Giovanni Carlo Ettorre

Poly-L-lactic acid — hydroxyapatite (PLLA-HA) bioabsorbable interference screws for tibial graft fixation in anterior cruciate ligament (ACL) reconstruction surgery: MR evaluation of osteointegration and degradation features

PurposeWe evaluated with magnetic resonance imaging (MRI) the degradation and osteointegration features of a new type of bioabsorbable interference (BioRCI) screw composed of poly-L-lactic acid and hydroxyapatite (PLLA-HA) used for tibial graft fixation in anterior cruciate ligament (ACL) reconstruction.Materials and methodsThirty-one patients underwent arthroscopic surgery for ACL reconstruction using doubled gracilis and semitendinosus tendons fixed to the tibial tunnel with PLLA-HA (BioRCI-HA) screws. Two groups of patients were evaluated, one group 10–13 months after surgery and the other after 30–40 months. The standard knee ligament evaluation form of the International Knee Documentation Committee (IKDC) was used for clinical assessment and MRI for the radiological assessment.ResultsMRI after 10–13 months revealed findings referable to healing and integration of the bone-graft-screw system, findings that disappeared at later follow-up examinations. The BioRCI-HA screw remained constantly visible in all patients, although with changes in signal intensity over time.ConclusionsBioRCI-HA screws allow adequate primary stability and superior osteoconduction and biocompatibility in comparison with plain PLLA screws. The absence of ferromagnetic artefacts allows accurate MRI follow-up and adequate evaluation of ligament synovialisation, screw degradation and graft osteointegration.RiassuntoObiettivoValutare con imaging RM gli aspetti dei processi di degradazione ed osteointegrazione di una nuova classe di viti ad interferenza bioriassorbibili in acidi L-polilattici ed idrossiapatite (PLLA-HA), utilizzate per la fissazione di innesti tendinei nelle plastiche Pro-LCA.Materiali e metodiTrentuno pazienti sono stati sottoposti ad intervento chirurgico di ricostruzione di LCA con tendini di muscoli gracile e semitendinoso duplicati, fissati a livello del tunnel tibiale con viti PLLA-HA. Due gruppi di pazienti sono stati valutati dopo l’intervento chirurgico rispettivamente a distanza, uno di 10–13 mesi, l’altro di 30–40 mesi, utilizzando la scheda dell’International Knee Documentation Committee (IKDC) per la valutazione clinica; la valutazione radiologica è stata effettuata mediante RM.RisultatiDall’analisi dei risultati RM è emerso che nei controlli più ravvicinati erano presenti reperti legati ai processi di guarigione ed integrazione osso-innesto-vite, non più evidenti nel follow-up effettuato tardivamente. La vite BioRCI-HA è stata sempre visibile in tutti i controlli con modificazioni dell’intensità di segnale nel tempo.ConclusioniLe viti BioRCI-HA garantiscono una adeguata stabilità primaria, una superiore osteoconducibilità ed una maggiore biocompatibilità rispetto alle viti semplici di PLLA. L’assenza di artefatti ferromagnetici delle viti ha consentito un’efficace valutazione con RM dei processi di sinovializzazione del neo-legamento, di quelli di degradazione delle viti bioriassorbibili e di osteointegrazione dell’innesto.

Pelvic floor imaging: comparison between magnetic resonance imaging and conventional defecography in studying outlet obstruction syndrome

