Marco Cavallaro

Characterization of Atypical Cystic Renal Masses With MDCT: Comparison of 5-mm Axial Images and Thin Multiplanar Reconstructed Images

OBJECTIVE The purpose of this study was to investigate whether cystic renal masses are better characterized on thin axial and multiplanar reconstructed MDCT images than on 5-mm images. MATERIALS AND METHODS The records of 70 complex cystic renal masses in 59 patients (45 men, 14 women; mean age, 68 +/- 13 years) who underwent 64-MDCT at two medical centers were studied. Twenty-three of the masses were confirmed on the basis of the histologic findings and 47 in 2-4 years of follow-up. Images were reviewed in two sessions by two radiologists with 12 and 2 years of experience. In the first session, 5-mm axial images were analyzed, and in the second, thin axial images and multiplanar reconstructions. To assess intraobserver variability, analysis was repeated after 1 month. Statistical analysis was performed with Wilcoxons signed rank test, receiver operating characteristic analysis, and weighted kappa statistics. RESULTS Radiologists 1 and 2 detected thicker cystic walls (p < 0.001, p < 0.005) and septa (p < 0.03, p < 0.05) and fewer septa (p < 0.005, p < 0.002) on 5-mm axial images and assigned significantly different Bosniak categories than they did in analysis of the volume data (p < 0.04, p < 0.05). Variability was reduced in thin axial and multiplanar views. No significant differences were found in characterization of lesions as benign or malignant in review of 5-mm axial images and volume data sets. The areas under the receiver operating characteristic curve were 0.89 for 5-mm images and 0.96 for volume data sets for radiologist 1 and 0.87 and 0.90 for radiologist 2. CONCLUSION Analysis of volume data sets is associated with less intraobserver and interobserver variability than review of 5-mm axial images. Wall thickness and the number and thickness of septa may differ, resulting in assignment of different Bosniak categories. Diagnostic performance in characterizing lesions as benign or malignant, however, is not statistically different for the thick and thin images.

64-Slice CT urography: 30 months of clinical experience

PurposeThis study sought to assess the diagnostic accuracy of 64-slice computed tomography urography (CTU) in evaluation of the urinary tract.Materials and methodsA total of 322 CTU procedures were carried out in 317 consecutive patients (mean age 64.4 years). The findings were compared with previous and subsequent patient workup considering both laboratory and imaging studies, such as urine cytology, abdominal ultrasound and CT, cystoscopy, retrograde pyelography, surgery and pathology.ResultsOut of 322 CTU examinations, 169 showed significant urinary tract changes, whereas 153 revealed no urinary disease, in good agreement with the follow-up. In particular, in bladder evaluation, for which we have a direct comparison with cystoscopy in 125 patients, we calculated a CTU sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy of 85%, 94%, 92%, 89% and 90%, respectively.ConclusionsCTU was accurate for urinary tract evaluation, but it cannot replace cystoscopy in patients in whom a malignant bladder disease is suspected.RiassuntoObiettivoScopo del nostro lavoro è stato valutare l’accuratezza diagnostica dell’uro-tomografia computerizzata (TC) eseguita con apparecchiatura a 64 strati nella valutazione delle patologie della via escretrice.Materiali e metodiSono stati effettuati 322 esami uro-TC su 317 pazienti consecutivi (età media 64,6 anni). L’esito è stato confrontato con il precedente e successivo iter diagnostico seguito dal paziente, tenendo in considerazione sia gli esami laboratoristici e strumentali, quali citologia urinaria, ecografia e TC addominale, cistoscopia, cistouretrografia retrograda, sia gli eventuali interventi chirurgici con relativa diagnosi istologica.RisultatiTra le 322 uro-TC eseguite, 169 hanno individuato significative alterazioni a carico dell’apparato urinario e 153 non hanno evidenziato aspetti di rilievo, con buona concordanza al follow-up. In particolare a livello vescicale, ove possediamo in 125 pazienti un riscontro diretto dei reperti mediante cistoscopia, abbiamo rilevato un valore di sensibilità dell’85%, una specificità del 94%, un valore predittivo positivo del 92%, un valore predittivo negativo dell’89%, per una accuratezza diagnostica del 90%.ConclusioniL’uro-TC si è dimostrata un esame accurato per lo studio della via escretrice, ma non può sostituirsi all’esecuzione di un esame cistoscopico nello studio dei pazienti con sospetta patologia neoplastica vescicale.

