Diagnostic Performance of an Artificial Intelligence System in Breast Ultrasound

OBJECTIVES

We study the performance of an artificial intelligence (AI) program designed to assist radiologists in the diagnosis of breast cancer, relative to measures obtained from conventional readings by radiologists.

METHODS

A total of 10 radiologists read a curated, anonymized group of 299 breast ultrasound images that contained at least one suspicious lesion and for which a final diagnosis was independently determined. Separately, the AI program was initialized by a lead radiologist and the computed results compared against those of the radiologists.

RESULTS

The AI program's diagnoses of breast lesions had concordance with the 10 radiologists' readings across a number of BI-RADS descriptors. The sensitivity, specificity, and accuracy of the AI program's diagnosis of benign versus malignant was above 0.8, in agreement with the highest performing radiologists and commensurate with recent studies.

CONCLUSION

The trained AI program can contribute to accuracy of breast cancer diagnoses with ultrasound.

Role of apparent diffusion coefficient values in prostate diseases characterization on diffusion-weighted magnetic resonance imaging

BACKGROUND

To evaluate if normal and pathological prostate tissue can be distinguished by using apparent diffusion coefficient (ADC) values on magnetic resonance imaging (MRI) and to understand if it is possible to differentiate among pathological prostate tissues using ADC values.

METHODS

Our population consisted in 81 patients (mean age 65.4 years) in which 84 suspicious areas were identified. Regions of interest were placed over suspicious areas, detected on MRI, and over areas with normal appearance, and ADC values were recorded. Statistical differences between ADC values of suspicious and normal areas were evaluated. Histopathological diagnosis, obtained from targeted biopsy using MRI-US fusion biopsies in 39 patients and from prostatectomy in 42 patients, were correlated to ADC values.

RESULTS

Histopathological diagnosis revealed 58 cases of prostate cancer (PCa), 19 patients with indolent PCa (Gleason Score ≤6) and 39 patients with clinically significant PCa (Gleason Score ≥7), 16 of high-grade prostatic intraepithelial neoplasia (HG-PIN) and 10 of atypical small acinar proliferation (ASAP). Significant statistical differences between mean ADC values of normal prostate tissue versus PCa (P<0.00001), HG-PIN (P<0.00001) and ASAP (P<0.00001) were found. Significant differences were observed between mean ADC values of PCa versus HG-PIN (P<0.00001) and ASAP (P<0.00001) with many overlapping values. Differences between mean ADC values of HG-PIN versus ASAP (P=0.015) were not significant. Significant differences of ADC values were also observed between patients with indolent and clinically significant PCa (P<0.00001).

CONCLUSIONS

ADC values allow differentiation between normal and pathological prostate tissue and between indolent and clinically significant PCa but do not allow a definite differentiation between PCa, HG-PIN, and ASAP.

Incidence of new foci of hepatocellular carcinoma after radiofrequency ablation: role of multidetector CT

PURPOSE

The authors sought to assess the incidence of new foci of hepatocellular carcinoma (HCC) using multidetector computed tomography (MDCT) in patients treated with radiofrequency ablation (RFA).

MATERIALS AND METHODS

Two readers retrospectively reviewed by consensus the follow-up MDCT studies of 125 patients (88 men and 37 women; mean age 68 years) with 141 HCCs (size 1-5.2 cm; mean 2.2 cm) treated with RFA. MDCT follow-up was performed at 1 and 3 months and every 6-12 months thereafter. Reviewers assessed: (1) the presence of new HCC foci in the same liver segment or in a different segment; (2) complete or incomplete tumour ablation; (3) tumour progression.

RESULTS

A total of 113 new HCCs (size 0.7-4.8 cm; mean 1.7 cm) were detected in 69/125 (55.2%) patients (mean follow-up 30.38±19.14 months). Of these, 86 (76.1%) new HCCs were multiple (p<0.0001), and 92 (81.4%) occurred in a different segment from that of the treated HCC (p<0.0001). New HCCs were observed in the first 12 months, between 12 and 24 months and after 24 months in 31/69 (44.9%), 24/69 (34.8%) and 14/69 (20.3%) patients, respectively (p=0.175). Mean diseasefree interval was 16.1±16.31 (range 1-52) months. Complete tumour ablation was achieved in 132/141 (93.6%) treated HCCs, and tumour progression occurred in 29/141 (20.6%) cases.

CONCLUSIONS

In patients with RFA-treated HCCs, MDCT follow-up revealed a high incidence of new HCCs, even after 1 year of follow-up. The new foci tended to be multiple and located in a liver segment different from that of the previously treated nodules.

Minor Hepatic Resection for Hepatocellular Carcinoma in Cirrhotic Patients: Kelly Clamp Crushing Resection Versus Heat Coagulative Necrosis with Bipolar Radiofrequency Device

Hemorrhage and postoperative liver insufficiency are frequent and serious complications of hepatic resection in cirrhotic patients. The aim of this study was to assess retrospectively whether the surgical techniques using Kelly clamp crushing resection or heat coagulative necrosis with a bipolar radiofrequency device can reduce the incidence of the above complications and an eventual recurrence of neoplasia on the liver slice. We retrospectively reviewed the results of 35 patients who had undergone resection for monofocal hepatocellular carcinoma at our center. Thirteen patients (Group A) had undergone liver resection with Kelly clamp crushing resection, 22 patients (Group B) had had liver resection assisted with a bipolar radiofrequency device. Radiofrequency-assisted liver resection was associated with diminished blood loss ( P < 0.0001), a lower blood transfusion rate ( P < 0.005), reduced operative time ( P < 0.0001), and better postoperative serum albumin levels ( P < 0.03). This nonrandomized retrospective study suggests that radiofrequency-assisted liver resection is associated with better results than the Kelly clamp crushing resection technique in cirrhotic patients with focal hepatocellular carcinoma and preserved liver function. These results should now be assessed prospectively in a randomized clinical trial.

