Ignazio Salamone

High-Resolution CT Grading of Tibial Stress Reactions in Distance Runners

OBJECTIVE The purpose of this study was twofold: to determine whether asymptomatic distance runners exhibit cortical tibial abnormalities on CT and to determine the diagnostic accuracy of CT in athletes with medial tibial stress syndrome. MATERIALS AND METHODS A cross-sectional study with high-resolution CT of both tibiae was performed on 41 subjects: 20 asymptomatic distance runners, 11 distance runners with unilateral or bilateral pain due to medial tibial stress syndrome (14 painful tibiae), and 10 volunteers not involved in a sport. The group was composed of 13 women and 28 men, ranging in age from 18 to 26 years. A total of 82 tibiae, 14 painful and 68 painless, were evaluated. On the basis of CT findings, tibiae were classified in three groups, and correlation between CT classification and symptoms was made. RESULTS Among distance runners, the presence of CT abnormalities was found in 14 (100%) of 14 painful tibiae in patients with medial tibial stress syndrome and in 8 (16.6%) of 48 painless tibiae. The difference was statistically significant (p < 0.001, Fishers exact test). Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of CT in diagnosing medial tibial stress syndrome were 100%, 88.2%, 63.6%, 100%, and 90.2%, respectively. CONCLUSION High-resolution CT has high diagnostic accuracy in depicting medial tibial stress syndrome. Cortical abnormalities can also be seen in some asymptomatic distance runners.

Can Contrast Media Increase Organ Doses in CT Examinations? A Clinical Study

OBJECTIVE The purpose of this article is to quantify the CT radiation dose increment in five organs resulting from the administration of iodinated contrast medium. MATERIALS AND METHODS Forty consecutive patients who underwent both un-enhanced and contrast-enhanced thoracoabdominal CT were included in our retrospective study. The dose increase between CT before and after contrast agent administration was evaluated in the portal phase for the thyroid, liver, spleen, pancreas, and kidneys by applying a previously validated method. RESULTS An increase in radiation dose was noted in all organs studied. Average dose increments were 19% for liver, 71% for kidneys, 33% for spleen and pancreas, and 41% for thyroid. Kidneys exhibited the maximum dose increment, whereas the pancreas showed the widest variance because of the differences in fibro-fatty involution. Finally, thyroids with high attenuation values on unenhanced CT showed a lower Hounsfield unit increase and, thus, a smaller increment in the dose. CONCLUSION Our study showed an increase in radiation dose in several parenchymatous tissues on contrast-enhanced CT. Our method allowed us to evaluate the dose increase from the change in attenuation measured in Hounsfield units. Because diagnostic protocols require multiple acquisitions after the contrast agent administration, such a dose increase should be considered when optimizing these protocols.

The chance finding at multislice computed tomography coronary angiography of an ectopic origin of the left circumflex coronary artery from the right sinus of Valsalva

Anomalous coronary arteries occur in less than 2% of the general population. Most coronary anomalies are clinically asymptomatic. However some of them may present with chest pain, syncope, heart failure and sudden death. Acute myocardial infarction has been also described. Extravascular coronary compression results in dynamic obstruction which can cause effort angina as well as syncope and anomalous coronary arteries with an inter-arterial course are associated with sudden cardiac death. Anomalous origin of the circumflex coronary artery from the right sinus of Valsalva is thought to be of little clinical significance without the presence of severe narrowing of the vessel. Adequate visualization of the anomaly is essential for proper patient management. It has reported the full capability and accuracy of computed tomography coronary angiography in the identification and evaluation of the ectopic origin of the left circumflex coronary artery from the right sinus of Valsalva, displaying accurately the origin, size, course, and relationship of the anomalous vessel with respect to surrounding structures. We report a case of chance finding at multislice computed tomography coronary angiography of an ectopic origin of the left circumflex coronary artery from the right sinus of Valsalva. Also this case focuses attention on the anomalous origin of the circumflex coronary artery from the right sinus of Valsalva and confirms the full capability and accuracy of computed tomography coronary angiography in its adequate visualization.

Protecting venous structures during radiosurgery for parasagittal meningiomas

Symptomatic edema is a potential complication of meningioma radiosurgery. Parasagittal meningiomas are at a particular risk for symptomatic edema, suggesting a role for a venous occlusive complication. The authors sought to develop a strategy to optimize CyberKnife stereotactic radiosurgical treatment parameters to reduce the irradiation of the peritumoral venous system. Multislice CT venography with 3D reconstructions was performed and coregistered with thin-section, contrast-enhanced, volumetric MR images. The tumor and critical volumes were contoured on the MR images. Venous anatomical details obtained from the CT venographic study were then exported onto the MR imaging and fused MR imaging-CT study. Target and critical structure volumes and dosimetric parameters obtained with this method were analyzed. The authors found that reducing the irradiation of veins that course along the surface of the meningioma, which may be at risk for radiation-induced occlusion, is feasible in parasagittal meningioma radiosurgery without compromising other treatment parameters including conformality, homogeneity, and target coverage. Long-term follow-up is needed to assess the clinical validity of this treatment strategy.

