Search

Purpose: To investigate the role of Helical CT and the usefulness of three-dimensional (3D) imaging for preoperative planning and follow-up of reconstructive maxillofacial surgery with alloplastic material in neoplastic disease involving this region., Material and Methods: From 1996 to 1999 eleven patients were examined with Helical CT and 3D images for planning of maxillofacial plastic and reconstructive surgery for advanced cancer of this anatomically complex region. A 3D-modulated titanium mesh (100%) or micronets was used to rebuild the anterior surface of maxillary bone and the orbital floor. The mesh was cut to the appropriate size and shape and curved where necessary. Within the residual sinusal cavity a siliconed filling was used surmounting an acrylic prosthesis with dental arch to rebuild the palate. A rehydrated bovine pericardium was affixed and moduled on the borders in two cases only. Three-dimensionally reconstructed CT images were obtained preoperatively and at least 6 months postoperatively in all patients. The images were generated on a computer workstation using the shaded surface display (SSD) software with threshold values ranging 425 to 630 HU, and a more closed window for the imaging of titanium mesh/bone interface in the postsurgical follow-up., Results: We always obtained an excellent complete spatial depiction of maxillofacial region both before and after surgery, with no artefacts so important as to affect the 3D reconstruction process and the image quality. Together with the head-neck surgical team we could work for preoperative planning through CT scans by different 3D points of view. The 3D reconstructed follow-up scans showed good filling of the defect in the area where the titanium mesh had been used. Then efficacious bone modelling and good biocompatibility of the alloplastic material were seen in all patients, with no inflammatory reactions., Conclusions: Titanium is a well-known material, which is widely used for cranioplasty. It is a radiolucent, nonferrous metal of low atomic number that allows very clear CT and MR images to be obtained. Further Ti features are strength, biocompatibility and easy handling. 3D Helical CT scan has proved to be the most complete and accurate imaging technique for reconstructive plastic surgery with alloplastic material in advanced maxillofacial cancer, also considering the anatomic and functional complexity of this area. The prospect is provided to identify virtual 3D presurgical ablation planes. These may allow the surgeon to improve plastic reconstruction and shorten intervention time.

Introduction: Magnetic Resonance Imaging (MRI) has been proposed as the diagnostic technique of choice to characterize adrenal tumors. However, the results of the current studies are controversial., Material and Methods: Forty-nine patients with unilateral adrenal masses were submitted to MRI for lesion characterization on the basis of MR signal intensity. Cytology and/or histology demonstrated 14 pheochromocytomas (pheos), 11 adenomas, 3 cysts, 2 myelolipomas, 4 carcinomas, 3 metastases and 1 fibrosarcoma; a clinical diagnosis of adenoma was made in the remaining 11 patients. MR studies were performed using spin-echo (SE) sequences with T1 (TR/TE = 600/17 ms) and T2 (TR/TE = 2000/15-90 ms) weighting. T1-weighted images were also acquired after Gadolinium-DTPA (Gd-DTPA) administration. MR studies were integrated with in- and out-of-phase (TR/TE = 100/4-6 ms) chemical-shift (CS) sequences. MR signal intensity (SI) was analyzed qualitatively and quantitatively; MR results were correlated with tumor type and hormone secretion., Results: The qualitative analysis of T2 images showed high signal intensity in the majority (80%) of adrenal lesions (14 pheos, 12 adenomas, 3 cysts, 2 myelolipomas and 8 malignancies). The quantitative analysis of post-Gd-DTPA T1 images permitted to distinguish adenomas, cysts and myelolipomas from pheos and malignancies. The qualitative analysis of post-Gd-DTPA T2 and T1 images permitted to distinguish pheos and cysts from adenomas and malignancies (p < .05); however, pheos and cysts as well as adenomas and malignancies were not differentiated. MR SI was similar in secreting and nonsecreting adenomas from both a qualitative and a quantitative viewpoints. CS MRI permitted to distinguish adenomas (decreased signal intensity on out-phase relative to in-phase images) from other benign and malignant lesions (no signal change from out-phase to in-phase images)., Conclusions: The qualitative analysis of MR SI on conventional T1 and T2 images does not permit to differentiate adrenal masses. The qualitative evaluation of T1 images after Gd-DTPA administration, the quantitative analysis and CS sequences are technical options improving lesion characterization.

