P. Milillo

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.

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.

Diffusion-weighted MRI with parallel imaging technique: apparent diffusion coefficient determination in normal kidneys and in nonmalignant renal diseases

The purpose of the study was to assess the capability and the reliability of apparent diffusion coefficient (ADC) measurements in the evaluation of different benign renal abnormalities. Twenty-five healthy volunteers and 31 patients, divided into seven different groups (A-G) according to pathology, underwent diffusion-weighted magnetic resonance imaging (DW MRI) of the kidneys using 1.5-T system. DW images were obtained in the axial plane with a spin-echo echo planar imaging single-shot sequence with three b values (0, 300, and 600 s/mm²). Before acquisition of DW sequences, we performed in each patient a morphological study of the kidneys. ADC was 2.40±0.20×10⁻³ mm² s⁻¹ in volunteers. A significant difference was found between Groups A (cysts=3.39±0.51×10⁻³ mm² s⁻¹) and B (acute/chronic renal failure=1.38±0.40×10⁻³ mm² s⁻¹) and between Groups A and C (chronic pyelonephritis=1.53±0.21×10⁻³ mm² s⁻¹) (P<.05). An important difference was also observed among Group D (hydronephrosis=4.82±0.35×10⁻³ mm² s⁻¹) and Groups A, B, and C (P<.05), whereas no differences were found between Groups B and C (P>.05). A considerable correlation between glomerular filtration rate and ADC was found (P=.04). In conclusion, significant differences were detected among different patient groups, and this suggests that ADC measurements can be useful in differentiating normal renal parenchyma from most commonly encountered nonmalignant renal lesions.

MR characterisation of dysplastic nodules and hepatocarcinoma in the cirrhotic liver with hepatospecific superparamagnetic contrast agents: pathological correlation in explanted livers

