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PubMed1989

Frequency and variation of the posterior pituitary bright signal on MR images.

Sagittal T1-weighted series with 3-mm sections have routinely been used for all cranial MR studies at our institution. It was apparent from examining these studies that the rate of occurrence of a normal posterior pituitary bright signal was lower than has been previously reported, particularly in older patients. This prompted both a retrospective and a prospective review and analysis of the posterior lobe bright signal in three patient categories. The overall frequency of posterior pituitary bright signal and the influence of sex and age were evaluated in one category. An age-related statistically significant decline in the frequency of posterior pituitary bright signal was found, with a decline rate of approximately 1% per year. An evaluation of the occurrence of anatomic variation in the location of posterior lobe bright signal was made in a second group of 1500 patients. Abberrant location of the posterior lobe was found to be uncommon and was seen most frequently in patients with a sellar fossula. Temporal variation in the presence or absence and size of the posterior lobe bright signal was evaluated in a third group of 36 patients who had at least two MR examinations available for review. Follow-up MR study showed an obvious posterior lobe bright signal in 8% of these patients for whom no bright signal was apparent at the time of initial examination. Loss of the posterior lobe bright signal was apparent in another 25% of patients. A significant change in size of the bright signal was apparent in 19% of patients within this category. Our results indicate that variation in the bright signal of the posterior pituitary lobe should be expected as a normal physiological occurrence.

Adolescent↗

PubMedDate not supplied

Frequency and variation of the posterior pituitary bright signal on MR images.

Sagittal T1-weighted series with 3-mm sections have routinely been used for all cranial MR studies at our institution. It was apparent from examining these studies that the rate of occurrence of a normal posterior pituitary bright signal was lower than has been previously reported, particularly in older patients. This prompted both a retrospective and a prospective review and analysis of the posterior lobe bright signal in three patient categories. The overall frequency of posterior pituitary bright signal and the influence of sex and age were evaluated in one category. An age-related statistically significant decline in the frequency of posterior pituitary bright signal was found, with a decline rate of approximately 1% per year. An evaluation of the occurrence of anatomic variation in the location of posterior lobe bright signal was made in a second group of 1500 patients. Aberrant location of the posterior lobe was found to be uncommon and was seen most frequently in patients with a sellar fossula. Temporal variation in the presence or absence and size of the posterior lobe bright signal was evaluated in a third group of 36 patients who had at least two MR examinations available for review. Follow-up MR study showed an obvious posterior lobe bright signal in 8% of these patients for whom no bright signal was apparent at the time of initial examination. Loss of the posterior lobe bright signal was apparent in another 25% of patients. A significant change in size of the bright signal was apparent in 19% of patients within this category. Our results indicate that variation in the bright signal of the posterior pituitary lobe should be expected as a normal physiological occurrence.

Adolescent↗

PubMed1983

[Cardiovascular malformations associated with tetralogy of Fallot. Apropos of a series of 250 cases of tetralogy of Fallot].

This study was undertaken in 39 patients with Fallot's tetralogy associated with one or more cardiovascular malformations. Some common anomalies, simple anatomical variations were excluded (right sided aortic arch, patent foramen ovale). Out of a total of 48 anomalies (6 children had 2, 3 or 4 associated malformations) there were 5 anomalous systemic venous drainages (including 4 supernumerary left superior vena cava), 8 secundum atrial septal defects (including one multiperforated defect), 2 muscular ventricular septal defects, 7 atrioventricular canals (5 in mongol children); 1 tricuspid hypoplasia, 1 absent left pulmonary artery, 1 mitral valve prolapse, 1 obstructive cardiomyopathy, 10 coronary anomalies (including 5 ectopic left anterior descending arteries arising from the right coronary artery), 8 patent ductus arteriosus (arising from the left subclavian in 4 cases of right aortic arch), 3 retro oesophageal subclavian arteries and one congenital subclavian steal syndrome. The incidence of associated malformations was 15 p. 100, but values of up to 30 p. 100 have been reported mainly in anatomical studies. The authors emphasise the diagnostic and therapeutic implications of these associated malformations. In most cases, especially Fallot's tetralogy with an endocardial cushion defect, 2D echocardiography proved to be an essential diagnostic tool. Catheter studies, however, remain necessary, especially for the detection of aortic and coronary anomalies: selective coronary angiography is sometimes required. Difficult surgical problems are mainly encountered when the associated anomaly has not been diagnosed preoperatively. Although the variations of systemic venous drainage are not of great importance, those of the aortic arch can influence the technique of palliative procedures. Muscular VSD must not be missed. Tricuspid hypoplasia may pose a complex surgical problem. Malformations of the left heart which are sometimes unrecognised, aggravate the situation considerably. The association of Fallot's tetralogy and atrioventricular canal can now be corrected under good conditions. Finally, variations in the coronary anatomy must be documented meticulously as they may contraindicate early complete repair.

