Intact intracranial breast prosthesis: a 28-year CT follow-up after treatment of late hemispherectomy complications.

Anatomical hemispherectomy has had excellent results in treating drug-resistant seizures of infantile hemiplegia. This technique of hemispherectomy consists in the removal of a whole hemisphere, with or without the basal ganglia, the end result being a large cavity left at the end of the operation. The technique, however, is considered to be weighted by important complications, in particular intracranial hemorrhages due to vessels tearing secondary to dislodgement of the remaining hemisphere. Several techniques have been consequently proposed to reduce the volume of the residual hemicranial cavity. An alternative measure is the filling of the cavity itself. We have demonstrated that this type of procedure can be carried out using a silicone breast prosthesis. In this report, we demonstrate also that such an implant can have a surprisingly long duration in its unusual location.

Intra-individual randomised comparison of gadobutrol 1.0 M versus gadobenate dimeglumine 0.5 M in patients scheduled for preoperative breast MRI.

OBJECTIVE: To demonstrate non-inferiority of gadobutrol versus gadobenate dimeglumine by intra-individually comparing 0.1 mmol/kg body weight doses for contrast-enhanced breast magnetic resonance imaging (MRI) and prospectively evaluating lesion detection and characterisation in a multicentre trial. METHODS: Two identical breast MRI examinations were performed in 72 patients with biopsy-proven breast cancer, separated by 1-7 days. Gadobutrol 1.0 M or gadobenate 0.5 M were administered in a randomised order. Lesion detection and characterisation were performed by two independent blinded readers. Lesion tracking, which compared on-site readings and histology from surgery or biopsy, was performed by a third reader. Differences in lesion detection and characterisation were compared between the two contrast agents. RESULTS: Among 103 lesions, 96 were malignant and 7 were benign. No difference in lesion detection was identified between the contrast agents (82.33 % for gadobutrol, 81.60 % for gadobenate). Assessment of sensitivity in lesion characterisation and Breast Imaging Reporting and Data Systems showed no difference between gadobutrol (92.63 %) and gadobenate (90.53 %). Regarding morphology, there was more non-focal enhancement for gadobutrol than for gadobenate (P = 0.0057). CONCLUSION: Non-inferiority of gadobutrol compared with gadobenate was demonstrated for breast lesion detection and sensitivity in lesion characterisation in breast MRI.

Incidental enhancing lesions found on preoperative breast MRI: management and role of second-look ultrasound.

PURPOSE: This study prospectively assessed second-look ultrasound (US) for the evaluation of incidental enhancing lesions identified on preoperative breast magnetic resonance imaging (MRI). MATERIALS AND METHODS: Between 2004 and 2007, 182 patients with malignant breast lesions detected on US and/or X-ray mammography and confirmed by cytology/histology underwent preoperative breast contrast-enhanced (CE)-MRI. Patients with incidental lesions on breast MRI underwent second-look high-resolution US directed at the site of the incidental finding. Diagnosis of incidental lesions was based on biopsy or 24-month follow-up. RESULTS: Breast MRI detected 55 additional lesions in 46/182 (25.2%) patients. Forty-two of 55 (76.3%) lesions were detected on second-look US in 38/46 (82.6%) patients. Malignancy was confirmed for 24/42 (57.1%) correlate lesions compared with 7/13 (53.8%) noncorrelate lesions. Second-look US depicted 8/9 (88.8%) Breast Imaging Reporting and Data System (BI-RADS) 5, 16/22 (72.7%) BI-RADS 4 and 18/24 (75%) BI-RADS 3 lesions. Sensitivity, specificity, accuracy and positive and negative predictive values for lesion detection/diagnosis was 100%, 88.9%, 94.6%, 90.3% and 100% for MRI and 64.3%, 70.4%, 67.3%, 69.2% and 65.5% for second-look US. Improved performance for US was obtained when masslike lesions only were considered. CONCLUSIONS: Second-look US is a confirmatory method for incidental findings on breast MRI, particularly for mass-like lesions.

Breast prosthesis: Management of patients after plastic surgery.

Breast augmentation and breast reconstruction are increasingly common operations. All radiologists need to be able to recognize the normal appearances of the more commonly used implants on various imaging modalities and breast radiologists in particular are facing new challenges when imaging the women involved. This work aims to review the normal and abnormal findings in women undergoing breast implant surgery using ultrasonography, mammography, and magnetic resonance imaging.

Evaluation of effectiveness of a computer system (CAD) in the identification of lung nodules with low-dose MSCT: scanning technique and preliminary results.

