(18)F-fluorodeoxyglucose positron emission tomography/computed tomography and magnetic resonance imaging in patients with liver metastases from uveal melanoma: results from a pilot study.

PURPOSE: (18)F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) and MRI are used for detecting liver metastases from uveal melanoma. The introduction of new treatment options in clinical trials might benefit from early response assessment. Here, we determine the value of FDG-PET/CT with respect to MRI at diagnosis and its potential for monitoring therapy. MATERIAL AND METHODS: Ten patients with biopsy-proven liver metastases of uveal melanoma enrolled in a randomized phase III trial (NCT00110123) underwent both FDG-PET coupled with unenhanced CT and gadolinium-diethylene triamine pentaacetic acid-enhanced liver MRI within 4 weeks. FDG-PET and MRI were evaluated blindly and then compared using the ratio of lesion to normal liver parenchyma PET-derived standardized uptake value (SUV). The influence of lesion size and response to chemotherapy were studied. RESULTS: Overall, 108 liver lesions were seen: 34 (31%) on both modalities (1-18 lesions/patient), four (4%) by PET/CT only, and 70 (65%) by MRI only. SUV correlated with MRI lesion size (r=0.81, P<0.0001). PET/CT detected 26 of 33 (79%) MRI lesions of more than or equal to 1.2 cm, whereas it detected only eight of 71 (11%) lesions of less than 1.2 cm (P<0.0001). MRI lesions without PET correspondence were small (0.6±0.2 vs. 2.1±1.1 cm, P<0.0001). During follow-up (six patients, 30 lesions), the ratio lesion-to-normal-liver SUV diminished in size-stable lesions (1.90±0.64-1.46±0.50, P<0.0001), whereas it increased in enlarging lesions (1.56±0.40-1.99±0.56, P=0.032). CONCLUSION: MRI outweighs PET/CT for detecting small liver metastases. However, PET/CT detected at least one liver metastasis per patient and changes in FDG uptake not related to size change, suggesting a role in assessing early therapy response.

Acute complications of Crohn's disease: comparison of multidetector-row computed tomographic enterography with magnetic resonance enterography.

OBJECTIVE: To compare multidetector-row computed tomographic (MDCT) enterography with magnetic resonance (MR) enterography performed upon acute exacerbation of Crohn's disease. SUBJECTS AND METHODS: Fifty-seven patients (mean age 33.5) with proven Crohn's disease and symptoms suggesting acute exacerbation were prospectively included. After oral administration of 1-2 liters of 5% methylcellulose, MDCT and MR enterography were performed on each patient (mean delay <24 h). Three radiologists blindly and independently evaluated each examination for technical quality and in terms of 8 pathological features of Crohn's disease. Observers' agreement, sensitivity and specificity resulted from comparison with the reference standard [surgery (n = 24), endoscopy (n = 17) and long-term follow-up (n = 16)]. RESULTS: MDCT enterography demonstrated fewer artifacts than MR enterography (p < 0.0001). In 48 MDCT/MR enterography examinations, active disease was demonstrated: abscesses (n = 11), fistulas (n = 13), stenoses (n = 23) and/or intestinal inflammation (n = 38). Observers' agreement (range 0.56-0.87) was not significantly different between MDCT and MR enterography, neither in terms of sensitivity (range 58-95%) nor specificity (range 67-100%) for each of the 8 pathological features. CONCLUSION: Statistically, MR enterography is of similar diagnostic value as MDCT enterography for acute complications of Crohn's disease. Since the typical Crohn's disease patient is young and will very likely undergo life-long imaging, and given concerns about radiation exposure with MDCT, MR enterography should be the preferred modality.

Solid pseudopapillary tumor of the pancreas in children: typical radiological findings and pathological correlation.

We report a case series of three children with solid pseudopapillary tumor of the pancreas (SPT) in which a complete radiological work-up, including ultrasound, computed tomography scans, and MRI, has been carried out. The aim of this article is to highlight the characteristic imaging findings of SPT in the pediatric age group and to establish a correlation with typical histopathological findings of the lesion.

Fetal MRI as complement to US in the diagnosis and characterization of anomalies of the genito-urinary tract.