Minor hepatic resection for hepatocellular carcinoma in cirrhotic patients: Kelly clamp crushing resection versus heat coagulative necrosis with bipolar radiofrequency device

Hemorrhage and postoperative liver insufficiency are frequent and serious complications of hepatic resection in cirrhotic patients. The aim of this study was to assess retrospectively whether the surgical techniques using Kelly clamp crushing resection or heat coagulative necrosis with a bipolar radiofrequency device can reduce the incidence of the above complications and an eventual recurrence of neoplasia on the liver slice. We retrospectively reviewed the results of 35 patients who had undergone resection for monofocal hepatocellular carcinoma at our center. Thirteen patients (Group A) had undergone liver resection with Kelly clamp crushing resection, 22 patients (Group B) had had liver resection assisted with a bipolar radiofrequency device. Radiofrequency-assisted liver resection was associated with diminished blood loss (P < 0.0001), a lower blood transfusion rate (P < 0.005), reduced operative time (P < 0.0001), and better postoperative serum albumin levels (P < 0.03). This nonrandomized retrospective study suggests that radiofrequency-assisted liver resection is associated with better results than the Kelly clamp crushing resection technique in cirrhotic patients with focal hepatocellular carcinoma and preserved liver function. These results should now be assessed prospectively in a randomized clinical trial.

Prevalence of myocardial bridging and correlation with coronary atherosclerosis studied with 64-slice CT coronary angiography

PURPOSE

This study aimed to assess the prevalence and characteristics of myocardial bridging in patients who underwent multislice computed tomography coronary angiography (MSCT-CA) and to evaluate the correlation between bridged coronary segments and atherosclerosis.

MATERIALS AND METHODS

A total of 277 patients (mean age 60+/-11 years) we consecutively examined with 64-slice MSCT-CA for suspected or known coronary atherosclerosis were retrospectively reviewed for myocardial bridging. Segments proximal and distal to the bridging were evaluated for atherosclerotic plaque, as were the remaining coronary segments.

RESULTS

Myocardial bridging was present in 82 patients (30%, mean age 59+/-12). Bridges were of variable length (<1 cm 58%; 1-2 cm 32%; >2 cm 10%) and depth (superficial 69%, intramyocardial 31%) and frequently localised in the mid-distal segment of the left anterior descending artery (95%). Myocardial bridging cannot be considered a significant risk factor for coronary atherosclerosis (odds ratio 0.49) compared with traditional cardiovascular risk factors. Coronary segments proximal to the bridge showed no atherosclerotic disease (33%), positive remodelling (27%), <50% stenosis (20%) or >50% stenosis (20%). We identified 12 noncalcified, 32 mixed and 17 calcified plaques. The distal segments were significantly less affected (p<0.0001).

CONCLUSIONS

MSCT-CA is a reliable, noninvasive method that is able to depict myocardial bridging and associated atherosclerotic plaque in the proximal segments.

Primary malignant fibrous histiocytoma of the mesocolon transversum

Primary malignant fibrous histiocytoma (MFH) is a rare and biologically aggressive tumor. Differential diagnosis must include cystic neoplasms of the pancreas (mucinous and serous cystoadenoma or cystocarcinoma), cystic lymphangioma or mesothelioma and retroperitoneal haematoma. Making the right diagnosis preoperatively may be often difficult, but MFH may be suspected when a huge retroperitoneal mass is found at imaging in elderly patients. We report a case of a primary abdominal MFH originating from the mesocolon transversum.

Dysphagia: epidemiology, risk factors and impact on quality of life--a population-based study

BACKGROUND

Data on the population epidemiology of dysphagia are scarce. Little is known about the prevalence, risk factors and impact on quality of life of dysphagia in the general community.

AIM

To determine the magnitude and impact of dysphagia in the general community.

METHODS

A random sample of 1000 individuals of Sydney, Australia, were mailed a validated self-report questionnaire to assess dysphagia. Measured were dysphagia symptoms, potential mechanisms, risk factors, psychological disorders, quality of life and demographics.

RESULTS

The response rate of included subjects (n = 926) was 73% (n = 672). Dysphagia ever was reported by 16% (n = 110). Multiple logistic regression analysis found that odynophagia was independently associated with gastro-oesophageal reflux disease (GERD) (OR = 3.41, 95% CI: 1.16-10.04). Intermittent dysphagia was independently associated with GERD (OR = 2.96, 95% CI: 1.76-4.98) and anxiety (OR = 1.09, 95% CI: 1.01-1.19). The presence of progressive dysphagia was independently associated with depression (OR = 1.34, 95% CI: 1.07-1.67). Progressive dysphagia was independently associated with reduced 'general health' (OR = 0.95, 95% CI: 0.90-0.99), while intermittent dysphagia was associated with a reduction in the 'role physical' subscale (OR = 0.98, 95% CI: 0.97-0.99).

CONCLUSIONS

Dysphagia is remarkably common in the general population. GERD is a risk factor for dysphagia as well as odynophagia. Intermittent dysphagia was associated with anxiety, while progressive dysphagia was associated with depression.

Digital cineradiographic study of swallowing in patients with amyotrophic lateral sclerosis

PURPOSE

This study was performed to evaluate the usefulness of digital cineradiography in detecting swallowing disorders in dysphagic patients affected by amyotrophic lateral sclerosis (ALS) with a view to planning an adequate therapeutic approach.

MATERIAL AND METHODS

From January 2005 to September 2006, 23 patients (10 men and 13 women; mean age 41.3+/-8.6 years) affected by ALS were evaluated with digital cineradiography to assess the grade of dysphagia. All patients were classified using the Hillel ALS Severity Scale (ALSSS). All examinations were performed with radiocontrolled equipment provided with a digital C-arm.

RESULTS

The cineradiographic technique enabled us to differentiate patients with disorders of the oral (17/23) and/or pharyngeal (19/23) swallowing phase from those without swallowing dysfunction (4/23). In 14/23 patients, passage of contrast medium into the upper airways was observed during swallowing, whereas in 5/23 cases, aspiration of contrast medium into the lower airways was recorded.

