Traumatic injuries: imaging of thoracic injuries.

Chest trauma is one of the most important causes of death, in particular in individuals under the age of 40 years. The mortality rate for chest trauma, often related to motor vehicle accidents, is approximately 15.5%; it increases dramatically to 77% with associated shock and head injury (Glasgow scores of 3-4). The accurate diagnosis of pathologies consequent to blunt chest trauma depends on a complete knowledge of the different clinical and radiological manifestations. The first diagnostic approach is classically based on chest X-ray often carried out on supine position at the hospital admission. A CT study must then be performed in all chest trauma patients in whom there is even the smallest diagnostic doubt on plain film. In particular, spiral CT (SCT) assumes a fundamental role in the demonstration of mediastinal hemorrhage and direct signs of aortic lesions. At present, SCT is routinely part of a diagnostic evaluation which also includes scans of the brain and the abdomen in polytraumatized patients. Magnetic resonance is the ideal method for visualizing diaphragmatic lesions. Furthermore, recent reports have demonstrated the high diagnostic value of MR in evaluating aortic injuries. The purpose of this article is to review the most common radiological patterns related to chest trauma.

Evolution of aortic dissection after surgical repair.

Patients after aortic dissection repair still have long-term unfavorable prognosis and need careful monitoring. The purpose of this study was to analyze the evolution of aortic dissection after surgical repair in correlation to anatomic changes emerging from systematic magnetic resonance imaging (MRI) follow-up. Between January 1992 and June 1998, 70 patients underwent surgery for type A aortic dissection. Fifty-eight patients were discharged from the hospital (17% operative mortality) and were followed by serial MRI for 12 to 90 months after surgery. In all, 436 postoperative MRI examinations were analyzed. In 13 patients (22.5%) no residual intimal flap was identified, whereas 45 patients (77.5%) presented with distal dissection, with a partial thrombosis of the false lumen in 24. The yearly aortic growth rate was maximum in the descending aortic segment (0.37 +/- 0.43 cm) and was significantly higher in the absence of thrombus in the false lumen (0.56 +/- 0.57 cm) (p <0.05). There were 4 sudden deaths, with documented aortic rupture in 2. Sixteen patients underwent reoperation for expanding aortic diameter. In all but 1 patient, a residual dissection was present (in 13 without any thrombosis of the false lumen). Close MRI follow-up in patients after dissection surgical repair can identify the progression of aortic pathology, providing effective prevention of aortic rupture and timely reoperation. Thrombosis of the false lumen appears to be a protective factor against aortic dilation.

Composite graft replacement of the ascending aorta: leakage detection with gadolinium-enhanced MR imaging.

PURPOSE: To assess the value of magnetic resonance (MR) imaging in the detection of postoperative complications after composite valve graft replacement. MATERIALS AND METHODS: Spin-echo and gradient-echo MR imaging was performed in 52 patients 1/2 to 200 months after composite graft replacement of the ascending aorta (22 for dissection, 30 for aneurysm). The prosthetic aortic segment, distal and proximal anastomoses, general morphologic characteristics, and diameter of the reimplanted coronary arteries were evaluated. In patients with abnormal perigraft thickening, additional spin-echo imaging was performed after injection of gadopentetate dimeglumine. RESULTS: Normal postoperative perigraft thickening (< or = 10 mm) was observed in 42 patients. Ten patients had abnormal periprosthetic thickening of 15-52 mm. Gadolinium-enhanced MR imaging demonstrated leakage in five of those 10 patients. The lack of enhancement excluded the presence of bleeding in the remaining five patients (three with chronic hematomas, one with infection, and one with granulation tissue). These findings were confirmed at surgery or with subsequent follow-up MR examinations. CONCLUSION: MR imaging was an optimal imaging modality for evaluating the morphologic characteristics of composite grafts and reimplanted coronary arteries. Gadolinium-enhanced MR imaging is a simple, accurate, and noninvasive method for detecting a leak, which necessitates urgent repeat surgery.

Contribution of magnetic resonance imaging in the differential diagnosis of cardiac amyloidosis and symmetric hypertrophic cardiomyopathy.

