Visualization of the macroscopic structure of hyaline cartilage with MR imaging.

The extracellular matrix of any tissue, including hyaline cartilage, has a structure that allows it to meet the physical demands placed upon that tissue. Accordingly, the structure of hyaline cartilage is not uniform. There is considerable variation from one joint to the next and even within a particular joint surface, probably reflecting a joint-specific architecture. This structure has a strong influence on T(2) relaxation. The relationship between T2 and matrix curvature relative to the main magnetic field (B(0)) provides tissue contrast. Images obtained with adequate resolution can exploit this contrast and demonstrate the structure of cartilage. Magnetic resonance imaging is thus capable of providing a detailed description of the structure of joint surfaces, information that is difficult to obtain even with histologic techniques.

In vitro MR imaging of hyaline cartilage: correlation with scanning electron microscopy.

OBJECTIVE: Our goal was to determine how the three-dimensional structure of hyaline cartilage affects its MR appearance and to correlate this appearance with detailed structural analysis using scanning electron microscopy and freeze-fracture sectioning techniques. MATERIALS AND METHODS: In vitro 7-T spin-echo MR images of hyaline cartilage specimens from four patients undergoing above-knee amputations were obtained parallel and perpendicular to the main magnetic field. Specimens were imaged with low- and high-power scanning electron microscopy after freeze fracturing. The corresponding images from both techniques were analyzed with specific attention to the three-dimensional structure of the cartilage, collagen fibril orientation, and respective changes in the MR appearance. RESULTS: Freeze fracturing of cartilage reveals a curved fracture plane. Expected changes in signal intensity predicted by the magic angle effect correlated with observed changes in signal intensity across the thickness of the sample. Changes in individual collagen fibril orientation did not correspond to MR layering. CONCLUSION: The three-dimensional organization of collagen in cartilage has a strong influence on the MR appearance of cartilage. This influence is caused by the restriction of water mobility and the resulting magic angle effect caused by curvature of the collagen network, possibly because of the influence on proteoglycan orientation.

Imaging of the Achilles' tendon.

The Achilles' tendon is amenable to imaging because of its superficial location and the presence of surrounding fat. This article reviews the ultrasound, the MR image, and the radiographic appearance of the normal and damaged tendon. The potential value to patient management is discussed for each modality.

Breast-feeding and alcoholism: the Trotter hypothesis.

OBJECTIVE: The authors' goal was to determine whether early termination of breast-feeding contributes to later alcohol dependence, as proposed more than 200 years ago by the British physician Thomas Trotter. METHOD: In 1959-1961, a multiple-specialty group of physicians studied 9, 182 consecutive deliveries in a Danish hospital, obtaining data about prepartum and postpartum variables. The present study concentrates on perinatal variables obtained from 200 of the original babies who participated in a 30-year high-risk follow-up study of the antecedents of alcoholism. RESULTS: Of the 27 men who were diagnosed as alcohol dependent at age 30, 13 (48%) came from the group weaned from the breast before the age of 3 weeks; only 33 (19%) of the 173 non-alcohol-dependent subjects came from the early weaning group. When challenged by other perinatal variables in a multiple regression analysis, early weaning significantly contributed to the prediction of the severity of alcoholism at age 30. CONCLUSIONS: The data support the hypothesis that early weaning may be associated with a greater risk of alcohol dependence later in life.

Micro-imaging of articular cartilage: T2, proton density, and the magic angle effect.

RATIONALE AND OBJECTIVES: This study was designed to determine the relative influences of proton density versus collagen fiber orientation (through its influence on T2) in defining the layers of articular cartilage as seen in long-repetition-time magnetic resonance (MR) images. The authors mapped the T2 and proton densities of articular cartilage at 0 degree and 55 degrees with respect to the main magnetic field (B0) to determine the influence of T2 and water content on the normal laminar appearance of hyaline cartilage. MATERIALS AND METHODS: Six patellae of white-tailed deer were imaged at 7 T. T2 and proton densities were calculated from echo time versus signal intensity plots obtained with a multiecho, composite pulse sequence. Regions of interest in the radial and transitional zones were compared with the articular facets at 0 degree and 55 degrees relative to B0. Transmission electron microscopy was performed for correlation. RESULTS: At 0 degree, T2 was longer in the transitional than in the radial zone (29 vs 11 msec). AT 55 degrees, T2 increased in both radial and transitional zones, although the difference between the zones decreased (37 vs 29 msec). There was no difference in proton density between the two layers. CONCLUSION: Collagen fiber orientation, through T2 effects, is the dominant influence on the appearance of layers in hyaline cartilage in long-repetition-time MR images; proton density is not a major factor, and the collagen fiber orientation in the transitional zone is not totally random.

