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.

Strain analysis reveals subtle systolic dysfunction in confirmed and suspected myocarditis with normal LVEF. A cardiac magnetic resonance study.

AIMS: Lake Louise Criteria (LLC) are time-dependent and some acute myocarditis (AM) with preserved left ventricular ejection fraction (LVEF) could be missed, due to the limited accessibility of Cardiac Magnetic Resonance (CMR). We aimed to assess the potential value of cardiac strain measured by feature tracking (FT) imaging in this population. METHODS AND RESULTS: Eighty-three patients with clinically suspected AM and normal LVEF were divided into 39 "confirmed AM" (positive LLC) and 44 "suspected AM" (negative LLC). An age and gender-matched sample of 42 normal subjects underwent CMR. In all groups, FT-derived biventricular strains and STE- global longitudinal strain (GLS) were assessed, being regularly measurable. Strain values < 5th percentile of the control group were considered abnormal. "Suspected" and "confirmed" AM were similar, except for medium time of CMR evaluation (5.2 vs 1 months from presentation, respectively; p = 0.004). Compared to healthy controls, both "suspected" and "confirmed" AM showed significantly impaired strain values. LV-global circumferential strain (GCS), right ventricular GCS and LV-GLS were abnormal in 15.4% and 15.9%, 20.5% and 15.9%, 7.7% and 9.1% in "confirmed" and "suspected" AM, respectively. STE analysis confirmed the results on LV-GLS, however a weak correlation emerged between STE and CMR-FT LV-GLS (p = 0.08). CONCLUSIONS: Compared to STE, CMR-FT analysis provided a more comprehensive and complementary biventricular strain evaluation that resulted similar in "confirmed" and "suspected" AM with normal LVEF. Conversely, mostly biventricular GCS was significantly reduced in up to 20% of patients, compared to healthy controls.

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.

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.

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.

Fiber density index in the evaluation of the spinal cord in patients with multiple sclerosis.

PURPOSE: The aims of this study were to determine fractional anisotropy (FA) and the fibre density index (FDi) in the cervical spinal cord of patients with multiple sclerosis (MS) by using diffusion-tensor magnetic resonance imaging (DT-MRI) to identify possible differences between MS patients and controls. MATERIALS AND METHODS: We studied 27 patients with MS - nine with primary progressive (PPMS), nine with secondary progressive (SPMS) and nine with relapsing-remitting (RRMS) disease - and 18 healthy individuals as controls. Conventional and DTI sequences with diffusion gradients applied in 32 directions were obtained. The results were compared between healthy controls and patients, between healthy controls and individual forms of MS and between the three forms of MS. Statistical analysis was performed by analysis of variance (ANOVA) and Student's t test. RESULTS: The FDi in the three subgroups of patients and in controls showed a statistically significant difference. Using the t test, we found results from both PPMS and SPMS groups were different from controls. The correlation between FA and FDi was significant both in healthy controls and in MS patients evaluated as a single group. CONSLUCIONS: Despite the small group of patients, these findings suggest that FDi associated with FA is a sensitive parameter for assessing spinal cord damage in patients with MS.

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).

Functional MRI during the execution of a motor task in patients with multiple sclerosis and fatigue.

PURPOSE: This study was undertaken to assess cortical activation during execution of a motor task in patients with multiple sclerosis (MS) and fatigue. MATERIALS AND METHODS: We enrolled 24 right-handed patients affected by relapsing-remitting MS and mild disability (12 with and 12 without fatigue) and 15 healthy volunteers. Magnetic resonance imaging (MRI) examination (1.5 T) was performed with conventional sequences and an echoplanar imaging (EPI) sequence for functional MRI (fMRI). The motor task consisted of sequential finger tapping performed with the right hand. Statistical maps of motor activation were obtained. Comparison between the two subgroups of patients and between patients and controls was performed with analysis of variance (ANOVA) statistical analysis (p<0.05). RESULTS: Compared with controls, patients without fatigue showed greater activation of the primary sensorimotor cortex bilaterally, of the right supplementary motor cortex, of the left premotor cortex, of the left cerebellum and of the superior parietal lobule bilaterally. Compared with patients without fatigue, patients with fatigue demonstrated greater activation of the right premotor area, of the putamen and the dorsolateral prefrontal cortex. CONCLUSIONS: Patients with fatigue have greater activation of the motor-attentional network when performing a simple motor task.

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.

Comparison between 64-row CT angiography and digital subtraction angiography in the study of lower extremities: personal experience.