Evaluation of the anterior ethmoidal artery by 3D dual volume rotational digital subtraction angiography and native multidetector CT with multiplanar reformations. Initial findings

Our purpose is to codify the anterior ethmoidal artery (AEA) course and its relationship with adjacent structures. Twenty patients with cerebrovascular disease underwent selective internal carotid dual volume angiography. Fusion of the vascular and bony images was obtained successively on a second console. MDCT of the cranium was performed in all patients. To identify the AEA course, multiplanar CT reformations were obtained. In all cases the entry-point of AEA and its course were identified by means of dual volume angiography. The information was confirmed by MDCT. In a second phase, we studied another 78 patients affected by inflammatory disease and polyposis only by means of MDCT, in order to confirm the previous data obtained by comparison between angiography and MDCT. In this second phase, 110/156 vessels were indirectly detected by means of visualization of the ethmoidal entry point. In the remaining cases, AEA was directly shown due to integrity of the thin ethmoidal bone lamellae or bony canal. Dual volume angiography is essential to identify the course of the AEA (standard of reference for the interpretation of CT). In patients with benign rhinosinusal pathology, where invasivity techniques are not justified, MPR reconstructions were of pivotal importance in the evaluation of the course of the artery with particular reference to its relationship with the frontal recess.

Role of coronal oblique reconstruction as a complement to CT study of the temporal bone: normal anatomy

Purpose.The purpose of this study was to demonstrate the usefulness of coronal oblique multiplanar reconstruction computed tomography (MPR CT) reformation parallel to the basal turn of the cochlea in the evaluation of the retrotympanum and hypotympanum to complete the standard CT examination of the temporal bone obtained with axial and coronal images.Materials and methods.We studied 30 patients aged 18–79 years for a total of 60 normal petrous pyramids. All examinations were performed on a multislice CT (MSCT) scanner (Sensation 16, Siemens, Erlangen, Germany) with axial volumetric acquisition and completed with reformations of coronal and coronal–oblique images. MSCT scan parameters for axial acquisition were set as follows: 0.75–mm scan collimation, FOV 300 mm, 170 mAs. Axial images were reconstructed at 0.7–mm thickness and with a reconstruction increment of 0.5 mm using a high–resolution bone algorithm.Results.Coronal oblique MPR CT reformations provided additional information with respect to standard CT images in all cases. In particular, they enabled measurement of the craniocaudal and laterolateral diameters of the sinus tympani. In all cases, there was optimal visualisation of the ponticulus and subiculum. Analysis of the pyramidal eminence was improved thanks to its visualisation in profile. Moreover, we obtained an optimal representation of the hypotympanum, which was always exhaustively explored with only one reconstruction. Finally, in all cases, it was possible to identify the facial nerve canal and main vascular structures and to measure the distance between these and the sinus tympani, pyramidal eminence and hypotympanum. The coronal oblique CT reformation was of no advantage in the evaluation of the fossa of the oval window and the niche of the round window.Conclusions.Coronal oblique MPR CT reformation should not be considered an alternative to the standard CT examination, but it can represent a valid integration to provide additional information on particularly crucial districts characterised by frequent involvement of inflammatory and/or expansile disease and because of their difficult endoscopic approach. Moreover, it can represent a meaningful aid to optimise surgical planning thanks to its different perspectives of observation.

Hepatobronchial fistula due to transphrenic migration of hepatic echinococcosis: MR demonstration

We present an uncommon case of hepatic hydatidosis, complicated by transphrenic migration of the cyst, in which the use of magnetic resonance performed with ultrafast, breath-hold, heavily T2-weighted sequences (HASTE) demonstrated a bronchial fistula.

Sclerostin levels in uremic patients: a link between bone and vascular disease.

Abstract Sclerostin is a marker of low-turnover bone disease in end stage renal disease patients. The aim of this study was to evaluate serum sclerostin in uremic patients, analyzing its behavior during a single hemodialysis session. Twenty-one adult patients on intermittent hemodialysis treatment were enrolled. Acetate Free Bio-filtration (AFB) was the technique employed. Uremic patients were characterized by higher levels of serum sclerostin when compared with values observed in healthy subjects. Sclerostin assessed in pre-dialysis samples was 1.4 ± 1.02 ng/mL, whereas, in post dialysis samples, a reduction of sclerostin values was observed (0.8 ± 0.6 ng/mL; p: 0.008). Sclerostin correlated with parameters of dialysis adequacy, such as creatinine levels and Kt/V values, and it was significantly associated with atherosclerotic disease. Receiver operating characteristics analysis revealed a good diagnostic profile in identifying atherosclerotic disease. Sclerostin, a full dialyzable substance during AFB dialysis, is closely associated with atherosclerotic disease. Its reduction obtained through AFB could represent a defensive mechanism, improving vascular disease and renal osteodystrophy.