CONCLUSIONS

The videofluoroscopic swallowing study has high diagnostic capabilities in the evaluation of swallowing disorders, as it is able to identify the degree and causes of impairment. In addition, the study proved useful for planning speech therapy and for follow-up in patients with ALS.

Forty-slice MDCT enteroclysis: evaluation after oral administration of isotonic solution in Crohn's disease

OBJECTIVE

The aim of this study was to evaluate the accuracy of multidetector computed tomography (MDCT) enteroclysis after oral hyperhydration with isotonic solution in detecting bowel wall alterations in patients with Crohn's disease.

MATERIALS AND METHODS

Twenty-eight patients with a diagnosis of Crohn's disease established by ileocolonoscopy and histology were enrolled in the study; 15 patients with negative ileocolonoscopy served as controls. In all cases, MDCT enteroclysis was performed after oral administration of 2,000 ml of isotonic solution and intravenous administration of N-butylscopolamine. Axial, isotropic multiplanar and volume-rendered reconstructions were used to evaluate bowel wall thickness, ulceration, contrast enhancement, extraparietal involvement and possible complications.

RESULTS

MDCT enteroclysis identified the typical signs of Crohn's disease in 26 patients (92.8%), with sensitivity of 92.8%, specificity of 100%, positive predictive value 100% and negative predictive value 75%.

CONCLUSIONS

MDCT enteroclysis after oral hyperhydration with isotonic solution showed a high level of accuracy in detecting small bowel changes in patients with Crohn's disease. It can be considered a safe and effective alternative to conventional radiography and small-bowel spiral computed tomography enema, especially in patients who refuse nasojejunal intubation.

Comprehensive cardiovascular ECG-gated MDCT as a standard diagnostic tool in patients with acute chest pain

Acute myocardial infarction, pulmonary embolism, and aortic dissection are diseases associated with acute chest pain and may lead to severe morbidity and mortality. These diseases may not be trivial to diagnose in the settings of emergency room. ECG-gated multi-detector computed tomography (MDCT), already established for the assessment of pulmonary embolism and aortic dissection, provides reliable information regarding the triage of patients with acute coronary syndrome in the emergency room. MDCT recently appeared to be logistically feasible and a promising comprehensive method for the evaluation of cardiac and non-cardiac chest pain in emergency department patients. The possibility to scan the entire thorax visualizing the thoracic aorta, the pulmonary arteries, and the coronary arteries could provide a new approach to the triage of acute chest pain. The inherent advantage of MDCT with cardiac state-of-the-art capabilities is the rapid investigation of the main sources of acute chest pain with a high negative predictive value. Recent studies also reports an advantage in terms of costs. With current evidence, the selection of patients with acute chest pain candidates to MDCT should remain restricted to avoid unjustified risk of ionizing radiation.

Giant hepatocellular adenoma as cause of severe abdominal pain: a case report

The authors describe the case of a large hepatocellular adenoma diagnosed in a 30-year old woman who came to us complaining of acute pain in the upper abdominal quadrants. The patient had been taking an oral contraceptive pill for the last ten years. We present the clinical features, the diagnostic work-up and the treatment prescribed.

Real-time spatial compound sonography of Achilles tendon in patients with heterozygous familial hypercholesterolaemia and normal physical examination

PURPOSE

This study was undertaken to assess the prevalence and ultrasound features of Achilles tendon xanthomas (ATX) in patients with heterozygous familial hypercholesterolemia (HFH) and normal physical examination studied with high-resolution ultrasonography (HRUS) and, secondarily, to evaluate the role of real-time spatial compound sonography (CS) in terms of image quality.

MATERIALS AND METHODS

Both Achilles tendons of 40 patients with HFH were studied with HRUS and CS. Two experienced radiologists evaluated by consensus the presence of ATX described as (1) tendon thickening and/or (2) focal hypoechoic areas and the quality of images obtained with the two techniques.

RESULTS

Ten out of 80 tendons showed thickening (mean: 11.2 mm). Twelve xanthomas 4.1-9.8 mm were identified in 9/80 tendons of five patients. In 5/80 tendons, both tendon thickening and focal hypoechoic areas were observed. There was no difference in the number of xanthomas detected at conventional US or CS. With respect to image quality, the performance of CS was considered significantly higher than HRUS in 72/80 (90%) cases and equal to HRUS in the remaining 8/80 (10%) (p<0.001).

CONCLUSIONS

CS is an effective tool in the assessment of ATX in patients with HFH and normal physical examination, and provides a better image quality when compared with HRUS.

Imaging processing for CT angiography of the cervicocranial arteries: evaluation of reformatting technique

PURPOSE

The aim of this study was to compare computed tomography angiography (CTA) sliding-thin-slab (STS) multiplanar reformatting (MPR), STS maximum intensity projection (MIP) and three-dimensional (3D) volume rendering (VR) reformatting techniques in the evaluation of cervicocranial arteries.

MATERIALS AND METHODS

Twenty patients examined with multislice CT were included in this study. CTA images were reformatted as STS-MIP, STS-MPR and 3DVR in orthogonal planes and in the oblique-coronal plane. Images were evaluated in consensus by two radiologists, with a third radiologist to resolve discordances in grading image quality parameters. The Spearman correlation analysis was performed to compare results and to obtain the correlation between scores resulting from the evaluation of parameters considered with the different techniques used (STSMIP, STS-MPR and 3DVR).

RESULTS

STS-MIP images were significantly superior to STSMPR images for all parameters considered (p<0.05). Obliquecoronal 3DVR images were significantly superior to obliquecoronal STS-MIP images in the evaluation of vertebrobasilar vessels (p<0.05); in all other cases, 3DVR images were equivalent to STS-MIP images.

CONCLUSION

STS-MIP images should be the primary reformatting technique for CTA of the cervicocranial arteries in addition to viewing the source images; 3DVR images can play an important role after a previsional diagnosis is made on the STS-MIP images.