The purpose of this study is to compare the accuracy of prenatal ultrasound (US) and prenatal magnetic resonance imaging (MRI) in the diagnosis and characterization of congenital abnormalities of the genito-urinary tract and to determine if the additional information obtained by MRI may influence the management of the fetus. We retrospectively evaluate 15 cases of congenital genito-urinary tract anomalies detected by prenatal US and with echographic inconclusive diagnosis. We compare the MRI findings with the US findings and the final diagnosis, obtained from neonatal outcomes, imaging studies and pathology records. Fetal US diagnosis was correct in 9 cases (60%) and MRI in 13 cases (86.7%). Prenatal MRI revealed additional information to US in 9 cases (60%), which modified the initial US diagnosis in 5 cases (33.3%) and changed the therapeutic approach in 5 fetuses (33.3%). Fetal MRI was better than US in cases of oligoamnios and in fetuses with genito-urinary pathology concerning the pelvic and perineum region. We believe that MRI should be considered as a complementary diagnostic method in cases of echographic suspicion of congenital pathology of the genito-urinary tract and inconclusive prenatal US.

Outcome of long-axis percutaneous sacroplasty for the treatment of sacral insufficiency fractures.

Our aim was to assess the clinical outcome of patients who were subjected to long-axis sacroplasty for the treatment of sacral insufficiency fractures. Nineteen patients with unilateral (n = 3) or bilateral (n = 16) sacral fractures were involved. Under local anaesthesia, each patient was subjected to CT-guided sacroplasty using the long-axis approach through a single entry point. An average of 6 ml of polymethylmethacrylate (PMMA) was delivered along the path of each sacral fracture. For each individual patient, the Visual Analogue pain Scale (VAS) before sacroplasty and at 1, 4, 24 and 48 weeks after the procedure was obtained. Furthermore, the use of analgesics (narcotic/nonnarcotic) along with the evolution of post-interventional patient mobility before and after sacroplasty was also recorded. The mean pre-procedure VAS was 8±1.9 (range, 2 to 10). This rapidly and significantly (P<0.001) declined in the first week after the procedure (mean 4±1.4; range, 1 to 7) followed by a gradual and significant (P<0.001) decrease along the rest of the follow-up period at 4 weeks (mean 3±1.1; range, 1 to 5), 24 weeks (mean 2.2±1.1; range, 1 to 5) and 48 weeks (mean 1.6±1.1; range, 1 to 5). Eleven (58%) patients were under narcotic analgesia before sacroplasty, whereas 8 (42%) patients were using nonnarcotics. Corresponding values after the procedure were 2/19 (10%; narcotic, one of them was on reserve) and 10/19 (53%; non-narcotic). The remaining 7 (37%) patients did not address post-procedure analgesic use. The evolution of post-interventional mobility was favourable in the study group as they revealed a significant improvement in their mobility point scale (P<0.001). Long-axis percutaneous sacroplasty is a suitable, minimally invasive treatment option for patients who present with sacral insufficiency fractures. More studies with larger patient numbers are needed to explore any unrecognised limitations of this therapeutic approach.

Estimation of sex and age of "virtual skeletons"--a feasibility study.

This article presents a feasibility study with the objective of investigating the potential of multi-detector computed tomography (MDCT) to estimate the bone age and sex of deceased persons. To obtain virtual skeletons, the bodies of 22 deceased persons with known age at death were scanned by MDCT using a special protocol that consisted of high-resolution imaging of the skull, shoulder girdle (including the upper half of the humeri), the symphysis pubis and the upper halves of the femora. Bone and soft-tissue reconstructions were performed in two and three dimensions. The resulting data were investigated by three anthropologists with different professional experience. Sex was determined by investigating three-dimensional models of the skull and pelvis. As a basic orientation for the age estimation, the complex method according to Nemeskéri and co-workers was applied. The final estimation was effected using additional parameters like the state of dentition, degeneration of the spine, etc., which where chosen individually by the three observers according to their experience. The results of the study show that the estimation of sex and age is possible by the use of MDCT. Virtual skeletons present an ideal collection for anthropological studies, because they are obtained in a non-invasive way and can be investigated ad infinitum.

Quality initiatives* radiation risk: what you should know to tell your patient.

