Differentiation between benign and malignant breast lesions using quantitative diffusion-weighted sequence on 3 T MRI.

AIM: To investigate the capability and diagnostic accuracy of diffusion-weighted imaging (DWI) in differentiating benign from malignant breast lesions using 3 T magnetic resonance imaging (MRI). MATERIALS AND METHODS: Women with suspicious or indeterminate breast lesions detected at MRI, mammogram and/or ultrasound were recruited for dynamic contrast-enhanced (DCE)-MRI and DWI prior to their biopsy. Image fusion of DCE-MRI with apparent diffusion coefficient (ADC) map was utilized to select the region of interest (ROI) for ADC calculation in the area that showed the most avid enhancement. DWI was performed using two sets of b-values at 500 and 1000 s/mm(2), respectively. RESULTS: Fifty women were recruited and the final analysis comprised 44 breast lesions, 31 of which were malignant and 13 were benign. Significant results were obtained between ADC values of benign and malignant lesions (p < 0.001). The cut-off ADC values for benign and malignant lesions were 1.21 × 10(-3) mm(2)/s for b = 500 s/mm(2) and 1.22 × 10(-3) mm(2)/s for b = 1000 s/mm(2), respectively. The sensitivity of DCE-MRI alone was 100% with a specificity of 66.7%. When DCE-MRI was combined with b = 1000 s/mm(2), the specificity rose to 100%, while only mildly affecting sensitivity (90.6%). No significant correlation was found between ADC values and prognostic factors, such as lymph node metastasis, tumour size, oestrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) status, and tumour grades. CONCLUSION: The present study provides consistent evidence to support DWI as a diagnostic tool for breast lesion characterization. A combination of DCE-MRI with DWI is suggested to improve the sensitivity and specificity of lesion characterization.

Improved diagnostic accuracy in differentiating malignant and benign lesions using single-voxel proton MRS of the breast at 3 T MRI.

AIM: To investigate the diagnostic accuracy of single-voxel proton magnetic resonance spectroscopy (SV (1)H MRS) by quantifying total choline-containing compounds (tCho) in differentiating malignant from benign lesions, and subsequently, to analyse the relationship of tCho levels in malignant breast lesions with their histopathological subtypes. MATERIALS AND METHODS: A prospective study of SV 1H MRS was performed following dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in 61 women using a 3 T MR system. All lesions (n = 57) were analysed for characteristics of morphology, contrast-enhancement kinetics, and tCho peak heights at SV (1)H MRS that were two-times above baseline. Subsequently, the tCho in selected lesions (n = 32) was quantified by calculating the area under the curve, and a tCho concentration equal to or greater than the cut-off value was considered to represent malignancy. The relationship between tCho in invasive ductal carcinomas (IDCs) and their Bloom & Richardson grading of malignancy was assessed. RESULTS: Fifty-two patients (57 lesions; 42 malignant and 15 benign) were analysed. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV), of predicting malignancy were 100, 73.3, 91.3, and 100%, respectively, using DCE-MRI and 95.2, 93.3, 97.6, and 87.5%, respectively, using SV (1)H MRS. The tCho cut-off for receiver operating characteristic (ROC) curve was 0.33 mmol/l. The relationship between tCho levels in malignant breast lesions with their histopathological subtypes was not statistically significant (p = 0.3). CONCLUSION: Good correlation between tCho peaks and malignancy, enables SV (1)H MRS to be used as a clinically applicable, simple, yet non-invasive tool for improved specificity and diagnostic accuracy in detecting breast cancer.

Imaging findings of extensive splenic infarction after cyanoacrylate injection for gastric varices--a case report.

Endoscopic injection of N-Butyl-2-cyanoacrylate is a widely accepted treatment for esophagogastric varices. This procedure is commonly associated with minor complications which include transient pyrexia and abdominal discomfort. Serious vascular complications secondary to systemic embolization of cyanoacrylate have rarely been reported. We describe the CT findings of extensive splenic infarction in a patient following cyanoacrylate injection for gastric varices.

Optimising the scan delay for arterial phase imaging of the liver using the bolus tracking technique.

