Are Dynamic Arterial Spin-Labeling MRA and Time-Resolved Contrast-Enhanced MRA Suited for Confirmation of Obliteration following Gamma Knife Radiosurgery of Brain Arteriovenous Malformations?

BACKGROUND AND PURPOSE: Intra-arterial DSA has been traditionally used for confirmation of cure following gamma knife radiosurgery for AVMs. Our aim was to evaluate whether 4D arterial spin-labeling MRA and contrast-enhanced time-resolved MRA in combination can be an alternative to DSA for confirmation of AVM obliteration following gamma knife radiosurgery. MATERIALS AND METHODS: In this prospective study, 30 patients undergoing DSA for confirmation of obliteration following gamma knife radiosurgery for AVMs (criterion standard) also underwent MRA, including arterial spin-labeling MRA and contrast-enhanced time-resolved MRA. One dataset was technically unsatisfactory, and the case was excluded. The DSA and MRA datasets of 29 patients were independently and blindly evaluated by 2 observers regarding the presence/absence of residual AVMs. RESULTS: The mean time between gamma knife radiosurgery and follow-up DSA/MRA was 53 months (95% CI, 42-64 months; range, 22-168 months). MRA total scanning time was 9 minutes and 17 seconds. Residual AVMs were detected on DSA in 9 subjects (obliteration rate = 69%). All residual AVMs were detected on at least 1 MRA sequence. Arterial spin-labeling MRA and contrast-enhanced time-resolved MRA showed excellent specificity and positive predictive values individually (100%). However, their sensitivity and negative predictive values were suboptimal due to 1 false-negative with arterial spin-labeling MRA and 2 with contrast-enhanced time-resolved MRA (sensitivity = 88% and 77%, negative predictive values = 95% and 90%, respectively). Both sensitivity and negative predictive values increased to 100% if a composite assessment of both MRA sequences was performed. Diagnostic accuracy (receiver operating characteristic) and agreement (κ) are maximized using arterial spin-labeling MRA and contrast-enhanced time-resolved MRA in combination (area under receiver operating characteristic curve = 1, P < .001; κ = 1, P < .001, respectively). CONCLUSIONS: Combining arterial spin-labeling MRA with contrast-enhanced time-resolved MRA holds promise as an alternative to DSA for confirmation of obliteration following gamma knife radiosurgery for brain AVMs, having provided 100% sensitivity and specificity in the study. Their combined use also enables reliable characterization of residual lesions.

Cone-beam computed tomography compared to X-ray in diagnosis of extremities bone fractures: A study of 198 cases.

CBCT is an imaging technique consisting of X-ray computed tomography, in which the x-rays are divergent, forming a cone. During 2015, a new model of CBCT, New Tom 5G XL (Verona), was used in the Radiology Department of The University of Verona, in collaboration with the Orthopaedics Department. Our study was carried out from October 2015 to October 2016 (198 patients). We compared CBCT with standard x-ray in the diagnosis of foot and anke fractures (and Lisfranc lesions), tibial plateau fractures, wrist and scaphoid fractures, elbow fractures. All patients were analyzed, of which 143 were positive or had documented bone lesions, while 55 were with no fractures seen. Of the 55 negative patients, 19 were considered positive at Standard RX, thus in 34.5% of cases the X-ray Standard examination overestimated the disease (false positive cases). Similarly, of the 143 positive patients, 21 were negative at RX, resulting in 14.6% of false negatives. We can say that if compared to standard X-ray, CBCT has higher sensitivity and specificity in the proper identification and typing of these kind of lesions, with low exposition dose if compared to MDCT. The most common rx-unrecognized fractures were in small bones of carpus and tarsus.

Heterogeneity of Cortical Lesion Susceptibility Mapping in Multiple Sclerosis.