High-resolution magnetic resonance imaging of articular cartilage: correlation with histology and pathology.

Current explanations of the link between magnetic resonance (MR) images and cartilage histology are reviewed. The influence of the three-dimensional cartilage matrix structure on T2 decay is emphasized and illustrated through the use of MR microimaging, T2 mapping, and correlative scanning electron microscopy (SEM). Special emphasis is given to the topics of T2 heterogeneity and orientation anisotropy. Common degenerative changes in the structure and biochemistry of cartilage are discussed and illustrated with examples of MR microimaging and T2 quantification with correlative SEM and light microscopy.

Liver biopsy: effects of biopsy needle caliber on bleeding and tissue recovery.

PURPOSE: To evaluate different-caliber biopsy cutting needles in terms of the benefits and potential risk of bleeding in a swine model. MATERIALS AND METHODS: A total of 190 sequential liver biopsy specimens were obtained in 11 Yorkshire pigs (weight, 50-70 lb [22.5-31.5 kg]) by using 14-, 18-, and 20-gauge cutting needles. For each biopsy procedure, blood loss was determined by weighing sponges used to absorb bleeding, and sample-tissue DNA content was measured with spectrofluorometry. Analysis of variance was used to compare results. RESULTS: The larger the caliber of needle, the greater the absolute blood loss (for 14-gauge, 1.69 g; for 18-gauge, 0.74 g; for 20-gauge, 0.32 g) and DNA content per sample (for 14 gauge, 40.38 microg; for 18-gauge, 12.18 microg; for 20-gauge, 5.86 microg). The ratio of blood loss to amount of DNA recovered did not differ among the different-caliber needles. To obtain the same amount of diagnostic tissue, more passes were needed with the smaller-caliber needles. CONCLUSION: Use of larger-caliber needles is more efficient despite the greater amount of blood loss, because more tissue can be recovered and because fewer passes are necessary, which reduces the chances of complications.

Symptomatic herniation pits of the femoral neck: anatomic and clinical study.

OBJECTIVE: The purpose of this study was to investigate the pathogenesis of herniation pits of the femoral neck, which are frequently considered a normal variant, and to describe the imaging abnormalities of such pits in three symptomatic patients. CONCLUSION: The changing relationship between the joint capsule and the iliopsoas muscle appears to be important in the pathogenesis of the herniation pit, especially in athletic persons. In some cases, these pits may enlarge, the overlying cortex may fracture, and significant clinical manifestations may be apparent.

The electroencephalogram after alcohol administration in high-risk men and the development of alcohol use disorders 10 years later.

BACKGROUND: In 1979 through 1980, electroencephalographic (EEG) responses to an alcohol challenge in 19 year-old sons of alcoholics as well as in sons of nonalcoholic control subjects were examined. The familial risk status of the subjects and greater EEG sensitivity to alcohol were hypothesized to predict the development of alcoholism 10 years later. METHODS: In 1990 through 1992, diagnostic interviews were completed to ascertain alcohol and other substance use disorders in these subjects and to update their family history. RESULTS: Updated family history of alcoholism predicted the development of substance dependence. Density of alcoholic relatives (the number of alcoholic relatives divided by the number of known relatives) was positively related to the severity of alcohol use disorders in the probands. Contrary to expectation, a greater EEG response at age 19 years was not related to the later development of alcohol dependence. Instead, the opposite was observed: a smaller EEG alpha frequency response to alcohol at age 19 years was related to the development of alcohol dependence and high quantity and frequency of alcohol consumption 10 years later. CONCLUSIONS: Lower EEG response to a small dose of alcohol may be associated with the later development of alcohol dependence. This result is based on a small number of subjects and should be interpreted with caution. Although this result is opposite to our 1980 hypothesis, it is consistent with much of the recent literature.

