Pietro Biondetti

Vascular Ehlers-Danlos syndrome: Imaging findings

OBJECTIVE Vascular Ehlers-Danlos syndrome (EDS), formerly known as EDS type IV, is an autosomal dominant disorder characterized by fragility of medium and large arteries due to type III procollagen deficiency. Our purpose was to review the imaging findings in a cohort of patients with a diagnosis of vascular EDS. MATERIALS AND METHODS The radiologic, surgical, and genetic databases at a single multispecialty medical practice were reviewed for a 35-year period between 1971 and 2006. Thirty-three patients with a clinical diagnosis of vascular EDS were identified. Imaging studies were available for 28 patients, 13 men and 15 women, with a mean age of 39.8 +/- 16 years at the time of diagnosis. A vascular radiologist reviewed a total of 189 imaging examinations: 87 CT, 27 MRI, 59 sonography, and 16 angiography. RESULTS Vascular abnormalities were present in 22 (78%) of 28 patients. Arterial abnormalities included 41 aneurysms, 19 dissections, 12 ectasias, and 10 occlusions. There was one splenic vein aneurysm and one carotid cavernous fistula. Six patients had a total of 10 parenchymal infarcts involving the brain (n = 5), kidney (n = 3), and spleen (n = 2). Nine patients had 10 hemorrhagic events, five related to spontaneous vascular rupture and five associated with interventional or surgical procedures. Six patients had 13 nonvascular findings. CONCLUSION The most common findings were arterial aneurysms and dissections, followed by arterial ectasias and occlusions. Life-threatening complications included hemorrhage and infarcts.

Evaluation of the post-pneumonectomy space by computed tomography

Twenty-two patients who had undergone pneumonectomy for various reasons were evaluated by computed tomography (CT) in order to study the post-pneumonectomy space (PPS). In 13 of 22 cases, the residual PPS contained fluid, even years following surgery. In 9 of 22 cases, the PPS was obliterated. Obliteration of the PPS, one of the events that may follow pneumonectomy, is significantly correlated with the expansion of the nonoperated lung (coefficient, 0.84). Obliteration of the PPS does not present a significant coefficient of correlation with the following parameters, also considered in this study: time interval between surgery and CT, presurgical tests of respiratory function, hemidiaphragm elevation, and retraction of operated hemithorax. The fluid contained in the PPS does not organize but persists or is reabsorbed. Mediastinal shift depends on the expansion of the residual lung. The mediastinum rotates following right pneumonectomy and shifts following left pneumonectomy. The usefulness of CT in the follow-up of the pneumonectomized patient is stressed.

The role of computed tomography in the evaluation of bullous lung disease

Three cases illustrate the value of computed tomography in bullous lung disease. Computed tomography offers additional information over standard radiography regarding the number, size, and origin of the bullae. Differential diagnosis between bullae and loculated pneumothorax is also possible. Computed tomography is indicated in postoperative follow-up to evaluate pulmonary re-expansion and to identify small residual peripheral bullae or pneumothorax.

Computer-assisted evaluation of perianal fistula activity by means of anal ultrasound in patients with Crohn's disease

OBJECTIVES:Assessment of the activity of perianal fistulas may be of clinical relevance in patients with Crohns disease. Fistula activity is currently evaluated by means of magnetic resonance imaging; anal ultrasound can also be used, but its diagnostic performance in this setting remains to be defined. Our aims were to evaluate the agreement between clinical examination, magnetic resonance imaging, and anal ultrasound in assessing perianal fistula activity, and to apply computerized analysis to improve the assessment of ultrasound images.METHODS:Thirty-one consecutive patients with Crohns perianal fistulas underwent clinical examination, and magnetic resonance and anal ultrasound imaging. Active fistulas were defined as the presence of active drainage or signs of local inflammation on clinical examination, and the definition was confirmed by surgical examination. Activity was assessed on the basis of T2 hyperintensity on magnetic resonance imaging and the degree of hypoechogenicity on anal ultrasound; the anal ultrasound images were also analyzed using dedicated computer image-analysis software.RESULTS:Twenty-five patients had an active fistula at clinical examination. The agreement between clinical examination and magnetic resonance imaging was good (k-value = 0.739), whereas that with anal ultrasound was only fair (k-value = 0.266–0.294); computer-assisted analysis of the anal ultrasound images improved the agreement from fair to good (k-value = 0.608–0.670).CONCLUSIONS:Anal ultrasound can be used to assess fistula track activity in patients with Crohns disease. The diagnostic performance of the technique can be improved to values comparable with those of magnetic resonance imaging by using a computer-assisted evaluation of the anal ultrasound images.