BACKGROUND AND PURPOSE: Quantitative susceptibility mapping has been used to characterize iron and myelin content in the deep gray matter of patients with multiple sclerosis. Our aim was to characterize the susceptibility mapping of cortical lesions in patients with MS and compare it with neuropathologic observations. MATERIALS AND METHODS: The pattern of microglial activation was studied in postmortem brain tissues from 16 patients with secondary-progressive MS and 5 age-matched controls. Thirty-six patients with MS underwent 3T MR imaging, including 3D double inversion recovery and 3D-echo-planar SWI. RESULTS: Neuropathologic analysis revealed the presence of an intense band of microglia activation close to the pial membrane in subpial cortical lesions or to the WM border of leukocortical cortical lesions. The quantitative susceptibility mapping analysis revealed 131 cortical lesions classified as hyperintense; 33, as isointense; and 84, as hypointense. Quantitative susceptibility mapping hyperintensity edge found in the proximity of the pial surface or at the white matter/gray matter interface in some of the quantitative susceptibility mapping-hyperintense cortical lesions accurately mirrors the microglia activation observed in the neuropathology analysis. CONCLUSIONS: Cortical lesion susceptibility maps are highly heterogeneous, even at individual levels. Quantitative susceptibility mapping hyperintensity edge found in proximity to the pial surface might be due to the subpial gradient of microglial activation.

Epilepsy in multiple sclerosis: The role of temporal lobe damage.

BACKGROUND: Although temporal lobe pathology may explain some of the symptoms of multiple sclerosis (MS), its role in the pathogenesis of seizures has not been clarified yet. OBJECTIVES: To investigate the role of temporal lobe damage in MS patients suffering from epilepsy, by the application of advanced multimodal 3T magnetic resonance imaging (MRI) analysis. METHODS: A total of 23 relapsing remitting MS patients who had epileptic seizures (RRMS/E) and 23 disease duration matched RRMS patients without any history of seizures were enrolled. Each patient underwent advanced 3T MRI protocol specifically conceived to evaluate grey matter (GM) damage. This includes grey matter lesions (GMLs) identification, evaluation of regional cortical thickness and indices derived from the Neurite Orientation Dispersion and Density Imaging model. RESULTS: Regional analysis revealed that in RRMS/E, the regions most affected by GMLs were the hippocampus (14.2%), the lateral temporal lobe (13.5%), the cingulate (10.0%) and the insula (8.4%). Cortical thinning and alteration of diffusion metrics were observed in several regions of temporal lobe, in insular cortex and in cingulate gyrus of RRMS/E compared to RRMS ( p< 0.05 for all comparisons). CONCLUSIONS: Compared to RRMS, RRMS/E showed more severe damage of temporal lobe, which exceeds what would be expected on the basis of the global GM damage observed.

Multicenter external validation of two malignancy risk prediction models in patients undergoing 18F-FDG-PET for solitary pulmonary nodule evaluation.

OBJECTIVES: To achieve multicentre external validation of the Herder and Bayesian Inference Malignancy Calculator (BIMC) models. METHODS: Two hundred and fifty-nine solitary pulmonary nodules (SPNs) collected from four major hospitals which underwent 18-FDG-PET characterization were included in this multicentre retrospective study. The Herder model was tested on all available lesions (group A). A subgroup of 180 SPNs (group B) was used to provide unbiased comparison between the Herder and BIMC models. Receiver operating characteristic (ROC) area under the curve (AUC) analysis was performed to assess diagnostic accuracy. Decision analysis was performed by adopting the risk threshold stated in British Thoracic Society (BTS) guidelines. RESULTS: Unbiased comparison performed In Group B showed a ROC AUC for the Herder model of 0.807 (95 % CI 0.742-0.862) and for the BIMC model of 0.822 (95 % CI 0.758-0.875). CONCLUSIONS: Both the Herder and the BIMC models were proven to accurately predict the risk of malignancy when tested on a large multicentre external case series. The BIMC model seems advantageous on the basis of a more favourable decision analysis. KEY POINTS: • The Herder model showed a ROC AUC of 0.807 on 180 SPNs. • The BIMC model showed a ROC AUC of 0.822 on 180 SPNs. • Decision analysis is more favourable to the BIMC model.