The Use of CEUS in the diagnosis of retinal/choroidal detachment and associated intraocular masses - Preliminary investigation in patients with equivocal findings at conventional ultrasound

PURPOSE To investigate whether contrast-enhanced ultrasound (CEUS) may help to diagnose retinal/choroidal detachment and may help to differentiate intraocular lumps in cases with equivocal features on conventional grayscale and Doppler modes. MATERIALS AND METHODS The institutional review board approved this retrospective study. The need for informed consent was waived. A computerized data search was performed in the database of our institution for patients with vitreous hemorrhage who underwent CEUS of the eye to assess retinal/choroidal detachment and/or associated masses. This process yielded a total of 31 patients (18 men, 13 women, age range: 39 - 88 years) in whom CEUS was performed because the findings on conventional grayscale and Doppler modes were equivocal. CEUS was performed using low acoustic power contrast-specific modes. A 2.4 - 4.8  mL bolus of SonoVue was injected, followed by a saline flush. All examinations were digitally recorded for retrospective analysis. Confirmation of CEUS findings was obtained at surgery (n = 20) or with binocular indirect fundoscopy performed after clearance of the ocular media (n = 11). Two readers with different levels of ultrasound experience independently reviewed the imaging features. A five-degree scale ranging from definitely absent (score 1) to definitely present (score 5) was used to assess the presence or absence of retinal/choroidal detachment on conventional ultrasound modes alone and with the addition of CEUS. ROC curve analysis was performed to assess the diagnostic accuracy of both methods. The inter-reader agreement was also evaluated. In patients with associated intraocular lumps, conventional Doppler modes and CEUS were used to differentiate non-tumor masses from tumor masses. RESULTS According to the reference standard, 13 patients had retinal detachment, 4 had choroidal detachment, and 3 had both retinal and choroidal detachment. There were 8 associated intraocular lumps (4 subretinal hemorrhages, 3 malignant melanomas, 1 metastasis). The inter-reader agreement was good (K = 0.644) and very good (K = 0.833) for conventional modes and CEUS, respectively. The diagnostic performance of CEUS was high for both readers (area ± standard error under the ROC curve: 0.966 ± 0.031 and 0.900 ± 0.055 for readers 1 and 2, respectively). There were 2 false-positive results and 1 false-negative result in patients with proliferative diabetic retinopathy. CEUS was effective in differentiating subretinal hemorrhage from hypovascular tumors. CONCLUSION CEUS can be used as a problem-solving technique when conventional ultrasound modes are not diagnostic for retinal/choroidal detachment and when intraocular lumps cannot be characterized as tumor or non-tumor masses on conventional modes. The evaluation of patients with proliferative diabetic retinopathy, however, may be problematic.