Multicenter comparison of high concentration contrast agent iomeprol-400 with iso-osmolar iodixanol-320: contrast enhancement and heart rate variation in coronary dual-source computed tomographic angiography.

Objectives:To compare a contrast agent with high iodine concentration with an iso-osmolar contrast agent for coronary dual-source computed tomography angiography (DS-CTA), and to assess whether the contrast agent characteristics may affect the diagnostic quality of coronary DS-CTA. Materials and Methods:Patients were randomized to receive either 80 mL of iodixa:nol-320 (Visipaque, GE Healthcare, Chalfont St. Giles, United Kingdom) or iomeprol-400 (Iomeron, Bracco Imaging SpA, Milan, Italy) at 5 mL/s. Mean, minimum, maximum heart rate, and its variation (max-min) were assessed during calcium scoring scan and coronary DS-CTA. Three off-site readers independently evaluated the image sets in terms of technical adequacy, reasons for inadequacy, vessel visualization, diagnostic confidence (based on a 5-point scale), and arterial contrast opacification in Hounsfield units (HUs). Results:Ninety-six patients were included in the final evaluation. No significant differences were observed for pre- and postdose heart rate values for iomeron-400 compared with iodixanol-320, and changes in heart rate variation were also not significantly different (−2.3 ± 11.7 vs. −2.5 ± 7.3 bpm, P > 0.1). Contrast measurements in all analyzed vessels were significantly higher for iomeprol-400 (mean, 391.5–441.4 HU) compared with iodixanol-320 (mean, 332.3–365.5 HU, all P ≤ 0.0038). There was no significant difference in qualitative visualization of coronary arteries (mean scores, 4.3–4.5 for iomeprol, 4.1–4.3 for iodixanol, P = 0.15–0.28), or in diagnostic confidence scores. HU were inversely correlated with the number of insufficiently opacified segments (all readers P ≤ 0.0006). Conclusions:The high-iodine concentration contrast medium iomeprol-400 demonstrated significant benefit for coronary arterial enhancement compared with the iso-osmolar contrast medium iodixanol-320 when administered at identical flow rates and volumes for coronary DS-CTA. In addition, higher enhancement levels were found to be associated with lower numbers of inadequately visualized segments. Finally, observed mean heart rate changes after intravenous contrast injection were generally small during the examination and comparable for both agents.

Lactate detection in the brain of growth-restricted fetuses with magnetic resonance spectroscopy

OBJECTIVE The objective of the study was to determine the feasibility of detecting fetal brain lactate, a marker of fetal metabolic acidemia, using a noninvasive technique, proton magnetic resonance spectroscopy ((1)H MRS), in intrauterine growth-restricted (IUGR) fetuses. STUDY DESIGN In vivo human fetal brain lactate detection was determined by (1)H MRS in 5 fetuses with IUGR. Oxygenation and acid-base balance data were obtained at birth. RESULTS (1)H MRS analysis showed the presence of a lactate peak in the brain of the most severely affected IUGR fetus, with abnormal umbilical artery Doppler and fetal heart rate tracing. This finding was consistent with the low oxygen content and high lactic acid concentration observed in umbilical blood obtained at delivery. CONCLUSION (1)H MRS allows the noninvasive detection of cerebral lactate in IUGR fetuses. Lactate detected by (1)H MRS may represent a possible marker of in utero cerebral injury or underperfusion.