PurposeThis study prospectively compared the diagnostic capabilities of magnetic resonance (MR) imaging with conventional defecography (CD) in outlet obstruction syndrome.Materials and methodsNineteen consecutive patients with clinical symptoms of outlet obstruction underwent pelvic MR examination. The MR imaging protocol included static T2-weighted fast spin-echo (FSE) images in the sagittal, axial and coronal planes; dynamic midsagittal T2-weighted single-shot (SS)-FSE and fast imaging employing steady-state acquisition (FIESTA) cine images during contraction, rest, straining and defecation. MR images (including and then excluding the evacuation phase) were compared with CD, which is considered the reference standard.ResultsComparison between CD and MR with evacuation phase (MRWEP) showed no significant differences in sphincter hypotonia, dyssynergia, rectocele or rectal prolapse and significant differences in descending perineum. Comparison between CD and MR without evacuation phase (MRWOEP) showed no significant differences in sphincter hypotonia, dyssynergia or enterocele but significant differences in rectocele, rectal prolapse and descending perineum. Comparison between MRWEP and MRWOEP showed no significant differences in sphincter hypotonia, dyssynergia, enterocele or descending perineum but significant differences in rectocele, rectal prolapse, peritoneocele, cervical cystoptosis and hysteroptosis.ConclusionsMR imaging provides morphological and functional study of pelvic floor structures and may offer an imaging tool complementary to CD in multicompartment evaluation of the pelvis. An evacuation phase is mandatory.RiassuntoObiettivoScopo del presente lavoro è stato confrontare prospettivamente le capacità diagnostiche della risonanza magnetica (RM) con quelle della defecografia tradizionale (DT) nello studio della sindrome da defecazione ostruita.Materiali e metodiDiciannove pazienti consecutivi con defecazione ostruita sono stati sottoposti ad RM della pelvi. Sono state acquisite sequenze statiche fast spin echo (FSE)-T2-pesate sui piani sagittale, assiale e coronale e sequenze dinamiche single shot fast spin echo (SSFSE) e fast imaging employing steady-state acquisition (FIESTA) sul piano sagittale mediano durante contrazione dello sfintere anale, riposo, ponzamento, defecazione. Le immagini RM (prima includendo, poi escludendo la fase di evacuazione) sono state confrontate con la DT considerata come standard di riferimento.RisultatiIl confronto DT vs RM con fase di evacuazione (RMCE) ha evidenziato differenze statisticamente non significative nell’ipotonia sfinteriale, dissinergia, rettocele, prolasso rettale, enterocele e differenze significative nel perineo discendente. Il confronto DT vs RM senza fase di evacuazione (RMSE) ha evidenziato differenze non significative nell’ipotonia sfinteriale, dissinergia, enterocele e differenze significative nel rettocele, prolasso rettale, perineo discendente. Il confronto RMCE vs RMSE ha evidenziato differenze non significative nell’ipotonia sfinteriale, dissinergia, enterocele, perineo discendente e differenze significative nel rettocele, prolasso rettale, peritoneocele, cervicocistoptosi, isteroptosi.ConclusioniLa RM consente di effettuare uno studio morfologico e funzionale del pavimento pelvico; può rappresentare un esame complementare alla DT nella valutazione multicompartimentale della pelvi. La fase di evacuazione è fondamentale.

Double-contrast MRI (DC-MRI) in the study of the cirrhotic liver: utility of administering Gd-DTPA as a complement to examinations in which SPIO liver uptake and distribution alterations (SPIO-LUDA) are present and in the identification and characterisation of focal lesions.