64-Slice CT urography: optimisation of radiation dose

PurposeThis study assessed means by which to optimise 64-slice computed tomography urography (CTU) in evaluating the urinary tract, with a view to obtaining the best trade-off between image quality and radiation dose.Materials and methodsImage quality was analysed in terms of spatial and contrast resolution on several scans of a phantom performed with automatic dose modulation and different reconstruction kernels and accepted noise level. Data were compared with the radiation dose values recorded for 52 patients who underwent CTU examination.ResultsRadiation dose and image quality differed considerably depending on the reconstruction parameters, even though a higher dose did not always imply better image definition. Data obtained in the phantom were consistent with those obtained in patients. Depending on the clinical problem, the radiation dose varied from 6.2 to 17.6 mSv.ConclusionsCTU cannot be considered a standard examination: the scan parameters need to be adapted to the image quality required for the specific clinical problem.RiassuntoObiettivoLo scopo del nostro lavoro è stato ottimizzare l’uro-tomografia computerizzata (TC) eseguita mediante apparecchiatura a 64 strati nello studio delle patologie della via escretrice per ottenere il miglior rapporto fra qualità di immagine e dose di esposizione.Materiali e metodiÈ stata analizzata la qualità di immagine in termini di risoluzione spaziale e di contrasto di diverse scansioni su fantoccio, ripetute con modulazione automatica di dose, variando il filtro di ricostruzione e il livello di rumore accettato; sono stati valutati i valori di esposizione e confrontato l’esito con quanto osservato in 52 pazienti sottoposti ad esame uro-TC.RisultatiLa dose di esposizione e la qualità d’immagine variano notevolmente modificando i parametri di ricostruzione, sebbene non sempre l’aumento di dose comporti un reale vantaggio in termini di definizione d’immagine. La variazione osservata su fantoccio è coerente con i risultati ottenuti nei pazienti esaminati. In base al quesito diagnostico l’esame ha comportato nei pazienti un’esposizione variabile da 6,2 a 17,6 mSv.ConclusioniL’uro-TC non può essere considerato un esame standardizzato: i parametri di scansione devono essere sempre valutati e modulati in base alla qualità di immagine richiesta dallo specifico problema clinico.

Magnetic resonance urography vs computed tomography urography in the evaluation of patients with haematuria

PurposeThis study was done to evaluate by direct comparison the image quality of magnetic resonance urography (MRU) and computed tomography urography (CTU) and to assess the diagnostic confidence of the two techniques in detecting urothelial malignancy in patients with haematuriaMaterials and methodsThirty-five patients with haematuria underwent both CTU and MRU. Two different investigators evaluated calyceal, renal pelvis, ureteral and bladder visibility. Their diagnostic confidence in detecting urothelial malignancy with the two procedures was assessed. A Wilcoxon matched-pairs test was performed to compare results. Inter-reader agreement was calculated by weighted kappa (WK) statistic. Patient history (further examinations, cystoscopy and histological specimens) was considered as reference standard to calculate receiver operating characteristic (ROC) curves of diagnostic confidence.ResultsCTU provided better visibility of urothelial structures (p<0.01) and allowed for greater diagnostic confidence (ROC area 0.994 vs. 0.938) than MRU, with a good inter-reader agreement (WK=0.62). Nevertheless, in obstructive patients with impaired excretory function, MRU, thanks to the static-fluid technique, offered better visualisation than CTU.ConclusionsThere is a potential role for MRU in urinary tract imaging, but as diagnostic confidence in detecting urothelial malignancy is poorer than in CTU, it might be stareserved for patients at low risk for malignancy and for evaluating obstructed patients.RiassuntoObiettivoScopo del nostro lavoro è stato valutare attraverso un confronto diretto la qualità d’immagine in urografia con risonanza magnetica (uro-RM) e urografia con tomografia computerizzata (uro-TC) e determinare la confidenza diagnostica delle due tecniche nel riconoscimento della patologia neoplastica uroteliale nei pazienti con ematuria.Materiali e metodiTrentacinque pazienti con ematuria sono stati studiati sia con uro-TC che con uro-RM. Due radiologi hanno valutato la visibilità delle strutture uroteliali ed è stata calcolata la confidenza diagnostica nel riconoscimento della patologia neoplastica uroteliale con le due procedure. I risultati sono stati confrontati utilizzando il test di Wilcoxon per dati appaiati. La concordanza inter-osservatore è stata calcolata con la statistica k. La storia clinica (ulteriori esami, cistoscopie, esami istologici) è stata considerata standard di riferimento per valutare l’accuratezza diagnostica mediante le curve receiver operating characteristic (ROC).RisultatiNella nostra serie l’uro-TC ha dimostrato una migliore visibilità delle strutture uroteliali (p<0,01), con una confidenza diagnostica maggiore rispetto all’uro-RM (area sotto la curva ROC 0,994 versus 0,938). Tuttavia nei pazienti ostruiti o con funzione escretoria ridotta o assente l’uro-RM, grazie alle sequenze di pielo-RM, offre una migliore visualizzazione rispetto all’uro-TC.ConclusioneVi è un ruolo potenziale per l’uro-RM nell’imaging del tratto urinario, ma dal momento che la confidenza diagnostica nella diagnosi di patologia neoplastica uroteliale è inferiore a quella dell’uro-TC, potrebbe essere riservata ai pazienti con basso rischio neoplastico e per la valutazione dei paziente ostruiti.

