[Cystic degeneration of the adventitia of the popliteal artery: ultrasound angiography-aided puncture]

A filiform stenosis of the popliteal artery was examined by sonography and the reason for the cystic lesion in the arterial wall was found to be an uncommon type of cystic degeneration of the adventitia. The narrow lumen could be demonstrated by sonography and the lesion was punctured under ultrasound control. A viscous secretion was removed and the patient's claudication was cured without recourse to surgery.

[Simplified percutaneous transluminal angioplasty by a new kind of guide wire--initial experiences]

A new guide wire for angioplasty of peripheral vessels was developed and tested in 20 patients. 24 occlusions mainly of the crural arteries were reopened, and 21 high-grade stenoses were treated. The use of the guide wire down to the foot is easy, cannulation times are short, and success rates of cannulation higher than with previous techniques.

[Teleradiology with personal computers]

A system to transmit radiographic images with the aid of a personal computer (PC) via phone line is presented. The pictures are recorded by a camcorder and digitized by the PC. They are sent to the receiver by a modem via phone line. The different steps can be programmed. MR and CT pictures as well as ordinary x-ray pictures have been transmitted. It takes about 45 s to send a picture. It arrives in good quality, and findings are clearly represented. After the sending process is completed, all pictures can be reviewed in seconds. The presented system is interesting for its low price when a PC is available.

[Results of meniscus sutures in the framework of reconstruction in combined injuries of the knee joint: clinical aspects, arthrosonography, arthrography and computerized tomography]

In spite of encouraging experimental results of suturing menisci in the not-vascularised area, even today in most of these cases subtotal resection will be done. The results of meniscal reconstruction in 15 patients with a longitudinal tear of the degeneration area as consequence of a combined injury of the knee joint are discussed. Only one patient suffered a postoperative rerupture. The others did not show any signs of continuing tears of the menisci during a study period of 18.7 months. Whereas in arthrography only in a few cases superficial notches, sign for a physiological recessus, were found, CT-scan as well as arthrosonography showed in large degree of correspondence change of density in the region of suture, which can be interpreted as a process of scar transformation. Thus it is recommendable to use suture of meniscus next to stabilizing measurements of injured knee-joint, even in the zone of degeneration.

[Computed tomography of the menisci]

Thirty patients were examined with CT of the menisci. All findings were confirmed by arthroscopy. One false positive diagnosis of a torn meniscus was made, caused by partial volume effect. In seven patients with irregular degenerative changes of the menisci, the abnormality could be clearly demonstrated. One meniscus ganglion was shown. Seven meniscus lesions, which were not shown by arthrography or arthroscopy, were clearly demonstrated by CT. The computer tomographic demonstration of menisci can replace knee arthrography as the examination of choice and should be performed before carrying out arthroscopy.

Assessment of resectability of esophageal cancer by computed tomography and magnetic resonance imaging

Sixty patients with esophageal cancer infiltration of mediastinal structures and metastasis to lymph nodes were prospectively evaluated by computed tomography and magnetic resonance imaging and then underwent surgical resection of the tumor (n = 57) or diagnostic thoracotomy (n = 3). Lymph nodes were excised from standardized locations and examined histologically. Sensitivity and specificity of both methods for all criteria were found so low that the value of these methods for planning surgery--or for stratification to different therapeutic arms in comparative studies--must be questioned.

Selective digital subtraction arteriography in necrosis of the femoral head

Selective digital subtraction arteriographic investigations of the arteries of the femoral head in 31 patients with traumatic and 34 patients with nontraumatic femoral head necrosis (FHN) were compared with investigations in a control group of 35 patients without hip disease. In the control group and in patients with nontraumatic FHN atypical arteriographic findings were found only in one third of cases. In traumatic FHN, however, vascular alterations could be detected in 97% of cases. This evidence suggests that damage to the femoral head vessels is a major etiological factor in traumatic, but not in nontraumatic, FHN. In late arterial phases of DSA a perinecrotic hypervascularization was the common feature in all nontraumatic necroses and could be observed in 71% of traumatic necroses. Its pathophysiological mechanism is discussed.

[MR and CT patterns of neurocysticercosis]

MRI and CT manifestations were studied in five cases of neurocysticercosis. As demonstrated by long-term follow-ups the disease usually causes multiple lesions the morphology of which depends on the life cycle of the parasite. Tissue lesions consist of three main types: 1) vital cysticerci, 2) inflammatory parenchymatous reactions following degenerating cysts and 3) calcified granulomas. MRI provides all information that is given by CT except for small calcifications which are usually missed. Morphological details of vital cysticerci like cyst wall and scolex are better outlined by MRI. When i.v. contrast medium is applied, it leads to nodular or annular enhancement of inflamed tissue. The sensitivity of MRI towards edema caused by parasite exceeds that of CT by several weeks. CT and MRI are complementary methods providing at the present time the highest degree of specificity in diagnosing neurocysticercosis.

[Imaging of femur head necrosis using MR tomography]

Magnetic resonance tomography (MR) was used to examine the femoral heads of 20 normals and of 56 patients with diseases of the femoral head, including Perthe's disease (four cases), adult necrosis of the femoral head (39 cases) and pain of unknown cause (13 cases). Femoral head necrosis and Perthe's disease regularly produce reduced signal intensity. The localisation of the areas of necrosis can be determined accurately in the coronary and sagittal plane. In 11 femoral heads, necrosis could be demonstrated unequivocally by MR in the presence of normal radiographic findings. Follow-up of nine patients with negative MR findings and indefinite symptoms confirmed the absence of necrosis.