PURPOSE: Evaluation of the effectiveness of computer-aided diagnosis (CAD) in the identification of pulmonary nodules. MATERIALS AND METHODS: Two observers (A1, A2) with different levels of experience independently evaluated 20 chest MSCT studies with and without the aid of a CAD system (LungCheck, R2 Technology, Inc). The study parameters were as follows: 140 kVs, 40 mAs, collimation 4 x 1 mm, slice thickness 1.25 mm, reconstruction interval 1.0 mm. The observers analysed the images with and without CAD and evaluated: 1) nodule size (longer axis); 2) number and location of nodules; 3) reading time for each observer. The gold standard was represented by the evaluation of both readers in consensus with the aid of the CAD system. RESULTS: Without CAD support the two readers identified 77 (A1) and 79 (A2) nodules and with CAD 81 (A1) and 82 (A2) nodules. Working in consensus the two observers identified 81 nodules without the aid of the CAD and 84 nodules with the aid of CAD. Total number of nodules identified by CAD was 104, 25 of which were false positive and 5 false negative. The average reading time with the aid of the CAD decreased by as much as 40% for both the observers. CONCLUSIONS: The preliminary results of our study suggest that the CAD technique is an accurate automatic support tool in the identification of pulmonary nodules. It reduces reading time and automatically supplies the size, volume, density and number of nodules, thus being useful both in screening programmes and in the follow-up of cancer patients, in whom comparison of the images is particularly difficult.

High-resolution multidetector CT in the preoperative evaluation of patients with renal cell carcinoma.

OBJECTIVE: The purpose of our study was to evaluate the accuracy of multidetector CT (MDCT) using a high-resolution protocol in the preoperative assessment of patients with renal cell carcinoma who are possible candidates for nephron-sparing surgery. MATERIALS AND METHODS: Forty patients with suspected renal cell carcinoma underwent MDCT. Contrast-enhanced acquisitions were obtained during arterial, nephrographic, and urographic phases using a thin-slice protocol. One-millimeter-thick source images were evaluated by two observers on a dedicated workstation for the identification and characterization of the tumor, presence of a pseudocapsule or invasion of perirenal fat, involvement of adrenal glands or surrounding tissues, presence of satellite lesions within Gerota's fascia, infiltration of renal vein and inferior vena cava, involvement of lymph nodes, and presence of distant metastases. Imaging findings were compared with surgical specimens using criteria from the Robson and TNM classification systems. RESULTS: The presence and size of all lesions were correctly shown in all patients. In evaluating Robson stage I of renal cell carcinoma, we were able to diagnose fat infiltration on 1-mm scans with 96% sensitivity, 93% specificity, and 95% accuracy; the positive and negative predictive values were, respectively, 100% and 93%. One hundred percent accuracy was achieved in staging high-grade lesions. CONCLUSION: High-resolution MDCT is accurate in the preoperative evaluation of patients with renal cell carcinoma.

High-resolution CT angiography of the abdomen.

Multislice computed tomographic angiography (MSCTA) is a versatile technique that combines speed, excellent contrast, superb spatial resolution, and extreme simplicity. It has a wide range of applications in the abdomen including all vascular pathologies, occlusive or dilative, with excellent demonstration of atherosclerotic plaques in large or smaller branches. MSCTA is the method of choice in the follow-up of patients undergoing endovascular procedures for aneurysms. It provides excellent results in assessing vascular involvement by neoplasms arising from the liver, biliary tract, pancreas, kidneys, and all other abdominal organs. MSCTA can be used successfully in potential living donors and in the follow-up of recipients. Although MSCTA is a brand new technique, several developments are under investigation, which should allow further advancements in speed and spatial resolution.

[Magnetic resonance angiography with contrast media in the study of carotid arteries]. / Angiografia con Risonanza Magnetica con mezzo di contrasto nello studio delle arterie carotidi.