Angiocardiography↗

PubMed2005

[About the tributaries of the arch of great saphenous vein. Concerning 40 dissections].

The arch of the great saphenous vein cross receives numerous tributaries from the abdominal wall, male external genitalia and pelvic limbs. These collaterals present many variations relating to their number and mode of anastomosis. Their misappreciation may lead to post operative recurrences after surgical treatment of varices. For a last study of these variations, we dissected 40 inguinofemoral regions in fresh black african corpes. The conventional type in a "vein strar" shape was present in 4 cases. An abdominal common vein produced through the merging of the superficial epigastric and superficial circumflex iliac veins was found in 5 cases. A genital common vein summarising the external pudendal veins was present in 19 cases. In 8 cases the abdominal and genital common vein was simultaneously present. An anterior saphenous vein was found in 15 cases, and a posterior saphenous vein in 5 cases. These results, confirm the importance of anatomic variations. Their knowledge is necessary to avoid recurrences after surgery of varicose veins.

Adult↗

PubMed2005

A systematic approach to magnetic resonance imaging interpretation of sports medicine injuries of the shoulder.

Magnetic resonance imaging has developed as a useful imaging modality in the evaluation of the athlete with shoulder pain. The multiplanar capabilities of magnetic resonance imaging make it ideal for detecting the anatomical variations of the osseous outlet that may contribute to the clinical syndrome of impingement. Its superb soft tissue contrast and spatial resolution allow for accurate differentiation between tendinopathy, partial-thickness tear, and full-thickness tear of the rotator cuff and also allow for detection of the subtle lesions of the capsule and labrum that are associated with shoulder instability. However, to accurately interpret the numerous images and pulse sequences obtained in a standard magnetic resonance examination of the shoulder, it is helpful to have a systematic approach to ensure that each of the pertinent anatomical structures are evaluated. This article will provide a systematic approach to the interpretation of a magnetic resonance examination of the shoulder. The normal imaging appearance of each anatomical structure will be described, and the most useful pulse sequences and imaging planes for the evaluation of each structure will be discussed. Finally, the signs of injury will be described and illustrated.

Acromion↗

PubMed1976

[False negative myelography in surgically confirmed lumbar intervertebral disk prolapse].

A consecutive series of 821 lumbar myelograms in patients operated on for prolapsed disks were analysed. 47 or 5-7% had to be listed false-negative in spite of excellent technical quality. To find out, whether anatomical variations or a special functional state of the subarachnoid space could have prevented a correct diagnosis, clinical symptoms and some special radiological parameters were examined and statistically evaluated: 1. Distances between peduncles of L4, L5, S1 2. Width of subarachnoid space in a coronal section of L4, L5, S1 3. Width of subarachnoid space in a sagittal section of L5 4. Distance between the posterior limit of the body of L5 and the anterior limit of the subarachnoid space. Measurement and statistical correlations did not reveal any correlation between false-negative myelograms and any of the anatomical variants measured. We still cannot rule out false-negative myelograms.