Assessing probability of malignancy in solid solitary pulmonary nodules with a new Bayesian calculator: improving diagnostic accuracy by means of expanded and updated features.

OBJECTIVES: A crucial point in the work-up of a solitary pulmonary nodule (SPN) is to accurately characterise the lesion on the basis of imaging and clinical data available. We introduce a new Bayesian calculator as a tool to assess and grade SPN risk of malignancy. METHODS: A set of 343 consecutive biopsy or interval proven SPNs was used to develop a calculator to predict SPN probability of malignancy. The model was validated on the study population in a "round-robin" fashion and compared with results obtained from current models described in literature. RESULTS: In our case series, receiver operating characteristic (ROC) analysis showed an area under the curve (AUC) of 0.893 for the proposed model and 0.795 for its best competitor, which was the Gurney calculator. Using observational thresholds of 5% and 10% our model returned fewer false-negative results, while showing constant superiority in avoiding false-positive results for each surgical threshold tested. The main downside of the proposed calculator was a slightly higher proportion of indeterminate SPNs. CONCLUSIONS: We believe the proposed model to be an important update of current Bayesian analysis of SPNs, and to allow for better discrimination between malignancies and benign entities on the basis of clinical and imaging data. KEY POINTS: • Bayesian analysis can help characterise solitary pulmonary nodules • Volume doubling time (VDT) is a good predictor of malignancy • A VDT of between 25 and 400 days is highly suggestive of malignancy • Nodule size, enhancement, morphology and VDT are the best predictors of malignancy.

Limited value of logistic regression analysis in solid solitary pulmonary nodules characterization: a single-center experience on 288 consecutive cases.

BACKGROUND AND OBJECTIVES: Preoperative characterization of the solitary pulmonary nodule is a delicate task faced by surgeons, radiologists, and clinicians. Mathematical models have been developed to overcome subjectivity. The Mayo Clinic model was suggested in the latest ACCP evidence-based clinical practice guidelines for the preoperative risk assessment of solitary pulmonary nodule malignancy. The aim of the study is to assess the validity of the Mayo Clinic model in a current continuous case series of biopsy-proven nodules. METHODS: The Mayo Clinic model was applied to estimate probability of malignancy in 288 consecutive cases in this single-center retrospective study. RESULTS: ROC curve analysis returned an AUC of 0.767, while analysis performed on 158 malignant nodules showed a mean predicted risk value of 38.15%. In our clinical setting, using a risk observational threshold set at 5% and a risk surgical threshold set at 60%, there would have been 4 cases of unnecessary surgery (false positives) at the cost of 13 cases of cancer progression (false negatives), while 68.75% of all nodules would have received non-decisional values. CONCLUSIONS: Surgeons should be aware that current data shows how the Mayo Clinic model is of little use in preoperative nodule characterization.

Benefits of double reading of screening mammograms: retrospective study on a consecutive series.

PURPOSE: The purpose of this study was to assess the performance of delayed second reading of screening mammograms when added to real-time reading plus immediate assessment. MATERIAL AND METHODS: The study setting was the mammography screening programme of an Italian Local Health Unit. Recall rate and cancer detection rate at first reading or informed second reading only were assessed in a cohort of 23,629 women aged 50-69 years screened during 2007-2008. Incremental recall rate, incremental cancer detection rate and incremental cost of second reading were determined. RESULTS: Recall rate was 13.0% at first and 2.7% at second reading (incremental recall rate +21.1%). Overall, recalls were more frequent in the younger decade and in the presence of denser breasts. Cancer detection rate was 7.06‰ (n=167) at first and 0.93‰ (n=22) at second reading (incremental cancer detection rate +13.1%). Compared with first reading, second reading detected more cancers depicted as isolated microcalcifications and distortions (40.9% vs. 16.2%, p=0.02) and at a lower stage (stage 0-I 81.8% vs. 69.5%, p=0.34). The cost of adding delayed second reading was + 3.65 per screened individual or 3,926.61 per incremental cancer detected. CONCLUSIONS: The study confirms the efficacy of second reading, even as an adjunct to real-time single reading plus immediate assessment. Incremental recall rate is acceptable in view of the incremental cancer detection rate, and both figures are within the range of literature reports on double-reading performance.