Purpose.The aim of this study was to compare the performance of double-contrast magnetic resonance imaging (DC-MRI) with the sequential use of superparamagnetic iron oxide (SPIO) and gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA) contrast agents compared with unenhanced MRI and SPIOenhanced MRI (SPIO-MRI) in the study of the cirrhotic liver. Special attention was paid to cases in which alterations of liver uptake and distribution of the SPIO contrast medium [SPIO-liver uptake and distribution alterations (SPIO-LUDA)] could lead to diagnostic errors at SPIO-MRI.Materials and methods.We used DC-MRI to study 67 patients suffering from hepatic cirrhosis and on a waiting list for liver transplant. The study was performed with a 1.5-Tesla device and characterised by three phases: the first phase without contrast material (unenhanced MRI), the second after the administration of ferumoxides (SPIO-MRI), and the third, a double-contrast study following the injection of a bolus of paramagnetic contrast material (DC-MRI). The sensitivity of unenhanced MRI, SPIOMRI and DC-MRI in identifying and characterising hepatic focal lesions was assessed, together with the diagnostic increment of one technique with respect to the others. The gold standard was histological confirmation in 38 cases and clinical–radiological follow-up in all cases. Liver function, kidney function, blood tests and urinalysis were performed in all patients 24–48 h before and after the MRI examination.Results.In 14/67 cases (20.8%), SPIO-LUDA were present, which posed a limitation to the SPIO-MRI examination. Focal lesions were absent in 44 patients, and the action of the ferumoxides was reduced by the presence of SPIO-LUDA in nine cases. There were five cases of confluent fibrosis, two of decompensated cirrhosis, one of vascular thrombosis, and one of scarring in a patient who had undergone hepatic resection for hepatocellular carcinoma (HCC). In all these cases, completion of the MR examination with the DC technique clarified the MR picture, confirming the absence of focal lesions. Twenty-three patients had a total of 68 lesions, which consisted of 37 dysplastic nodules (DN), 19 HCC nodules, two relapses of HCC following chemoembolisation, two HCC associated with portal thrombosis, one cancer-cirrhosis, two angiomas and five small cysts. SPIO-LUDA were present in five patients, thus limiting the identification, characterisation or assessment of the real size of the lesions. SPIO-LUDA were the result of vascular thrombosis in one case and fibrosis in four cases. In all of these cases, DC-MRI proved useful for diagnosis. The sensitivity of unenhanced MRI, SPIO-MRI and DC-MRI for lesion detection was 57.3%, 67.6% and 75%, respectively. The results obtained in the characterisation of the lesions were 20.5%, 63.2% and 73.5% for unenhanced MRI, SPIO-MRI and DC-MRI, respectively. The diagnostic increment of SPIO-MRI over unenhanced MRI for lesion identification and characterisation was 9% and 42.7%, respectively, whereas the diagnostic increment of DC-MRI over SPIO-MRI was 7.4% and 10.3%, respectively.Conclusions.In our study, the combined use of two contrast agents, negative and positive, provided greater diagnostic confidence and caused no side effects in the patients.

Imaging findings of mucopolysaccharidoses: a pictorial review

IntroductionMucopolysaccharidosis (MPS) represent a heterogeneous group of inheritable lysosomal storage diseases in which the accumulation of undegraded glycosaminoglycans (GAGs) leads to progressive damage of affected tissues. The typical symptoms include organomegaly, dysostosis multiplex, mental retardation and developmental delay. Definitive diagnosis is usually possible through enzymatic assays of the defective enzyme in cultured fibroblasts or leukocytes.Imaging findingsRadiological and neuroradiological findings are reported. The most important neuroradiological features include abnormal signal intensity in the white matter, dilatation of periventricular spaces, widening of cortical sulci, brain atrophy, enlargement of extraventricular spaces and spinal cord compression. With reference to the skeletal system, most important radiological findings include multiplex dysostosis, which is represented by several bone malformations found in the skull, hands, legs, arms and column. The abnormal storage of GAGs leads to liver and spleen enlargement; it also damages cartilage layers and synovial recesses in the joints.ConclusionThe aim of this pictorial essay is to describe the imaging findings of MPS, represented by skeletal and neurological features; skeletal X-ray and MR allow an assessment of the severity of disease, to plan medical and surgical therapy and to evaluate response to treatment.Teaching Points• To describe the imaging findings common to different types of MPS.• To describe multiplex dysostosis encountered in the axial and appendicular skeleton.• To evaluate neuroradiological features of MPS, including brain abnormal signal intensity and atrophy.• To evaluate important otorhinolaryngological problems, such as otitis media and airways obstruction.