Anthropometry↗

PubMedDate not supplied

Variations in the blood supply of the left ventricular apex.

Contraction or perfusion abnormalities of the left ventricular apex are generally assumed to result from left anterior descending (LAD) artery disease since this vessel is the usual source of blood supply to this area of myocardium. Such an assumption may be erroneous since the left ventricular apex may be supplied by the LAD alone, both the LAD and posterior descending (PD) branch of the right coronary artery, or the PD alone. Blood supply of the left ventricular apex was prospectively studied angiographically in 431 adult patients. In 77.7%, the apex was totally supplied by the LAD. In 12.1%, the apex received dual blood supply from both the LAD and PD. In 10.2%, the LAD terminated well before the apex, which was totally supplied by the PD. With the latter two anatomic variations, the LAD tended to be shorter and smaller in caliber than usual, while the PD was longer and larger than usual. A short, narrow LAD therefore does not necessarily indicate coronary disease if the left ventricular apex is partially or completely supplied by the PD. Dysfunction or perfusion abnormalities of the apex do not necessarily indicate LAD disease.

Coronary Angiography↗

PubMed1997

Morphology of holes in aponeuroses as caused by perforating nerves or vessels at the medial epicondyle of the elbow.

In the present paper the morphology of holes in aponeuroses of origin of muscles is generally modelled. These holes result from perforations of the aponeuroses by nerves or vessels, or from joints which are crossed by the line of origin of the aponeurosis. The concept of aponeurotic holes as morphological entities comprehensively explains frequent small-scale anatomic variations in muscles, such as muscles with multiple separate origins in parallel. It also contributes to a better understanding of nerve compressions and their surgical treatment. The model is illustrated by dissection results of the aponeuroses at the medial epicondyle of the elbow, which are typically perforated by the n. medianus, the a. brachialis, and the n. ulnaris.

Blood Vessels↗

PubMed2001

The role of angiography in the lower extremity using free vascularized fibular transplants for mandibular reconstruction.

BACKGROUND: Fibular osteocutaneous free tissue transfer represents the work horse procedure in the reconstruction of large oromandibular defects. Before the fibula is harvested the blood supply of the lower leg and foot should be examined, as the perfusion may be based predominantly on the peroneal artery and venae comitantes. To avoid postoperative ischaemia of the lower leg, adequate perfusion must be guaranteed before sacrificing the peroneal vessels. Anatomical variations and peripheral arterial occlusive disease add to the risk of ischaemia. Various methods of evaluating the blood supply have been described. MATERIAL AND METHODS: Fifty-two consecutive cases of fibular flaps were evaluated to study the arterial blood supply of the lower extremity. For angiography, the right femoral artery was punctured using the Seldinger technique and a total of 20-25 ml contrast medium (Imeron 300) was infused and images required at a rate of 0.5/sec. RESULTS: A patent three-vessel supply to both feet could only be detected in 21 patients. Thirty-one angiograms revealed anatomic and/or arteriosclerotic alterations. Angiography provided accurate information in all patients and allowed successful fibular transfer in those patients who were found preoperatively to have regular conditions. CONCLUSION: Preoperative assessment of the blood supply of the lower extremity is important before fibular osteocutaneous free tissue transfer. We advocate angiography as interpretation is not examiner dependent.

Adult↗

PubMed1995

Variations in the lumbosacral ligament and associated changes in the lumbosacral region resulting in compression of the fifth dorsal root ganglion and spinal nerve.