OBJECTIVE: To optimize the delay time before the initiation of arterial phase scan in the detection of focal liver lesions in contrast enhanced 5 phase liver CT using the bolus tracking technique. PATIENTS AND METHODS: Delay - the interval between threshold enhancement of 100 hounsfield unit (HU) in the abdominal aorta and commencement of the first arterial phase scan. Using a 16 slice CT scanner, a plain CT of the liver was done followed by an intravenous bolus of 120 ml nonionic iodinated contrast media (370 mg I/ml) at the rate of 4 mL/s. The second phase scan started immediately after the first phase scan. The portal venous and delay phases were obtained at a fixed delay of 60 s and 90 s from the beginning of contrast injection. Contrast enhancement index (CEI) and subjective visual conspicuity scores for each lesion were compared among the three groups. RESULTS: 84 lesions (11 hepatocellular carcinomas, 17 hemangiomas, 39 other hypervascular lesions and 45 cysts) were evaluated. CEI for hepatocellular carcinomas appears to be higher during the first arterial phase in the 6 seconds delay group. No significant difference in CEI and mean conspicuity scores among the three groups for hemangioma, other hypervascular lesions and cysts. CONCLUSION: The conspicuity of hepatocellular carcinomas appeared better during the early arterial phase using a bolus tracking technique with a scan delay of 6 seconds from the 100 HU threshold in the abdominal aorta.

Optimising the scan delay for arterial phase imaging of the liver using the bolus tracking technique

Objective: To optimize the delay time before the initiation of arterial phase scan in the detection of focal liver lesions in contrast enhanced 5 phase liver CT using the bolus tracking technique. Patients and Methods: Delay - the interval between threshold enhancement of 100 hounsfield unit (HU) in the abdominal aorta and commencement of the first arterial phase scan. Using a 16 slice CT scanner, a plain CT of the liver was done followed by an intravenous bolus of 120 ml nonionic iodinated contrast media (370 mg I/ml) at the rate of 4 mL/s. The second phase scan started immediately after the first phase scan. The portal venous and delay phases were obtained at a fixed delay of 60 s and 90 s from the beginning of contrast injection. Contrast enhancement index (CEI) and subjective visual conspicuity scores for each lesion were compared among the three groups. Results: 84 lesions (11 hepatocellular carcinomas, 17 hemangiomas, 39 other hypervascular lesions and 45 cysts) were evaluated. CEI for hepatocellular carcinomas appears to be higher during the first arterial phase in the 6 seconds delay group. No significant difference in CEI and mean conspicuity scores among the three groups for hemangioma, other hypervascular lesions and cysts. Conclusion: The conspicuity of hepatocellular carcinomas appeared better during the early arterial phase using a bolus tracking technique with a scan delay of 6 seconds from the 100 HU threshold in the abdominal aorta.

Is utilisation of computed tomography justified in clinical practice? Part I: application in the emergency department.

Computed tomography (CT) is currently a widely available imaging technique in clinical practice. Technical developments of CT imaging, especially the emergence of multislice CT, with increased scanning speed and volume as well as higher spatial and temporal resolution, have significantly enhanced the diagnostic value of CT in many clinical applications. CT has become an important diagnostic imaging modality in the emergency department, with high diagnostic accuracy and efficacy in both traumatic and non-traumatic conditions. There is, however, a growing concern about the risk of associated radiation exposure in the population exposed to CT examination. Justification of the application of CT is one of the main principles that physicians need to be aware of when choosing CT as the first-line technique for diagnosis. This article reviews the clinical applications of CT imaging in the emergency department, with a focus on patients presenting with headache, repeat and multiple CT imaging and whole body screening for trauma patients, and explores whether the applications are clinically justified.

Uterine artery embolisation for symptomatic fibroids: the University of Malaya Medical Centre experience.