Computed tomography coronary angiography in asymptomatic patients

PurposeThis study assessed the accuracy of computed tomography coronary angiography (CT-CA) for detecting significant coronary artery disease (CAD; ≥50% lumen reduction) in intermediate/high-risk asymptomatic patients.Materials and methodsA total of 183 consecutive asymptomatic individuals (92 men; mean age 54±11 years) with more than one major risk factor (obesity, hypertension, diabetes, hypercholesterolaemia, family history, smoking) and an inconclusive or nonfeasible noninvasive stress test result (stress electrocardiography, stress echocardiography, nuclear stress scintigraphy) underwent CT-CA in an outpatient setting. All patients underwent conventional coronary angiography (CAG) within 4 weeks. Data from CT-CA were compared with CAG regarding the presence of significant CAD (≥50% lumen reduction).ResultsMean calcium score was 177±432, mean heart rate during the CT-CA scan was 58±8 bpm and the prevalence (per-patient) of obstructive CAD was 19%. CT-CA showed single-vessel CAD in 9% of patients, two-vessel CAD in 9% and three-vessel CAD in 0%. Per-patient sensitivity, specificity, positive predictive value and negative predictive value of CT-CA were 100% (90–100), 98% (96–99), 97% (85–99), 100% (97–100), respectively. Positive and negative likelihood ratios were 151 and 0, respectively.ConclusionsCT-CA is an excellent noninvasive imaging modality for excluding significant CAD in intermediate/ high-risk asymptomatic patients with inconclusive or nonfeasible noninvasive stress test.RiassuntoObiettivoObiettivo di questo lavoro è stato valutare l’accuratezza diagnostica dell’angiografia coronarica con tomografia computerizzata (CT-CA) nell’individuazione delle stenosi coronariche significative (riduzione del lume coronarico >-50%) confrontata con la coronarografia convenzionale (CAG) in una popolazione di soggetti asintomatici a rischio intermedio/alto.Materiali e metodiCentottantatre soggetti consecutivi asintomatici (92 maschi e 91 femmine; età media 54±11 anni) con più di un fattore di rischio (obesità, ipertensione arteriosa, diabete mellito, dislipidemia, familiarità, fumo di sigaretta) e stress test inconclusivo o non eseguibile (stress elettrocardiogramma [ECG], stress ecocardiografia, o stress tomografia computerizzata a emissione di fotoni singoli [SPECT]) sono stati sottoposti a CT-CA. Tutti i pazienti sono stati sottoposti a coronarografia convenzionale (CAG) entro 4 settimane dalla CT-CA. I risultati della CT-CA sono stati confrontati con la CAG per la rilevazione di stenosi coronariche significative.RisultatiIl calcium score medio, la frequenza cardiaca media e la prevalenza di malattia per paziente sono risultati 177±432, 58±8 battiti per minuto (bpm), e 19%, rispettivamente. La CT-CA ha mostrato malattia significativa mono-vasale nell’9% dei casi, bi-vasale nel 9% dei casi, e tri-vasale in nessun paziente. La sensibilità, specificità, valore predittivo positivo della CT-CA per paziente sono risultati 100% (90%–100%), 99% (96%–99%), 97% (85%–99%), 100% (97%–100%), rispettivamente. I likelihood ratio positivo e negativo per paziente sono risultati 151 e 0, rispettivamente.ConclusioniLa CT-CA è un ottimo strumento per l’esclusione di malattia coronarica significativa nel asintomatico ad intermedio/alto rischio con stress test in conclusivo o non eseguibile.

Influence of the X-ray beam quality on the dose increment in CT with iodinated contrast medium

BACKGROUND In computed tomography (CT), the image contrast is given by the difference in X-ray attenuation in the various tissues of the patient and contrast media are used to enhance image contrast in anatomic regions characterized by similar attenuation coefficients. OBJECTIVE Aim of the present work is to enlarge the range of applicability of the method previously introduced for organ dosimetry in contrast-enhanced CT, by studying the effects of X-ray beam quality on the parameters of the model. Furthermore, an experimental method for the evaluation of the attenuation properties of iodinated solutions is proposed. METHODS Monte Carlo simulations of anthropomorphic phantoms were carried out to determine a bi-parametrical (a and b) analytical relationship between iodine concentration and dose increase in organs of interest as a function of the tube kilo-voltage peak potential (kVp) and filtration. Experimental measurements of increments in Hounsfield Units (HU) were conducted in several CT scanners, at all the kVp available, in order to determine the parameter γ which relates the HU increment with the iodine mass fraction. A cylindrical phantom that can be filled with iodine solutions provided with an axial housing for a pencil ionization chamber was designed and assembled in order to measure the attenuation properties of iodine solutions under irradiation of a CT scanner and to obtain a further validation of Monte Carlo simulations. RESULTS The simulation-derived parameters of the model, a and b, are only slightly dependent upon the tube kilo-voltage peak potential and filtration, while such scanner-dependent features influence mainly the experimentally-derived γ parameter. Relative dose variations registered by the ionization chamber inside the iodine-filled cylindrical phantom decrease when the X-ray mean energy increases, and reaches about 50% for 10 mg/ml of iodine. CONCLUSIONS The dosimetric method for contrast-enhanced CT can be applied to all CT scanners by adopting average simulative parameters and by carrying out a simple measurement with a series of iodine contrast solutions. The novel experimental methodology introduced can provide a direct measurement of iodine attenuation properties.