Digital tomosynthesis and ground glass nodules: Optimization of acquisition protocol. A phantom study.

INTRODUCTION: Ground-glass nodules may be the expression of benign conditions, pre-invasive lesions or malignancies. The aim of our study was to evaluate the capability of chest digital tomosynthesis (DTS) in detecting pulmonary ground-glass opacities (GGOs). METHODS: An anthropomorphic chest phantom and synthetic nodules were used to simulate pulmonary ground-glass nodules. The nodules were positioned in 3 different regions (apex, hilum and basal); then the phantom was scanned by multi-detector CT (MDCT) and DTS. For each set (nodule-free phantom, nodule in apical zone, nodule in hilar zone, nodule in basal zone) seven different scans (n = 28) were performed varying the following technical parameters: Cu-filter (0.1-0.3 mm), dose rateo (10-25) and X-ray tube voltage (105-125 kVp). Two radiologists in consensus evaluated the DTS images and provided in agreement a visual score: 1 for unidentifiable nodules, 2 for poorly identifiable nodules, 3 for nodules identifiable with fair certainty, 4 for nodules identifiable with absolute certainty. RESULTS: Increasing the dose rateo from 10 to 15, GGOs located in the apex and in the basal zone were better identified (from a score = 2 to a score = 3). GGOs located in the hilar zone were not visible even with a higher dose rate. Intermediate density GGOs had a good visibility score (score = 3) and it did not improve by varying technical parameters. A progressive increase of voltage (from 105 kVp to 125 kVp) did not provide a better nodule visibility. CONCLUSION: DTS with optimized technical parameters can identify GGOs, in particular those with a diameter greater than 10 mm. IMPLICATIONS FOR PRACTICE: DTS could have a role in the follow-up of patients with known GGOs identified in lung apex or base region.

Charcoal suspension tattoo: new tool for the localization of malignant laterocervical lymph nodes.

We present a retrospective study to evaluate safety and effectiveness of ultrasound (US)-guided tattooing with charcoal of suspicious laterocervical lymph nodes. When an open biopsy of a laterocervical lymph node is needed, the choice of the lymph node to excise and examine is fundamental to avoid rebiopsy. Surgeons tend to choose the most surgical approachable enlarged lymph node that does not always correspond to the one with worst echographic aspect. We present 16 cases of patients with laterocervical adenopathy with inconclusive or non-adequate results at fine needle aspiration cytology addressed to open biopsy. Those patients underwent US-guided preoperative injection of a charcoal suspension inside the lymph node to excise to mark it, and then excisional biopsy was performed. Sixteen marked lesions (100 %) were detected intraoperatively and dissected. The injected charcoal was detected intraoperatively in all cases. In 14 patients (87, 5 %) it was inside the lesion; in two cases (12, 5 %), the charcoal suspension was found in the tissues above the lesion. The procedure was well tolerated in all cases. No major procedure-related complications were encountered. US-guided charcoal tattooing is a new, safe, well-tolerated, and easy-to-perform technique for the marking of US suspicious laterocervical lymph nodes. This preliminary study shows a high technical success rate (76 %) and high percentage of intraoperative detection of marked lesions (100 %) with a low rate of complications.

The use of CEUS in the diagnosis of retinal/choroidal detachment and associated intraocular masses - preliminary investigation in patients with equivocal findings at conventional ultrasound.