BACKGROUND: Magnetic resonance imaging (MRI) provides a high-resolution study of atrial and ventricular myocardium depicting morphologic alterations in cardiomyopathies. Furthermore, in systemic amyloidosis, MRI demonstrates the capability to detect amyloid protein by tissue characterization. The aim of this study was to evaluate the potential of MRI in the diagnosis of cardiac amyloidosis. METHODS: MRI was performed in 16 patients with cardiac amyloidosis and in 10 patients with symmetric hypertrophic cardiomyopathy. Myocardial ventricular and atrial thickness (septum, posterior, and lateral wall), right and left ventricular diastolic diameter, and atrial surface were compared. Ventricular myocardium signal intensity was then evaluated by sequences with an echo time (TE) of 20 and 60 ms as the expression of myocardial texture modification. RESULTS: Significant morphologic differences between cardiac amyloidosis and hypertrophic cardiomyopathy were found in the right atrium surface (21.9 vs 17.2 cm2, respectively; P = .05), myocardial thickness of right atrial wall (9.3 vs 4.9 mm; P < .0001 ), and right ventricular free wall (10.6 vs 8.9 mm; P = .011 ). No significant differences were found in the interventricular septum (16.6 vs 17.8 mm), left ventricular posterior wall (18.2 vs 18.8 mm), and left atrial surface (17.4 vs 17.2 cm2). The signal intensity of cardiac amyloidosis was significantly lower with both TE 20 and TE 60 in comparison with hypertrophic cardiomyopathy and to a group of healthy volunteers. CONCLUSIONS: MRI has a potential role in the noninvasive diagnosis of cardiac amyloidosis identifying typical morphologic markers and suggesting the presence of infiltrative disease by tissue characterization.

Evolution of post-traumatic aortic aneurysm in the subacute phase: magnetic resonance imaging follow-up as a support of the surgical timing.

OBJECTIVES: A recent surgical series documented that in traumatic aortic rupture (TAR) a surgical repair postponed to the treatment of associated lesions reduced operative and overall mortality. Nevertheless some isolated cases may develop to free rupture. Until now, no imaging follow-up studies of post-traumatic aortic lesions have been reported in the early stage. The aim of this study is to analyze the behaviour of traumatic aortic ruptures in the subacute phase, in order to detect the morphological characteristics of unstable post-traumatic aneurysms. METHODS: Twenty-five consecutive patients affected by traumatic aortic rupture (one intimal hemorrhage, 19 partial lesions and five circumferential lesions) were admitted to the department of cardiac surgery. Magnetic resonance imaging (MRI) was the imaging method used to confirm the diagnosis. No one was operated on during the acute phase. All patients were treated with beta-blockers and vasodilators as well as limited fluid administration. Delayed surgery was carried out in 18 patients at 243 days (+/-127), after the resolution of associated lesions. A scheduled MRI follow-up was performed at 7, 15 and 30 days and immediately before the operation. The parameters examined were increase of post-traumatic aneurysm, increase of periaortic hematoma and modification of the thoracic associated lesions. RESULTS: At 30 days a 3.0 +/- 3.7 mm median increase of the aneurysm was observed, while in the subsequent period the lesions became substantially stable, resulting in a 4.4 +/- 3.6 mm increment at the end of the follow-up. The circumferential lesions presented a higher increment with respect to the partial lesions. In three cases an augmentation of 6, 7 and 12 mm was detected and surgical repair was anticipated. In 13 cases a periadventitial hematoma surrounding the aortic aneurysm decreased through the time. One case of intimal hemorrhage healed spontaneously, with no aneurysm formation. Thoracic associated lesions (pleural and pericardial effusions, rib fractures, lung focal contusions and two cases of ARDS) resolved at 30-60 days. CONCLUSIONS: Despite common knowledge, considering TAR highly evolutive in the acute and subacute phase, this study demonstrated that this pathological entity is relatively stable if a proper pharmacological treatment is administrated. MRI follow-up is recommended in order to detect isolated cases of unstable aneurysm.

Intramural posttraumatic hematoma of the ascending aorta in a patient with a double aortic arch.

We report a case of posttraumatic intramural hematoma (IMH) of the ascending aorta in a patient with a double aortic arch and coronary artery disease. This unusual and asymptomatic finding came to our observation because the patient presented an acute myocardial infarction and underwent coronary angiography. The diagnosis was performed by magnetic resonance imaging (MRI) which defined well the anatomy of aorta and showed the characteristics of the hematoma. The data were useful in planning the surgical repair.