Incidentally discovered thyroid nodules: incidence, and greyscale and colour Doppler pattern in an adult population screened by real-time compound spatial sonography

PURPOSE

Our aim was to assess the incidence and ultrasound features of thyroid nodules in an adult population screened by means of high-resolution ultrasonography (HRUS) and to evaluate the contribution of real-time spatial compound sonography (CS) in terms of image quality.

MATERIALS AND METHODS

A total of 704 consecutive patients (400 women, 304 men) without thyroid disease underwent HRUS and CS examination of the thyroid gland. Number, size, location, echotexture and colour Doppler pattern of detected nodules were assessed. Two radiologists also assessed image quality of the two techniques.

RESULTS

Seven hundred and eleven thyroid nodules (size range 0.18-4.1 cm; mean: 1.1 cm) were detected in 233 subjects (33.1%). Of these, 416 (58.5%) were found in 143 women whereas 295 (41.5%) were detected in 90 men. In both genders, the number of detected nodules increased with age, with the highest prevalence in the seventh decade (p<0.001). There were 461/711 (64.9%) thyroid nodules that were hypoechoic, and 449/711 (63.1%) had peripheral vascularity only (p<0.001). Fine-needle aspiration (FNA) revealed no malignancies. CS was graded better than HRUS in 621/711 (87.3%) cases (p<0.001).

CONCLUSIONS

The prevalence of benign, small, hypoechoic thyroid nodules with peripheral vascularity was high in our series, thus suggesting a conservative approach. CS provided better image quality compared with HRUS.

Gastrointestinal stromal tumour: 40-row multislice computed tomography findings

PURPOSE

The purpose of this study was to describe the findings and evaluate the role of multidetector (40-slice) computed tomography (MDCT) in the preoperative assessment of gastrointestinal stromal tumours (GISTs).

MATERIALS AND METHODS

Thirteen patients with histologically proven GIST (size: 4-30 cm; mean: 9 cm) underwent 40-slice MDCT after the ingestion of 1,000 ml of water. Images were obtained before and 70 s after intravenous injection of 120 ml of iodinated contrast agent. Two experienced radiologists reviewed the CT findings to evaluate lesion site, size, margins, attenuation, growth pattern, enhancement pattern, ascites, lymphadenopathy, direct invasion to adjacent organs and distant metastasis. Multiplanar maximum intensity projection and three-dimensional (3D) reconstructions were also obtained.

RESULTS

Seven out of 13 GISTs were located in the jejunumileum, 3/13 in the stomach, 2/13 in the rectum and in one case, the origin remained unknown. Eleven out of 13 were exophytic, and ten had well-defined borders. Two out of 13 showed calcifications. Thirteen out of 13 exhibited inhomogeneous enhancement due to areas of necrosis and cystic degeneration. Direct invasion to adjacent organs (n=3), ascites (n=3), and liver (n=1) and peritoneal (n=1) metastases were also detected. Bowel obstruction, vascular invasion and lymphadenopathy were never seen.

CONCLUSIONS

MDCT allowed reliable preoperative assessment of GIST, providing useful clues for lesion characterisation.

Characterization of benign hepatic tumors arising in fatty liver with SonoVue and pulse inversion US

BACKGROUND

We describe the spectrum of contrast-enhancement patterns of benign hepatic tumors arising in fatty liver on contrast-enhanced ultrasound (US).

METHODS

Sixteen patients (12 women and four men) with 27 benign hepatic tumors (17 hemangiomas, eight focal nodular hyperplasias, and two hepatocellular adenomas) arising in fatty liver underwent baseline and pulse inversion US after administration of SonoVue. Two experienced radiologists evaluated baseline echogenicity and dynamic enhancement pattern of each lesion in comparison with adjacent liver parenchyma.

RESULTS

After administration of SonoVue, in the arterial phase 13 of 17 hemangiomas showed peripheral globular enhancement and one showed a rim of peripheral enhancement, followed by progressive centripetal fill-in, which was complete in 10 of 14 cases and incomplete in four. Three of 18 hemangiomas showed rapid and complete fill-in in the arterial phase. Eight of eight focal nodular hyperplasias became hyperechoic in comparison with adjacent liver parenchyma in the arterial phase and slightly hyperechoic or isoechoic in the portal venous and delayed phases. Both adenomas showed strong arterial contrast enhancement that became less intense in the portal venous and delayed phases.

CONCLUSION

Contrast-enhanced US after administration of SonoVue enables depiction of typical contrast-enhancement patterns in most benign hepatic tumors arising in fatty liver, thus providing useful clues for characterization.

Pancreatic carcinoma versus chronic focal pancreatitis: contrast-enhanced power Doppler ultrasonography findings

BACKGROUND

We assessed the potential usefulness of contrast-enhanced power Doppler ultrasonography (US) for differentiating pancreatic carcinoma from chronic focal pancreatitis.

METHODS

Twenty-six consecutive patients with ductal carcinoma (n=16) and chronic focal pancreatitis (n=10) underwent power Doppler US examinations before and after intravenous injection of an air-based contrast agent (Levovist, Schering, Berlin, Germany). Final diagnosis was obtained by surgery in all patients. The following parameters before and after intravenous administration of contrast agent were evaluated for each lesion: number, morphology and course of the vessels within the lesion and time to maximum detectable enhancement. Number of the lesion vessels and time to maximum enhancement for each lesion were compared by with Student t test.

RESULTS

After injection of contrast agent, nine of 16 (56.2%) carcinomas showed a larger total number of vessels (p<0.005) and faster enhancement (p<0.0001) compared with chronic focal pancreatitis. Irregular vessels with a serpiginous course that penetrated the tumor was predominant in carcinoma (eight of 16 cases), whereas focal pancreatitis presented mostly as avascular masses (five of 10 cases).

CONCLUSION

Contrast-enhanced power Doppler US provides useful findings for differentiating pancreatic carcinoma from chronic focal pancreatitis.

Analysis of different contrast enhancement patterns after microbubble-based contrast agent injection in liver hemangiomas with atypical appearance on baseline scan

BACKGROUND

We describe different possible enhancement patterns in liver hemangiomas with atypical appearance on baseline ultrasound after microbubble-based contrast agent injection.