Diffusion-weighted MRI in a liver protocol: Its role in focal lesion detection

AIM To evaluate the role of diffusion-weighted imaging (DWI) in the detection of focal liver lesions (FLLs), using a conventional magnetic resonance imaging (MRI) protocol. METHODS Fifty-two patients (22 males, average age 55.6 years, range: 25-82 years), studied using a 1.5 Tesla magnetic resonance scanner, were retrospectively analyzed; detection of FLLs was evaluated by considering the number of lesions observed with the following sequences: (1) respiratory-triggered diffusion-weighted single-shot echo-planar (DW SS-EP) sequences; (2) fat-suppressed fast spin-echo (fs-FSE) T2 weighted sequences; (3) steady-state free precession (SSFP) images; and (4) dynamic triphasic gadolinium-enhanced images, acquired with three-dimensional fast spoiled gradient-echo (3D FSPGR). Two radiologists independently reviewed the images: they were blinded to their respective reports. DW SS-EP sequences were compared to fs-FSE, SSFP and dynamic gadolinium-enhanced acquisitions using a t-test. Pairs were compared for the detection of: (1) all FLLs; (2) benign FLLs; (3) malignant FLLs; (4) metastases; and (5) hepatocellular carcinoma (HCC). RESULTS Interobserver agreement was very good (weighted κ = 0.926, CI = 0.880-0.971); on the consensus reading, 277 FLLs were detected. In the comparison with fs-FSE, DW SS-EP sequences had a significantly higher score in the detection of all FLLs, benign FLLs, malignant FLLs and metastases; no statistical difference was observed in the detection of hepatocellular carcinoma (HCCs). In the comparison with SSFP sequences, DW SS-EP had significantly higher scores (P < 0.05) in the detection of all lesions, benign lesions, malignant lesions, metastases and HCC. All FLLs were better detected by dynamic 3D FSGR enhanced acquisition, with P = 0.0023 for reader 1 and P = 0.0086 for reader 2 in the comparison with DW SS-EP sequences; with reference to benign FLLs, DW SS-EP showed lower values than 3D FSPGR enhanced acquisition (P < 0.05). No statistical differences were observed in the detection of malignant lesions and metastases; considering HCCs, a very slight difference was reported by reader 1 (P = 0.049), whereas no difference was found by reader 2 (P = 0.06). CONCLUSION In lesion detection, DWI had higher scores than T2 sequences; considering malignant FLLs, no statistical difference was observed between DWI and dynamic gadolinium images.

Magnetic resonance cholangiopancreatography and contrast-enhanced magnetic resonance cholangiopancreatography versus endoscopic ultrasonography in the diagnosis of extrahepatic biliary pathology

PurposeThis study compared the diagnostic accuracy of magnetic resonance cholangiopancreatography (MRCP) and endoscopic ultrasonography (EUS) in evaluating the cause of extrahepatic bile duct dilatation.Materials and methodsForty-five patients (26 men, mean age 57 years) with extrahepatic biliary dilatation, as shown by transabdominal ultrasound, with or without elevated biliary and pancreatic serum indices, were prospectively studied with MRCP and EUS between September 2007 and October 2008. EUS and MRCP were performed within no more than 24 h of each other to reduce the possibility of changes due to stone migration. Image analysis was carried out in a double-blind fashion.ResultsMRCP had 88.9% diagnostic accuracy, 91.9% sensitivity and 75% specificity, with 94.4% positive predictive value and 66.7% negative predictive value. EUS had 93.3% diagnostic accuracy, 97.3% sensitivity and 75% specificity; the positive and negative predictive values were 94.7% and 85.7%, respectively.ConclusionsMRCP and EUS do not show significant statistical differences in diagnostic accuracy. MRCP is an accurate, noninvasive modality in the study of extrahepatic biliary pathology. EUS is especially reliable in patients with extrahepatic biliary obstruction caused by endoluminal sludge.RiassuntoObiettivoScopo di questo lavoro è stato confrontare l’accuratezza diagnostica della colangiopancreatografia con risonanza magnetica (CPRM) e dell’ecografia endoscopica (EUS) nel valutare la causa di dilatazione in pazienti con aumentato diametro della via biliare extra-epatica.Materiali e metodiQuarantacinque pazienti (età media 57 anni, 26 maschi) sono stati studiati da settembre 2007 a ottobre 2008 con CPRM e EUS. Sono stati inclusi nello studio pazienti con dilatazione della via biliare extra-epatica rilevata all’ecografia trans-addominale, con o senza innalzamento degli indici sierologici bilio-pancreatici. Lo studio è stato condotto in modalità prospettica ed in doppio cieco. Per ridurre al minimo possibili variazioni legate alla migrazione di calcoli, EUS e CPRM sono state eseguite con intervallo non superiore alle 24 ore.RisultatiLa CPRM ha dimostrato accuratezza diagnostica, sensibilità e specificità rispettivamente dell’88,9%, 91,9% e 75%, con valore predittivo positivo del 94,4% e valore predittivo negativo del 66,7%. La EUS ha evidenziato accuratezza diagnostica, sensibilità e specificità del 93,3%, 97,3% e 75%; valore predittivo positivo e negativo sono stati rispettivamente 94,7% e 85,7%.ConclusioniCPRM ed EUS non presentano differenze statisticamente significative nell’accuratezza diagnostica. La CPRM è metodica accurata non invasiva nella patologia biliare extraepatica; la EUS è particolarmente attendibile nei pazienti con ostruzione biliare extra-epatica da sludge.