BACKGROUND: Transcatheter uterine artery embolisation (UAE) for the treatment of symptomatic fibroids has been performed in several centres in the United States, Western Europe and Asia with promising results. This study reports the authors' experience with UAE at the University Malaya Medical Centre. METHOD: Fifty women with symptomatic uterine fibroids who declined surgery were treated by transcatheter UAE. The uterine arteries were selectively catheterised and embolised with polyvinyl alcohol particles. Post-procedure analgesia was administered via patient-controlled analgesic pump. The patients were followed up at an interval of 6/12 clinically and with MRI. RESULTS: Transcatheter UAE was performed on all 50 patients with no major complications. 49 patients had both uterine arteries embolised while 1 patient had only the right uterine artery embolised on account of hypoplasia of the left uterine artery due to previous myomectomy. The mean hospital stay was 3.5 days (range, 2 to 7). At a mean follow-up of 24/52, all patients reported improvements in their presenting symptoms. Objective improvement in terms of reduction of uterine and fibroid sizes was determined on MRI. One patient, who initially responded with a decrease in uterine and dominant fibroid size, became symptomatic (menorrhagia) after 6 months and subsequent endometrial sampling revealed cystic glandular hyperplasia for which total abdominal hysterectomy was performed. Two other patients had no change in symptoms and after hysterectomy, the pathology revealed concurrent adenomyosis. Another 2 patients with cervical fibroids were treated with hysterectomy as there was no gross reduction in the size of fibroid following UAE. Overall, 90% of the patients had dramatic improvement of anaemia and symptoms at 1 year follow-up. CONCLUSION: Out of the 50 patients, 17 patients had total disappearance of their fibroids and 28 patients had more than 50% reduction in the size of fibroids after 1 year. 5 patients ended up with total abdominal hysterectomy. These results suggest that UAE is an appealing alternative to hysterectomy or myomectomy for many women with symptomatic fibroids.

Transarterial embolisation of hepatocellular carcinoma with doxorubicin-eluting beads: single centre early experience.

PURPOSE: This is a retrospective study to evaluate the results of our early experience of using doxorubicin eluting beads (DEB) to treat patients with early and intermediate hepatocellular carcinoma (HCC). MATERIAL AND METHODS: A cohort of 19 patients (84.2% male; 15.8% female; mean age 59.2 years ± 11.0; range, 32-80 years) with documented HCC of size 1.8-10cm (mean, 4.0cm ± 1.8 ) undergoing DEB transarterial chembolisation (TACE) was reviewed. All patients had at least one image examination (multiphase computed tomography or magnetic resonance imaging) after embolisation. RESULTS: A total of 32 procedures were performed. The objective response according to the European Association for the Study of the Liver criteria was 57.9% at 1-month, 42.8% at 6-month and 50.0% at 1-year follow up. There were 4 (21.1%) treatment-related complications (1 liver abscess, 2 pancreatitis and 1 tumour rupture) which resulted in 2 deaths. One death occurred 3 weeks after second embolisation, due to ruptured pancreatic pseudocyst, giving a 5.3% 30-day mortality rate. Another patient died 2 months after embolisation caused by tumour rupture. Eight patients received radiofrequency ablation after embolisation for residual or recurrent tumours. The 1-year survival rate in the DEB TACE only group was 80% while the 1- and 2-year survival rate in the group that received radiofrequency after DEB TACE was 85.7% and 100% respectively. CONCLUSION: DEB TACE is safe and effective in select group of patients. Survival may be improved when combined with other treatment modality.

The transjugular intrahepatic portosystemic shunt (TIPS).

The creation of an intrahepatic portosystemic shunt via a transjugular approach (TIPS) is an interventional radiological procedure used to treat the complications of portal hypertension. TIPS insertion is principally indicated to prevent or arrest variceal bleeding when medical or endoscopic treatments fail, and in the management refractory ascites. This review discusses the development and execution of the technique, with focus on its clinical efficacy. Patient selection, imaging surveillance, revision techniques, and complications are also discussed.

Pneumocephalus: an uncommon finding in trauma.

Pneumocephalus (Intracranial aerocele), defined as intracranial air, is an uncommon complication in head injury patients. It can present immediately following head trauma or be delayed for many days before clinical symptoms occur. We present two cases of extensive pneumocephalus after trauma. The diagnosis was made by computed tomography (CT). When pneumocephalus is suspected, CT can play a vital role in determining the precise location of the gas collection, its relationship to the basal skull fracture site or air sinuses and the amount of mass effect on the brain.