[Findings of NMR tomography in the diagnosis of osteomyelitis and arthritis]

The findings on MR tomography in fourteen patients with osteomyelitis and eight patients with arthritis are described. A retrospective analysis showed that MR was superior in demonstrating changes in the bone marrow and spread of infection round the bone. These changes are shown more accurately and with better contrast after the use of gadolinium DTPA. T1 and T2 sequences appear to be necessary.

[Selective arterial DSA of the femur head vessels]

Selective arterial DSA of the arteries of the femoral head was carried out in 39 patients. The appearances were studied in nine patients without any hip abnormality, in 13 idiopathic and eight post-traumatic cases of femoral head necrosis and in nine patients with recent fractures. In every patient the vessels were well demonstrated. In the presence of idiopathic aseptic necrosis there was always hypervascularity around the necrotic area. As in the normal controls, pathological findings were seen in the deep branch of the medial circumflex femoral artery and in the nutrient artery in one-third of patients. Post-traumatic aseptic necrosis, recent fractures and dislocations always showed abnormalities of the vessels to the femoral head. The changes in the femoral head vessels demonstrated by DSA are probably not of great significance for the development of idiopathic aseptic necrosis, however they are found regularly following trauma.

[Detection of narcotic-containing packages in "body-packers" using imaging procedures. Studies in vitro and in vivo]

The increase in narcotic smuggling through swallowing small packages ("body packing") has created problems in detection and in avoiding acute intoxication. Five such cases are reported. Experiments have been carried out in vitro in order to investigate how such narcotic packages could best be shown by radiological examination, by CT or by MRT.

[Clinical significance of computerized tomography of the posterior area of the foot]

Computertomographic examinations of the hindfoot in the frontal and horizontal view will show us morphological findings, which we could not see with conventional X-ray-technique. Out of these findings we are able to control our operative reconstruction as well as late changes in bone healing. The horizontal view will show us the osseous structures of the talus and calcaneus as well as of the navicular and cuboid bone, as it is necessary for preoperative evaluation of the hindfoot.

[Imaging of cruciate ligament injuries using MR tomography]

The cruciate ligaments of the knee joint can be demonstrated by magnetic resonance tomography, without using invasive methods. High resolution coils and section thickness of less than 5 mm are necessary. Sixty-six patients and volunteers were examined; the results show that the normal cruciate ligaments present as homogeneous zones of low signal intensity within the surrounding fat. Injuries to the cruciate ligaments interrupt the image of the ligaments, change their anatomical position or produce a signal of intermediate intensity. Eighteen operations were carried out on fifteen patients with cruciate ligament injuries and there was good agreement between the MR and the operative findings. Sixteen patients had had previous cruciate surgery and in these there was only partial correlation with the clinical findings.

[MR tomography of gynecologic diseases of the minor pelvis]

The results of MR examinations of 31 women with gynaecological diseases are described; all had CT and histological confirmation at operation. The extent and relationship of the lesions were well demonstrated by the three-dimensional sections of MR, in some cases better than on CT. Variations in the signals allowed better differentiation of myomas and ovarian carcinomas from normal tissue. Like CT, MR tomography was not reliable in showing the extent of infiltration into neighbouring structures.

[Applicability of nuclear spin tomography to heart diseases]

Thirty-one patients with abnormalities of the heart and ten controls were examined by ECG-triggered nuclear resonance tomography. All patients had previously been completely investigated. Chamber sizes and mural thickness could be reliably demonstrated and, in addition, it was possible to show areas which could not be easily investigated by echocardiography. Visualisation of the valves was limited, but intra- and para-cardial lesions could be differentiated by a double echo technique. Absence and defects of septa could be shown exactly, as well as accurate demonstration of the relationship of the large vessels to the cardiac chambers.

[Imaging of the Achilles tendon on the computed tomogram. Normal findings and pathological changes]

Ligaments and tendons, including the Achilles tendon, show the highest density among normal soft tissue structures in the body. Traumatic and degenerative changes of the Achilles tendon are often associated with marked thickening and reduction in density associated with increased opacity of the space in front of the Achilles tendon. These changes are easily demonstrated by CT, whereas conventional radiological techniques only show non-specific changes. Twenty-five patients were examined, including nine with pain, seven following rupture of the Achilles tendon and nine post-operative controls; it was found that CT can add information important for the diagnosis and treatment planning of abnormalities of the Achilles tendon.

The effects of fluid-mechanical factors on MR imaging in the arterial model

Blood flow is a significant factor in MR imaging. The purpose of this investigation was to study fluid-mechanical effects on MR imaging. MR images generated by the pulsatile flow of bovine blood in an elastic model of the aorta with both renal arteries were studied. The high-frequency pulse sequence was synchronized to an ECG trigger signal. It was demonstrated that different flow velocities, laminar and turbulent flow, and backward flow can be visualized with MR imaging.

[The aortic aneurysm in the magnetic resonance tomogram]

Aortic aneurysms can be visualised in the transverse, sagittal and coronary planes using magnetic resonance (MR) thereby enabling their cranio-caudal distension as well as their breadth and depth to be accurately determined. The important question concerning the vessel exits of the main branches of the aorta and their involvement in the aneurysm can be reliably answered. In the case of dissecting aortic aneurysms, the two lumina as well as the dissected vessel wall can be seen in the image. By choosing suitable recording parameters it is possible to differentiate between flowing blood and a thrombus attached to the vessel wall. The thrombus is recognisable from the decrease it causes in the signal intensity of the T2-selected image, whereas flowing blood emits a stronger signal in the T2-selected image than in the T1-selected image. An indication of the flow behaviour and flow rate of blood can be obtained from the differences in the signal intensity distribution in the vessel lumen.