PURPOSE: Purpose of our study was to determine the feasibility and accuracy of contrast enhanced Turbo-MRA (CE-MRA) in the evaluation of patients with carotid artery stenosis, using a dynamic technique with multiple acquisitions. MATERIAL AND METHODS: 37 patients with suspected carotid artery stenosis were studied with a 1.5 T magnet (Siemens Vision Plus) using, with a neck phased array coil, a dynamic tridimensional T1 weighted spoiled GRE (TR/TE/NEX: 3.8/1.4/1; Matrix = 110 x 160; FOV = 163 x 260 mm TA = 10 seconds for each sequence); 4 consecutive sequences were performed during the same breath hold, acquired after i.v. bolus injection with a power injector (Spectris, Medrad) of 15 ml of Gd-DTPA followed by 10 ml of saline solution (flow rate 2 ml/s). The beginning of the sequence coincided with the injection of Gd-DTPA. Images were reconstructed using a standard MIP algorithm, by selecting which of the sequences provided the highest enhancement. In all patients a DSA was also performed. Images were separately evaluated using conventional angiography as the gold standard and assessed for degree of stenosis by using NASCET criteria, and morphology of the plaque. RESULTS: CE-MRA correctly evaluated the degree of stenosis in 71 of the 74 patients, while overestimated the remaining 3 cases correctly evaluated by DSA. In 12 cases ulcerations were adequately demonstrated by one of the radiologist, while 11 on 12 were depicted by the other one. CE MRA allowed to detect tandem lesions of the internal carotid arteries (by both radiologists) in 13 of 74 carotids studied. Stenosis at the origin of the common carotid arteries were correctly detected in 9 cases. Sensitivity, specificity and accuracy were respectively of 98, 97 and 99%. DISCUSSION AND CONCLUSIONS: In order to perform an optimal CE-MRA a dynamic technique must be performed to avoid venous filling. The possibility to use ultrafast imaging allows to selectively image the carotid arteries without jugular filling. The well known tendency to overestimate the degree of stenosis has not been found in this group of patients. CE-MRA is a rapid, reliable method to evaluate patients with suspected carotid artery stenosis. These results allow to consider dynamic CE-MRA as a valid method for direct imaging of the carotid arteries.

Localization of pancreatic insulinomas with MR imaging at 0.5 T.

OBJECTIVE: To determine the role of MR imaging in the localization of pancreatic insulinomas in patients with clinical and laboratory diagnosis of insulin-producing tumor. MATERIAL AND METHODS: Thirty-one patients presenting with signs and symptoms of pancreatic insulinomas were prospectively included in our study. Twenty-six patients underwent surgery, and pathologic specimens were examined: 5 patients, in whom the initial diagnosis of insulinoma was excluded, were also studied and then followed up. All patients were studied with a high gradient power 0.5 T magnet. Images were evaluated by 2 radiologists blinded to previous investigations, tests and results. RESULTS: MR imaging correctly localized 24 of the 26 insulinomas (2 were false-negative and 1 false-positive) and was correctly negative in the 5 control patients. The interobserver agreement had a kappa value of 0.89. CONCLUSION: MR imaging was accurate in localizing pancreatic insulinomas and as a consequence, patients in our institution are now submitted to surgery directly after the MR examination. Invasive methods are considered only in cases in which, despite clear biochemical results, MR imaging has not demonstrated a pancreatic focal lesion.

[MR imaging of pancreatic neoplasms]. / La risonanza magnetica del carcinoma pancreatico.

The role of MR imaging in the assessment of pancreatic adenocarcinoma is in identification, characterization and staging of the neoplastic lesion. Technique optimization is required in order to obtain high qualities images competitive with spiral CT. The choice of imaging protocol is strictly related to the available equipment as well as fast imaging capabilities. Contrast-enhanced study using breath-hold sequences is required if working at high field strength with high gradient performance; on mid-low field strength nonbreath-hold acquisition techniques, using respiratory compensation techniques, can be implemented. The use of fat saturation pulses may increase the sensitivity of MR in detecting pancreatic lesions. Other advantages of MR imaging are represented by the availability of additional noninvasive techniques for the evaluation of the biliary tree (MR-cholangiopancreatography) and splanchnic vessels (MR-angiography). Lesion identification is based on TIw sequences where the lesion appears hypointense compared with the surrounding pancreas; increased lesion-pancreas contrast is obtained when fat suppression is used. On dynamic studies following gadolinium injection, pancreatic tumors are hypovascular compared with surrounding normal pancreatic gland. Problems in correctly defining the size of the lesions may be encountered in patients presenting with inflammatory changes of the pancreatic parenchyma surrounding the carcinoma (epineoplastic pancreatitis). For lesion characterization MRI is not able to characterize focal pancreatic lesions, allowing a differential diagnosis between pancreatic cancer and focal hypertrophic chronic pancreatitis. Even the use of MR-cholangiopancreatography is not helpful for characterizing focal pancreatic masses. MR imaging is accurate in local staging (assessment of peripancreatic fat infiltration) thanks to the higher contrast resolution, but in vascular staging and in the evaluation of lymphnodal involvement it suffers the same limitations as computed tomography. Future perspective are represented by the use of magnetic resonance angiography for the evaluation of vascular encasement and the use of specific contrast agents for lymphadenopathy. Identification of hepatic metastases with MRI has been proven to be high, with sensitivity and specificity comparable to CT. The use of liver-specific contrast agents (either positive or negative) is becoming almost routine and it is proving to further improve the diagnostic value of MRI.