The importance of Good Clinical Practice guidelines and its role in clinical trials.

Good Clinical Practice (GCP) is an international ethical and scientific quality standard for the design, conduct, performance, monitoring, auditing, recording, analyses and reporting of clinical trials. It also serves to protect the rights, integrity and confidentiality of trial subjects. It is very important to understand the background of the formation of the ICH-GCP guidelines as this, in itself, explains the reasons and the need for doing so. In this paper, we address the historical background and the events that led up to the formation of these guidelines. Today, the ICH-GCP guidelines are used in clinical trials throughout the globe with the main aim of protecting and preserving human rights.

Mastoiditis secondary to mycobacterium abscessus imaged with gallium-67 scintigraphy.

Atypical mycobacterium is rarely seen as a cause of chronic mastoiditis but has been increasingly recognized over the past few years. Mycobacterium abscessus is the most pathogenic and chemotherapy-resistant, rapid-growing mycobacterium of all the four groups. This paper presents a case of a 57-year-old woman who had chronic mastoiditis with recurrent exacerbations. The initial computed tomography (CT) findings showed the presence of an inflammatory process and she was treated with the appropriate antibiotics. The patient subsequently underwent a tissue biopsy when she presented with another exacerbation. At this time, the CT scan did not identify the ongoing exacerbation, but the Gallium-67 scintigraphy did.

Gartner duct cyst in pregnancy presenting as a prolapsing pelvic mass.

Gartner duct cysts are the remnants of the Wolffian duct and they are rarely seen in adulthood. We present a case of a pregnant patient with a prolapsing vaginal mass. A diagnosis of Gartner duct cyst was made after MRI was performed. The Gartner duct cyst was drained when the patient went into labour allowing vaginal delivery to be performed.

Benign teratoma of the liver: a rare cause of cholangitis.

Teratomas are neoplasms characterised by an abnormal growth of tissues derived from the three germinal layers. The term 'teratoma' is derived from the Greek root 'teratos', meaning monster. Germ cells develop in the embryo and subsequently become the cells that make up the reproductive system. During fetal development, these cells follow a midline path and descend into the pelvis as ovarian cells or the scrotal sac as testicular cells. The presence of germ cells in extragonadal sites is because of the failure of these cells to migrate along the urogenital ridge. Therefore, teratomas occur in order of decreasing frequency in the ovaries, testes, anterior mediastinum, retroperitoneum, sacrococcygeal region and cranium.Liver teratomas are very rare; of the 25 hepatic teratomas described in the literature, only five have occurred in adults. The majority of the cases were in female children below the age of three, mostly arising in the right lobe of liver.We report a case of an adult male with benign mature teratoma arising in the left lobe of liver, compressing the common bile duct and causing obstructive jaundice.

Accidental blood exposure: risk and prevention in interventional radiology.

There is a growing concern about the transmission of bloodborne pathogens during medical procedures among health care workers and patients. Over the last three decades, radiological services have undergone many changes with the introduction of new modalities. One of these new disciplines is interventional radiology (IR) which deals with procedures such as arteriography, image-guided biopsies, intravascular catheter insertions, angioplasty and stent placements. Despite these developments, the potential for accidental blood exposure and exposure to other infectious material continues to exist. Therefore, it is important for all radiologists who perform invasive procedures to observe specific recommendations for infection control. In this review, we look at the different policies for protection and universal standards on infection control.

Malignant ovarian mixed germ cell tumour: a rare combination.

Ovarian germ cell tumours are very rare and affect mainly young girls and women. Due to this, the conservation of reproductive potential is of great concern. One of the most remarkable advances in oncology is in the treatment of malignant ovarian germ cell tumours. Two histological groups are distinguished: dygerminomas, equivalent to testicular seminomas, and non-dysgerminomatous tumours. We report a case of a 30-year-old nulliparous woman who presented with persistent per vaginal bleeding and was found to have a malignant mixed germ cell tumour comprising of both embryonal carcinoma and choriocarcinoma.