Sixty-five lumbosacral regions from adult cadavers were dissected and the position and relations of the lumbosacral ligament noted. The lumbosacral ligament was present in all specimens; in 22 (34%) it extended medially across the ventral ramus of the fifth lumbar nerve, and in six (9%) of these the underlying nerve was compressed and visibly flattened. On two of these specimens the nerve, together with its dorsal root ganglion, was removed, processed, and stained with Masson's trichrome. The compressed nerve showed increased thickness of endoneurial and perineurial connective tissue, and the cells of the dorsal root ganglion were smaller and surrounded by increased connective tissue, particularly at the periphery of the ganglion. Observation of the lumbosacral ligament and surrounding anatomical structures suggests that anatomical variation in this region may be attributed to the health of the lumbosacral articular elements. In those specimens showing compression of the fifth lumbar spinal nerve there was also narrowing of the lumbosacral interspace. In these the disc itself was compressed and showed degenerative changes. The articular processes at the lumbosacral joint were irregular, with thinning and fissuring of the artiuclar cartilage. It is suggested that the processes which lead to the further development of the ligament, by the formation of additional fibrous bands, are mechanical in nature and result from instability at the lumbosacral region itself. Instability subsequently leads to the initiation of a chain of degenerative changes, involving pathology at the lumbosacral disc and zygapophyseal joints.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1992

Regional administration of lymphokine-activated killer cells can be superior to intravenous application.

A patient with liver metastases of human lymphocyte antigen (HLA) class II-negative malignant melanoma was treated with several cycles of adoptive immunotherapy with interleukin-2 and lymphokine-activated killer (LAK) cells. The authors evaluated the efficacy of regional transfer of LAK cells versus systemic intravenous administration. Initially, the patient was treated according to a regional treatment protocol, consisting of perfusion of the spleen with interleukin-2 and transfer of LAK cells into the portal vein; a partial remission was observed. Because of technical problems, interleukin-2 and LAK cells were administered intravenously in a second treatment cycle. This systemic treatment course resulted only in a minor mixed response of the hepatic metastases. A third treatment course was administered with the use of intravenous interleukin-2 infusion and arterial perfusion of the liver with LAK cells. The patient had separate hepatic arteries to both lobes of the liver as an anatomic variation. Because most of the tumor mass was present in the right lobe of the liver, a third of the LAK cells were injected into the right hepatic artery and the remaining cells were administered intravenously. The lesions in the right lobe of the liver regressed, but disease progression occurred in the left lobe. A fourth treatment cycle, consisting of intravenous infusion of interleukin-2 and arterial perfusion of both lobes of the liver with LAK cells, resulted in a complete response of all hepatic lesions, which has lasted 18 months to date. Because, in this patient, tumor regression was observed only in anatomic areas of the liver, which were perfused with LAK cells, it is suggested that the regional administration of LAK cells was essential for successful treatment.

Adult↗

PubMed2000

A variation of the brachial plexus characterized by the absence of the musculocutaneous nerve: a case report.

A variation of the brachial plexus characterized by the absence of the musculocutaneous nerve on both sides was observed during the dissection of a 72 year-old female cadaver. The long thoracic nerve included only the fibers from C5 and C6 on the left side. The musculocutaneous nerve was absent and two branches from the lateral cord innervated the coracobrachialis muscle. The median nerve innervated the biceps brachii and brachialis muscles in the arm and also gave off the lateral antebrachial cutaneous nerve. Additionally, a communicating branch was found from the median nerve to the ulnar nerve in the forearm. The knowledge of the anatomical variations of the peripheral nerve system can help give explanation when encountering an incomprehensible clinical sign.

Aged↗

PubMed1999

Laparoscopic ultrasonography versus operative cholangiography during laparoscopic cholecystectomy: review of the literature and a comparison with open intraoperative ultrasonography.