[Course of idiopathic pulmonary fibrosis of the Wells grade III at presentation. Study using high-resolution computerized tomography]. / Evoluzione della fibrosi polmonare idiopatica del grado III di Wells all'esordio. Studio con Tomografia Computerizzata ad alta risoluzione.

PURPOSE: We studied the HRCT and functional evolution of idiopathic pulmonary fibrosis (IPF) patients presenting with Wells grade III--prevalent fibrosis. MATERIAL AND METHODS: We sequentially studied the HRCT and functional findings of 16 IPF patients, at presentation and at 1 year. All patients had a typical grade III IPF pattern; those with the most severe clinical presentation were treated (9/16). The main HRCT parameters were the extent of interstitial involvement and emphysema (visual score) and the mean diameter of lung cysts in honeycombing regions. RESULTS AND CONCLUSIONS: Most of our grade III IPF patients exhibited a slowly progressive deterioration, with no accelerated parenchymal opacification. Deterioration was found on HRCT images in 56.2% of patients (p = .02), with a mean monthly increase of .56%. Fibrosis extent, evaluated as HRCT visual score at presentation, was significantly correlated with viability and PaO2, values (p = .01). Follow-up HRCT scores were also significantly correlated with viability (p = .004). The mean diameter of honeycomb lung cysts increased in 25% of patients. Emphysema was associated at presentation in 50% of patients--all of them former smokers; it was less diffuse than interstitial involvement (15% of total lung volume versus 46.7% at presentation) and was not seen to progress on follow-up images. The comparison between treated (T) and untreated (NT) patients confirmed more severe HRCT and functional damage in T patients at presentation. Moreover, T patients presented a significantly more rapid deterioration, despite treatment, than NT patients, who had less severe and slower HRCT and functional evolution, excluding DLCO deterioration (p = .01). To conclude, grade III IPF patients can be subdivided into two subgroups, with rather different prognosis and evolution, on the basis of HRCT and functional findings at presentation. The current treatment seems useless in grade III IPF. HRCT findings, integrated with the visual score of disease extent, and lung function tests can be used to monitor grade III IPF evolution.

Delayed surgery of traumatic aortic rupture. Role of magnetic resonance imaging.

BACKGROUND: Traumatic aortic rupture (TAR) is a pathological entity with a high mortality, both spontaneous and perioperative. Delayed surgical repair has been proposed when associated lesions are stabilized. The aim of this study was to validate MRI for detecting both the presence and type of TAR and to monitor posttraumatic aneurysm and associated lesions. METHODS AND RESULTS: Twenty-four consecutive patients with acute chest trauma and suspected aortic rupture, as suggested by emergency CT or chest radiographs, were subjected to MRI and/or angiography in random order. Such parameters as the presence and type of lesion; presence of periaortic, pericardial, mediastinal, or pleural effusion; and presence of associated lesions were considered in every patient. Follow-up imaging was performed exclusively by MRI every 1 to 2 months. TAR was present in 20 patients. No patient underwent surgery in the acute phase; 14 patients underwent surgery at 6.8 +/- 2.7 months; 5 are waiting for surgery; and 1 healed spontaneously. There was no overall mortality. For detection of TAR, the accuracy of MRI was 100%; angiography, 84%; and CT, 69%. In detecting the type of lesion, the diagnostic accuracy of MRI was 92%. During follow-up, a significant increase in the posttraumatic aneurysm was observed in 2 patients, and surgical repair was initiated. CONCLUSIONS: In chest trauma patients, MRI provides complete anatomic data to assess the severity of aortic and thoracic lesions. Moreover, along with the concept of delayed surgical repair of TAR, MRI is the ideal modality to monitor and follow TAR before surgical repair.

[Diagnostic contribution of magnetic resonance in clinically suspected arrhythmogenic dysplasia of the right ventricle]. / Contributo diagnostico della risonanza magnetica nel sospetto clinico di displasia aritmogena del ventricolo destro.