Plantar compartments of the foot: MR appearance in cadavers and diabetic patients.

PURPOSE: To demonstrate the plantar compartments of the foot on magnetic resonance (MR) images. MATERIALS AND METHODS: The plantar compartments of four cadaveric feet underwent MR imaging and were sectioned. Fifteen MR studies in 11 patients with compartmental fluid were evaluated. The epicenter of infection was determined from review of the history, radiographs, and MR images. RESULTS: In the cadaveric feet, distribution of contrast material conformed to the compartmental anatomic features. MR findings in the specimen correlated exactly with gross findings. All seven feet with infection centered at the second through fourth metatarsal heads demonstrated only central compartment fluid. In seven of eight feet with a more medial or lateral epicenter of infection, fluid was seen in the lateral or medial compartment and in the central compartment. In one foot with a lateral epicenter of infection, fluid was confined to the lateral compartment. CONCLUSION: MR imaging accurately depicts the compartmental anatomic features of the foot.

Magnetic resonance imaging of the shoulder.

MRI has rapidly become a commonly used technique for evaluation of the shoulder. It provides a wealth of information regarding the entire shoulder girdle, and it is the most accurate noninvasive method available for imaging the rotator cuff. There have been numerous technical improvements in MRI in the relatively short time that clinical MRI has been in existence. Further refinements in design, new imaging sequences, and additional clinical experience should help to increase the accuracy and flexibility of this imaging modality.

The relationship between phallometrically measured deviant sexual arousal and clinical characteristics in juvenile sexual offenders.

The current study examined the relationship between clinical characteristics and a phallometrically derived deviance quotient index in two samples of 44 and 54 juvenile sex offenders. Results support an association between higher measured deviant arousal and having a male victim only, consistent with the literature on adult child molesters. However, results reflected greater fluidity in the offense patterns of the juvenile offenders, and generally less correspondence between measured arousal and offense histories than what has been cited for adults. The authors review whether there is empirical support for a conditioning model of deviant arousal onset in juveniles, and suggest caution in the interpretation of phallometric data with this population.

A 30-year follow-up study of the sons of alcoholic men.

The nature-nurture question in the etiology of alcoholism is discussed. The research results from twin and adoption studies indicate a considerable genetic (= biological) component in the etiology of alcoholism. A longitudinal high-risk study of alcoholism is presented. The sons of alcoholic men and matched controls have been followed prospectively since before birth. The main results from previous phases of the study and a recent 30-year follow-up assessment are presented.

Alcohol as muse.

It has been argued that American writers do not drink any more than American plumbers. If so, as one commentator said, American plumbing would be a mess. No one can question the fact that American writers in this century have been excessive drinkers. Explanations why this might occur are presented in this paper. Walker Percy locates the problem in the dualing hemispheres of the brain. Others think alcohol is (as Hemingway said) a good way to end the day and shut off the creative process. An historian has proposed that alcoholics are loners, that writers also are loners, and this is why so many writers are alcoholic. Although the argument for this view is persuasive, it does not explain why the United States has so many more alcoholic writers than other countries, or, why the "epidemic" occurred in the twentieth century. Alcohol was largely not a problem for Americans in earlier centuries and, although there have been alcoholic writers in European countries, their numbers never approached a majority. Drinking is the "joy of Russia," but there have been very few alcoholic Russian writers. Dylan Thomas, Brendan Behan, and Evelyn Waugh notwithstanding, alcoholic writers have not been common in the United Kingdom or Ireland. It is easy to think of reasons why writers drink. It is more difficult to explain why so many drank in this country during this century.

Childhood antecedents of antisocial behavior: parental alcoholism and physical abusiveness.

Hierarchical logistic regression was used to assess the independent and interactive effects of paternal alcoholism and physical child abuse on antisocial behavior in young adult men. Men with alcoholic fathers (N = 131) did not report or exhibit more antisocial behavior than comparison subjects (N = 70). Men with physical abuse histories, however, reported more aggressive and antisocial behaviors during a clinical interview and were rated by a clinical interviewer as more likely to act out aggression. Arrest records did not distinguish the groups. There was no evidence that paternal alcoholism and childhood victimization interacted to increase the risk of antisocial behavior.