PurposeThe authors sought to evaluate the potential of magnetic resonance (MR) imaging with superparamagnetic iron oxide (SPIO) contrast material for identifying, characterising and differentiating dysplastic nodules (DN) and hepatocellular carcinoma (HCC) in the cirrhotic liver by correlating the results with pathological findings on the explanted liver.Material and methodsMR imaging was used to study the liver of 400 cirrhotic patients awaiting liver transplantation, 31 of whom were selected to receive a liver. Of these 31 patients, we included in the study 22 patients (mean age 53 years; range 46–57 years) who underwent liver transplantation within 12–24 h after MR examination. Patients were studied with a 1.5-T device, and scans were acquired before and after the administration of paramagnetic contrast material. For every lesion, we recorded signal intensity on unenhanced baseline T1- and T2-weighted images and enhancement pattern after SPIO administration. Histological examination of the entire liver provided the definitive diagnosis of the lesions.ResultsHistological examination identified 59 lesions: 14 HCC, 4 HCC-DN, 39 DN, and 2 cystoadenomas. Among the 14 HCC, three were well differentiated, eight were moderately differentiated and three were poorly differentiated. Of the 39 DN, 28 were low-grade and 11 high-grade lesions. Unenhanced baseline MR imaging correctly identified and characterised 20 lesions, equal to 33.90% of all lesions: 6 HCC, 12 DN and 2 DN with a subfocus of HCC. SPIO-enhanced MR imaging showed greater sensitivity detecting and characterising 45 lesions, equal to 76.27% of all lesions identified at histology: 14 HCC, 27 DN and 4 DN with subfocus of HCC. SPIO administration improved the sensitivity of MR imaging in lesion detection and characterisation by 42.37%. False negative results with SPIO-enhanced MR imaging occurred in 12 DN (31%), which histological examination revealed to be low-grade DN with a diameter <1 cm.ConclusionsSPIO-enhanced MR imaging proved to be of value in detecting and characterising lesions in the cirrhotic liver, allowing differentiation of DN from HCC and providing an early diagnosis of neoplastic degeneration of DN.RiassuntoObiettivoObiettivo di questo studio è stato valutare le potenzialità della risonanza magnetica (RM) eseguita con mezzo di contrasto (MdC) superparamagnetico (superparamagnetic iron oxide particles, SPIO) nell’identificazione, caratterizzazione e diagnosi differenziale tra noduli displasici (ND) ed epatocarcinoma (HCC) nel fegato cirrotico, confrontando i risultati della RM con quelli dell’esame anatomo-patologico eseguito su fegato espiantato.Materiali e metodiAbbiamo studiato con RM il fegato di 400 pazienti cirrotici in attesa di trapianto, 31 dei quali selezionati per reperimento d’organo da trapiantare. Dei 31 pazienti selezionati per il trapianto d’organo, sono stati inclusi nello studio 22 pazienti, di età media di 53 anni (range 46–57 anni), sottoposti a trapianto di fegato a distanza di circa 12–24 ore dall’esecuzione dell’esame RM. I pazienti inclusi nello studio sono stati sottoposti ad esame RM con un apparecchio da 1,5 T. Sono state eseguite scansioni prima e dopo somministrazione endovenosa di MdC SPIO. Per ogni lesione identificata è stata indicata l’intensità di segnale nelle sequenze di base pesate in T1 e in T2 ed il comportamento dopo iniezione di MdC SPIO. La diagnosi definitiva delle lesioni è stata effettuata con l’esame istologico di tutto il fegato espiantato.RisultatiCon l’esame istologico sono state identificate 59 lesioni: 14 HCC, 4 HCC-ND, 39 ND, 2 cistoadenomi. Dei 14 HCC, 3 sono risultati ben differenziati, 8 moderatamente differenziati, 3 scarsamente differenziati. Dei 39 ND, 28 erano a basso grado di malignità e 11 ad alto grado di malignità. Con l’esame RM di base abbiamo identificato e caratterizzato correttamente 20 lesioni, pari al 33,90% delle lesioni complessivamente individuate, di cui 6 HCC, 12 ND e 2 ND con foci di HCC. L’esame RM, eseguito dopo somministrazione di MdC SPIO, ha mostrato una maggiore sensibilità identificando e caratterizzando complessivamente 45 lesioni, pari al 76,27% delle lesioni totali individuate con l’esame istologico: 14 HCC, 27 ND e 4 ND con foci di HCC. Dopo la somministrazione di MdC SPIO la sensibilità della RM nella identificazione e caratterizzazione delle lesioni è aumentata rispetto alle immagini di base del 42,37%. I falsi negativi con la RM-SPIO sono stati 12 noduli displasici, pari al 31%, che all’esame istologico sono risultati essere ND a basso grado di malignità e con diametro inferiore al cm.ConclusioniLa RM con utilizzo di MdC SPIO, nella nostra esperienza è risultata utile nella identificazione e caratterizzazione delle lesioni epatiche nel fegato cirrotico mostrandosi in grado di differenziare i noduli displasici dagli HCC e ha consentito una diagnosi precoce della trasformazione carcinomatosa dei noduli displasici.

Jaw osteonecrosis in patients treated with bisphosphonates: MDCT evaluation.

PurposeThis study was done to evaluate the use of multidetector computed tomography (MDCT) in the evaluation of jaw osteonecrosis, a recently described medical entity in patients receiving long-term intravenous or oral bisphosphonates, and to help radiologists recognise it to enable early diagnosis and appropriate management.Material and methodsThirty-eight patients with a history of neoplasm (breast, prostate, multiple myeloma, pancreas) or osteoporosis and bisphosphonate use and recent oral surgery who presented with pain in the mouth and temporomandibular joints, soft tissue infections, altered taste and numbness were examined with MDCT.ResultsIn all patients, MDCT revealed the presence of structural bony alterations referable to osteonecrosis associated with orosinusal fistula in four of them and bony intraoral spicules in 25.ConclusionsJaw osteonecrosis is an established medical entity discovered in patients who have undergone treatment with bisphosphonates and dental extraction or other oral surgery. MDCT with multiplanar (MPR), volume rendering (VR) and three-dimensional (3D) reconstructions allows accurate assessment of affected bone structures, enabling early diagnosis and suitable treatment planning. Radiologists should be aware of the risk of osteonecrosis in patients treated with bisphosphonates and be able to distinguish it from other bone diseases (osteomyelitis and osteoradionecrosis) with which it enters the differential diagnosis.RiassuntoObiettivoValutare con TC multidetettore (TC-MD) l’osteonecrosi mascellare, recente entità nosologica riscontrabile in pazienti sottoposti a terapia iv od orale per lungo tempo con bifosfonati, ed allertare i radiologi a riconoscerla come tale per una diagnosi precoce ed un adeguato management terapeutico.Materiali e metodiSono stati esaminati con TC-MD 38 pazienti, con storia di neoplasia (mammella, prostata, mieloma multiplo, pancreas) od osteoporosi, terapia con bifosfonati e recente chirurgia orale, giunti alla nostra osservazione con algie a livello del cavo orale e delle articolazioni temporo-mandibolari, infezioni dei tessuti molli, alterazioni del gusto e della sensibilità.RisultatiIn tutti i pazienti, all’esame TC, è stata riscontrata la presenza di alterazioni ossee strutturali riferibili ad osteonecrosi, associate in 4 di essi a fistola oro-sinusale ed in 25 a spicule ossee endo-orali.ConclusioneLa TC-MD con ricostruzioni multiplanari (MPR), volume rendering (VR) e 3D consente una valutazione accurata dell’osteonecrosi mascellare associata a terapia con bifosfonati fornendo informazioni utili sulle strutture ossee coinvolte per un adeguato planning terapeutico. I medici radiologi devono essere a conoscenza del rischio di osteonecrosi al quale vanno incontro i pazienti trattati con bifosfonati ed essere in grado di distinguerla da altri processi patologici dell’osso (osteomielite e osteoradionecrosi) con le quale entra in diagnosi differenziale.