The authors report their experience in the study of bleeding aneurysms of the celiac arteries. Eleven patients were examined with US, CT, and angiography (8 hepatic artery aneurysms and 3 splenic artery aneurysms). Clinical findings included digestive bleeding, upper abdominal pain, palpable pulsating masses, and jaundice. Patient history included blunt abdominal trauma, penetrating trauma due to gunshot, acute pancreatitis, recent hepatic biopsy. In all cases US showed an abdominal mass ranging in size from 2 to 10 cm. US findings included cyst-like lesions (8 cases), a lobulated solid-like lesion, and complex lesions (2 cases). Continuity of the lesion with adjacent arterial vessels was noted in 5/11 cases, and pulsing activity in 3/11 cases. US patterns, although not specific, play an important role in the diagnosis when associated to other elements such as arterial continuity, mass pulsatility, patient history, and gastrointestinal bleeding. They suggest the need for more specific imaging exams, i.e. CT and angiography, and help avoid dangerous diagnostic biopsies. CT was performed to confirm US findings in 5 cases, and detected either hypodense cystic masses, or inhomogeneous masses with arterial enhancement after bolus injection of cm. CT was used to better demonstrate the lumen, patency of the vessel, the walls of the vessel, and the parietal thrombotic component. The typical arterial enhancement was the decisive finding for the diagnosis, even though a total continuity with arterial vessels was never observed. Angiography was the method of choice for the preoperative demonstration of hepatic artery aneurysms (10 cases) and for occlusive treatment with Gianturco coils (3 cases).

Ultrasounds have a high diagnostic value mainly in the structural assessment of the neoplasia. They are also very useful for the evaluation of the spread. In this paper the authors analyze the criteria for a differentiated diagnosis of Wilms' tumour.

A series of 75 patients with retroperitoneal masses (60 malignant and 15 benign tumours) have been studied. Urography and angiography were employed. The results of the two methods are correlated. The following criteria are taken into consideration: a) site; b) nature; c) extension of the mass. The importance of a precise definition of the extension of the tumour is stressed. In fact this can greatly influence the choice of the therapy.

The authors compare the results of sonography (US) and percutaneous transhepatic cholangiography (PTC) in the study of 48 patients with obstructive jaundice. The results obtained were correlated to various diagnostic levels and to the different causes of obstruction. The analysis of the results led the authors to believe that, in most cases, the association of both techniques is absolutely necessary in order to define the whole diagnostic picture.

The authors evaluated the reliability of echography in the involvement of the inferior vena cava in the abdominal tumors. 137 patients were studied with echography and 125 with inferior cavography too. All the diagnosis were confirmed with arteriography and/or CT and/or surgical findings. The reliability of the echographic method was significant, and particularly in case of emboli and tumor invasion.

Ultrasound (US) play a very important role in the diagnosis of Wilms' tumour. The authors analyze the findings in 12 children affected by this neoplasia. The resolution power of 4 different diagnostic levels is also analyzed. They are: a) mass identification; b) diagnosis of the tumour nature; c) diffusion balance; d) recurrence control. The most relevant resolution power lies in the diagnosis of nature and in the recurrence control.

The authors demonstrate the interest of the association among echography, angiography and angiotomography in the diagnosis of the primitive or secondary expansive formation of the liver. The casuistry is based on 22 multiple metastases of the liver, 5 primitive tumours, 3 hepatic echinococcus, 1 abscess of the left lobe, 1 renal tumour and 1 retroperitoneal neuroblastoma with secondary hepatic localizations. The analysis of the comparison of the results among the various methods employed has shown that the identification of the lesion is (resolvable) by echography; the study of the intrahepatic vessels compromise pertains to angiography; echography, even giving significant help in judging about a possible engagement of the vena cava, necessarily needs cavography.