Water/cortical bone decomposition: A new approach in dual energy CT imaging for bone marrow oedema detection. A feasibility study.

INTRODUCTION: Many studies aimed at validating the application of Dual Energy Computed Tomography (DECT) in clinical practice where conventional CT is not exhaustive. An example is given by bone marrow oedema detection, in which DECT based on water/calcium (W/Ca) decomposition was applied. In this paper a new DECT approach, based on water/cortical bone (W/CB) decomposition, was investigated. MATERIALS AND METHODS: Eight patients suffering from marrow oedema were scanned with MRI and DECT. Two-materials density decomposition was performed in ROIs corresponding to normal bone marrow and oedema. These regions were drawn on DECT images using MRI informations. Both W/Ca and W/CB were considered as material basis. Scatter plots of W/Ca and W/CB concentrations were made for each ROI in order to evaluate if oedema could be distinguished from normal bone marrow. Thresholds were defined on the scatter plots in order to produce DECT images where oedema regions were highlighted through color maps. The agreement between these images and MR was scored by two expert radiologists. RESULTS: For all the patients, the best scores were obtained using W/CB density decomposition. CONCLUSIONS: In all cases, DECT color map images based on W/CB decomposition showed better agreement with MR in bone marrow oedema identification with respect to W/Ca decomposition. This result encourages further studies in order to evaluate if DECT based on W/CB decomposition could be an alternative technique to MR, which would be important when short scanning duration is relevant, as in the case of aged or traumatic patients.

Acute vascular abdomen. General outlook and algorithms.

Acute vascular abdomen is a severe and life-threatening pathology due to arterial degeneration, leading to hemorrhage or arterial occlusion leading to ischemia. Differential diagnosis of patients with severe abdominal pain and/or shock include several vascular and traumatic diseases, the most common being rupture of abdominal aortic aneurysm (AAA), or less frequently rupture of visceral artery aneurysm. Also acute aortic dissection, iatrogenic injury and acute mesenteric ischemia may lead to acute vascular abdomen. Clinical evaluation of the haemodynamic status of the patient may be very difficult, and may require airway maintenance and ventilation with a rapid treatment of hemorrhagic shock. In the stable patient with an uncertain diagnosis, CT scan, NMR and selective angiography may be helpful in diagnosis before vascular repair. On the contrary, the unstable patient, after hemodynamic resuscitation, must be operated on expeditiously. We present our vascular algorithms, to assess timing of diagnosis and treatment of this severe acute disease.

[Vascular pathology. A study of some blood parameters indicative of leukocyte activation and platelet dysfunction]. / Patologia vascolare. Studio di alcuni parametri ematici indicativi di attivazione leucocitaria e disfunzione piastrinica.

BACKGROUND: In vascular pathology the endothelial lesions easily reflect on blood cells, inducing a reactive state. In the present study the eventual presence of activation signals in leukocytes and platelets was tested. METHODS: Fifty-eight subjects with major vascular pathology and 14 with lower limbs venous insufficiency were studied, together with a control group of 25 normal subjects. Elastase PMN, superoxide ion, leukocytes and subpopulation count, platelet factor 3, clot retraction, heparin in neutralizing activity (HNA plasmatic and intraplatelet), platelet count and volume were tested. RESULTS: As regards leukocytes, it was observed a significative increase of elastase PMN and monocytes number for both the studied pathologies, of superoxide ion and leukocyte number only for major vascular pathology; for platelets, an inhibition of functionality, revealed by clot retraction test for arterious and venous pathologies and by HNA test only for the venous one. CONCLUSIONS: As regards the leukocyte activation, elastase PMN is particularly responsive to the endothelial lesion both in arterious and in venous districts, while superoxide ion appears to increase in presence of a marked alteration. The level of monocytes is indicative of an inflammatory condition and of leukocytes of an atherosclerotic inflammatory process. As for platelets, the test clot retraction is specifically sensible to the endothelial abnormality in both the arterious and venous pathologies with addition of an abnormal HNA test only in venous insufficiency. This platelet dysfunction is probably due to endothelial release of vasoactive and heparin amplifying substances.

[Long-term results of radical lumbar ganglionectomy. Our experience]. / Risultati a lungo termine della gangliectomia lombare radicale. Nostra esperienza.

