Evolving concepts and management of endoleaks after endovascular aneurysm repair: where do we stand in 2019?

In recent years, there has been tremendous progress in endovascular aneurysm repair (EVAR) techniques and devices. This process has seen a change in incidence, risk factors, and treatment of endoleaks as well as in follow-up protocols after EVAR. In particular, recent literature has highlighted new concepts in the evaluation and prevention/treatment of type I and II endoleak after standard EVAR. There is also recent evidence regarding new imaging protocols for follow-up after EVAR, which include magnetic resonance imaging and contrast-enhanced ultrasound. This comprehensive review aims to outline the most recent concepts on imaging follow-up, pathophysiology/risk factors, and management of endoleaks.

Noninvasive imaging of the coronary arteries using a 64-row multidetector CT scanner: initial clinical experience and radiation dose concerns.

PURPOSE: We present our initial clinical experience with a recently introduced 64-detector computed tomography (64-MDCT) scanner that makes use of a periodic motion of the focal spot in the longitudinal direction (z-flying focal spot), which enables it to reach a final spatial resolution of 0.4 x 0.4 x 0.4 mm(3) and a temporal resolution of 83 ms. MATERIALS AND METHODS: A total of 114 patients (108 men, six women; age range 36-77 years, mean 63.1 years) underwent retrospective electrocardiogram (ECG)-gated examination of the coronary arteries using a 64-MDCT scanner (Somatom Sensation 64, Siemens Medical Solutions, Germany). Acquisition parameters were the following: collimation 64 x 0.6 mm, 800 quality reference milliampere second (mAs), 120 kVp, 0.33-s gantry rotation time and pitch 0.2. Images were acquired in all cases after i.v. administration of 80 ml of contrast agent (Iomeron 400 mgI/dl, Bracco, Italy) + 30 ml of saline at 4 /s and delay time determined using a bolus triggering technique. Oral betablockers were administered to patients with heart rate (HR) >75 bpm. To reduce radiation exposure, an automatic exposure control system was applied in all cases to adapt tube current to patient size and anatomic shape (CARE Dose 4D, Siemens Medical Solutions, Germany). The optimal temporal window for raw data reconstruction was chosen from an initial preview of images reconstructed with different phase settings (range 0%-95% RR interval with 5% gap) at a selected anatomical level in the mid part of the right coronary artery. CT dose index volume and effective dose were quantified in all patients using dedicated software. RESULTS: Mean HR recorded during image acquisition was 65.6+/-19.2 bmp (range: 44-96 bmp), and beta-blockers were administered to 16/114 patients (14.0%). Technical adequacy was achieved in all patients but two (2/114; 1.7%). In patients with HR <60 bmp, the best reconstruction intervals were identified in the end-systolic (30%-35% of the RR interval) and end-diastolic (60%-65% of the RR interval) phases; with faster HR (>80 bmp), high image quality was observed in end-systole (30%-35% of the RR interval). Mean CT dose index (CTDI) volume was 36.53+/-8.30 mGy per patient. In comparison with a conventional examination with fixed mAs, the use of the CARE Dose 4D system provided a 33.3% CTDI volume reduction (p<0.001). Mean effective dose was 9.5+/-3.4 millisievert (mSv) per patient (range 7.1-17.7). CONCLUSIONS: The 64-MDCT scanner diagnostic performance for coronary CT angiography is further improved with better spatial and temporal resolution and faster scan times; besides, initial clinical results are promising. The use of dose-reducing acquisition techniques is mandatory to limit radiation exposure to the patient.

High-resolution multidetector CT in the preoperative evaluation of patients with renal cell carcinoma.

OBJECTIVE: The purpose of our study was to evaluate the accuracy of multidetector CT (MDCT) using a high-resolution protocol in the preoperative assessment of patients with renal cell carcinoma who are possible candidates for nephron-sparing surgery. MATERIALS AND METHODS: Forty patients with suspected renal cell carcinoma underwent MDCT. Contrast-enhanced acquisitions were obtained during arterial, nephrographic, and urographic phases using a thin-slice protocol. One-millimeter-thick source images were evaluated by two observers on a dedicated workstation for the identification and characterization of the tumor, presence of a pseudocapsule or invasion of perirenal fat, involvement of adrenal glands or surrounding tissues, presence of satellite lesions within Gerota's fascia, infiltration of renal vein and inferior vena cava, involvement of lymph nodes, and presence of distant metastases. Imaging findings were compared with surgical specimens using criteria from the Robson and TNM classification systems. RESULTS: The presence and size of all lesions were correctly shown in all patients. In evaluating Robson stage I of renal cell carcinoma, we were able to diagnose fat infiltration on 1-mm scans with 96% sensitivity, 93% specificity, and 95% accuracy; the positive and negative predictive values were, respectively, 100% and 93%. One hundred percent accuracy was achieved in staging high-grade lesions. CONCLUSION: High-resolution MDCT is accurate in the preoperative evaluation of patients with renal cell carcinoma.