The steady increase in the number of radiologic procedures being performed is undeniably having a beneficial impact on healthcare. However, it is also becoming common practice to quantify the health detriment from radiation exposure by calculating the number of cancer-related deaths inferred from the effective dose delivered to a given patient population. The inference of a certain number of expected deaths from the effective dose is to be discouraged, but it remains important as a means of raising professional awareness of the danger associated with ionizing radiation. The risk associated with a radiologic examination appears to be rather low compared with the natural risk. However, any added risk, no matter how small, is unacceptable if it does not benefit the patient. The concept of diagnostic reference levels should be used to reduce variations in practice among institutions and to promote optimal dose indicator ranges for specific imaging protocols. In general, the basic principles of radiation protection (eg, justification and optimization of a procedure) need to be respected to help counteract the unjustified explosion in the number of procedures being performed.

Computed tomographic angiography in acute pulmonary embolism: do we need multiplanar reconstructions to evaluate the right ventricular dysfunction?

PURPOSE: To compare the indices of right ventricular dysfunction (RVD) obtained from axial transverse images with those derived from the reconstructed 4-chamber and short-axis views in patients with acute pulmonary embolism (PE). MATERIALS AND METHODS: Eighty-eight patients with acute PE were retrospectively enrolled. For each patient, axial transverse images and reconstructed 4-chamber and short-axis views were reviewed. Measurements of the ratios of right ventricle to left ventricle (RV/LV) diameters and RV/LV areas were then obtained from all series. Values derived from each method were compared and correlated to arterial obstruction index. RESULTS: In the studied cohort, RV/LV diameters and RV/LV areas obtained from axial transverse images and the reconstructed 4-chamber views were not statistically different. In contrast, a statistically significant difference was observed between the values of RV/LV areas derived from both axial transverse and 4-chamber views and those obtained from short-axis views (P < 0.0001). There was a weak to moderate correlation between both RV/LV diameters and RV/LV areas and the computed tomographic obstruction index. However, when the study cohort was divided into 3 subgroups with an arterial obstruction index of less than 15% (n = 26), 15% to 30% (n = 21), and greater than 30% (n = 41), those who had values greater than 30% revealed the highest correlation with the indices of RVD. CONCLUSIONS: In patients with acute PE, the indices of RVD derived from axial transverse images and the reconstructed 4-chamber views yield comparative values. Given the simplicity of the former analysis, it should be taken into consideration for risk stratification in acute PE.

Radiological profile of anemia on unenhanced MDCT of the thorax.

Our aim was to investigate the diagnostic value of unenhanced MDCT in anemic patients. Fifty consecutive patients with proven anemia and 50 nonanemic matched group for age, sex and body mass index were evaluated. In either group, hemoglobin levels were assessed no more than 24 h from an unenhanced CT of the thorax. For each patient, the presence of a hyperattenuating aortic wall (aortic ring sign) and/or dense interventricular septum (subjective parameters) were identified by two radiologists who were blinded to the laboratory findings. Furthermore, the aortic CT attenuation values (objective parameter) were also obtained and correlated with the hemoglobin levels. The sensitivity and specificity in detecting anemia were calculated for each variable, and ROC analysis was generated for subjective and objective parameters. Subjective image analysis revealed that the aortic ring sign was more sensitive than the interventricular septum sign for anemia detection (84% vs. 72%), whereas this latter sign was more specific (100% vs. 92%). A good correlation (r = 0.60) was observed between the aortic CT attenuation values and the hemoglobin levels in the whole study population. Using a threshold of < or = 35 HU for anemia diagnosis, the sensitivity and specificity of aortic CT attenuation value were 84% and 94%, respectively, with the largest area under the curve (0.89) among all diagnostic criteria. However, the best trade-off between sensitivity (80%) and specificity (100%) was obtained from combining both subjective and objective analysis. Interpreting anemia upon unnenhanced MDCT of the thorax is quite feasible. A diagnostic approach that considers both subjective and objective analysis offers the best trade-off between sensitivity and specificity.

Optimal 3-T MRI for depiction of the finger A2 pulley: comparison between T1-weighted, fat-saturated T2-weighted and gadolinium-enhanced fat-saturated T1-weighted sequences.