Evaluation of the biliary and pancreatic system with 2D SSFSE, breathhold 3D FRFSE and respiratory-triggered 3D FRFSE sequences.

PurposeThe authors compared biliary and pancreatic imaging obtained through 2D single-shot fast spin-echo (SSFSE), breath-hold 3D fast recovery fast spin-echo (FRFSE) and respiratory-triggered 3D FRFSE sequences.Materials and methodsA total of 106 magnetic resonance cholangiopancreatography (MRCP) examinations performed between December 2007 and September 2008 were evaluated with a comparison of 2D SSFSE (thin section and thick slab), breath-hold 3D FRFSE and respiratory-triggered 3D FRFSE sequences. The biliary tract was divided into seven segments: right hepatic duct, left hepatic duct, common hepatic duct, cystic duct, common bile duct, cystic duct junction and biliarypancreatic confluence. The main pancreatic duct was divided into three segments (head, body and tail). Visualisation of biliary variants was also compared. Two blinded radiologists evaluated segment visibility using a quantitative scale. The Student’s t test for paired samples was used for statistical analysis.ResultsCompared with 2D SSFSE, respiratory-triggered 3D FRFSE sequences showed better visibility of the right hepatic duct (p=0.0277), the cystic duct (p=0.0081), the cystic duct junction (p=0.0010), the biliary-pancreatic confluence (p=0.0334) and biliary variants (p=0.0198). In the comparison between breath-hold 3D FRFSE and 2D SSFSE, a significant statistical difference was found in visualisation of the cystic duct (p=0.027), the cystic duct junction (p=0.020), the biliary-pancreatic confluence (p=0.0338) and biliary variants (p=0.0311).ConclusionsThree-dimensional FRFSE offers a significant benefit over conventional 2D imaging.RiassuntoObiettivoScopo del nostro studio è stato confrontare l’imaging biliare e pancreatico mediante 2D single-shot fast spin-echo (SSFSE), 3D fast recovery fast spin-echo (FRFSE) breath-hold e 3D FRFSE triggerate.Materiali e metodiCentosei esami di colangiopancreatografia in risonanza magnetica (RM) — eseguiti tra dicembre 2007 e settembre 2008 — sono state analizzati confrontando SSFSE 2D (con spessore sottile e con slab), FRFSE 3D breath-hold e FRFSE 3D triggerate con il respiro. L’albero biliare è stato suddiviso in 7 segmenti: dotto destro, dotto sinistro, dotto epatico comune, dotto cistico, coledoco, inserzione cistico-coledocica e confluenza coledoco-pancreatica. Il dotto pancreatico è stato ripartito in 3 parti (testa, corpo e coda). È stata confrontata anche la visualizzazione di varianti biliari. Due radiologi in cieco hanno valutato la visibilità dei segmenti mediante una scala quantitativa; le analisi statistiche sono state effettuate mediante test t di Student per dati appaiati.RisultatiRispetto alle SSFSE 2D, FRFSE triggerate hanno evidenziato migliore visualizzazione dell’epatico destro (p=0,0277), del cistico (p=0,0081), della giunzione cistico-coledocica (p=0,0010) e delle varianti biliari (p=0,0198); nel confronto 3D FRFSE breath-hold versus SSFSE 2D, è stata rilevata differenza statisticamente significativa nella visualizzazione del cistico (p=0,027), del punto d’inserzione del cistico (p=0,020), della confluenza coledoco-pancreatica (p=0,0338) e delle varianti biliari (p=0,0311).ConclusioniFRFSE 3D rappresentano un importante valore aggiunto all’imaging convenzionale 2D.