BACKGROUNDS: Magnetic Resonance (MR) imaging gives information about the complex anatomy of the right ventricle (RV). Because of the capability of tissue characterization, in addition to the functional and morphologic analysis, MR imaging is an optimal technique to investigate patients (pts) with clinical suspicion of arrhythmogenic right ventricular dysplasia (ARVD). METHODS: The purpose of the current study was to investigate a group of 55 pts with ventricular arrhythmias in order to detect ARVD. MR was performed with a 0.5 magnet (MR MAX PLUS G:E. Medical System). Electrocardiographically gated spin-echo and gradient-echo MR images of the heart were obtained in both transverse and sagittal planes. Sustained ventricular tachycardia (SVT) was present in 14 pts, non sustained ventricular tachycardia (NSVT) in 13 pts, left bundle block ventricular premature complexes > 10000/24 h (VPC/LBB) in 28 pts. The abnormalities analyzed were: presence of focal or diffuse fatty replacement of myocardium, segmental or global dilation of the RV, reduction of ejection fraction with akinetic or dyskinetic areas, disarrangement of the trabecular pattern with the hypertrophy of the moderator band. RESULTS: When intramyocardial fatty replacement and at least two of the abnormalities were present we considered the MR aspects compatible with the diagnosis of ARVD. We detected the presence of ARVD in 8/14 pts with SVT, in 4/13 pts with NSVT, in 4/28 pts VPC/LBB: In 10/16 pts with ARVD left ventricular abnormalities (areas of fatty replacement of the myocardial wall and/or reduction of ejection fraction) were also present. The left ventricular involvement was detected in 5 pts with SVT, in 2 pts with NSVT, in 3 pts with VPC/LBB: Even if in 31 pts it was not possible to identify aspects compatible with the diagnosis of ARVD, some structural abnormalities of RV were also present. Because of its non-invasiveness MR is an excellent technique for the detection of ARVD, and of minor right ventricular abnormalities.

[Clinical significance of magnetic resonance and echocardiographic correlations in the evaluation of hypertrophic cardiomyopathy]. / Significato clinico della risonanza magnetica e correlazioni ecocardiografiche nella valutazione della cardiomiopatia ipertrofica.

Relatively few clinical studies have investigated the role of MRI in the patients with hypertrophic cardiomyopathy. To assess MR capabilities in defining the presence, distribution and severity of left ventricular hypertrophy, the prevalence and clinical correlations of right ventricular hypertrophy and the prevalence and clinical implications of structural myocardial abnormalities, MRI and echocardiography were performed on 37 unselected patients with hypertrophic cardiomyopathy. The two methods were in agreement in 100% of cases in diagnosing the disease and classifying left ventricular hypertrophy as asymmetric, concentric or apical, and in 92% of cases in assessing the topographic distribution of hypertrophy of ventricular segments. A statistically significant linear correlation was found between echocardiographic and MR measurements of interventricular septum (r = 0.69, p < 0.0001, SEE = 4) and left posterior wall of the left ventricle (r = 0.67, p < 0.0001, SEE = 2.4). Right ventricular hypertrophy (right anterior wall diastolic thickness > 5 mm) was demonstrated by MRI in 23 of 33 patients (70%). In this group, left posterior wall thickness and left atrial diameter were higher (15 +/- 4 vs 11 +/- 2, p < 0.01 and 45 +/- 9 vs 38 +/- 5 mm, p < 0.05, respectively). On T2-weighted sequences, areas of reduced signal intensity, probably due to myocardial fibrosis, were detected in 16 cases (43%). This group was characterized by higher max. septal thickness (25 +/- 7 vs 21 +/- 6 mm, p < 0.05) and max. left posterior wall thickness (15 +/- 9 vs 7 +/- 8 mm, p < 0.05). All the three cases with dilated and hypokinetic left ventricle showed this kind of tissue abnormality. In conclusion, MRI provided clear, accurate and exhaustive data on the presence and distribution of left ventricular hypertrophy in hypertrophic cardiomyopathy. Right ventricular hypertrophy and structural abnormalities of ventricular myocardium can also be detected and quantified. Right ventricular involvement is associated with more severe hypertrophy of left ventricular posterior wall. Structural myocardial abnormalities, probably due to fibrosis, are related to the extent of left ventricular hypertrophy.

[The role of magnetic resonance in studying hypertrophic cardiomyopathy: the echocardiographic correlations and clinical implications]. / Ruolo della risonanza magnetica nello studio della cardiomiopatia ipertrofica: correlazioni ecocardiografiche ed implicazioni cliniche.