BACKGROUND: Laparoscopic ultrasonography (LUS) has been used increasingly over the last several years as a new imaging modality. To define the role of LUS during laparoscopic cholecystectomy, we evaluated LUS by prospectively comparing it with operative cholangiography (OC), by reviewing the literature on LUS, and by retrospectively comparing it with intraoperative ultrasonography performed during open cholecystectomy. STUDY DESIGN: LUS and OC were compared prospectively in 100 consecutive patients during laparoscopic cholecystectomy. The success rate of examination, the time required, the accuracy in diagnosing bile duct calculi, and the delineation of biliary anatomy were evaluated. RESULTS: The success rate of examination was 95% for LUS and 92% for OC. The main reason for unsatisfactory LUS was incomplete visualization of the distal common bile duct. The time required was 8.2 minutes for LUS and 15.9 minutes for OC (p<0.0001). Nine patients had bile duct calculi. LUS had one false-negative result and OC had two false-positives and one false-negative. The accuracies of LUS and OC were comparable except for a slightly better positive predictive value of LUS (100% versus 77.8%; p>0.1). In a literature review, 12 recent prospective studies comparing LUS and OC and three studies on open intraoperative ultrasonography were reviewed. Twelve studies of LUS with a total of 2,059 patients demonstrated results similar to the present study. The success rate was 88% to 100% for both tests. The time for LUS was approximately 7 minutes, about half of the time needed for OC. Overall, LUS was associated with fewer false-positive results than OC; the positive predictive value and specificity of LUS were better, while the sensitivity and negative predictive value of LUS and OC were comparable. OC detected ductal variations or anomalies more distinctly than LUS. Compared with open intraoperative ultrasonography, LUS had a slightly lower success rate and required a slightly longer time because it was technically more demanding, but the two procedures had a similar accuracy for diagnosing bile duct calculi. CONCLUSIONS: Because of their different advantages and disadvantages, LUS and OC can be used in a complementary manner. There is a learning curve for LUS because of its technical difficulty. Once learned, however, LUS can be used as the primary screening procedure for bile duct calculi because of its safety, speed, and cost-effectiveness. OC can be used selectively, particularly when ductal anatomic variations or anomalies or bile duct injuries are suspected.

Cholangiography↗

PubMed1996

[Double outlet left ventricle: a rare and unusual cardiopathy. Apropos of 7 new cases].

Double outlet left ventricle is a very rare condition due to an abnormality of conotruncal morphogenesis. The authors report 7 new cases to the 119 already published, one with an anatomical variation not previously described. Three of the cases reported were of the most usual type similating tetralogy of Fallot. Two of these cases underwent complete correction with excellent results 13 months and 2 years after surgery. The third patient aged 6 months is well after initial palliative neonatal surgery. A case with an L-malposition pedicle with subpulmonary ventricular septal defect and pulmonary outflow tract obstruction died after early palliative surgery (Blalock-Taussig). A case with subaortic ventricular septal defect, pulmonary stenosis, and tricuspid atresia, underwent physiopathological correction (Fontan procedure) after a Waterston shunt and is well at 19 years of age. The other two cases presented more unusual anatomical forms aortic outflow obstruction: one had hypoplasia of the aortic arch with an isthmic coarctation requiring a Crafoord procedure in the neonatal period associating with banding followed by complete correction at 19 months of age. After 3 years, the patient is asymptomatic. The last case with atresia of the aortic valve and severe hypoplasia of the ascending aorta died after corrective surgery of first intent. Other cases have been described in the literature with different clinical presentations: absence of pulmonary or aortic obstruction; intact interventricular septum. The anatomical variability is due to the complex embryogenesis of the conotruncal region and explains the clinical diversity of this congenital cardiac malformation.

Aortic Valve↗

PubMed1986

Anterior diaphragm: variations in the CT appearance.

The anterior portion of the diaphragm has three typical appearances on computed tomographic (CT) scans, depending on the cephalocaudal relation of the xiphoid to the central tendon of the diaphragm. The anterior diaphragm most often appears as a relatively smooth or slightly undulating soft-tissue curve, concave posteriorly and continuous across the midline with the lateral diaphragmatic arcs. In the next most frequent CT appearance, the diaphragmatic line is discontinuous in the midline. On each of these images, the muscular line diverges rather than converges as it approaches the anterior chest wall. Less commonly, the anterior portions of the diaphragm are imaged on CT not as a thin line but instead as a broad band with irregular, ill-defined, or angular margins. Occasionally, the anterior diaphragmatic muscle is not identified on CT because the muscle fibers are inseparable from adjacent structures, or are extremely short or even absent. An understanding of these anatomic variations permits the correct diagnosis of Morgagni hernias and explains previously described variants of plain radiographic configurations of pneumoperitoneum.