METHODS

From a series of 253 consecutive lesions that were indeterminate on baseline ultrasound and then scanned after injection of air-filled microbubble contrast agent, 65 focal liver lesions were retrospectively selected on the basis of a diagnosis of liver hemangioma on multiphase contrast-enhanced computed tomography (n = 23), magnetic resonance imaging (n = 27), or histology (n = 15). Each lesion was scanned during arterial phase (30 s after microbubble injection) and late phase (5 min after injection). On-site sonologists performed retrospective assessment of contrast-enhancement patterns by consensus.

RESULTS

Centripetal fill-in preceded (n = 50) or not preceded (n = 3) by peripheral nodular/rim-like enhancement was the prevalently observed contrast-enhancement pattern, equivalent to the typical enhancement pattern of liver hemangiomas on contrast-enhanced computed tomography or magnetic resonance imaging. In the remaining lesions, additional enhancement patterns (diffuse contrast enhancement with rapid fill-in and a late hyper-isoechoic appearance, n = 6; peripheral nodular enhancement with a late hypoechoic appearance, n = 3; or persistent heterogeneous and hyperechoic appearance, n = 3) were observed.

CONCLUSION

Different contrast-enhancement patterns are possible in atypical liver hemangiomas after microbubble injection. Typical centripetal fill-in is the prevalent pattern and its evidence allows diagnosis.

MR findings in lipoma arborescens of the knee: our experience

PURPOSE

This paper describes the role of MR imaging in the identification of the different macroscopic patterns of lipoma arborescens.

MATERIALS AND METHODS

Between June 1995 and January 2004, a total of 6387 MR examinations of the knee were retrospectively assessed for the presence of lipoma arborescens. The MR examinations were performed using a superconductive 0.5 T MR unit with a transmitting/ receiving coil dedicated for the extremities. The MR images were acquired with SE T1-weighted, GE T2-weighted and STIR sequences in sagittal, coronal and axial planes with 3-mm thickness and 1-mm gap.

RESULTS

Lipoma arborescens was identified in 9 patients (mean age: 36 years). In 2/9 cases a localized lipoma arborescens was detected as a well-marginated single nodule on the suprapatellar bursa without irregularity or synovial hyperplasia. In the remaining 7 cases diffuse lipoma arborescens was identified on the wall of the suprapatellar bursa. In one case of diffuse lipoma arborescens there was involvement of both knees. In all cases the MR findings were verified at surgery and the final diagnosis was made by histological examination.

CONCLUSIONS

MR imaging shows a high accuracy in the identification and characterization of lipoma arborescens, due to its multiplanar capabilities and high contrast resolution. MRI allows correct evaluation of size and grade, accurate treatment planning and effective follow-up, avoiding the need for synovial biopsy.

Vesicoureteral reflux in young patients: comparison of voiding color Doppler US with echo enhancement versus voiding cystourethrography for diagnosis or exclusion

We assessed the accuracy of voiding color Doppler ultrasonography (US) with echo enhancement for diagnosis or exclusion of vesicoureteral reflux (VUR) versus voiding cystourethrography (VCUG) and evaluated patient tolerance of the echo-enhancing agent. One hundred twenty-two patients (ages range, 1 month to 17 years) with 244 ureterorenal units underwent voiding color Doppler US with echo enhancement, which was followed by VCUG on the same day. After US of the urinary tract, the bladder was filled with saline solution via catheter. Then an echo-enhancing agent was instilled, and color Doppler US was performed. Reflux was diagnosed when microbubbles appeared in the ureter or the pelvicaliceal system. VUR was detected in 98 units. All grades of reflux were identified. In 13 units (13.3%), grade I reflux diagnosed at voiding color Doppler US was not observed at VCUG. No reflux was detected in 146 units by either method. In 231 (94.2%) of the 244 ureterorenal units, there was concordance between the two methods. The echo-enhancing agent was well tolerated by all patients. Voiding color Doppler US with echo enhancement is useful for the diagnosis or exclusion of VUR, being as good as VCUG. Therefore, it may reduce the number of patients exposed to ionizing radiation.

[Advantages in the ultrasound guided central venous catherization (new notes of technique)]

The authors analyzed the results of 175 central venous catheterization CVC of internal jugular vein performed with the ultrasound guide (US) from January 1998 to October 2002. The average performing time was 4.5 minutes, 98.2% of success and 4% of complications (one vagal hypotension, one artery puncture, four catheter dislocation, one haematoma). The US guide CVC is a safe procedure with short performing time, low rate of failures and complications and high rate of success; it is helpful in all patients with vascular anatomical variations, with not visualized or palpable landmarks and with coagulation disorders.

Pigmented villonodular synovitis of the foot: MR findings

PURPOSE

To evaluate the MRI findings in the various forms of pigmented villonodular synovitis (PVNS) of the foot.

MATERIALS AND METHODS

Seven hundred and fifty-three MR studies of the foot performed at our institute between June 1994 and April 2000 were retrospectively reviewed for the presence of PVNS. Spin echo (SE) T1W, Gradient echo (GE) T2*W, and fat suppression (Short Time Inversion Recovery: STIR) images were acquired with a 0.5 T superconductive unit (Vectra, GE Medical System, Milwaukee, WI, USA) provided with a dedicated transmitter/receiver coil. The site and type of lesions, the signal intensity patterns, and the presence of associated changes were evaluated.

RESULTS

On the basis of the MR images and the above parameters, six patients (3 men, 3 women, age range: 35-48 years) with PVNS were selected. Three out of six PVNS were nodular, whereas the remaining three were diffuse. Of the three nodular forms, one was found in the sub-talar joint and the remaining two antero-medially to the talus. Instead, all of the diffuse lesions were located on the metatarsus. Perilesional oedema was seen in all cases, although more obvious in the nodular forms, whereas bone involvement (osteochondral erosion) was observed only in the diffuse metatarsal PVNS. Intra-articular bloody effusion was never observed. The MRI findings were confirmed by surgery in all cases.