OBJECTIVE: To compare three spin-echo sequences, transverse T1-weighted (T1WI), transverse fat-saturated (FS) T2-weighted (T2WI), and transverse gadolinium-enhanced (Gd) FS T1WI, for the visualisation of normal and abnormal finger A2 pulley with magnetic resonance (MR) imaging at 3 tesla (T). MATERIALS AND METHODS: Sixty-three fingers from 21 patients were consecutively investigated. Two musculoskeletal radiologists retrospectively compared all sequences to assess the visibility of normal and abnormal A2 pulleys and the presence of motion or ghost artefacts. RESULTS: Normal and abnormal A2 pulleys were visible in 94% (59/63) and 95% (60/63) on T1WI sequences, in 63% (40/63) and 60% (38/63) on FS T2WI sequences, and in 87% (55/63) and 73% (46/63) on Gd FS T1WI sequences when read by the first and second observer, respectively. Motion and ghost artefacts were higher on FS T2WI sequences. Seven among eight abnormal A2 pulleys were detected, and were best depicted with Gd FS T1WI sequences in 71% (5/7) and 86% (6/7) by the first and the second observer, respectively. CONCLUSION: In 3-T MRI, the comparison between transverse T1WI, FS T2WI, and Gd FS T1WI sequences shows that transverse T1WI allows excellent depiction of the A2 pulley, that FS T2WI suffers from a higher rate of motion and ghost artefacts, and transverse Gd FS T1WI is the best sequence for the depiction of abnormal A2 pulley.

Portal vein normal anatomy and variants: implication for liver surgery and portal vein embolization.

The normal anatomy of the portal vein is defined as a division of the main portal vein into two branches-the left (supplying segments II, III, and IV) and right portal veins; the right dividing secondarily into two branches-the anterior (supplying segments V and VIII) and the posterior (supplying segments VI and VII) portal veins. Variants are frequent and account for 20 to 35% of the population. The most frequent variants are portal trifurcation with division of the main portal vein into the left, right anterior, and posterior branches, and the early origin of the right posterior branch directly from the portal vein. The presence of portal vein variants increases the risk of bile duct hilar anatomical variation. These variants must be diagnosed before complex hepatectomy, split or living donor transplantation, and before complex interventional procedures such as portal vein embolization. The purpose of this article is to review normal and variant portal venous anatomy and their implications for liver surgery and preoperative portal vein embolization.

Detection of ingested cocaine-filled packets--diagnostic value of unenhanced CT.

PURPOSE: Emergency departments are facing nowadays an increasing number of illegal drug-related health problems, associated with medicolegal and/or social consequences. Body stuffers are street cocaine dealers, who either store wrapped packets of drugs in their rectum or hastily swallow them, prompted by fear of police's arrest. These packets can be life threatening in case of leakage. We evaluate the diagnostic value of unenhanced multidetector CT (MDCT) for detection of cocaine-filled packets (CFP) ingested by body stuffers in a phantom model. MATERIALS AND METHODS: Our phantom simulated normal bowel contents in which a varying number of true and false CFP were randomly mixed. Both only differ in radiological density. During 18 different reading sessions, four radiologists independently evaluated the presence and number of true and false CFP. Interobserver agreement, sensitivity, specificity, positive and negative predictive value were calculated. RESULTS: Interobserver agreement for detection of any packets, for visualization of true, and false CFP was good (kappa=0.63, 0.74 and 0.58, respectively). Sensitivity, specificity, positive and negative predictive value for detection of any packets was 95.6%, 100%, 100% and 62.5%, respectively; for visualization of the true CFP 86.5%, 100%, 100% and 77.6%, respectively; and for the false packets 98.1%, 65%, 88.6% and 87.5%, respectively. CONCLUSION: Unenhanced MDCT without bowel preparation is a fast, reliable and easily reproducible imaging modality for the immediate detection of ingested CFP, thus facilitating medicolegal management of body stuffers.

[Diffuse parenchymal lung disease, multidisciplinary approach and role of pathology]. / Les pneumopathies interstitielles diffuses chroniques: un mariage de raison entre pathologiste, clinicien et radiologue.

The diagnostic approach to diffuse parenchymal lung disease (DPLD) and especially to the idiopathic interstitial pneumonias has changed over the last two decades, mostly thanks to the development of high resolution CT. Though far from replacing pathology, this additional tool has contributed to the definition of new and more precise diagnostic criteria especially for idiopathic interstitial pneumonias, integrating data provided by the three main contributors: lung specialist, radiologist and pathologist. The purpose of this article is to review the role of histopathology in the multidisciplinary approach of the diagnosis of DPLD and idiopathic interstitial pneumonias.

