Alessandro Villa

Atypical Ductal Hyperplasia Diagnosed at 11-Gauge Vacuum-Assisted Breast Biopsy Performed on Suspicious Clustered Microcalcifications: Could Patients Without Residual Microcalcifications Be Managed Conservatively?

OBJECTIVE The purpose of our study was to establish whether it might be safe for women with a diagnosis of atypical ductal hyperplasia (ADH) at stereotactically guided vacuum-assisted breast biopsy without any residual microcalcification after the procedure to undergo mammographic follow-up instead of surgical biopsy. MATERIALS AND METHODS From October 2003 to January 2009, 1173 consecutive 11-gauge vacuum-assisted breast biopsy procedures were performed. ADH was found in the specimens of 114 patients who underwent vacuum-assisted breast biopsy for a single cluster of suspicious microcalcifications smaller than 15 mm; 49 had residual microcalcifications, and 65 had microcalcifications completely removed by the procedure. Of 49 patients with residual microcalcifications, 41 underwent surgical biopsy. Of 65 patients without residual microcalcifications, 26 underwent surgical biopsy, 35 were not surgically treated and were managed conservatively with mammographic follow-up, and 4 had follow-up of less than 24 months. RESULTS In 41 patients with residual microcalcifications who underwent surgical biopsy, 8 malignant lesions were found at surgery. The underestimation rate was 20% (8/41). In 26 patients without residual microcalcifications who underwent surgical biopsy, no malignant lesions were found. One malignant lesion was found in the 35 patients managed conservatively at follow-up. The underestimation rate in patients without residual microcalcifications using surgical biopsy or mammographic follow-up as the reference standard was 1.6% (1/61). CONCLUSION Patients without residual microcalcifications after vacuum-assisted breast biopsy could possibly be managed in a conservative way with mammographic follow-up.

Diffusion tensor magnetic resonance imaging of the normal breast: reproducibility of DTI-derived fractional anisotropy and apparent diffusion coefficient at 3.0 T

PurposeDiffusion-weighted imaging (DWI) may improve the diagnostic performance of conventional breast magnetic resonance imaging (MRI). Diffusion tensor imaging (DTI) is an extension of DWI. If DTI-derived measurements are to be clinically useful, particularly for predicting and/or monitoring therapeutic effects, they must be robust and reliable. The purpose of this study was to assess intra- and interobserver reproducibility of DTIderived fractional anisotropy (FA) and apparent diffusion coefficient (ADC) at 3.0 T.Materials and methodsThis prospective study was approved by the Institutional Review Board, and participants provided written informed consent. Sixty normal contralateral breasts of 60 patients (28–85 years, median 57) were analysed with a DWI sequence following a standard MRI protocol. Four authors performed all postprocessing and analyses independently and in different sessions. The same authors, blinded to the initial results, repeated the image postprocessing and analysis 4 weeks after the initial session.ResultsMean ADC and FA for DTI sequences were, respectively, 1.92±0.30 and 0.32±0.09. Intra- and seinterobserver agreement of the four radiologists for ADC and FA were good (acceptable). Kappa values for ADC were intra-R1=0.82; intra-R2=0.84; intra-R3=0.89; intra-R4=0.88; inter-R1-R2=0.73; inter-R1-R3=0.74; inter-R1-R4=0.81; inter-R2-R3=0.76; inter-R2-R4=0.77; inter-R3-R4=0.83. Kappa values for FA were intra-R1=0.60; intra-R2=0.72; intra-R3=0.84; intra-R4 = 0.66; inter-R1-R2=0.64; inter-R1-R3=0.69; inter-R1-R4=0.72; inter-R2-R3=0.80; inter-R2-R4=0.71; inter-R3-R4=0.73. Within-subject coefficient of variation was 15% for ADC and 30% for FA. Repeatability with α=0.05 was 0.37×10−3 mm2/s for ADC and 0.112 for FA.ConclusionsADC and FA measurements obtained with DTI are reproducible and may be valid, reliable and sensitive to change. ADC values obtained with DTI are more reproducible than FA.RiassuntoObiettivoL’imaging di diffusione (DWI) può migliorare la performance diagnostica della convenzionale risonanza magnetica (RM) della mammella. L’imaging con tensore di diffusione (DTI) è un recente sviluppo della DWI. Affinché i valori derivanti dallo studio con DTI siano clinicamente utili, in particolare per la prognosi o il monitoraggio degli effetti della terapia, devono essere affidabili e attendibili. Lo scopo di questo studio è quello di valutare la riproducibilità intra- e inter-osservartore dell’anisotropia frazionaria derivante dalla DTI e il coefficiente di diffusione apparente (ADC) utilizzando un apparecchio di risonanza magnetica da 3,0 T.Materiali e metodiQuesto studio prospettico è stato approvato dal Comitato Etico del nostro istituto e le pazienti coinvolte hanno firmato il consenso informato. Sessanta mammelle normali controlaterali, rispetto a quelle malate, di 60 pazienti (28–85 anni di età, mediana di 67 anni) sono state analizzate con una sequenza DTI seguendo il protocollo standard per RM della mammella. Quattro radiologi hanno eseguito il post-processing e l’analisi delle immagini indipendentemente l’uno dall’altro e in sedute diverse. Gli stessi autori, senza conoscere i dati derivati dalla loro prima osservazione, hanno poi ripetuto il post-processing e l’analisi delle immagini 4 settimane dopo la prima sessione.RisultatiI principali valori di ADC e dell’anisotropia frazionaria (FA) per le sequenze DTI sono stati rispettivamente 1,92±0,30 e 0,32±0,09. L’accordo per i risultati intraed inter-osservatori dei quattro radiologi sia per ADC che per FA è stato buono. Il coefficiente di variazione per lo stesso osservatore è stato del 15% per il valore ADC e del 30% per il valore FA. I valori di k per l’ADC erano: intra-R1=0,82; intra-R2=0,84; intra-R3=0,89; intra-R4=0,88; inter-R1-R2=0,73; inter-R1-R3=0,74; inter-R1-R4=0,81; inter-R2-R3=0,76; inter-R2-R4=0,77; inter-R3-R4=0,83. I valori di per l’FA erano: intra-R1=0,60; intra-R2=0,72; intra-R3=0,84; intra-R4=0,66; inter-R1-R2=0,64; inter-R1-R3=0,69; inter-R1-R4=0,72; inter-R2-R3=0,80; inter-R2-R4=0,71; inter-R3-R4=0,73. La ripetibilità con α=0,05 era 0,37×10−3mm2/s per ADC e 0,112 per l’FA.ConclusioniI valori di ADC e FA ottenuti con la tecnica DTI sono riproducibili, e possono essere considerati validi e attendibili.