DISCUSSION

The high contrast resolution and multiplanar capabilities of MRI allow the complete evaluation of the structures of the foot affected by PVNS, and of the extent of soft tissue (bursae, synovial or nervous structures), bone and articular involvement. Although not specific, the presence of haemosiderin results in characteristic MR findings, due to the shortening of both T1 and T2 relaxation times. GET2* images are particularly well suited to this

PURPOSE

Furthermore, in our experience, FIR images added better depiction of associated swelling.

CONCLUSIONS

According to our results, MRI is now the most reliable technique for identifying and classifying PVNS, and allows correct treatment planning and effective monitoring.

Isolated hydatid disease of the spleen: CT findings in 4 patients and differential diagnosis

AIM

To report our experience with four cases of isolated hydatid disease of the spleen studied by spiral Computed Tomography (CT) and to review the literature with special attention to the differential diagnosis with other focal lesions of the spleen.

MATERIALS AND METHODS

The spiral CT images and clinical records of four patients (1 man, 3 women; age range 26-45 yrs) affected by isolated hydatid disease of the spleen were retrospectively evaluated. None of the patients had a history of hydatid disease. All the patients were evaluated by plain and enhanced spiral CT of the abdomen. All patients underwent preoperative chest X-ray and surgery; all surgical specimens were studied by histology.

RESULTS

Spiral CT depicted all the hydatid lesions of the spleen. It showed the location, size, low density of their content without enhancement after iv contrast medium injection, the possible presence of daughter cysts, the appearance of the wall with calcifications, and excluded the presence of complications. The preoperative chest X-ray was negative for focal pulmonary lesions in all cases. Pathology confirmed the diagnosis of hydatid disease in all cases.

CONCLUSIONS

According to our results and to the literature, spiral CT plays an important role in the pre-surgical evaluation of patients with hydatid disease of the spleen, and provides useful information for differentiating the disease from other isolated cyst-like lesions of the spleen.

Pitfalls and limitations of Magnetic Resonance Imaging in bucket-handle tears of knee menisci

PURPOSE

The aim of the present study was to assess the accuracy of magnetic resonance imaging (MRI) in the diagnosis of bucket-handle tears of the knee menisci, determining the sensitivity and specificity of the imaging for each of the signs typical of these tears.

MATERIALS AND METHODS

MR examinations of 495 patients suffering from knee traumas were assessed retrospectively. Forty-eight patients had arthroscopically-proven bucket-handle tears of the meniscus. MR examinations were performed using a 0.5-T superconducting magnet, with T1-weighted spin-echo (SE) and gradient-echo (GE) T2*-weighted sequences. Imaging findings used for the diagnosis were: a) double posterior cruciate ligament sign; b) flipped meniscus sign; c) presence of a displaced fragment of the meniscus in the intercondylar notch, visible in coronal and axial images; d) truncated triangular shape of the peripheral non-displaced portion of the meniscus, visible in coronal images.

RESULTS

A total of 43 out of 48 bucket-handle tears of the meniscus were correctly diagnosed at MR, thus overall MR accuracy was 98%. In 12 (28%) cases three signs were present simultaneously the double posterior cruciate ligament (sensitivity 28%, specificity 99%, accuracy 93%) + the displaced fragment in the intercondylar notch (sensitivity 69.8%, specificity 98.7%, accuracy 96.2%) + the truncated triangular shape of the peripheral portion of the meniscus (sensitivity 74.4%, specificity 98%, accuracy 96%). In 18 (42%) cases two signs were present together the displaced fragment of the meniscus + the truncated triangular shape of the peripheral portion of the meniscus. In 13 (30%) cases only one sign was presenting two cases the truncated triangular shape of the peripheral portion of the meniscus and in 11 cases the flipped meniscus sign (sensitivity 25.6%, specificity 93.4%, accuracy 87.5%). No statistically significant differences were found comparing the results for tears of the medial meniscus with those for the lateral meniscus.

CONCLUSIONS

MR imaging is highly accurate in diagnosing bucket-handle tears of the menisci due to its ability to identify a displaced fragment of the meniscus in the intercondylar notch or flipped over the anterior horn of the meniscus of origin. We speculate that bucket-handle tears not found by MR imaging are cases where the meniscus was displaced after MR examination.

Intra-articular osteoid osteoma: diagnostic imaging in three cases

PURPOSE

To report our experience pertaining to three cases of intra-articular osteoid osteoma assessed by means of integrated imaging and review of literature.

MATERIALS AND METHODS

Medical records, radiologic and nuclear medicine findings pertaining to three cases of intra-articular osteoid osteoma were retrospectively evaluated and compared with those of surgery. All the patients (2 males, one female; age range 8-38 ys) affected by intra-articular osteoid osteoma respectively of the elbow, tibio-talar joint and hip were evaluated by means of radiographic examination and Magnetic Resonance Imaging (MRI). SE T1-w and T2-w, GRE T2*-w, GRE 3D T1-w and STIR pulse sequences were used and axial, coronal and sagittal images were acquired. Two patients underwent CT scan. One patient underwent skeletal scintigraphy. All the patients underwent surgery.

RESULTS

In 2 out of 3 cases plain radiography allowed the radiologist to suspect the presence of the lesion. In the remaining one, plain radiography failed to detect both the nidus and the perilesional osteosclerosis; nevertheless, a small osteochondral erosion of the humeral condyle suggested the presence of joint inflammation, thus leading to further investigation. CT scan well depicted the presence of the nidus and, in one case, the presence of joint effusion. MRI was always able to detect the nidus, which presented as lesion of low to intermediate signal in T1-w images, low signal in the T2-w images in one patient and high signal in the remaining two; in these latter STIR images showed high intensity nidus and edema of neighbouring cancellous bone. Furthermore, in all patients MRI clearly depicted joint effusion. Skeletal scintigraphy demonstrated both the lesion and the inflammatory involvement of neighbouring soft tissue. In all patients histologic specimen confirmed the diagnosis of osteoid osteoma with joint inflammation and synovitis.