Mechanism of traumatic knee injuries and MRI findings

Bone bruises are focal abnormalities in subchondral bone marrow due to trabecular microfractures as a result of traumatic force. These trauma-induced lesions are better detected with magnetic resonance (MR) imaging using water-sensitive sequences. Moreover, the pattern of bone bruise is distinctive and allows us to understand the dynamics of trauma and to predict associated soft injuries. This article discusses the mechanism of traumatic injury and MR findings.

Case report: Multimodality imaging of van Neck-Odelberg disease.

Synchondrosis ischiopubic syndrome (SIS), also known as van Neck–Odelberg disease, is a syndrome characterized by an atypical ossification pattern of the ischiopubic synchondrosis. Its radiological features may mimic stress fracture, neoplasm, osteomyelitis, or posttraumatic osteolysis, causing problems in diagnosis, sometimes leading to unnecessary workup. We report two cases in which the correlation between the clinical and multimodality imaging data enabled the correct diagnosis of SIS.

An unusual sigmoid phytobezoar in a patient with a transplanted kidney: A case report

Bezoars are masses formed by the concretion of stomach contents or debris within the gastrointestinal tract. Bezoars are rare and account for only 0.4–4% of all cases of gastrointestinal obstruction and mainly occur in the stomach or small intestine. Intestinal obstruction caused by colonic bezoars is extremely rare. A 39-year-old man with a transplanted kidney came to the hospital because of abdominal pain, constipation, and distension. We performed an abdominal computed tomography scan and found an ovoid intraluminal mass with a mottled gas pattern in the distal sigmoid colon. Subsequently, the patient underwent laparotomic surgery and removal of the bezoar. We report a rare case of large bowel obstruction due to colonic phytobezoar, which was confirmed intraoperatively.

Spontaneous Disappearance of a Pericardial Cyst: Case Report and Literature Review

Pericardial cysts are rare benign anomalies generally discovered as incidental findings on radiographic images. Rarely, pericardial cysts cause symptoms and may lead to complications. A 56-year-old woman presented to the emergency department for mild chest pain. A cardiovascular and respiratory examination revealed no abnormalities, while a chest X-ray and subsequent thoracic computed tomography (CT) showed a pericardial cyst. The patient refused both percutaneous treatment and thoracic surgery. Three years later, a thoracic CT scan showed that the pericardial cyst had disappeared. Although the spontaneous resolution of these lesions is rare, this article highlights the possibility of conservative management in select cases.

Childhood Ataxia with Cerebral Hypomyelination Syndrome: A Variant of Patient with Early Childhood Onset Related to EIF2B3 Mutation: A Case Report

Childhood ataxia with central nervous system hypomyelination (CACH) syndrome is an autosomal recessive transmitted leukodystrophy characterised by early childhood onset and acute deterioration following febrile illnesses or head trauma. We describe the case of a child with early onset of CACH syndrome. He presented with cerebellar ataxia beginning around two years of age with mild mental retardation. MRI showed diffuse white matter signal changes with thinning of the corpus callosum.