CT Demonstration of Portal and Superior Mesenteric Vein Thrombosis in Hepatocellular Carcinoma

Three eases of hepatocellular carcinoma in which computed tomography (CT) demonstrated thrombosis of the portal vein are reported. In one patient, extension of the thrombus into the superior mesenteric vein was identified as well. The outstanding CT features of portal vein thrombosis were: (a) enlargement of the vein, (b) intraluminal low density area, and (c) hyperdense peripheral ring due to the enhancement of the venous wall. These findings may be useful in differentiating hepatocellular carcinoma from hepatic metastases.

Bowel and mesenteric injuries from blunt abdominal trauma: a review

The bowel and the mesentery represent the third most frequently involved structures in blunt abdominal trauma after the liver and the spleen. Clinical assessment alone in patients with suspected intestinal and/or mesenteric injury from blunt abdominal trauma is associated with unacceptable diagnostic delays. Multi-detector computed tomography, thanks to its high spatial, time and contrast resolutions, allows a prompt identification and proper classification of such conditions. The radiologist, in fact, is asked not only to identify the signs of trauma but also to provide an indication of their clinical significance, suggesting the chance of conservative treatment in the cases of mild and moderate, non-complicated or self-limiting injuries and focusing on life-threatening conditions which may benefit from immediate surgical or interventional procedures. Specific and non-specific CT signs of bowel and mesenteric injuries from blunt abdominal trauma are reviewed in this paper.

CT demonstration of bilateral Castleman tumors in the mediastinum.

A case of bilateral Castleman tumors in the posterior mediastinum is described. Computed tomography proved to be an accurate, noninvasive method of investigation since it identified not only a large mass but also a smaller mass, which was not visible on standard chest X-ray film. Complete surgical excision was possible. The high attenuation values of both masses demonstrated the hypervascularity of the lesion.

Can the unenhanced phase be eliminated from dual-phase CT angiography for chest pain? Implications for diagnostic accuracy in acute aortic intramural hematoma.

OBJECTIVE The purposes of this study were to retrospectively assess the frequency of acute aortic intramural hematoma and evaluate whether the elimination of the unenhanced imaging acquisition series from the dual-phase MDCT angiography (CTA) protocol for chest pain might affect diagnostic accuracy in detecting intramural hematoma and justify the reduced radiation dose. MATERIALS AND METHODS From October 2006 to November 2012, 306 patients (mean age, 65.0 years) with acute chest pain underwent emergency CTA with a 64-MDCT scanner. Two experienced cardiovascular radiologists, blinded to the diagnosis, assessed the images in two different sessions in which enhanced (single-phase CTA) and combined unenhanced and contrast-enhanced (dual-phase CTA) findings were evaluated. Sensitivity, specificity, and accuracy along with 95% CIs were calculated. Surgical and pathologic diagnoses, including findings at clinical follow-up and any subsequent imaging modality, were used as reference standards. RESULTS Thirty-six patients were suspected of having intramural hematoma; 16 patients underwent both surgery and transesophageal echocardiography (TEE), and the remaining 20 underwent TEE. Single-phase CTA showed a higher number of false-negative and false-positive results than dual-phase CTA. With intramural hematoma frequency of 12% (95% CI, 8.38-15.91%), sensitivity, specificity, and accuracy were 94.4% (81.3-99.3%), 99.3% (97.4-99.9%), and 98.7% (96.7-99.6%) for combined dual-phase CTA and 68.4% (51.4-82.5%), 96.3% (93.2-98.2%), and 92.8% (89.3-95.4%) for single-phase CTA. Dual-phase was significantly better than single-phase CTA with respect to sensitivity (p=0.002), specificity (p=0.008), overall accuracy (p<0.001), and interrater agreement (p=0.001). CONCLUSION The frequency of acute aortic intramural hematoma is similar to that previously reported. The acquisition of unenhanced images during the chest pain dual-phase CTA protocol significantly improves diagnostic accuracy over single-phase CTA.