[Dynamic magnetic resonance of the knee. Considerations on techniques and anatomy with a magnetic resonance system with open magnet]. / Risonanza Magnetica dinamica del ginocchio. Considerazioni di tecnica e di anatomia con un sistema di Risonanza Magnetica con magnete aperto.

MRI is currently considered the best technique to study the joints--knee joints in particular. Most studies are performed with the knee straightened out or slightly flexed, which position is mandatory with contemporary MR units. Recently, however, the MR equipment for limb studies and the larger tunnels of total body magnets have permitted partially dynamic knee studies, up to 30-40 degrees flexion; this joint excursion cannot be exceeded. In 1996, Muhle and Niitsu demonstrated that dynamic MRI can be useful to study cruciate ligament injuries, some types of meniscal injuries, all femoropatellar conditions and, mostly, cruciate ligament reconstruction. We used an open magnet MR unit for thorough functional dynamic knee studies, acquiring the images at 0-120 degrees flexion. The open magnet MR unit permits free joint movements. We examined 25 subjects: 10 healthy volunteers and 15 patients with meniscal, capsuloligamentous, femoropatellar or synovial conditions. This technique schedules axial, coronal or sagittal images, according to the diagnostic suspicion, suitably directed with the patient in lateral decubitus and with the knee flexed to maximum joint excursion. Dynamic MR findings are easily transferred to an X-ray film, so that the radiologist can send them to the orthopedist with no need of any videotape or TV take. The current cine MR programs display the dynamic images of the moving joint on an MR monitor, but this option is not yet widely available. The quality of dynamic MR studies is exactly the same as that of conventional images, with a particular emphasis on the small diagnostic details of the injuries. We report our preliminary experience with this technique, indicating some possible clinical applications of dynamic MRI which permits thorough studies of knee flexion-extension.

[Assessment with magnetic resonance of reconstruction of the posterior cruciate ligament. Preliminary experience]. / Valutazione con Risonanza Magnetica della plastica ricostruttiva del legamento crociato posteriore. Esperienza preliminare.

Posterior cruciate ligament (PCL) tears are definitely less common than anterior cruciate ligament (ACL) tears: their incidence in literature ranges 3-20% of all capsuloligamentous injuries versus 45-90% for ACL tears. Recent papers reported that if these injuries are not operated on, they evolve first into medial femorotibial and femoropatellar arthrosis and then into tricompartmental arthrosis. There are several MR studies dealing with ACL reconstruction, while MR studies on PCL reconstruction are lacking, both because the frequency of the latter injuries is lower and because they are difficult to demonstrate. We report our preliminary experience with PCL reconstruction studied with MRI in 12 patients submitted to arthroscopy. We used the ipsilateral patellar tendon (11 cases) or the contralateral one (1 case). The patients were submitted to MRI 4-16 months after surgery. Axial, coronal and sagittal images were acquired, together with oblique sagittal and coronal slices to show the graft completely. We also used SE, GE and fat suppression STIR MR sequences, trying to identify which of them are the most useful in patients with healing or exudative reaction in the intercondylar notch. MR exams were performed with a dedicated permanent magnet (0.2 T) and a permanent total body unit (0.3 T). The graft was clearly depicted on all images in 11 patients, while graft retear was shown in 1 patient. MRI did depict the whole graft in all patients, which finding is useful to study the signal intensity changes which indicate graft trophism. MRI also depicted correctly the femoral and tibial tunnel position and alignment, the presence of possible impingement with bone, the presence and extent of the healing reaction or of serum-hematic material in the intercondylar notch. The latter factor prevents the graft depiction, in which case the MR techniques providing the highest possible contrast in the different structures under examination are mandatory. Finally, MRI permitted to study possible associated capsuloligamentous or meniscal injuries and the state of femorotibial and femoropatellar chondral covering, the presence of articular synovia changes and the amount of possible joint effusion. We believe that MRI exhibited a high standard of sensitivity, versatility and diagnostic accuracy in the examination of surgical patients submitted to arthroscopic PCL reconstruction. Further studies and long-term follow-up will help define the use of MRI in these patients.