PURPOSE: To investigate whether contrast-enhanced ultrasound (CEUS) may help to diagnose retinal/choroidal detachment and may help to differentiate intraocular lumps in cases with equivocal features on conventional grayscale and Doppler modes. MATERIALS AND METHODS: The institutional review board approved this retrospective study. The need for informed consent was waived. A computerized data search was performed in the database of our institution for patients with vitreous hemorrhage who underwent CEUS of the eye to assess retinal/choroidal detachment and/or associated masses. This process yielded a total of 31 patients (18 men, 13 women, age range: 39 - 88 years) in whom CEUS was performed because the findings on conventional grayscale and Doppler modes were equivocal. CEUS was performed using low acoustic power contrast-specific modes. A 2.4 - 4.8  mL bolus of SonoVue was injected, followed by a saline flush. All examinations were digitally recorded for retrospective analysis. Confirmation of CEUS findings was obtained at surgery (n = 20) or with binocular indirect fundoscopy performed after clearance of the ocular media (n = 11). Two readers with different levels of ultrasound experience independently reviewed the imaging features. A five-degree scale ranging from definitely absent (score 1) to definitely present (score 5) was used to assess the presence or absence of retinal/choroidal detachment on conventional ultrasound modes alone and with the addition of CEUS. ROC curve analysis was performed to assess the diagnostic accuracy of both methods. The inter-reader agreement was also evaluated. In patients with associated intraocular lumps, conventional Doppler modes and CEUS were used to differentiate non-tumor masses from tumor masses. RESULTS: According to the reference standard, 13 patients had retinal detachment, 4 had choroidal detachment, and 3 had both retinal and choroidal detachment. There were 8 associated intraocular lumps (4 subretinal hemorrhages, 3 malignant melanomas, 1 metastasis). The inter-reader agreement was good (K = 0.644) and very good (K = 0.833) for conventional modes and CEUS, respectively. The diagnostic performance of CEUS was high for both readers (area ± standard error under the ROC curve: 0.966 ±â€Š0.031 and 0.900 ±â€Š0.055 for readers 1 and 2, respectively). There were 2 false-positive results and 1 false-negative result in patients with proliferative diabetic retinopathy. CEUS was effective in differentiating subretinal hemorrhage from hypovascular tumors. CONCLUSION: CEUS can be used as a problem-solving technique when conventional ultrasound modes are not diagnostic for retinal/choroidal detachment and when intraocular lumps cannot be characterized as tumor or non-tumor masses on conventional modes. The evaluation of patients with proliferative diabetic retinopathy, however, may be problematic.

Preoperative vascular mapping with multislice CT of deep inferior epigastric artery perforators in planning breast reconstruction after mastectomy.

PURPOSE: Our aim was to evaluate the usefulness of computed tomography angiography (CTA) in vascular mapping for planning breast reconstruction after mastectomy using a free flap made with the deep inferior epigastric perforators (DIEP). MATERIALS AND METHODS: We retrospectively evaluated 41 patients, mean age 57 years, scheduled for mastectomy. CTA was performed with a 64-row scanner (Aquilion 64, Toshiba Medical Systems, Japan), with injection of 100 ml of contrast medium (iomeprol 350 mgI/ml, Bracco, Italy) at 4.5 ml/s. Maximum intensity projection (MIP) and three-dimensional volume-rendering (VR) reconstructions were made to mark perforator positions. Presentation frequency, anatomy and artery opacification quality were evaluated. RESULTS: DIEP were always depicted (n=81) and subdivided according to Taylor's classification into type I (65%), type II (28%), and type III (7%). We observed a mean of three (range, 1-5) DIEP arteries on the right and two (range, 1-5) on the left side. The superficial inferior epigastric artery (SIEA) was depicted in 6/41 patients, bilaterally in three cases. Opacification was optimal in 30/41 cases, venous contamination due to late arterial phase in eight and low opacification due to early scan in three. CONCLUSIONS: Studying DIEP with CTA is useful in the surgical planning of breast reconstruction, even though it requires careful optimisation owing to the critical timing of opacification typical of that vascular district.

First application of computed radiology to mammography with synchrotron radiation.

OBJECTIVE: The aim of this study was to evaluate the feasibility of phase-contrast mammography with synchrotron radiation using a high-resolution computed radiology (CR) system devoted to mammography. MATERIALS AND METHODS: The study was performed at the Synchrotron Radiation for Medical Physics (SYRMEP) beamline of the Elettra synchrotron radiation (SR) facility in Trieste (Italy); X-ray beams were in the range 16-22 keV with a high degree of monochromaticity and spatial coherence. The CR system evaluated is the FCR Profect CS by Fujifilm Global. The first images were obtained from test objects and surgical breast specimens. Images obtained using SR and both screen-film and the CR system were compared with images of the same samples acquired with digital mammography equipment. In view of the good quality of the results obtained, the CR system was used in two mammographic examinations with SR. RESULTS: Images acquired using SR and both screen-film and CR were obtained with the same level of delivered dose. Image quality obtained with CR was similar or superior to that of screen-film images. Moreover, the digital images obtained with SR were always better than those acquired using the digital mammography system. CONCLUSIONS: Phase-contrast mammography with SR using the studied CR system is a feasible option.

The role of CEUS in the characterization of hepatocellular nodules detected during the US surveillance program--current practices in Europe.