CT dose optimization when changing to CT multi-detector row technology.

The purpose of this article was to review the strategies to control patient dose in adult and pediatric computed tomography (CT), taking into account the change of technology from single-detector row CT to multi-detector row CT. First the relationships between computed tomography dose index, dose length product, and effective dose in adult and pediatric CT are revised, along with the diagnostic reference level concept. Then the effect of image noise as a function of volume computed tomography dose index, reconstructed slice thickness, and the size of the patient are described. Finally, the potential of tube current modulation CT is discussed.

Proximal splenic artery embolization for blunt splenic injury: clinical, immunologic, and ultrasound-Doppler follow-up.

BACKGROUND: To evaluate the clinical, US (ultrasound)-Doppler and hematologic findings after proximal splenic artery embolization (PSAE) for blunt injury. METHODS: From August 1998 to February 2003, 37 patients (28 men and 9 women; 20-89 years old, mean 40 years) underwent PSAE for blunt injuries. One patient required secondary splenectomy after PSAE. Early complications were investigated during the hospital stay. Delayed follow-up included review of the outpatient records, telephone interview, consultation, US-Doppler splenic study, Howell-Jolly body search, and serum antibody titer determinations (pneumococcus and Haemophilus influenzae B). RESULTS: No early postprocedural complications were depicted. Ten patients were lost on follow-up. Two patients had a telephone interview that revealed no complication. Twenty-four patients were examined 6 to 63 (mean 26) months after the embolization. No late complication was reported. Splenic measurements were in the normal range: length (53-110 mm; mean, 73), width (49-110 mm; 76), thickness (26-56 mm; 38), volume (61-508 mL; 226), standard ellipsoid formula volume (32-265 mL; 118), corrected volume (29-238 mL; 106), and splenic volumetric index (2.3-18.8; 8.4). The spleen was homogeneous in 23 patients (96%). Intrasplenic vascularization was present and splenic vein was patent in all patients. Howell-Jolly bodies were found in two patients. All patients (24 of 24) evaluated for exposure-driven immunity against Haemophilus Influenza b had sufficient immunity. Seventeen of the 18 patients (94%) evaluated for exposure-driven immunity against pneumococcus had sufficient immunity. Five of the six patients (83%) evaluated for pneumococcus vaccine response had a sufficient response. CONCLUSIONS: Proximal splenic artery embolization in blunt splenic injuries is a well-tolerated technique without major long-term impact on the splenic anatomy and immune function.

Finger A2 pulley lesions in rock climbers: detection and characterization with magnetic resonance imaging at 3 Tesla--initial results.

OBJECTIVES: To evaluate magnetic resonance imaging (MRI) at 3 T in the diagnosis and characterization of lesions of the finger flexor A2 pulley in patients with clinically suspected A2 pulley lesions. MATERIALS AND METHODS: Eight consecutive patients with clinically suspected lesions of the A2 pulley were included in this retrospective study. 3 T MRI was performed with T1-weighted, T2-weighted fat suppressed, and T1-weighted fat suppressed contrast enhanced sequences. The A2 pulley of all the fingers visible on the images were analyzed and pulley lesions characterized. RESULTS: All asymptomatic pulleys were normal at MRI. In the 8 symptomatic fingers 7 pulleys were abnormal at MRI. With the clinical examination as gold standard, sensitivity, specificity, positive predictive value, and negative predictive value of MRI were 87.5%, 100%, 100%, and 95.2% respectively. Characterization of the different pulley lesion was possible. CONCLUSION: MRI at 3 T allows reliable direct visualization and characterization of traumatic A2 pulley lesions.

Video-assisted thoracoscopic resection of a small pulmonary nodule after computed tomography-guided localization with a hook-wire system. Experience in 45 consecutive patients.