PURPOSE: This study was undertaken to evaluate the potential of 64-row multislice computed tomography (CT) versus digital subtraction angiography (DSA) in detecting significant lesions of lower-extremity inflow and runoff arteries. MATERIALS AND METHODS: Fifty-three patients underwent 64-row multislice CT and DSA over a mean of 36 days. The vascular tree was divided into 33 segments. Three readers independently reviewed the axial CT scans and multiplanar oblique and two- and three-dimensional reconstructions (maximum intensity projection and volume rendering) images to assess degree of stenosis according to four categories: 1 (0%-49% stenosis); 2 (50%-99% stenosis); 3 (occluded); 4 (not evaluable). In all cases, DSA was performed by arterial catheterisation. RESULTS: In 53 patients, 1,440 segments were evaluated (infrarenal aorta and 16 arterial segments for each leg; 42 bilateral studies, 11 unilateral studies). Compared with DSA, CT angiography yielded 97.2% sensitivity, 97% specificity, 92.5% positive predictive value, 98.9% negative predictive value, 97.1% diagnostic accuracy and 95.4% concordance on the degree of stenosis. CONCLUSIONS: Sixty-four-row multislice CT proved to be helpful in detecting haemodynamically significant lesions in peripheral arterial occlusive disease and improved the results obtained with 4- and 16-slice multidetector CT. In addition, owing to the high spatial resolution and rigorous technique, no variations in the data obtained below the knee were detected, overcoming a limitation of earlier generations of CT scanners.

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.

Evaluation of white matter damage in patients with Alzheimer's disease and in patients with mild cognitive impairment by using diffusion tensor imaging.

PURPOSE: The objective of this study was to evaluate white matter tissue damage in patients with Alzheimer's disease (AD) and in patients with mild cognitive impairment (MCI) using diffusion tensor imaging (DTI). MATERIALS AND METHODS: Forty-seven subjects were evaluated: 14 patients with AD, 15 with MCI and 18 healthy volunteers. All subjects were studied using conventional magnetic resonance imaging (MRI) and DTI (32 directions) with a 1.5 T magnet. Fractional anisotropy (FA) was measured in the following regions: frontal, occipital, parietal and temporal white matter and in the genu and splenium of the corpus callosum. The results were compared between the different groups and correlated with the Mini-Mental State Evaluation (MMSE) scores. RESULTS: A statistically significant difference was obtained between controls and MCI patients (p < 0.007) and between controls and AD patients (p < 0.05) with regard to FA of the white matter in the splenium. A statistically significant difference was obtained between controls and AD patients with regard to FA in the genu (p < 0.016). Moreover, there was a statistically significant difference between controls and AD patients considering the genu (p < 0.016) and the frontal white matter on the right side (p < 0.024). The MMSE scores correlated with the FA values measured in the genu, the splenium and frontal white matter on the right side. No significant differences were identified between patients with AD and those with MCI. CONCLUSIONS: DTI could be of value in the early detection of white-matter damage in patients with MCI and AD. The DTI values correlate with the neuropsychological tests.

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.

CT urography: the end of IVU?

A review of the literature on the diagnostic accuracy of multidetector computed tomography urography (MDCTU) and intravenous urography (IVU) reveals a lack of comparative studies. However, the available data indicate that MDCTU has a high diagnostic accuracy. MDCTU is also preferred by patients, as it does not require bowel preparation. Full acceptance of this technique by the urologist will depend on optimisation of the communication process with a careful selection of the images to be transmitted. MDCTU has a higher cost than IVU but allows some diagnostic algorithms to be simplified. The real concern potentially limiting the widespread use of MDCTU is its higher radiation dose when compared with IVU. Although low-dose protocols will soon be available, a substantial dose reduction can already be achieved by tailoring MDCTU to the clinical problem rather than using a standardised approach. Our analysis indicates that IVU will definitely lose any residual role it may still have. In our department, the last urographic procedure was performed in May 2006.

Renal artery stenosis: comparative evaluation of gadolinium-enhanced MRA and DSA.

PURPOSE: This study was undertaken to evaluate the accuracy of contrast-enhanced magnetic resonance angiography (CE-MRA) in detecting renal artery stenosis using intra-arterial digital subtraction angiography (DSA) as the gold standard. MATERIALS AND METHODS: Thirty-five consecutive patients with possible renovascular hypertension were prospectively studied; 26 of them underwent both MRA and DSA. In these 26 cases, two readers assessed the number of renal arteries, the presence of stenoses and their degree. Results were compared with DSA, and sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy of MRA were determined. Interobserver variability was also calculated. RESULTS: DSA showed 51 main renal arteries (one patient had a single kidney) and six accessory arteries (total number of arteries 57) in the 26 patients considered. Both MRA readers detected all of the 51 main renal arteries and only one accessory vessel. When the presence of stenosis was considered, the readers' results, respectively, were as follows: sensitivity 77% and 72%, specificity 69% and 69%, PPV 86% and 85%, NPV 55% and 50% and diagnostic accuracy 75% and 71%. When the detection of significant stenosis was considered, the results, respectively, were: sensitivity 83% and 83%, specificity 73% and 78%, PPV 60% and 65%, NPV 90% and 91%, and diagnostic accuracy 76% and 80%. Interobserver variation was good when considering stenosis detection (kappa=0.69) and excellent when considering detection of significant stenosis (kappa=0.85). CONCLUSIONS: MRA results do not appear as positive as in the majority of papers in the literature. Multiple reasons can probably be invoked to explain this difference. The mean age of our patients, higher than in many other studies, should be noted and may have accounted for their possible poor cooperation. Moreover, all of the missed significant stenoses were distally located, and therefore, the failure to detect them might be related to the suboptimal spatial resolution of MRA. Nevertheless, MRA showed a high NPV for detecting significant stenoses, a finding of considerable clinical relevance in that it allows patients with normal MRA findings to be spared additional more invasive procedures.