A Lyapunov-stable, sensor-based model for real-time path-tracking among unknown obstacles

The article proposes a feedback control system for real-time navigation and obstacle avoidance that is made of two components: (i) a sensor-based, real-time model that generates and periodically updates the path on-line in order to avoid both known and unforeseen obstacles, and (ii) a feedback-control model that is capable of driving a unicycle vehicle along the collision free path. The system has some unique characteristics, among which it requires very few computational resources as a consequence of its extreme simplicity. In spite of this, it is formally demonstrated to be asymptotically stable, as well as computationally efficient to be implemented in real-world scenarios where obstacles are not known, and possibly move in the environment.

Role of respiratory-triggered diffusion-weighted MRI in the assessment of pleural disease

OBJECTIVE: To evaluate the correlation between apparent diffusion coefficient (ADC) values and histopathological features in a cohort of patients with suspected malignant pleural disease. METHODS: We evaluated 56 consecutive patients undergoing a chest MRI examination for clinical suspicion of malignant pleural disease; all patients underwent thoracoscopic biopsy for histological assessment. All MRI examinations were performed with a 1.5-T scanner using a dedicated protocol, including a respiratory-triggered diffusion-weighted sequence with three b-values (0, 100 and 750). The ADC values were calculated, and a statistical analysis was performed. RESULTS: The average ADC value in non-neoplastic pleural disease (NNPD) resulted in 1.84 ± 0.37 × 10-3 mm2 s-1, whereas we obtained an average value of 0.96 ± 0.19 × 10-3 mm2 s-1 in epitheliod, of 0.76 ± 0.33 × 10-3 mm2 s-1 in biphasic and of 0.67 ± 0.2 × 10-3 mm2 s-1 in sarcomatoid pleural mesotheliomas. Histology revealed the presence of malignant pleural mesothelioma (MPM) in 44 patients, chronic pleuritis in 8 patients and atypical mesothelial hyperplasia in 4 patients. Statistical analysis showed a significant difference between NNPD and MPM (p < 0.001) and between epithelioid and sarcomatoid MPM subtypes (p = 0.0004), whereas biphasic MPMs showed a wide range of overlapping with the other groups. CONCLUSION: We observed a statistically significant difference between NNPD, epitheliod and sarcomatoid subtypes of MPM regarding ADC values. ADVANCES IN KNOWLEDGE: Our study confirmed previous data regarding distribution of ADC values in pleural disease using a respiratory-triggered diffusion-weighted technique that allowed us to minimize motion artefacts and to reduct acquisition time.