Positive predictive value for malignancy on surgical excision of breast lesions of uncertain malignant potential (B3) diagnosed by stereotactic vacuum-assisted needle core biopsy (VANCB): a large multi-institutional study in Italy.

Percutaneous core biopsy (CB) has been introduced to increase the ability of accurately diagnosing breast malignancies without the need of resorting to surgery. Compared to conventional automated 14 gauge needle core biopsy (NCB), vacuum-assisted needle core biopsy (VANCB) allows obtaining larger specimens and has recognized advantages particularly when the radiological pattern is represented by microcalcifications. Regardless of technical improvements, a small percentage of percutaneous CBs performed to detect breast lesions are still classified, according to European and UK guidelines, in the borderline B3 category, including a group of heterogeneous lesions with uncertain malignant potential. We aimed to assess the prevalence and positive predictive values (PPV) on surgical excision (SE) of B3 category (overall and by sub-categories) in a large series of non-palpable breast lesions assessed through VANCB, also comparison with published data on CB. Overall, 26,165 consecutive stereotactic VANCB were identified in 22 Italian centres: 3107 (11.9%) were classified as B3, of which 1644 (54.2%) proceeded to SE to establish a definitive histological diagnosis of breast pathology. Due to a high proportion of microcalcifications as main radiological pattern, the overall PPV was 21.2% (range 10.6%-27.3% for different B3 subtypes), somewhat lower than the average value (24.5%) from published studies (range 9.9%-35.1%). Our study, to date the largest series of B3 with definitive histological assessment on SE, suggests that B3 lesions should be referred for SE even if VANCB is more accurate than NCB in the diagnostic process of non-palpable, sonographically invisible breast lesions.

Diffusion-weighted magnetic resonance imaging in focal breast lesions: analysis of 78 cases with pathological correlation.

PURPOSE: This study assessed the usefulness of magnetic resonance diffusion-weighted imaging (DWI) in distinguishing between benign and malignant breast lesions. MATERIALS AND METHODS: Gadolinium-enhanced magnetic resonance imaging (MRI) and DWI with determination of the apparent diffusion coefficient (ADC) were performed on 78 women, each with a focal breast lesion at least 7 mm in diameter, which was studied by cytology or histology. RESULTS: Final diagnoses were obtained by cytology in 29 cases and histology in 49 (11 percutaneous biopsies and 38 surgical specimens). There were 43 benign lesions (13 fibrocystic disease, eight fibroadenoma, seven adenosis, five normal breast tissue, four inflammatory lesions, three intramammary lymph nodes, two scleroelastosis and one fat necrosis) and 35 malignant lesions (30 invasive ductal carcinoma, two invasive lobular carcinoma, one ductal carcinoma in situ, one carcinomatous mastitis and one metastasis from neuroendocrine carcinoma). The mean ADC values were 1.677±0.151 for benign lesions and 1.298±0.129 for malignant lesions (p<0.001). With an ADC cutoff value of 1.48, DWI had 88.6% sensitivity [confidence interval (CI) 78.1%-99.1%] and 95.3% specificity (CI 88.9%-100%), with 31 true positives, four false negatives (three invasive ductal carcinoma and one carcinomatous mastitis), 41 true negatives and two false positives (one fat necrosis and one fibroadenoma). With the cutoff value set at 1.52, DWI sensitivity (35 true positive, no false negative) was 100% and specificity was 86% (CI 75.7%-96.3%) due to 37 true negatives and six false positives (an additional two fibroadenoma and two fibrocystic disease compared with those recorded with the cutoff set at 1.48). The overall accuracy of DWI considering both cutoff values (72 correct evaluations out of 78 cases) was 92.3% (CI 86.4%-98.2%). CONCLUSIONS: DWI is a reliable tool for characterising focal breast lesions.