Imaging of haemodialysis: renal and extrarenal findings

AbstractElectrolyte alterations and extra-renal disorders are quite frequent in patients undergoing haemodialysis or peritoneal dialysis. The native kidneys may be the site of important pathologies in patients undergoing dialysis, especially in the form of acquired renal cystic disease with frequent malignant transformation. Renal neoplasms represents an important complication of haemodialysis-associated acquired cystic kidney disease and imaging surveillance is suggested. Extra-renal complications include renal osteodistrophy, brown tumours, and thoracic and cardiovascular complications. Other important fields in which imaging techniques may provide important informations are arteriovenous fistula and graft complications. Teaching points • Renal neoplasms represent a dreaded complication of haemodialysis.• In renal osteodystrophy bone resorption typically manifests along the middle phalanges.• Brown tumours are well-defined lytic lesions radiographically, possibly causing bone expansion.• Vascular calcifications are very common in patients undergoing haemodialysis.• Principal complications of the AV fistula consist of thrombosis, aneurysms and pseudoaneurysms.

Obstructive Uropathy, Pyonephrosis, and Reflux Nephropathy in Adults

Urinary tract obstruction refers to the structural or functional changes in the urinary tract that impede the normal flow of urine and is a clinical situation which may be clearly defined by imaging. The different causes of renal obstruction may be easily detected by ultrasound (US) and characterized, thanks to the panoramicity of the new imaging modality such as computed tomography urography (CTU) and magnetic resonance urography (MRU). Pyonephrosis represents the chronic suppurative infection in an obstructed kidney. Grayscale US with tissue harmonic imaging represents the most sensitive imaging technique to detect pyonephrosis. The vesicoureteral reflux is the retrograde flow of urine from the bladder toward the kidney.

Magnetic Resonance Imaging of the Kidney

This chapter describes the correct imaging technique for the magnetic resonance (MR) examination of the kidney, from the fundamental morphologic sequences to the MR urography sequences up to diffusion sequences. The basic MR features of vascular and infectious renal diseases and solid benign and malignant renal tumors up to the cystic renal tumors are described. The advanced applications of the MR technique in the kidney are described as a general introduction to the following chapters describing the different renal pathologies.

Normal Radiological Anatomy and Anatomical Variants of the Kidney

The kidneys are highly vascularized organs. Each kidney receives the highest blood flow per gram of organ weight in the body (1.2 L/min corresponding to 20 % of the cardiac output and a perfusion value of 400 mL/min/100 g). The most employed indicator of the renal function is the glomerular filtration rate (GFR), which can be estimated according to different formulas. The calculation of the GFR is essential for a correct employment of iodinated and gadolinium-based contrast agents. The most widely used equations for estimating GFR are the Cockcroft–Gault and the Modification of Diet in Renal Disease Study Group (MDRD) formulas.

Chronic Renal Infections and Renal Fungal Infections

Chronic renal infections are becoming increasingly rare because of the availability of effective antibiotics and early detection and treatment of both acute renal and urinary tract infections and conditions predisposing a patient to chronic infections. The aim of the present chapter is to illustrate the fundamental imaging features of the different forms of chronic renal infections and the modern imaging of renal tuberculosis with multidetector CT urography. From pathological point of view, the chronic renal infections include two types, interstitial chronic pyelonephritis and granulomatous pyelonephritis, namely, xanthogranulomatous pyelonephritis, malacoplakia, and renal tuberculosis. In this chapter the findings and the role of ultrasonography (US), computed tomography (CT), intravenous excretory urography, and CT urography in the different chronic renal infections are reviewed.