeloma: differences in lesion conspicuity at short-tau inversion recovery and diffusion-weighted MRI.

OBJECTIVES: The objective of this study was to compare the relative conspicuity of bone metastases on short-tau inversion recovery (STIR) and diffusion-weighted MRI (DWI) whole-body MR sequences for breast, prostate and myeloma malignancies. METHODS: 44 whole-body MRI scans were reviewed retrospectively (coronal T(1) weighted, STIR and DWI with b=800). On each scan, up to four of the largest bone lesions were identified on T(1) weighting, and the region of interest signal intensity was measured on STIR and DWI, as well as the background signal intensity. The mean lesion signal to background ratio was calculated for each patient and then for each malignancy group. RESULTS: In prostate cancer patients, the DWI signal/background ratio was greater than that of STIR in 22 out of 24 patients (mean DWI lesion/background ratio 3.91, mean STIR lesion/background ratio 2.31; p=0.0001). In multiple myeloma, the DWI ratio was higher in 6/7 patients (DWI group mean ratio 7.59, STIR group mean ratio 3.7; p=0.0366). In 13 breast cancer patients, mean STIR and DWI signal/background were similar (DWI group mean ratio 4.13, group mean STIR ratio 4.26; p=0.8587). CONCLUSION: Bone lesion conspicuity measured by lesion/background signal intensity was higher on DWI b=800 than on STIR in patients with prostate cancer and multiple myeloma. DWI should be used in whole-body MR oncology protocols in these conditions to maximise lesion detection.

Role of chest radiography after the insertion of a subclavian vein catheter for ambulatory chemotherapy.

OBJECTIVE: To determine the need for routine chest radiography after the insertion of a catheter via the subclavian vein for ambulatory chemotherapy. METHODS: The case notes of all patients who had undergone catheter insertion between 1994 and 1998 were reviewed retrospectively. RESULTS: Of 3844 cases, there were 52 (1.4%) complications detected on chest radiographs after catheter insertion, 46 of which were pneumothoraces; 15 of the 46 patients had a clinical risk factor at insertion (technical difficulty or symptoms), and 14 had a risk factor after insertion (respiratory symptoms and signs). For 22 (47.8%) pneumothoraces, there was no clinical risk factor identified; 3 of these patients required intercostal drain insertion. Other complications (n = 6) included catheter malposition and kinking, and chest radiography made an important contribution to management in at least 1 of these cases. CONCLUSION: In approximately 0.1% of cases of catheter insertion in the subclavian vein, chest radiography detected a clinically occult complication significant enough to require intervention.

Fibroid embolisation: a technique not without significant complications.

Uterine artery embolisation is a new minimally invasive technique used for the treatment of fibroids. Twenty-one women underwent bilateral uterine artery embolisation at our unit, and we assessed the efficacy, morbidity and patient satisfaction with the procedure. Mixed outcomes were found. Reduction in fibroid volume measured by magnetic resonance imaging was impressive, and the majority of women felt their symptoms had improved. One woman achieved a full term pregnancy following the procedure. However, the procedure involved a significant inpatient stay, analgesia requirement, and a slower recovery time than anticipated. One woman died following overwhelming sepsis occurring 10 days after the procedure. Further studies are required to assess the role this technique may play in the management of uterine fibroids.

Benign metastasizing leiomyoma with intracaval leiomyomatosis.

We present an unusual case of benign metastasizing leiomyoma in association with intracaval leiomyomatosis. To our knowledge, this is the first reported case of metastasizing leiomyoma with coexistent intravenous leiomyomatosis (IVL). Magnetic resonance imaging is useful for the diagnosis of pelvic and caval IVL.

Uterine fibroleiomyoma: MR imaging appearances before and after embolization of uterine arteries.

PURPOSE: To evaluate the magnetic resonance (MR) imaging appearances of uterine fibroleiomyoma before and after embolization and to determine whether there are preembolization MR imaging characteristics that are predictive of a successful outcome. MATERIALS AND METHODS: MR imaging was performed in 18 patients (32 fibroleiomyomas) before and at 2 and 6 months after embolization of the uterine arteries. On each occasion, fibroleiomyoma signal intensity and gadolinium enhancement characteristics were assessed in comparison with those of myometrium on T1-weighted and gadolinium-enhanced images or with those of skeletal muscle on T2-weighted images. Fibroleiomyoma volume was measured by using the ellipsoid formula. RESULTS: The mean fibroleiomyoma volume before embolization was 340 cm3 (range, 15-1,383 cm3). The mean reduction in fibroleiomyoma volume was 43% at 2 months and 59% at 6 months. Before embolization, high signal intensity on T1-weighted images was predictive of a poor response (P = .008), and high signal intensity on T2-weighted images was predictive of a good response (P = .007). The degree of gadolinium enhancement was not correlated with fibroleiomyoma volume reduction (P = .46). CONCLUSION: MR imaging was useful for evaluation of changes in fibroleiomyoma volume after uterine arterial embolization. MR imaging characteristics of fibroleiomyomas before embolization can help predict subsequent response to treatment.

Right atrial metastatic melanoma detected by dynamic contrast enhanced spiral CT.

The use of and transoesophageal echocardiography has been well described in the diagnosis of intracardiac metastases. We present a case of a right atrial mass in a patient with metastatic melanoma which was unexpectedly detected by dynamic enhanced spiral CT. The diagnosis was subsequently confirmed by MRI. It is likely that the increasingly widespread use of spiral CT will result in a greater detection rate of intracardiac tumours.

The radiological investigation of suspected lower limb deep vein thrombosis.

A postal survey was performed to determine the current practices and attitudes of radiologists towards the imaging of suspected lower limb deep vein thrombosis (DVT). One hundred and twenty-seven departments responded to a questionnaire sent in March 1996. The results show that 87% of hospitals possess colour Doppler ultrasound (CDUS) machines and that 46% of departments perform ultrasound as the first line investigation in over 90% of cases. Thirty per cent of departments considered calf vein visualization to be generally adequate and 34% thought that clinicians in their hospitals invariably anticoagulated patients with isolated calf thrombus. In hospitals where venography was routinely used as the first line investigation, the most common reasons were: the perceived inferiority of ultrasound (US) in demonstrating below-knee clot, its time-consuming nature and the limited access to suitable ultrasound machines. The widespread use of ultrasound is encouraging, however, there are clearly diverse views. A significant minority of departments depend principally upon venography in the diagnosis of DVT.

Aneurysm of the left brachiocephalic vein: an unusual cause of mediastinal widening.

A case of left brachiocephalic venous aneurysm is presented. Thoracic venous aneurysms are rare with only 27 previous cases in the medical literature, the majority involving the superior vena cava. There are only two previous reports of isolated brachiocephalic venous aneurysm. Venous aneurysms are usually first detected as mediastinal widening on a chest radiograph and can be further defined using CT, MRI or angiography. The aetiology is uncertain. Management is usually conservative, but surgical correction has been performed.