CONCLUSIONS

According to our results and literature data the pre-surgical diagnosis of osteoid osteoma is very difficult to achieve. Indeed, only the combination of clinical information and radiologic and nuclear medicine findings enables the radiologist to make the right diagnosis.

[Sportsman hindfoot pain: role of magnetic resonance imaging]

PURPOSE

To assess the outcome of Magnetic Resonance Imaging (MRI) in the diagnosis of sportsman hindfoot pain.

MATERIALS AND METHODS

Fortythree professional athletes (31 men, 12 women, age range: 17-37 years) affected by hindfoot pain underwent MRI. Spin echo (SE) T1W, Gradient echo (GE) T2*W, and fat suppression (Short Time Inversion Recovery: STIR) images were acquired with a 0.5 T superconductive unit (Vectra, GE Medical System, Milwaukee, WI, USA). A dedicated extremities transmitter/receiver coil was used. The lesion site, the presence of anatomic variants (os trigonum, Haglund's deformity), and signal intensity changes were evaluated.

RESULTS

In all cases MRI allowed the identification of the cause of the hindfoot pain, in relation to soft tissue (bursae, synovial or nervous structures), bone and articular diseases. Particularly, as regards soft tissue diseases, tendinous abnormalities and inflammatory bursal involvement were frequently found (77% of cases). Bone diseases (22% of cases with posterior talalgia alone), mostly involved the heel (60%), whereas cartilagineous diseases were present in 9% of cases. In 60% of cases an intra-articular osseous or cartilagineous displaced fragment coexisted, determinating joint locking during foot flexo-extension movements. In 38% of cases contemporary involvement of different articular structures was observed.

DISCUSSION

Both MRI high contrast resolution and multiplanar capabilities allow the complete evaluation of hindfoot region. In our experience sagittal and axial planes were particularly well suited for the diagnosis and the assessment of disease extension. Furthermore, T2W (GET2*) and fat suppression (STIR) images allow high sensitivity even in early disease detection, when hyperemia or fluid collection occur.

CONCLUSIONS

According to our results, it seems possible to state that nowadays MRI is the most reliable technique for identifying the causes of hindfoot pain, in order to provide a correct and effective pre-therapeutic planning.

[Usefulness of CT colonography in the preoperative evaluation of patients with distal occlusive colorectal carcinoma]

PURPOSE

To evaluate the role of preoperative virtual colonoscopy to study the proximal colon in patients with distal occlusive carcinomas, diagnosed by conventional colonoscopy.

MATERIAL AND METHODS

We examined 19 patients aged 46 to 83 years (13 men and 6 women) with distal occlusive colorectal carcinomas diagnosed by conventional colonoscopy, who were preoperatively studied with virtual colonoscopy. Patients with acute bowel obstruction were excluded. Results were compared with the findings of preoperative conventional colonoscopy and barium enema examination, intraoperative colon palpation, histopathologic outcome, postoperative conventional colonoscopy and barium enema examination.

RESULTS

Virtual colonoscopy identified all 19 distal occlusive colon carcinomas and 22 synchronous lesions, 2 cancers (prevalence 10,6%) and 20 polyps (prevalence 68,4%). Both synchronous cancers were confirmed intraoperatively by direct palpation. Postoperative conventional colonoscopy, which was performed in 18 patients, confirmed the presence of 15 polyps in 12 patients. Three subcentimeter polyps were removed during conventional colonoscopy and were missed at virtual colonoscopy. Two polyps shown by virtual colonoscopy were not found at conventional colonoscopy. Postoperative barium enema was performed in three patients and confirmed three polyps identified at virtual colonoscopy. Preoperative barium enema was performed in five patients and failed to adequately demonstrate the proximal colon. Virtual colonoscopy showed a sensitivity of 87% and a specificity of 75%.

CONCLUSIONS

Virtual CT colonoscopy can be considered an important diagnostic technique to evaluate preoperatively the proximal colon in patients with distal occlusive carcinomas,as it gives better results than barium enema or conventional colonoscopy, as well as being well tolerated and less invasive.

[Normal anatomy and pathological conditions of subscapular muscle: US findings compared with surgery]

PURPOSE

To compare US results with those of surgery in the assessment of the subscapularis tendon.

MATERIAL AND METHODS

From January 1995 to December 1998 1500 patients underwent US of the shoulder. 12 of these patients had an injured subscapularis tendon. US results of these patients were evaluated retrospectively and compared with those of surgery. US examinations of the subscapularis tendon were performed with two US units (AU4 Idea and HDI 3000), using linear arrays 10-13 MHz transducers. The following features of the tendon were evaluated: morphology, thickness and echotexture.

RESULTS

A) US findings. US showed: - chronic degenerative tendon changes with diffusely inhomogeneous echotexture (5 cases); - focal tears with small hypoechoic ill-defined areas or gross hypo-anechoic areas involving the full thickness of the tendon (4 cases); - complete tendon tear with disappearance on US of the subscapularis tendon or with severe thickening of the tendon (2 cases); - in 1 case of recent anterior dislocation of the shoulder a bulky hematoma was seen with coexisting thickening and subtotal tear of the tendon. B) Surgical findings. US findings were confirmerd at surgery in 10 of the 12 patients. In the patient with anterior dislocation of shoulder the diagnosis hematoma was confirmed, but the subscapularis tendon was undamaged. Moreover, in 1 out of the 5 patients with US diagnosis of chronic degenerative tendon changes, a small focal tear of the tendon was found at surgery.

CONCLUSION

US is a first level investigation which is able to demonstrate early changes of the subscapularis tendon and nearby structures. Awareness of pitfalls might decrease the use of second level investigations such as CT arthrography and MR imaging, which on the other hand allow a better definition and assessment of the extent of the injury.

[Benign hepatic tumors: MRI features before and after administration of superparamagnetic contrast media]

PURPOSE

To assess the yield of superparamagnetic iron oxide (SPIO)-enhanced MR images in the detection and characterization of benign hepatic tumors and to evaluate the potential role and safety of SPIO administration in the diagnosis of these tumors.