Clinical studies evaluating the role of magnetic resonance imaging (MRI) in patients with hypertrophic cardiomyopathy are scanty. To assess the capability of MRI to define the presence, distribution and severity of left ventricular hypertrophy, the prevalence and clinical implications of right ventricular hypertrophy, the prevalence and clinical implications of myocardial structural abnormalities, MRI and echocardiography were performed in 37 unselected patients (age 10-72 years, mean 38 +/- 19) with hypertrophic cardiomyopathy. The concordance between the two methods was 100% in the diagnosis and classification of left ventricular hypertrophy as asymmetric, concentric or apical. A significant linear correlation was found between echocardiography and MRI measurements of interventricular septum (r = 0.69, p < 0.0001, SEE = 4) and left ventricular posterior wall (r = 0.67, p < 0.0001, SEE = 2.4). Right ventricular hypertrophy (right anterior wall diastolic thickness > 5 mm) was disclosed by MRI in 23/33 patients (70%). In this group, left posterior wall thickness and left atrial diameter were higher (15 +/- 4 versus 11 +/- 2 mm, p < 0.01 and 45 +/- 9 versus 38 +/- 5 mm, p < 0.05 respectively). On T2 weighted sequences, areas of reduction of signal intensity, probably caused by myocardial fibrosis, were detected in 16 cases (43%). This group was characterized by a higher value in maximal septal thickness (26 +/- 7 versus 21 +/- 6 mm, p < 0.05) and in maximal left posterior wall thickness (15 +/- 9 versus 7 +/- 8 mm, p < 0.01). All the 3 cases with dilated and hypokinetic left ventricle showed this type of tissue abnormality.(ABSTRACT TRUNCATED AT 250 WORDS)

[Role of magnetic resonance in the follow-up of surgically treated aortic dissection]. / Ruolo della risonanza magnetica nel follow-up della dissezione aortica operata.

Twenty-one patients were examined with MRI 0.5 to 200 months after surgical aortic dissection. The series included 15 type-I dissections, 1 type-II dissection and 5 complicated type-III dissections. MR images demonstrated the persistence of the intimal flap with patency of both the true and the false lumen in 17 cases, the complete obliteration of the false lumen in 1 case and the partial thrombosis of the false lumen in 3 cases. Coronary artery ostial reimplantation was depicted in all the patients who underwent this kind of surgery; in 1 case, a small hematoma was present at the site of reimplantation. In 3 patients, an organized hematoma was seen between the prosthetic graft and the native aortic wall; in 1 case the aortic lumen was markedly reduced, while in the extant 2 cases, signal intensity features were suggestive of subacute hematoma due to prosthetic graft degeneration. Seven patients underwent two MR exams: the first one immediately after surgery (in most cases) and the second one at 3-11 months. Aortic diameter progressively increased in 4 patients, 3 of them with Marfan syndrome. In conclusion, MRI proved an accurate technique to assess aortic size beyond the prosthetic graft and to demonstrate the residual dissecting process and the postoperative problems in the prosthetic conduit.

Comparison of propafenone and disopyramide for treatment of chronic ventricular arrhythmias: placebo-controlled, double-blind, randomized crossover study.

In a double blind, placebo-controlled study, the efficacy of propafenone, a new antiarrhythmic drug was compared to that of disopyramide. Sixteen patients with frequent and complex premature ventricular contractions (PVCs) were studied by serial 24-hour ambulatory monitoring, while they were receiving propafenone, 300 mg, and disopyramide, 200 mg, both every 8 hours. A reduction in the mean frequency of PVCs per hour, in comparison to the placebo period, from 574 +/- 535 to 100 +/- 130, was observed after propafenone (p less than 0.005) and from 629 +/- 455 to 231 +/- 280 after disopyramide (p less than 0.008). A greater than 70% reduction in PVCs in comparison to placebo was observed in 11 of 14 after propafenone and 9 of 15 after disopyramide (NS). A greater than or equal to 90% reduction in PVCs was observed in 9 of 16 with propafenone and in 4 of 15 with disopyramide (p less than 0.05). The suppression of complex PVCs (repetitive, polymorphic, or more than 5/min with bigeminism) was observed in 11 of 14 after propafenone and in 9 of 14 after disopyramide. The abolition of nonsustained ventricular tachycardia was observed in 6 of 6 and 3 of 5, respectively, after propafenone and disopyramide (p less than 0.05). A lower incidence of side effects, 4 of 16 vs 8 of 16, was observed during propafenone than during disopyramide treatment. We conclude that propafenone, in a dose of 900 mg daily, is more effective than disopyramide, in a dose of 600 mg daily, in the treatment of frequent and complex PVCs and nonsustained ventricular tachycardias. Propafenone also showed a lower incidence of side effects.