The basic pathological feature for the differential diagnosis between hepatocellular carcinoma (HCC) and non-malignant hepatocellular nodules in cirrhotic patients detected during ultrasound (US) is the vascular supply to the nodule. Computed tomography (CT) and magnetic resonance imaging (MRI) are considered reference imaging techniques for depicting hepatocellular nodule vascularity in the noninvasive diagnosis of HCC. Contrast-enhanced US (CEUS) improves the diagnostic performance of unenhanced US in the diagnosis of HCC, giving an overall diagnostic accuracy that is similar to that of CT, even for nodules smaller than 2 cm. An additional diagnostic feature of CEUS relative to CT is the possibility to visualize contrast wash-in to hepatic nodules during the arterial phase and contrast washout during the portal venous and late phases. Sensitivity for the diagnosis of HCC with combined assessment of CEUS and CT is higher than for separate assessments of CEUS and CT due to the reduction of false-negative findings. CEUS represents a competitive imaging method from an economic point of view, and is an effective imaging tool for assessing the therapeutic outcome after surgery, ablation therapy, and transarterial chemoembolization (TACE).

64-Slice CT urography: optimisation of radiation dose.

PURPOSE: This study assessed means by which to optimise 64-slice computed tomography urography (CTU) in evaluating the urinary tract, with a view to obtaining the best trade-off between image quality and radiation dose. MATERIALS AND METHODS: Image quality was analysed in terms of spatial and contrast resolution on several scans of a phantom performed with automatic dose modulation and different reconstruction kernels and accepted noise level. Data were compared with the radiation dose values recorded for 52 patients who underwent CTU examination. RESULTS: Radiation dose and image quality differed considerably depending on the reconstruction parameters, even though a higher dose did not always imply better image definition. Data obtained in the phantom were consistent with those obtained in patients. Depending on the clinical problem, the radiation dose varied from 6.2 to 17.6 mSv. CONCLUSIONS: CTU cannot be considered a standard examination: the scan parameters need to be adapted to the image quality required for the specific clinical problem.

Effect of Tadalafil on prostate haemodynamics: preliminary evaluation with contrast-enhanced US.

PURPOSE: Phosphodiesterase-5 (PDE-5) inhibitors have an established role in the treatment of erectile dysfunction, but there is increasing evidence that these drugs are effective also for the treatment of lower urinary tract symptoms and benign prostatic hyperplasia (BPH). The mechanism of action of PDE-5 inhibitors in the prostate, however, is poorly understood. It is conceivable that these drugs act by reducing the smooth muscle tone of the organ, but this effect could produce vascular changes as well. The aim of this study was to investigate whether administration of Tadalafil, a PDE-5 inhibitor, in patients with BPH produces haemodynamic changes in the prostate that can be assessed using contrast-enhanced US (CEUS). MATERIALS AND METHODS: Twelve consecutive patients with BPH underwent transrectal CEUS before and 90 min after administration of 20 mg Tadalafil. CEUS was performed during bolus injection of SonoVue (4.8 ml) using a nondestructive US mode. The same scan plane, imaging parameters and technique were used before and after Tadalafil administration. Digital clips were recorded and processed using dedicated software (QontraXt v.3.60. Signal intensity (SI) changes in a region of interest (ROI) encompassing the entire prostate were fitted to a gammavariate curve. Changes in enhancement peak, time to peak (TTP), sharpness of the bolus transit and area under the curve (AUC) were considered for further analysis. RESULTS: After Tadalafil administration, the enhancement peak and AUC increased significantly (p<0.01), reflecting changes in prostate vascularity. TTP and sharpness did not change significantly. CONCLUSIONS: In patients with BPH, vascular changes are observed in the prostate after Tadalafil administration, which can be detected with CEUS.

Radiological-pathological correlation in intratumoural tissue components of solid lung tumours.

The aim of this paper is to describe the intratumoural tissue components of solid lung tumours evidenced by macroscopic and/or microscopic examination of the autopsy or surgical specimen and visible on computed tomography (CT) without and with contrast material administration. Seven intratumoural tissue components can be identified both at CT and at pathology: (1) solid component, (2) haemorrhagic component, (3) coagulation necrosis, (4) liquefaction necrosis, (5) parenchymal consolidation, (6) diffuse peripheral component and (7) fibrotic component. Necrotic and haemorrhagic components are typically observed in malignant lesions, whereas solid and fibrotic components may be seen both in solid lung malignancies and in benign lesions.

The mammography project at the SYRMEP beamline.

A clinical program for X-ray phase contrast (PhC) mammography with synchrotron radiation (SR) has been started in March 2006 at the SYRMEP beamline of Elettra, the SR facility in Trieste, Italy. The original beamline layout has been modified substantially and a clinical facility has been realized. In order to fulfill all security requirements, dedicated systems have been designed and implemented, following redundancy criteria and "fail safe" philosophy. Planar radiographic images are obtained by scanning simultaneously the patient and the detector through the stationary and laminar SR beam. In this first phase of the project a commercial screen-film system has been used as image receptor. Upon approval by the respective authorities, the mammography program is about half way to conclusion. Up to now about 50 patients have been examined. The patients are volunteers recruited by the radiologist after conventional examinations at the hospital resulted in an uncertain diagnosis. As an example one case of PhC SR mammography is shown and compared to conventional digital mammography. Preliminary analysis shows the high diagnostic quality of the PhC SR images that were acquired with equal or less delivered dose compared to the conventional ones.