MATERIAL AND METHODS

Eighteen patients underwent MRI before and after administration of SPIO particles. Spin echo (SE) T1, DP, T2 and Gradient echo (GE) T2* images were acquired with a.5 T superconductive unit. MR diagnosis was bioptically proved in 12 patients. In the remaining six patients, who had hemangiomas only, diagnosis was confirmed by at least two imaging techniques-such as MR, CT, ultrasonography, radio-labeled red cells scintigraphy-and by both clinical and imaging follow-up.

RESULTS

Thirthy-four tumors were detected on the MR images: 29/34 (85,3%) before and 33/34 (97%) after SPIO administration - 6 focal nodular hyperplasias (FNH), 6 adenomas and 22 hemangiomas. One small tumor (adenoma) was detected on the unenhanced MR images only, while 4 lesions (3 adenomas, 1 FNH) were detected after SPIO administration only.

DISCUSSION

SPIO-enhanced MRI increased the detection rate of benign hepatic tumors compared to non-enhanced MRI. Iron oxide was also useful in the characterization of such lesions as it was able to demonstrate any heterogeneity resulting from the presence of central scars or septa. Nevertheless, in our experience it was useful to compare baseline with SPIO-enhanced MRI, even if time consuming. Indeed the uptake of iron oxide particles by well-differentiated lesions and normal hepatic parenchyma, is comparable, so that well-differentiated lesions appear isointense and therefore undetectable.

CONCLUSIONS

In our experience, although numerically limited, SPIO-enhanced MRI was clinically safe and more effective than non-enhanced MRI in both the detection and characterization of benign hepatic tumors, providing useful clues for diagnosis.

Design and implementation of a World Wide Web teaching files database on diagnostic radiology

INTRODUCTION

The aim of this project was to demonstrate the feasibility and effectiveness of a teaching files database on diagnostic radiology accessible via the Internet and the World Wide Web. The Italian experience in developing a national database named "RadioDB" is presented.

MATERIALS AND METHODS

"RadioDB" is sponsored by the Italian Society of Radiology (SIRM) and is based on a multicenter academic collaboration. It constitutes a collection of multimedia case record and teaching files. "RadioDB" is based on a Pentium workstation running a Structured Query Language (SQL) database and a World Wide Web server. Each case record contains at least one radiological image and a text file for case comment with key words and codes from the American College of Radiology (ACR). In most cases, a complete teaching file is also available. Peer reviewed teaching files available on this server are contributed via anonymous file transfer protocol (FTP) through the Internet from various Italian academic Departments of Radiology.

RESULTS

Worldwide users can easily access and search "RadioDB" database through a World Wide Web query interface and retrieve on-the-fly case record and teaching files. Users can search the database by author name, description, key words, free text or ACR codes.

CONCLUSIONS

"RadioDB" enlarges the base of current off-line educational materials offering and it allows radiologists to improve their medical education.

[Focal liver lesions. A comparison between magnetic resonance under base conditions and after a superparamagentic contrast medium]

INTRODUCTION

Superparamagnetic iron oxide (Spio) is a negative contrast material which is phagocytosed by reticuloendothelial cells. It significantly decreases the signal intensity of the organs where it is taken up selectively, especially on T2-weighted images. According to previous reports, it improves the visualization of focal liver lesions with(out) a low content of Kupffer's cells. We investigated the yield of Spio-enhanced MRI in the detection and characterization of focal liver lesions.

MATERIALS AND METHODS

Eighteen patients underwent MRI before and after the administration of Spio particles. T1, PD, T2 SE and T2* GE images were acquired with a .5 T superconductive unit. The Spio dose was .075 mL/kg which was administered i.v. in 35-45 minutes' infusions. Images were acquired about 30-90 minutes after the end of administration. Scanning was repeated in one patient about 8 hours after the end of Spio administration.

RESULTS

Baseline MRI showed hepatocellular carcinoma (HCC) in 10 patients, metastases in 4, 1 dysplastic lesion, 1 single and 1 multiple hemangioma, 1 focal nodular hyperplasia (FNH) and 1 intrahepatic cholangiocarcinoma. No lesion was detected in one patient. Spio-enhanced MRI detected 7 more lesions that baseline MRI, with 11.47% sensitivity improvement. Moreover, Spio-enhanced MRI detected more lesions that baseline MRI in 5/18 patients (27.78%). PD/T2 SE images were the most sensitive ones, followed by T2* GE and finally by T1 SE. Nearly all HCC nodules (17/18), all metastatic lesions and the cholangiocarcinoma did not take up iron oxide and were relatively hyperintense to the liver. However, in one well-differentiated HCC, the nodule partially took up the contrast agent and became isointense, with high-signal borders on PD/T2 SE images. Both the dysplastic lesion and FNH took up iron oxide; the former was isointense to the liver, while the latter appeared slightly hyperintense, with a high-signal central scar. Finally, hemangiomas became hyperintense on Spio-enhanced T1 SE images and had slightly decreased signal intensity on Spio-enhanced T2 SE images.

CONCLUSIONS

In our experience iron oxide was an effective contrast material. Spio-enhanced MRI improved the detection and characterization of focal liver lesions relative to baseline MRI. Several liver-specific contrast agents are now available or in an advanced experimental stage. Therefore, future studies could be aimed at assessing the effectiveness of iron oxide versus other contrast agents and at establishing the role of Spio-enhanced MRI versus spiral CT and CT during arterial portography.

Nocardial adrenal abscess: CT and MR findings

To our knowledge, four bacterial adrenal abscesses in adults have already been reported in the international literature, but an adrenal Nocardia abscess has never been described previously. In this report the CT and MR imaging appearances and the differential diagnosis of the entity are discussed. The mass could resemble a malignancy. The observation of a rapid growth and colliquation of the mass helped in distinguishing it from a malignancy. The associated pulmonary infection provided a further clue to the diagnosis. The diagnosis was confirmed by surgery.