Flat epithelial atypia: conservative management of patients without residual microcalcifications post-vacuum-assisted breast biopsy

OBJECTIVE To determine the malignancy rate (defined in this study as stability or absence of malignancy developed on close imaging follow-up post-biopsy) of conservative management in patients with a vacuum-assisted breast biopsy (VAB) diagnosis of flat epithelial atypia (FEA), performed on single group of microcalcifications, completely removed during procedure. METHODS This is a retrospective, monocentric, observational study, approved by IRB. Inclusion criteria were: VAB performed on a single group of microcalcifications; the absence of residual calcifications post-VAB; diagnosis of isolated FEA as the most advanced proliferative lesion; radiological follow-up at least of 12 months. The personal history of breast cancer or other high-risk lesions was an exclusion criteria. The patients enrolled were conservatively managed, without surgical excision, through close follow-up: the first two mammographies performed with an interval of 6 months after biopsy, followed by annual mammographic and clinical checks. RESULTS 48 consecutive patients were enrolled in the study, all females, with age range of 39-76 years (mean 53,3 years) and radiological follow-up range of 13-75 months (mean 41.5 months). All the lesions were classified as BI-RADS 4b. The diameter range of the group of calcifications was 3-10 mm (mean 5, 6 mm). In each patient, 7 to 15 samples (mean 11) were obtained. Among all the patients, there was only one case (2%) of new microcalcifications, developed in the same breast, 26 months after and 8 mm from the site of previous VAB, and interpreted as ADH at surgical excision. All the checks of the other patients were negative. CONCLUSION Even with a limited follow-up, we found a malignancy rate lower than 2%, through a defined population. Further studies with bigger number of patients and extended follow-up are needed to reinforce this hypothesis. Advances in knowledge: Surgical excision may not be necessary in patients with VAB diagnosis of isolated FEA, without residual microcalcifications post-procedure and considered concordant with the mammographic presentation, considering the low rate of malignancy at subsequent follow-ups.

A rare diagnosis of a focal liver lesion

Splenosis can be considered as a benign condition due to the presence of heterotopic splenic tissue in abdomen, thorax and pelvis because of a massive splenic trauma or surgery. Here we report the case of a patient with an unknown hepatic mass, chronic hepatitis C, liver cirrhosis and a previous splenectomy after abdominal trauma. In our case lesion could not be clearly defined by ultrasound, computed tomography and magnetic resonance. Classical features of malignancy were not demonstrated at computed tomography, while at magnetic resonance imaging the differential diagnosis of the lesion appeared quite difficult and debate. Then an ultrasound-guided biopsy demonstrated the liver mass in left hepatic lobe consisted of splenic tissue and some millimetric accessory spleens in the left upper quadrant. So the possibility of an intra-hepatic splenosis should be taken into account in patients with an unknown liver mass and a history of previous abdominal trauma, followed by splenectomy. The conclusive diagnosis of intra-hepatic splenosis was given by ultrasound-guided biopsy.

L'imaging con tensore di diffusione nello studio della mammella normale: Riproducibilità dell'anisotropia frazionaria derivante dalla DTI e dal coefficiente apparente di diffusione con una risonanza magnetica da 3.0 T