[Synovial cyst of the cruciate ligament. Findings with magnetic resonance in 8 symptomatic cases]. / Le cisti del ganglio sinoviale dei legamenti crociati. Aspetti con Risonanza Magnetica in 8 casi sintomatici.

Intraarticular ganglion cysts are uncommon findings: only 30 cases have been reported since the first paper by Caan in 1924 and they were all associated with cruciate ligaments. Many different cystic or pseudocystic lesions are found in articular knee conditions: the most common cystic lesions are popliteal cysts (Baker's cysts), followed by synovial pseudocysts of the posterior cruciate ligament, meniscal cysts and, finally, ganglion cysts of the cruciate ligaments. In our series of 1600 knee MR exams carried out in our MR department since June, 1994, we have found 8 ganglion cysts of the cruciate ligaments. MR studies are always performed on a dedicated 0.2-T permanent magnet (Artoscan, Esaote Biomedica, Genoa, Italy). Five patients were operated on with arthroscopy. The ganglion cysts affected the anterior cruciate ligaments in 4 cases and the posterior cruciate ligaments in 4 cases. The symptoms were mainly pain radiating to the medial side and worsening in forced flexion or extension. The diagnostic suspicion was meniscal tears in 4 patients, chondral lesions in 3 and a loose intraarticular body in one patient. The shape and structure of ganglion cysts in the cruciate ligaments are clearly depicted with MRI. The ganglion cysts in the anterior cruciate ligaments are usually spindle-shaped and within the ligament, while those in the posterior cruciate ligaments have a well-defined outline, with multilocular appearance, and they are usually localized along the ligament, most often on the dorsal aspect. MR signal studies show intermediate signal intensity on SE T1-weighted images and markedly increased signal intensity on SE T2-weighted images. These typical patterns may change depending on lesion content, for instance in the presence of hemoglobin due to an associated angioma. The origin of ganglion cysts in the cruciate ligaments is still unknown, even though many theories have been suggested, including a synovial herniation in ligament fibers, the ectopic inclusion of synovial tissue, a posttraumatic connectival degeneration and, finally, the proliferation of totipotent mesenchymal cells. From a histologic point of view, "synovial ganglion" is a much better definition than "synovial ganglion cyst", because the typical wall of real synovial cysts is missing. The MR patterns are typical of the morphological features described and of the presence of high protein fluid content.

[Occult or unknown traumatic osteochondral lesions of the knee. Assessment of 19 cases studied with conventional radiology and magnetic resonance]. / Le lesioni osteo-condrali traumatiche occulte o misconosciute del ginocchio. Valutazioni su 19 casi studiati con radiologia tradizionale e con risonanza magnetica.

Occult fractures of the knee represent a major cause of posttraumatic knee pain in patients with negative plain films. These injuries can cause severe sequelae if they are not properly diagnosed and rapidly treated. In our series of 1330 exams of the knee we found 19 traumatic osteochondral injuries (1.5%). MR studies were performed with a dedicated permanent magnet (0.2 T) (Artoscan, Esaote Biomedica, Genoa, Italy). All the patients were submitted to conventional radiography (AP and LL projections). In 14 patients oblique plain films were also performed. The following osteochondral injuries were found: 2 purely chondral fractures, 5 occult fractures (4 tibial and 1 of the medial femoral condyle) and 12 plateau fractures of the tibial posterior margin (8 lateral and 4 medial). CT of the knee was performed in 3 patients only. In 19 patients MRI correctly showed the traumatic injury and depicted: fracture site, the morphologic characteristics of fracture line, cortical bone and articular cartilage involvement, the exact extent of marrow signal changes, the associated injury of menisci or cruciate ligaments. To conclude, MR sensitivity and diagnostic accuracy are excellent in the patients with traumatic injuries of the knee. In the patients with posttraumatic knee joint pain, MRI appears to be an extremely useful tool in the detection and assessment of bone and cartilage disorders.