BACKGROUND: This study is a single-institution validation of video-assisted thoracoscopic (VATS) resection of a small solitary pulmonary nodule (SPN) previously localized by a CT-guided hook-wire system in a consecutive series of 45 patients. METHODS: The records of all patients undergoing VATS resection for SPN preoperatively localized by CT-guided a hook-wire system from January 2002 to December 2004 were assessed with respect to failure to localize the lesion by the hook-wire system, conversion thoracotomy rate, duration of operation, postoperative complications, and histology of SPN. RESULTS: Forty-five patients underwent 49 VATS resections, with simultaneous bilateral SPN resection performed in 4. Preoperative CT-guided hook-wire localization failed in two patients (4%). Conversion thoracotomy was necessary in two patients (4%) because it was not possible to resect the lesion by a VATS approach. The average operative time was 50 min. Postoperative complications occurred in 3 patients (6%), one hemothorax and two pneumonia. The mean hospital stay was 5 days (range: 2-18 days). Histological assessment revealed inflammatory disease in 17 patients (38%), metastasis in 17 (38%), non-small-cell lung cancer (NSCLC) in 4 (9%), lymphoma in 3 (6%), interstitial fibrosis in 2 (4%), histiocytoma in one (2%), and hamartoma in one (2%). CONCLUSIONS: Histological analysis of resected SPN revealed unexpected malignant disease in more than 50% of the patients indicating that histological clarification of SPN seems warranted. Video-assisted thoracoscopic resection of SPN previously localized by a CT-guided hook-wire system is related to a low conversion thoracotomy rate, a short operation time, and few postoperative complications, and it is well suited for the clarification of SPN.

Interventional management of gastroduodenal lesions complicating intra-arterial hepatic chemotherapy.

Herein we report the efficacy of embolization of small patent gastric or duodenal vessels for treating gastroduodenal complications after hepatic arterial infusion therapy (HAIC). Catheter ports were implanted percutaneously from a femoral approach in three cases or surgically in the gastroduodenal artery in two cases. Acute abdominal pain developed on average after four HAIC courses of 5FU-oxaliplatin, mytomycin, oxaliplatin or fotemustine. Esophagogastroduodenoscopy showed gastroduodenal lesions (gastroduodenitis with or without ulcerations) in all cases. Despite the interruption of the HAIC, symptoms persisted and led to selective hepatic arteriography showing a patent right gastric artery (n = 4) or a recanalized gastroduodenal artery (n = 1) responsible for gastroduodenal misperfusion. Successful embolizations of the arteries responsible for gastroduodenal misperfusion (right gastric artery in four cases and gastroduodenal artery in one case) using 0.018 platinium coils relieved the patients' symptoms and allowed the HAIC to continue. In gastroduodenal complications of HAIC, a selective hepatic arteriography should be performed to search any artery responsible for the misperfusion of the toxic agent in the gastroduodenal area. Embolization of these arteries allowed the HAIC to be restored.

A new, easy, fast, and safe method for CT-guided sacroplasty.

Sacral insufficiency fractures constitute clinical challenges because no effective surgical techniques can be applied and only a conservative treatment is currently performed. Sacroplasty is increasingly used to treat sacral insufficiency fractures. A computed tomography (CT)-guided technique concerning the placement of the sacroplasty needles within the sacral wings by using a laser alignment light guidance associated with a CT gantry tilt in a plane parallel to the sacral bone is presented. This method allowed a fast and precise placement of the needle in and along the sacral wings, thus preventing the use of multiple needles to reach the fracture sites.

Impact of the introduction of 16-row MDCT on image quality and patient dose: Phantom study and multi-centre survey.

The purpose was to compare the image quality and patient dose between 4- and 16-row MDCT units and to evaluate the dispersion of the dose delivered for common clinical examinations. Four 4- and 16-row MDCT units were used in the study. Image noise levels from images of a CatPhan phantom were compared for all units using a given CTDI(vol) of 15.0+/-1.0 mGy. Standard acquisition protocols from ten centres, shifted from 4- to 16-row MDCT (plus one additional centre for 16-row MDCT), were compared for cerebral angiography and standard chest and abdomen examinations. In addition, the protocols used with 16-row MDCT units for diagnosis of the unstable shoulder and for cardiac examinations were also compared. The introduction of 16-MSCT units did not reduce the performance of the detectors. Concerning the acquisition protocols, a wide range in practice was observed for standard examinations; DLP varied from 800 to 5,120 mGy x cm, 130 to 860 mGy x cm, 410 to 1,790 mGy x cm and 850 to 2,500 mGy x cm for cerebral angiography, standard chest, standard abdomen and heart examinations, respectively. The introduction of 16-row MDCT did not, on average, increase the patient dose for standard chest and abdominal examinations. However, a significant dose increase has been observed for cerebral angiography. There is a wide dispersion in the doses delivered, especially for cardiac imaging.