Analysis of interval cancers observed in an Italian mammography screening programme (2000-2006).

PURPOSE: The purpose of this study was to assess the interval cancer (IC) proportional incidence and review IC cases observed in an Italian mammography screening programme during 2000-2006. MATERIALS AND METHODS: ICs were identified through linkage of a screening database with the local cancer registry and hospital discharge records to calculate proportional (observed/expected) incidence. Negatively reported mammograms preceding ICs underwent blind review (randomly mixed with negative controls in a 2:1 ratio) by three expert radiologists and classified according to European guidelines criteria (OC=occult, MS=minimal sign, SE=screening error) according to majority report. Proportional IC incidence and rate of reviewed IC classified as SE were compared with European guideline standards. RESULTS: Proportional IC incidence was 10.8% in the first and 40.0% in the second year of the interval (European standard=30% or 50%, respectively). Sensitivity estimate for the 2-year interval was 74.6%. ICs were reviewed as SE, MS or OC in 15.0%, 14.0% or 71.0% of cases, respectively. Corresponding review results for negative controls were 7.0%, 25.0% or 68.0%, respectively. Positive predictive value for IC was 51.7% for SE and 21.8% for MS reporting category, respectively (p=0.008). European standard (<20% reviewed as SE) was reached. CONCLUSIONS: The study shows that the sensitivity of the mammography programme was good, complying with European guideline recommendations. Assessment of IC-based early indicators of screening efficacy is feasible in a current screening programme and should become a routine procedure.

Characterisation of carotid atherosclerotic plaque: comparison between magnetic resonance imaging and histology.

PURPOSE: The aim of this study was to identify and characterise by magnetic resonance imaging (MRI) carotid plaque constituents such as lipid-rich necrotic core, intraplaque haemorrhage and calcification in patients treated with carotid endarterectomy (CEA) using histological evaluation as the reference standard. MATERIALS AND METHODS: Nineteen patients (13 men and six women) scheduled for CEA between March and August 2004 were imaged on a 1.5-T scanner (Magnetom Symphony, Siemens, Erlangen, Germany). The protocol included four types of sequences [T1, T2, proton density (PD) and three-dimensional time of flight (3D-TOF)]. Images were reviewed for integrity of the fibrous cap, presence of lipid-rich necrotic core, intraplaque haemorrhage and calcification. Signal intensity was assessed relative to the adjacent sternocleidomastoid muscle. Four cross-sections for each lesion were compared with the corresponding histological specimens and independently reviewed by two radiologists and one pathologist. RESULTS: MRI detected lipid-rich necrotic core with a sensitivity and specificity of 91.6% and 95.0%, respectively, whereas it defined intraplaque haemorrhage alone with a sensitivity and specificity of 91.6% and 100%, respectively. Calcification was recognised with a sensitivity and specificity of 80% and 93.7%, respectively. CONCLUSIONS: MRI is able to identify signs of carotid plaque instability with a high sensitivity and specificity. Therefore, it may be useful in evaluating and guiding the treatment of haemodynamically nonsignificant stenoses with a potential embolic risk and, in the future, to assess coronary plaque.

[Breast calcifications with percutaneous vacuum-assisted biopsy diagnosis of malignancy or atypical hyerplasia: correlations with surgical findings]. / Calcificazioni mammarie con diagnosi di malignità o iperplasia atipica su biopsia percutanea vacuum-assisted: correlazioni dopo escissione chirurgica.