The evolving role of MRI in oncohaematological disorders.

Magnetic resonance imaging (MRI) has opened new possibilities to current diagnostic radiology in the evaluation of bone marrow. Compared with other imaging modalities, MRI is the only technique able to directly visualise bone marrow with its different components of red and yellow marrow. Other advantages of MRI are high-contrast resolution and multiplanar view, as well as extensive coverage of the skeleton with whole-body MRI (WBMRI). However, specificity of signal alterations of bone marrow is low. Therefore, MRI findings need to be integrated with clinical and laboratory findings as well as with haematological and oncological evaluation. MRI provides information that effectively aids diagnosis, staging and follow-up of various bone marrow disorders. There is increasing interest in the capabilities of MRI in the evaluation of bone marrow, in particular of haematological malignancies. According to some authors much work remains to be done to improve sensitivity and specificity of MRI in order to define the real clinical value of this imaging modality in the multidisciplinary management of patients with a haematological malignancy. This article presents recent developments and perspectives in the use of MRI in oncohaematological diseases.

US, colour-Doppler US and fine-needle aspiration biopsy in the diagnosis of thyroid nodules.

PURPOSE: The purpose of this study was to correlate the diagnosis of benign or malignant thyroid nodules obtained with grey-scale ultrasound (US) and colour-Doppler US with the cytological findings after US-guided fine-needle aspiration (FNA). MATERIALS AND METHODS: Between January 2004 and June 2005, 516 thyroid nodules in 420 patients (181 solitary thyroid nodules and 239 multiple nodules) were prospectively evaluated with US, colour-Doppler US and US-guided FNA. The nodules were classified as sonographically benign, suspicious or malignant in accordance with established US criteria. Cytological findings were classified as inadequate, benign, indeterminate, suspicious or malignant. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy of US and colour-Doppler US were evaluated using FNA as the reference procedure. RESULTS: The sensitivity, specificity, PPV, NPV and overall accuracy values of grey-scale US were 46%, 73%, 34%, 82% and 67%, respectively, for solitary thyroid nodules and 35%, 72%, 14%, 90% and 68%, respectively, for multiple nodules. The evaluation of nodule vascularity with colour-Doppler US produced a slight increase in sensitivity but a slight reduction in specificity. CONCLUSIONS: Thyroid nodules cannot be accurately characterised using grey-scale US or colour-Doppler US.

Contribution of CT to treatment planning in patients with GIST.

PURPOSE: The aim of this study was to illustrate the morphological and structural computed tomography (CT) patterns of gastrointestinal stromal tumours (GIST) and to discuss the technique's role in identifying lesions at a higher risk for malignant potential, in treatment planning and in the follow-up of patients with GIST. MATERIALS AND METHODS: We retrospectively reviewed the CT scans of 26 patients who underwent surgery for histologically confirmed GIST of the stomach (20 cases), the duodenum (1), the caecum (1), the small bowel (2), the descending colon (1) and the rectum (1). CT exams were performed with a single-slice scanner and a 5-mm collimation before and after the intravenous administration of contrast material. RESULTS: CT allowed us to correctly define the site, size and structure of lesions in all cases and to identify signs of invasion of neighbouring structures in some cases. The lesions exhibited solid density on the unenhanced scan and poor enhancement after contrast-medium administration; lesion structure was homogeneous in ten cases and inhomogeneous in 16; in one case, histology revealed microcalcification that had not been detected by CT. CONCLUSIONS: CT, with its panoramic capabilities and high contrast resolution, provides essential information for treatment planning and for the follow-up of GIST patients treated with surgery or chemotherapy.

The radiologist and the cytologist in diagnosing thyroid nodules: results of cooperation.