[Meniscal deformities associated with fractures of the tibial proximal extremity. Considerations in 7 cases]. / Deformazioni meniscali associate a fratture dell'estremo tibiale prossimale. Considerazioni su 7 casi.

Lateral tibial plateau fractures are a fairly frequent event in emergency clinical practice. In these fractures, when bone depression exceeds 5 mm, surgery is indicated. On the rule, conventional plain films combined with tomography can answer diagnostic questions about bone trauma. CT and MRI permit to study associated meniscocapsular injuries for better therapeutical management. Since February, 1991, we have examined 24 patients with tibial plateau fractures with conventional radiography and CT. CT was performed using thin sections, within 0 to 48 hours of the traumatic event. In our series, 7 patients had a lateral meniscal trauma associated with a fracture of the homologous tibial plateau; in all of these 7 women, surgery confirmed complete meniscal avulsion. In these cases, CT showed the following signs of meniscocapsular disinsertion: marked diastasis between capsular structure, popliteal tendon and meniscal profile; associated hypodense hemorrhagic fluid in the popliteal recess; inhomogeneous densitometry of the popliteal tendon resulting from hemorrhagic infarction. Furthermore, CT showed a characteristic and constant morphological alteration of the lateral meniscus with fibrocartilage deformation, that is with a wider or more narrow pattern relative to its normal "C"-like shape. We conclude that this morphological alteration of meniscal fibrocartilage, when associated with a tibial fracture, is a diagnostic CT sign of complete meniscal avulsion. This finding can be a useful integration to other CT signs of this meniscal injury, towards better and more complete therapeutical management.

[Clinical usefulness of a computerized tomography study of morphology of the femoral canal in patients candidates for hip prosthesis]. / Utilità clinica dello studio con tomographia computerizzata della morfologia del canale femorale nei pazienti candidati a protesizzazione dell'anca.

In the last few years hip arthroplasty has been increasingly used and both metaphysis and diaphysis of the proximal femur are studied preoperatively for best compliance between prosthesis and bone. Indeed, the best results can be obtained by reducing the risk of stem end mobilization, which means to choose the prosthesis fitting the femoral canal best and to limit the use of cement prostheses, which are at high risk of mobilization in time, to advanced osteoporosis patients. We used a simple and repeatable CT technique to study femoral canal structure and size. After accurately positioning the patients inside the gantry, we acquired some axial scans at scheduled levels referring to the horizontal midline of the lesser trochanter. The axial scans were acquired 2 cm above and 5 and 10 cm below the horizontal midline in 105 patients. Measurements were bilateral in 13 patients. Finally, the results were compared with the surgical outcome. Femoral canal cross-diameters and cortical bone width varied greatly, which variations were confirmed in bilateral measurements and in the same patient between the two femurs. Femoral canal structure, which can be remodelled, influences the choice of the stem and thus the amount of cement. We believe this method to be fundamental for correct surgical planning and for best treatment outcome.

Specific diagnosis by CT and HRCT in six chronic lung diseases.

CT and high-resolution CT (HRCT) are both important modalities for imaging lung chronic disease, and certain features (distribution of disease in the axial plane, unilateral or bilateral disease, bronchovascular bundle thickening, septal thickening, central dot thickening, polygons, distortion of parenchyma, air-space disease, nodules) are well known to suggest specific diagnoses. In a series of 54 consecutive patients with six specific diseases (scleroderma or UIP, sarcoidosis, lymphangitic carcinomatosis, drug toxicity, lymphomas, eosinophilic granuloma), these diagnostic CT features were always present. In 50/54 cases, a histologic proof was obtained. In 36 patients with histologic confirmation of four different diseases and in six normal controls, we compared sensibility, specificity, and accuracy of chest radiography, chest CT, and HRCT and found the highest diagnostic accuracy by HRCT together with standard CT.

[Cholesteatoma of the Prussak's space. Diagnosis with computerized tomography]. / I colesteatomi della tasca di Prussak. Diagnosi con tomografia computerizzata.