Diaphragm↗

PubMed2003

[Topographic anatomy of the tibial nerve in the medial malleolus: application to the effect of nerve block anesthesia].

To better understand the anatomical variations and pathogeny of tarsal tunnel syndrome, the tibial nerve were dissected in 20 ankles of fresh black African cadavers. The tibial nerve located to 1.75 cm on average from the posterior side of the malleolus and to 2 cm from medial side of the calcaneus tendon. The nerve always ended according to dichotomic method. 90% cases of bifurcation were noted under the flexor retinaculum at 1 cm from the malléolo_calcaneus line; in 10% of dissections, we found proximal bifurcation at 5 cm from this line. The medal calcaneus branch which is a collateral branch of tibial nerve was constant, unique in 80% of cases and double in 20% of cases. The anatomical constatations allow a more precise anesthesia of tibial nerve block. We use constant anatomical marks formed by calcaneus tendon and internal malleolus tip. Olso we more understand the possibility of lesion of tibial nerve at the ankle during the synovites, or ossifications of flexor rétinaculum.

Black People↗

PubMed2004

Anatomic characteristics and clinical importance of the superficial branch of the radial nerve.

The aim of this study was to demonstrate anatomic variations of the superficial branch of the radial nerve (SBRN) and to discuss the importance of this branch for surgical approaches. Upper extremities of 24 cadavers without any known history of disease or trauma were examined, the SBRN became subcutaneous at a mean of 9.20 cm and bifurcated at a mean of 4.90 cm proximal to the styloid process of the radius in 48 specimens. At the level of the extensor retinaculum, the mean distance of the closest branch to the first dorsal compartment was 0.54 cm, while its mean distance to the dorsal tubercle (Lister's tubercle) was 1.58 cm. The relations of the three branches of the SBRN (SR1, SR2, SR3) to the anatomic snuffbox and lateral antebrachial cutaneous nerve (LABCN) were also examined. It was demonstrated that on eight wrists, SR2 went through the snuffbox (16.67%). On ten specimens, SR3 had connections with LABCN (20.83%). In four specimens, the SBRN did not have any bifurcation and was directly divided into SR1, SR2, and SR3. It should be very helpful to know the anatomic characteristics of the SBRN, especially for hand surgeons, to minimize the risk of injury of the SBRN during surgical approaches.

Aged↗

PubMed1994

Anatomic standardization: linear scaling and nonlinear warping of functional brain images.

UNLABELLED: An automated method was proposed for anatomic standardization of PET scans in three dimensions, which enabled objective intersubject and cross-group comparisons of functional brain images. METHODS: The method involved linear scaling to correct an individual brain size and nonlinear warping to minimize regional anatomic variations among subjects. In the linear-scaling step, the anteroposterior length and width of the brain were measured on the PET images, and the brain height was estimated by a contour-matching procedure using the midsagittal plane. In the nonlinear warping step, individual gray matter locations were matched with those of a standard brain by maximizing correlation coefficients of regional profile curves determined between predefined stretching centers (predominantly in white matter) and the gray matter landmarks. RESULTS: The accuracy of the brain height estimation was compared with skull x-ray estimations, showing comparable accuracy and better reproducibility. Linear-scaling and nonlinear warping methods were validated using [18F]fluorodeoxyglucose and [15O]water images. Regional anatomic variability on the glucose images was reduced markedly. The statistical significance of activation foci in paired water images was improved in both vibratory and visual activation paradigms. A group versus group comparison following the proposed anatomic standardization revealed highly significant glucose metabolic alterations in the brains of patients with Alzheimer's disease compared with those of a normal control group. CONCLUSION: These results suggested that the method is well suited to both research and clinical settings and can facilitate pixel-by-pixel comparisons of PET images.

Algorithms↗