Percutaneous, stereotactic, vacuum-assisted biopsy has become a widely used alternative to open surgical biopsy for the initial diagnosis of breast calcifications. We retrospectively assessed the accuracy of the technique in the diagnoses of malignancy and atypical hyperplasia by correlation with the findings of the subsequent surgical excision. We studied 330 consecutive cases of breast calcifications, 216 (65.5%) of which were determined to be benign and 114 (34.5%) to be malignant or atypical at vacuum-assisted biopsy using an 11 gauge instrument. Of the latter 93 were available for comparison with the subsequent surgery, the specific diagnoses as revealed by percutaneous biopsy were as follows: 11 cases of atypical ductal hyperplasia (ADN), 67 cases of ductal carcinoma in situ (DCIS), 6 infiltrating ductal carcinomas (IFDC), 2 cases of atypical lobular hyperplasia and 7 of lobular carcinoma in situ (LCIS). At histological analysis after surgical excision, 3 (27%) of 11 cases previously diagnosed as ADH and 6 (9%) of 67 cases diagnosed as DCIS were shown to actually be higher grade lesions (DCIS/IFDC and IFDC, respectively). Of the 7 lesions diagnosed at vacuum-assisted biopsy as LCIS, surgery and histological analysis showed one infiltrating globular carcinoma and two DCIS. A total of 21 lesions (4 ADH, 14 DCIS, 1 IFDC, 2 LCIS) were completely removed at percutaneous biopsy; the remaining cases were found totally concordant. These data Indicate a substantial accuracy of the percutaneous biopsy: some lesions (particularly those thought to be ADH and DCIS) can be underestimated for sampling error.

Simultaneous measurement of gastric emptying of a solid meal by ultrasound and by scintigraphy.

OBJECTIVE: Although ultrasonic imaging may represent a valid alternative to scintigraphy for measurement of gastric emptying, most studies comparing the two methods have been carried out with liquid meals. The aim of this study was to compare scintigraphic and ultrasonographic measurements of gastric emptying of a solid meal in healthy subjects and in patients with possible delay in emptying. METHODS: Nineteen subjects were studied: five controls, six patients with gastroesophageal reflux, and eight patients with dysmotility-like dyspepsia. Gastric emptying was measured by both scintigraphy and ultrasonography after ingestion of an 800-calorie solid, realistic meal containing 99mTc-labeled chicken liver. Scintigraphic measurements were made every 15 min for 6 h, and ultrasonic imaging of antral sections was undertaken every 15 min for the first 1 h and every 30 min thereafter. Total emptying times were calculated independently using the two methods, and the emptying patterns recorded by the two methods were compared. RESULTS: Maximal antral dilation occurred 30 min (range 0-90 min) after the end of the meal and persisted until 96 +/- 42 min, by which time gastric radioactivity had decreased from its maximum by 43% +/- 23%. From this time on, the antral cross-sectional area returned toward the basal value, declining faster than the gastric counts recorded by scintigraphy. Total emptying times measured by ultrasound and by scintigraphy were in good agreement in all subjects, with a mean difference of only 4.5 min (limits of agreement, -17.1 to 21.6 min). CONCLUSIONS: Ultrasonographic measurement of antral cross-sectional area provides a valid alternative to scintigraphy for the measurement of total gastric emptying of a solid meal. It is less reliable if other parameters of gastric emptying such as T(1/2) are required.

[Adrenal involvement in renal carcinoma. Diagnostic value of computerized tomography]. / Coinvolgimento surrenalico nel carcinoma renale. Valore diagnostico della Tomografia Computerizzata.

PURPOSE: We investigated the sensitivity and specificity of computed tomography (CT) in the detection of ipsilateral involvement of the adrenal glands by renal cancer. MATERIAL AND METHODS: We reviewed 350 cases of radical nephrectomy for renal cancer; the adrenal gland had been removed during nephrectomy in 185 cases. RESULTS: Histology confirmed adrenal gland involvement from renal cancer in 9 cases, namely 4 metastatic nodules and 5 cases of direct tumor invasion. Adrenal involvement was identified by preoperative CT in 3 cases only: the gland was undetectable in 2 of them, being masked by a large tumor mass, while it appeared normal on CT images in the 4 patients with metastatic nodules. CONCLUSIONS: An adrenal gland appearing normal during preoperative CT assessment of renal cancer is not very likely to be involved by cancer (2.4% of cases in our series), while a gland missed at CT is very likely involved because it may be masked by a large tumor.