Prussak's space localization represents the early stage of the cholesteatoma arising from the pars flaccida of the tympanic membrane. From Prussak's space the mass spreads to the antrum and to mastoid air cells. Its demonstration is infrequent probably due to the limited use of CT in inflammatory diseases of the middle ear. On CT scans, cholesteatomas present as small soft-tissue masses, and their growth is responsible for scutum and ossicular chain erosion. The mass may also spread posteriorly to the aditus and antrum, and involve tendons and ligaments, which is a different behavior than that of fluid collections or granulation tissue. The authors report 9 cases of Prussak's cholesteatoma evaluated by means of HRCT.

[Mucocele of the paranasal sinus. CT assessment]. / Mucoceli dei seni paranasali. Valutazione TC.

The authors report 7 cases of mucoceles of the paranasal sinuses evaluated with plain films and CT. All patients were submitted to surgery. Five patients were affected with frontal mucoceles and 4 with sphenoid ones. In 2 cases the lesion was double. Symptoms were correlated with both site and compressive changes due to expansile growth. All cases were evaluated by means of axial and coronal pre- and post-contrast scans: a satisfactory morphological depiction of the lesion was always achieved. CT values were also calculated, and the relationship of mucocele to the adjacent structures was demonstrated. The modalities of expansile growth, the lack of enhancement in post-contrast scans, and the possible "ring sign" in cases with intracranial spread allow a correct radiological diagnosis. CT is the diagnostic method of choice for best lesion demonstration: it makes a correct diagnosis possible and allows the thorough evaluation of the involved structures for surgical planning.

[Fibrous dysplasia of the facial bones. A CT study]. / La displasia fibrosa delle ossa facciali. Studio TC.

The authors report 7 cases of fibrous dysplasia of the facial bones which were evaluated with CT. The involvement of the facial bones by fibrous dysplasia is an uncommon event, which causes different syndromes according to the extent of bone invasion. In all the cases occurred to our observation CT allowed an exact spatial evaluation of the dysplasia, and therefore a correct surgical planning. Moreover, CT densitometric values and CT appearance of fibrous dysplasia often suggested the correct diagnosis.

CT demonstration of peritoneal metastases after intraperitoneal injection of contrast media.

Thirty-three patients with ovarian carcinoma who had no evidence of metastases or ascites demonstrated on computed tomography (CT) with and without contrast agent were examined with CT after injection of approximately 3000 cc of a 2.4% solution of nonionic contrast media into the peritoneum. After intraperitoneal injection with CT (IPC CT), 22 were diagnosed as having intraperitoneal metastases. Of these, 19 were found to be true positives and 3 false negatives. Three other patients diagnosed as normal were found to have metastases. In all patients the peritoneum was well outlined and generally any metastases smaller than 1 cm were demonstrated. It was possible to identify compartmentalization of the peritoneum and to determine the location of the lesion to be in the peritoneum or the extraperitoneal space. This information is necessary in the planning of chemotherapy, particularly endoperitoneal chemotherapy. Tiny metastases to the omentum or adherent loops of small bowel could not be seen well.

Mucocele of neurosurgical interest: clinical considerations on five cases.

The authors present five patients with mucocele, submitted to neurosurgery. Two had mucoceles spreading from the frontal and/or the anterior ethmoidal sinuses and had only compressive mass symptoms, either on the ocular globe or on the frontal lobe or on both. Three patients had mucoceles growing from the sphenoid and/or posterior ethmoidal sinuses. In these latter, the mass symptoms were less evident. All the patients suffered excruciating retro-ocular pain and two presented cranial nerve damage. The correct diagnosis in these cases is crucial to avoid a too aggressive treatment since these patients are generally sent to a neurosurgeon for a suspected cranial base malignancy or an invasive pituitary adenoma. The principles of a correct differential diagnosis and of operative treatment are outlined based on an analysis of the literature and the authors experience.

Duodenal stenosis from retroperitoneal fibrosis secondary to traumatic retroperitoneal hematoma: a case report.

A case is presented of retroperitoneal fibrosis secondary to post-traumatic retroperitoneal hematoma, resulting in duodenal obstruction six years after the traumatic event. The fibrotic encasement of the duodenum and the head of pancreas made it necessary to perform an "en bloc" resection, with excellent results both immediately and after three years of follow-up.

Lipoma of the omentum in a child.

A solitary giant lipoma of the omentum and gastrocolic ligament in an 8-year-old boy is reported. The patient had a large abdominal mass and signs of partial intestinal obstruction. Radiographs showed the characteristic radiolucency of a fatty mass, excluding a mesenteric cyst.