We present our experience of 15 patients operated on by lumbar sympathectomies between 1987-1993, to confirm the effective and permanent efficacy of sympathectomy in peripheral vascular disease of the lower limbs. The patients, 9 men and 6 women (age 58-86) presented with rest pain (12), and minimal toe lesions (3). After an eco color-Doppler and angiography of the lower limbs, a radical operative sympathectomy (L2-L5) was performed in all patients. Associated diseases were: ischemic cardiopathy (61.7%), renal failure (25%), diabetic disease (61.7%), carotid stenosis (25%), abdominal aortic aneurysm (12%). In four patients, was performed during the same surgical time, 2 abdominal aortic aneurysm repairs, and 2 aorto-bifemoral bypasses. No patients died, operative morbidity was 12.5% (2 cases). The clinical and instrumental follow-up performed on 6 patients (38.3%) after 3 years, demonstrated in all cases the regression of the rest pain (12 patients) and the healing of the toe lesions (3 diabetic patients). Our results confirm the efficacy of sympathectomy especially when performed in young patients. The small number of diabetic patients in our study made statistical evaluation difficult, but it is generally considered that the results are worse in diabetic patients, because the microvascular lesions in these patients reduce peripheral vasodilatation.

Indications and role of isolated profundaplasty in patients affected by limb ischemia.

The deep femoral artery is the primary source of blood supply to the lower extremity in presence of superficial and/or popliteal occlusion. The atherosclerotic involvement of the profunda femoris artery is relatively less frequent and generally is localized in the initial segment of the artery. The profundaplasty employed to relieve limb threatening ischemia is infrequently used as an isolated procedure. However many authors demonstrated that restoration of flow through this vessel alone, in patients without significative lesions of the aorto-femoral district, will effectively relieve ischemia when the superficial femoral artery is also occluded. Our experience gained in the last eight years concerns 24 patients (21 male, 3 female). All the patients had severe ischemia of the lower limb with invalidating claudication (13), rest pain (9) and gangrene (2). On the basis of our results, we think that the operation is recommended, whenever possible, in patients with critical ischemia when the possibilities of more extensive revascularizing procedures are absent.

[Renal arteriovenous fistulae]. / Fistole arterovenose renali.

Arteriovenous fistulas (AVFs) involving the kidney are rare. They are generally classified as congenital, idiopathic or acquired. The authors present 5 cases of renal arterio-venous communications observed in recent years. These cases don't include the congenital type and represent the forms of AVFs that are more frequently observed (1 idiopathic, 3 iatrogenic, 1 associated with malignancy). This study is aimed at examining the clinical picture and the procedures of detection and monitoring of renal AVFs. The various adopted therapeutic procedures (nephrectomy, surgical ablation, radiological embolization) are analyzed.

[Hemostatic factors of endothelial origin in major vascular pathology]. / Fattori emostatici di origine endoteliale in patologia vascolare maggiore.

There is an altered hemostatic balance in vascular-based diseases. The aim of this study was to compare a group (no. = 38) of vascular patients (aortic aneurysm, carotid obstructions arteriopathies of lower limbs) and a control group (no. = 40) and assess variations in the following endothelial factors: tPA, PAI1, vWf, fibronectin and dimer D, in differentiated degrees according to the type of pathology. These were the indicative signs of endothelial mobilization resulting in the renewed continuity of the stratum with the formation of a hemostatic plug. vWf was found to be particularly significant as a marker of an ongoing atheromasic process and its extension to various vascular districts.

[Physiopathology of venous stasis at the microcirculation level]. / Fisiopatologia della stasi venosa a livello del microcircolo.

The division of the venous circulation in to two sectors, one constituted by the superficial and deep venous trunks (macrocirculation) and the other by the capillaries and precapillary venules (microcirculation), is surely schematical but aids the comprehension of many hemodynamic effects connected to hampered venous return and to the incompetence of the valvular devices. In fact many of the effects of stasis and venous hypertension (oedema, red cell diapedesis, skin dystrophies) cannot be explained merely by hydraulic mechanisms but require a primary alteration of the microvascular wall associated with structural changes of the perivascular connective tissue. The alterations that occur in microcirculation are of the utmost importance in the formation of the venules ulcerations. The passage of fibrinogen through large pores in the venules of the patients affected by venous hypertension derived from venous insufficiency creates a pericapillary fibrin deposition that cannot be removed because of inadequate blood and tissue fibrinolysis. This accumulation acts as a barrier to the diffusion of oxygen and other nutrients, determining a stasis dermatitis that may lead to tissue necrosis and ulceration. The more precise knowledge of the phenomena connected with the venous stasis at the level of microcirculation (pericapillary fibrin deposition, endothelial ischemia, blocked lymphatic drainage) will not only allow a deeper comprehension of the clinical signs but hopefully will lead to a more effective treatment of the postphlebitic syndrome.