[Echographic assessment of cutaneous neoplasms]. / Valutazione ecografica delle neoplasie cutanee.

A hundred and fifteen skin tumors were evaluated by means of US. Three variables were considered for each lesion--i.e., borders, echostructure and thickness--and the results compared with histology. High agreement was observed in melanomas: in these tumors, indeed, thickness is well known to be relevant for both surgical planning and prognosis. US scans with a 10 MHz transducer allowed the accurate assessment of borders and structure only in certain, mainly benign, kinds of skin tumors--e.g., angiomas, pilomatrixomas, sebaceous cysts and lipomas--, but also in lymphomas. On the contrary, most malignant neoplasms exhibit hypoechoic structure and borders from clear-cut to blurred. Finally, US proved to be highly reliable in demonstrating lesion thickness before surgery. High agreement was once again observed with histology relative to this variable: thickness (in mm) was the same in 30% of cases, overestimated by US (mean: 0.3 mm) in 44% of cases and underestimated by US (mean: 0.15 mm) in 26% of cases. Particularly, in 41 melanomas, histology-US agreement rate was 44% for the Breslow index, with r = 0.95 and 88% for the Clark index.

Small renal-cell carcinomas: clinical and imaging features.

The authors review the clinical, pathological and imaging characteristics of 20 patients with histological confirmation of 23 renal-cell carcinomas measuring < or = 3 cm in size. All lesions were unilateral. All patients were submitted to CT investigations, which identified 20 tumours (86%) and failed to identify 3 small-sized neoplastic nodular formations (0.4, 0.4, 0.8 cm) in patients with double tumour localisation in the same kidney. 15 patients underwent ultrasonography (US) which detected 11 carcinomas out of 17 (65%); of the 6 tumours (in 4 patients) not detected by US, 4 were identified by CT; 2 of these patients were subsequently re-examined by US with identification of the tumour. US failed to detect the 2 small tumours unidentified by CT (the third patient did not undergo US). 17 patients had no renal symptoms, and identification of the tumour was an incidental finding. The increasingly widespread use of US and CT enables a large number of kidneys to be examined and thus permits identification of a greater number of small-sized kidney tumours, allowing early surgical intervention with a greater chance of success. The technical options in surgical therapy may be multiple, though the use of any operation other than nephrectomy tends to be limited by the possible presence of small neoplastic nodular formations in the same kidney, which may not be detectable by US or CT owing to their very small size.

[Intra-renal ultrasound and color Doppler: pathology or nephrologic significance]. / Eco e color Doppler intra-renale: patologia di interesse nefrologico.

Us-Doppler examination of the native kidney gives more detailed information on nephrological vascular disease. Since there is a close connection between renal functional units (nephrons) and vascular and interstitial compartments, alterations in intrarenal flow will obviously occur in all types of medical nephropathy, irrespective of the origin of the anatomopathological damage. Altered intrarenal flow occur with increased vascular impedance, in turn related to an increased resistance index (RI). In nephropathy with dilatation, the RI can distinguish obstructive from non-obstructive dilatation (high and normal RI, respectively). Personal experience of 80 kidneys with nonobstructive medical nephropathy has shown a good correlation between increased RI and deterioration of renal function, demonstrating that, renal function being equal, RI is higher in Vascular than Tubulo-interstitial and Glomerular nephropathies. For medical nephropathy of transplanted kidneys, Us-Doppler evaluation can be combined with conventional Doppler for diagnosing acute rejection. In this series, an elevated RI (0.90) is highly predictive of acute rejection (92% specificity) but has low sensitivity (30%). At the threshold value of RI = 0.80, sensitivity is 66% and specificity is 78%. However, it is considered that far more reliable information is obtained if Doppler examination is combined with conventional U.S. morphology.