Lung perfusion in patients with pulmonary hypertension: comparison between MDCT pulmonary angiography with minIP reconstructions and 99mTc-MAA perfusion scan.

OBJECTIVES: Alterations in lung perfusion are a well-known feature of pulmonary hypertension (PH) seen on nuclear medicine studies. Abnormal radiotracer distribution in patients with PH may be caused by arterial thromboembolic occlusion, like in chronic thromboembolic pulmonary hypertension, by parenchymal destruction as in interstitial lung disease and pulmonary emphysema or by distal arteriopathy, like in idiopathic pulmonary arterial hypertension and other nonembolic forms. The different imaging pattern on radionuclide perfusion studies represents an important element for differential diagnosis. The aim of this study was to evaluate minimum intensity projection (minIP) images as an alternative to perfusion scintigraphy. We compared lung parenchyma attenuation patterns as depicted in minIP reconstructions with scintigraphic findings of lung perfusion in patients affected by pulmonary hypertension from various etiologies. METHODS: One hundred and seven consecutive patients affected by PH of different etiology (37 of those had chronic thromboembolic pulmonary hypertension) who had undergone both multidetector computed tomography pulmonary angiography and 99mTc-MAA perfusion scan were included. Five-millimeter thickness contiguous axial, coronal, and sagittal minIP images were reconstructed from the contrast enhanced computed tomography datasets. Two radiologists evaluated the images and qualitatively graded pulmonary attenuation as homogeneous, inhomogeneous with nonsegmental patchy defects, or inhomogeneous with segmental defects. The presence of parenchymal and pleural alterations was recorded. MinIP perfusion grading results were then compared with those of perfusion scintigraphy. RESULTS: In 87 of 107 patients (81.3%), the attenuation pattern seen on minIP images (39 homogeneous patterns, 13 with nonsegmental patchy defects, and 39 with segmental defects) correlated with the nuclear medicine scans. In the remaining 20 patients (18.7%), the imaging pattern was discordant because of 7 false-positive and 2 false-negative thromboembolic patterns at minIP and 11 false-positive thromboembolic patterns at perfusion scan. Air-trapping and parenchymal disease caused false-positive findings at minIP and perfusion scans, respectively. The sensitivity and specificity of minIP in detection of a chronic thromboembolic perfusion pattern were 94.5% and 90%, whereas perfusion scan had 100% sensitivity and 84% specificity. CONCLUSION: MinIP reconstructions can identify different patterns of pulmonary parenchymal attenuation, which show high concordance with perfusion patterns seen on radionuclide studies in patients with pulmonary hypertension. MinIP is a promising technique to evaluate lung perfusion in PH and may be used as an alternative to scintigraphy in the diagnostic work-up of these patients.

Cardiac anomalies in Turner Syndrome.

This is the case of a 30-year-old woman with Turner Syndrome, with Mosaicism, exhibiting a bicuspid aortic valve with aortic stenosis, ascending aortic dilatation, pseudocoarctation of the aorta, left superior vena cava and lusoria subclavian artery. The successful surgical procedure consisted of the replacement of the aortic root and ascending aorta with a composite valved graft.

Descending thoracic aortic diseases: stent-graft repair.

PURPOSE: To evaluate endovascular treatment of descending thoracic aorta with commercially available self-expanding stent-grafts. MATERIALS AND METHODS: Seventy patients with aortic dissection, intramural hemorrhage, degenerative and posttraumatic aneurysm, penetrating atherosclerotic ulcer, and pseudoaneurysm underwent endovascular treatment. Eleven patients had impending rupture and were treated on an emergency basis. Stent-grafts were customized or selected on the basis of spiral computed tomographic (CT) or magnetic resonance (MR) imaging measurements. Preprocedure diagnostic angiography was performed in patients with aortic dissection and in other selected patients. All procedures were performed in an operating room and monitored with digital subtraction angiography (DSA) and transesophageal echocardiography (TEE). Follow-up was at 1, 3, 6, and 12 months after treatment and yearly thereafter. RESULTS: Stent positioning was technically successful in 68 cases. At DSA and TEE, complete aneurysm or false-lumen exclusion was achieved in 66 (97%) cases. No intraoperative mortality or complications occurred. In-hospital complications included transient monoparesis (one patient) and extension of dissection into ascending aorta (one patient) that was repaired surgically. Early endoleak was observed in five (7%) patients: In three (type 2), endoleak resolved spontaneously; in one (type 1), it was persistent; and in one (type 1), treatment was converted to surgery. At long term, one (1%) patient died of aortic rupture; another, of respiratory insufficiency. Five (7%) late endoleak (type 1, one caused by migration of the stent) cases were observed. In three (4%), endovascular treatment was successful; in two (3%), surgery was performed. In one patient with persistent postimplantation syndrome, treatment was converted to surgery after successful aneurysm sealing. Procedure failure (ie, aortic disease-related mortality or conversion to surgery) occurred in six (9%) patients. CONCLUSION: Endovascular stent-graft repair is less invasive in patients with chronic and acute descending thoracic aortic aneurysm and dissection.

Indications for, timing of, and results of catheter-based treatment of traumatic injury to the aorta.

OBJECTIVE: The optimal treatment for and timing of surgery to repair traumatic aortic injury are still controversial. Endovascular treatment is a viable option in patients with both acute and chronic aortic trauma. However, appropriate patient selection criteria, treatment timing, and long-term durability of endovascular repair remain to be defined. We sought to identify appropriate selection criteria and optimal timing of treatment as well as to assess the long-term durability of endovascular repair. SUBJECTS AND METHODS: From July 1997 to December 2001, 19 patients with traumatic aortic injury (11 patients with acute and eight with chronic injuries) were selected for endovascular treatment. In all patients, the lesions were sited at the proximal segment of the descending aorta at a distance of 10 +/- 17 mm (mean +/- SD) from the left subclavian artery. Nine of the patients with acute injuries were treated after clinical stabilization of other severe associated lesions, whereas two patients, in whom hemodynamic and imaging findings suggested an impending rupture, received emergency treatment. Single-detector helical CT or MR imaging was used for patient selection and stent-graft customization before treatment and for evaluation of patients during the follow-up period. RESULTS: Endovascular stent positioning was successful in all patients. None of the patients developed complications. Aneurysm exclusion and shrinkage were confirmed at followup examinations. A partial covering of the subclavian artery occurred in six patients without interrupting the blood flow. All patients remain asymptomatic after a mean follow-up period of 20 months (range, 1-56 months). CONCLUSION: Endovascular repair represents an alternative, minimally invasive treatment, particularly suitable for use in patients with traumatic aortic injuries. The decision of whether to provide immediate emergency treatment or to delay treatment should be based on the lesion characteristics on imaging and clinical findings. The durability of treatment seems to be related to the absence of alteration to the aortic wall at the extremities.