PurposeDiffusion-weighted imaging (DWI) may improve the diagnostic performance of conventional breast magnetic resonance imaging (MRI). Diffusion tensor imaging (DTI) is an extension of DWI. If DTI-derived measurements are to be clinically useful, particularly for predicting and/or monitoring therapeutic effects, they must be robust and reliable. The purpose of this study was to assess intra- and interobserver reproducibility of DTIderived fractional anisotropy (FA) and apparent diffusion coefficient (ADC) at 3.0 T.Materials and methodsThis prospective study was approved by the Institutional Review Board, and participants provided written informed consent. Sixty normal contralateral breasts of 60 patients (28–85 years, median 57) were analysed with a DWI sequence following a standard MRI protocol. Four authors performed all postprocessing and analyses independently and in different sessions. The same authors, blinded to the initial results, repeated the image postprocessing and analysis 4 weeks after the initial session.ResultsMean ADC and FA for DTI sequences were, respectively, 1.92±0.30 and 0.32±0.09. Intra- and seinterobserver agreement of the four radiologists for ADC and FA were good (acceptable). Kappa values for ADC were intra-R1=0.82; intra-R2=0.84; intra-R3=0.89; intra-R4=0.88; inter-R1-R2=0.73; inter-R1-R3=0.74; inter-R1-R4=0.81; inter-R2-R3=0.76; inter-R2-R4=0.77; inter-R3-R4=0.83. Kappa values for FA were intra-R1=0.60; intra-R2=0.72; intra-R3=0.84; intra-R4 = 0.66; inter-R1-R2=0.64; inter-R1-R3=0.69; inter-R1-R4=0.72; inter-R2-R3=0.80; inter-R2-R4=0.71; inter-R3-R4=0.73. Within-subject coefficient of variation was 15% for ADC and 30% for FA. Repeatability with α=0.05 was 0.37×10−3 mm2/s for ADC and 0.112 for FA.ConclusionsADC and FA measurements obtained with DTI are reproducible and may be valid, reliable and sensitive to change. ADC values obtained with DTI are more reproducible than FA.RiassuntoObiettivoL’imaging di diffusione (DWI) può migliorare la performance diagnostica della convenzionale risonanza magnetica (RM) della mammella. L’imaging con tensore di diffusione (DTI) è un recente sviluppo della DWI. Affinché i valori derivanti dallo studio con DTI siano clinicamente utili, in particolare per la prognosi o il monitoraggio degli effetti della terapia, devono essere affidabili e attendibili. Lo scopo di questo studio è quello di valutare la riproducibilità intra- e inter-osservartore dell’anisotropia frazionaria derivante dalla DTI e il coefficiente di diffusione apparente (ADC) utilizzando un apparecchio di risonanza magnetica da 3,0 T.Materiali e metodiQuesto studio prospettico è stato approvato dal Comitato Etico del nostro istituto e le pazienti coinvolte hanno firmato il consenso informato. Sessanta mammelle normali controlaterali, rispetto a quelle malate, di 60 pazienti (28–85 anni di età, mediana di 67 anni) sono state analizzate con una sequenza DTI seguendo il protocollo standard per RM della mammella. Quattro radiologi hanno eseguito il post-processing e l’analisi delle immagini indipendentemente l’uno dall’altro e in sedute diverse. Gli stessi autori, senza conoscere i dati derivati dalla loro prima osservazione, hanno poi ripetuto il post-processing e l’analisi delle immagini 4 settimane dopo la prima sessione.RisultatiI principali valori di ADC e dell’anisotropia frazionaria (FA) per le sequenze DTI sono stati rispettivamente 1,92±0,30 e 0,32±0,09. L’accordo per i risultati intraed inter-osservatori dei quattro radiologi sia per ADC che per FA è stato buono. Il coefficiente di variazione per lo stesso osservatore è stato del 15% per il valore ADC e del 30% per il valore FA. I valori di k per l’ADC erano: intra-R1=0,82; intra-R2=0,84; intra-R3=0,89; intra-R4=0,88; inter-R1-R2=0,73; inter-R1-R3=0,74; inter-R1-R4=0,81; inter-R2-R3=0,76; inter-R2-R4=0,77; inter-R3-R4=0,83. I valori di per l’FA erano: intra-R1=0,60; intra-R2=0,72; intra-R3=0,84; intra-R4=0,66; inter-R1-R2=0,64; inter-R1-R3=0,69; inter-R1-R4=0,72; inter-R2-R3=0,80; inter-R2-R4=0,71; inter-R3-R4=0,73. La ripetibilità con α=0,05 era 0,37×10−3mm2/s per ADC e 0,112 per l’FA.ConclusioniI valori di ADC e FA ottenuti con la tecnica DTI sono riproducibili, e possono essere considerati validi e attendibili.

Diffusion tensor magnetic resonance imaging of the normal breast: reproducibility of DTI-derived fractional anisotropy and apparent diffusion coefficient at 3.0 T L'imaging con tensore di diffusione nello studio della mammella normale: riproducibilità dell'anisotropia frazionaria derivante dalla DTI e dal coefficiente apparente di diffusione con una risonanza magnetica da 3.0 T