MR imaging of ovarian masses: classification and differential diagnosis

AbstractObjectiveWe propose a Magnetic Resonance Imaging (MRI) guided approach to differential diagnosis of ovarian tumours based on morphological appearance.BackgroundCharacterization of ovarian lesions is of great importance in order to plan adequate therapeutic procedures, and may influence patient’s management. Optimal assessment of adnexal masses requires a multidisciplinary approach, based on physical examination, laboratory tests and imaging techniques. Primary ovarian tumours can be classified into three main categories according to tumour origin: epithelial, germ cell and sex cord-stromal tumours. Ovarian neoplasms may be benign, borderline or malignant. Using an imaging-guided approach based on morphological appearance, we classified adnexal masses into four main groups: unilocular cyst, multilocular cyst, cystic and solid, predominantly solid. We describe MR signal intensity features and enhancement behaviour of ovarian lesions using pathologically proven examples from our institution.ConclusionMRI is an essential problem-solving tool to determine the site of origin of a pelvic mass, to characterize an adnexal mass, and to detect local invasion. The main advantages of MRI are the high contrast resolution and lack of ionizing radiation exposure. Although different pathological conditions may show similar radiologic manifestations, radiologists should be aware of MRI features of ovarian lesions that may orientate differential diagnosis.Teaching Points• Diagnostic imaging plays a crucial role in detection, characterization and staging of adnexal masses. • Characterization of an ovarian lesion may influence patient’s management. • Different pathological conditions may have similar radiologic manifestations. • Non-neoplastic lesions should always be taken into consideration.

Locally advanced rectal cancer: Qualitative and quantitative evaluation of diffusion-weighted MR imaging in the response assessment after neoadjuvant chemo-radiotherapy

Purpose to investigate the added value of qualitative and quantitative evaluation of diffusion weighted (DW) magnetic resonance (MR) imaging in response assessment after neoadjuvant chemo-radiotherapy (CRT) in patients with locally advanced rectal cancer (LARC). Methods 31 patients with LARC (stage ≥ T3) were enrolled in the study. All patients underwent conventional MRI and DWI before starting therapy and after neoadjuvant CRT. All patients underwent surgery; pathologic staging represented the reference standard. For qualitative analysis, two radiologists retrospectively reviewed conventional MR images and the combined set of conventional and DW MR images and recorded their confidence level with respect to complete response (ypCR). For quantitative analysis, tumor’s apparent diffusion coefficient (ADC) values were measured at each examination. ADC pre-CRT, ADC post-CRT and Δ ADC post−ADC pre of the three groups of response (ypCR, partial response ypPR, stable disease ypSD) were compared. Receiver-operating characteristics (ROC) curve analysis was employed to investigate the discriminatory capability for ypCR, responders (ypCR, ypPR) and ypSD of each measure. Results addition of DWI to conventional T2-weighted sequences improved diagnostic performance of MRI in the evaluation of ypCR. A low tumor ADC value in the pre-CRT examination, a high ADC value in the post-CRT examination, a high Δ ADC post−ADC pre [>0.3 (×10−3 mm2/s)] were predictive of ypCR. Conclusions DW sequences improve MR capability to evaluate tumor response to CRT. Nevertheless, no functional MR technique alone seems accurate enough to safely select patients with ypCR.

Rare pancreatic neoplasm: MDCT and MRI features of a typical solid pseudopapillary tumor.

Solid pseudopapillary tumor of the pancreas is a rare neoplasm, predominantly observed in young women and with greatest incidence in the second and third decade. It has clinically good behavior, although large at the time of diagnosis. We report the case of a thirty-year-old woman with a giant mass in the pancreas, incidentally discovered during an abdominal ultrasonography. The mass was later investigated by multidetector computed tomography and magnetic resonance imaging. The cystic-solid appearance of the encapsulated lesion suggested to radiologists the possibility of a solid pseudopapillary tumor. Imaging features of this pancreatic neoplasm and differential diagnosis from other cystic pancreatic tumors are discussed in our report, in order to help radiologists and clinicians achieve correct diagnosis and management.