PURPOSE: This study was done to evaluate the effectiveness of cooperation between the radiologist and the cytopathologist in ultrasound-guided fine-needle aspiration biopsy (FNAB) of thyroid nodules. MATERIALS AND METHODS: Since 1995, FNAB of thyroid nodules at our department has been performed under ultrasound guidance by the radiologist with a cytopathologist present on-site. The results of ultrasound-guided FNAB procedures performed at our department in 1995, 1999, and 2005 were retrospectively evaluated and compared with those of other departments in the Trieste Province where thyroid nodules are sampled by palpation-guided FNAB performed by a clinician. RESULTS: From 1995 to 2005, the number of ultrasound-guided FNAB procedures performed at our department rose steadily, whereas the number of inadequate samples fell progressively. In patients who underwent surgery, the number of discrepancies between the cytological findings and the final histological diagnoses decreased progressively. CONCLUSIONS: Ultrasound-guided FNAB performed by the radiologist with a cytopathologist present on-site is superior to palpation-guided FNAB. The results are optimised by cooperation between the radiologist and cytologist.

Three-dimensional quantitative assessment of lung parenchyma in cystic fibrosis: preliminary results.

PURPOSE: The aim of this study was to assess the feasibility of three-dimensional (3D) reconstructions and quantitative analysis of the volume of each component of the lung with cystic fibrosis (CF). MATERIALS AND METHODS: Twenty-two patients with CF (mean age 17+/-8 years) were included in the study. The patients underwent an unenhanced single-slice spiral computed tomography (CT) chest scan with the following parameters: collimation 3 mm, table feed 6 mm x rot(-1), reconstruction interval 1 mm, soft tissue reconstruction kernel. Four image data sets were obtained: native axial slices, cine-mode display, virtual bronchographic volume-rendered images with algorithm for tissue transition display and virtual endoluminal views. The lungs were segmented manually from the hilum to the visceral pleura on the axial images, and the entire lung volume was calculated. A histogram was generated representing the fractional volume of tissues, the density of which was within a preset range. A curve was then obtained from the histogram. RESULTS: Native axial images and cine-mode display allowed complete evaluation of lung volumes. Virtual bronchography allowed a better assessment of the distribution of bronchiectasis. Virtual bronchoscopy was limited by the fact that it visualised only the surface, without differentiating mucus from the bronchial wall. Manual segmentation and generation of density-volume curves required 41+/-7 min for each lung. Three curve patterns were identified depending on disease severity. CONCLUSIONS: Volume-density analysis of lungs with CF is feasible. Its main advantage is that image analysis is not analogical, as the assessment is not performed using scoring systems or similar ordinal scales. This technique cannot differentiate acute from chronic findings, and the predictive value of the curve should be assessed.

Clinical and diagnostic imaging of bisphosphonate-associated osteonecrosis of the jaws.

OBJECTIVES: It is important to recognize osteonecrosis of the jaws in patients treated with bisphosphonates because an early diagnosis can make a significant difference to the outcome of the disease. The aim of this study is to describe the radiological features of bisphosphonate osteonecrosis (BON) in order to aid its prompt recognition. METHODS: A conventional radiograph, a computed tomograph (CT), a magnetic resonance image (MRI) and a 99Tc(m)-MDP 3-phase bone scan were carried out for 11 patients with BON. The main imaging findings of osteonecrosis are described. RESULTS: Conventional radiography and CT displayed osteolytic lesions with the involvement of cortical bone. MRI demonstrated the characteristic features of osteonecrosis and the oedema of soft tissues. Both CT and MRI were very useful in defining the extent of the lesions. 99Tc(m)-MDP three-phase bone scan was the most sensitive tool to detect the osteonecrosis at an early stage. CONCLUSIONS: 99Tc(m)-MDP three-phase bone scans who could be used as a screening test to detect subclinical osteonecrosis in patients who have received bisphosphonates. CT scans and MRI are useful in defining the features and extent of osteolytic lesions.

[The definition and realization of a computerized archive for radiological data of scientific interest]. / Definizione e realizzazione di un archivio informatico per dati radiologici di interesse scientifico.

The general requirements are analyzed of a system designed to acquire and manage radiological data of scientific interest. These requirements consist in: easy implementation, to develop the system in the same environment where it is going to be used; easy use, to avoid excessive needs and resources for the system to be managed in practice; reduced implementation cost, in terms of resources required for its implementation; user-oriented approach, in the sense of meeting the radiologists' requirements, and flexibility, for the system to be an effective tool for the widest range of possible applications. Two actual applications of this general approach are then discussed, one relative to breast investigations data, and the other to digital procedures (US, CT, DSA, MR) data. For each application the software tools employed are analyzed, together with the archive structures and the used codes, the collecting data procedures and the programs. For the breast investigations archive the possibility of obtaining standard periodic reports is pointed out. These reports summarize the global department activity in this area during selected periods (six months-one year). They allow interesting clinical conclusions to be drawn. As for the digital procedures archive, the possibility is stressed of searching different combinations of scientific data out of tens of thousands of cases in just a few minutes.