PurposeDiffusion-weighted imaging (DWI) may improve the diagnostic performance of conventional breast magnetic resonance imaging (MRI). Diffusion tensor imaging (DTI) is an extension of DWI. If DTI-derived measurements are to be clinically useful, particularly for predicting and/or monitoring therapeutic effects, they must be robust and reliable. The purpose of this study was to assess intra- and interobserver reproducibility of DTIderived fractional anisotropy (FA) and apparent diffusion coefficient (ADC) at 3.0 T.Materials and methodsThis prospective study was approved by the Institutional Review Board, and participants provided written informed consent. Sixty normal contralateral breasts of 60 patients (28–85 years, median 57) were analysed with a DWI sequence following a standard MRI protocol. Four authors performed all postprocessing and analyses independently and in different sessions. The same authors, blinded to the initial results, repeated the image postprocessing and analysis 4 weeks after the initial session.ResultsMean ADC and FA for DTI sequences were, respectively, 1.92±0.30 and 0.32±0.09. Intra- and seinterobserver agreement of the four radiologists for ADC and FA were good (acceptable). Kappa values for ADC were intra-R1=0.82; intra-R2=0.84; intra-R3=0.89; intra-R4=0.88; inter-R1-R2=0.73; inter-R1-R3=0.74; inter-R1-R4=0.81; inter-R2-R3=0.76; inter-R2-R4=0.77; inter-R3-R4=0.83. Kappa values for FA were intra-R1=0.60; intra-R2=0.72; intra-R3=0.84; intra-R4 = 0.66; inter-R1-R2=0.64; inter-R1-R3=0.69; inter-R1-R4=0.72; inter-R2-R3=0.80; inter-R2-R4=0.71; inter-R3-R4=0.73. Within-subject coefficient of variation was 15% for ADC and 30% for FA. Repeatability with α=0.05 was 0.37×10−3 mm2/s for ADC and 0.112 for FA.ConclusionsADC and FA measurements obtained with DTI are reproducible and may be valid, reliable and sensitive to change. ADC values obtained with DTI are more reproducible than FA.RiassuntoObiettivoL’imaging di diffusione (DWI) può migliorare la performance diagnostica della convenzionale risonanza magnetica (RM) della mammella. L’imaging con tensore di diffusione (DTI) è un recente sviluppo della DWI. Affinché i valori derivanti dallo studio con DTI siano clinicamente utili, in particolare per la prognosi o il monitoraggio degli effetti della terapia, devono essere affidabili e attendibili. Lo scopo di questo studio è quello di valutare la riproducibilità intra- e inter-osservartore dell’anisotropia frazionaria derivante dalla DTI e il coefficiente di diffusione apparente (ADC) utilizzando un apparecchio di risonanza magnetica da 3,0 T.Materiali e metodiQuesto studio prospettico è stato approvato dal Comitato Etico del nostro istituto e le pazienti coinvolte hanno firmato il consenso informato. Sessanta mammelle normali controlaterali, rispetto a quelle malate, di 60 pazienti (28–85 anni di età, mediana di 67 anni) sono state analizzate con una sequenza DTI seguendo il protocollo standard per RM della mammella. Quattro radiologi hanno eseguito il post-processing e l’analisi delle immagini indipendentemente l’uno dall’altro e in sedute diverse. Gli stessi autori, senza conoscere i dati derivati dalla loro prima osservazione, hanno poi ripetuto il post-processing e l’analisi delle immagini 4 settimane dopo la prima sessione.RisultatiI principali valori di ADC e dell’anisotropia frazionaria (FA) per le sequenze DTI sono stati rispettivamente 1,92±0,30 e 0,32±0,09. L’accordo per i risultati intraed inter-osservatori dei quattro radiologi sia per ADC che per FA è stato buono. Il coefficiente di variazione per lo stesso osservatore è stato del 15% per il valore ADC e del 30% per il valore FA. I valori di k per l’ADC erano: intra-R1=0,82; intra-R2=0,84; intra-R3=0,89; intra-R4=0,88; inter-R1-R2=0,73; inter-R1-R3=0,74; inter-R1-R4=0,81; inter-R2-R3=0,76; inter-R2-R4=0,77; inter-R3-R4=0,83. I valori di per l’FA erano: intra-R1=0,60; intra-R2=0,72; intra-R3=0,84; intra-R4=0,66; inter-R1-R2=0,64; inter-R1-R3=0,69; inter-R1-R4=0,72; inter-R2-R3=0,80; inter-R2-R4=0,71; inter-R3-R4=0,73. La ripetibilità con α=0,05 era 0,37×10−3mm2/s per ADC e 0,112 per l’FA.ConclusioniI valori di ADC e FA ottenuti con la tecnica DTI sono riproducibili, e possono essere considerati validi e attendibili.