Quantitative diffusion weighted imaging for differentiation of benign and malignant breast lesions: The influence of the choice of b‐values

Purpose:

To evaluate the influence of the choice of different combinations of b‐values on the ADC and on the diagnostic performance of quantitative diffusion weighted imaging (DWI) in breast lesions.

Materials and Methods:

Seventy‐three patients (90 lesions) underwent 3 Tesla (T) breast MRI including a DWI‐scan using b‐values 0, 150, 499, and 1500 s/mm² and histological analysis. Five combinations of b‐values were used to calculate the ADC, each with different sensitivities to perfusion and diffusion effects. The median ADC of benign lesions, noninvasive carcinomas and invasive carcinomas and the diagnostic performance of the five methods were compared.

Results:

Eighty‐eight lesions were analyzed (37 benign, 13 noninvasive carcinomas, 38 invasive carcinomas). The median ADC was highest in benign lesions, intermediate in noninvasive carcinomas and lowest in invasive carcinomas for all methods. Calculating the ADC with the lowest 2 b‐values yielded the highest ADC for all lesions types; the highest 2 b‐values yielded the lowest ADC. The area under the receiver operating characteristic curve was approximately equal for all methods.

Conclusion:

The ADC of breast lesions varied substantially with the choice of different b‐values, indicating that absolute ADC threshold values to differentiate benign and malignant lesions should be interpreted with caution. However, the diagnostic performance of quantitative DWI was not affected by the choice of different b‐values. J. Magn. Reson. Imaging 2010;31:1100–1105. © 2010 Wiley‐Liss, Inc.     

Analysis of cDNA sequences of feline SAAs

Feline amyloidosis is an uncommon disorder caused by deposits of amyloid in a variety of organs. Most frequently encountered types are amyloid derived of pancreatic islet amyloid polypeptide (AIAPP) in older cats and of the apolipoprotein, apo-serum amyloid A (AA) in Abyssinian/Somali (Aby) and Siamese/Oriental (Siam) cats occurring at a relatively young age. For the AA protein of the Aby, Siam and domestic shorthair cat (DSH) breed different amino acid sequences have been described. It is not yet clear, however, whether the tendency to develop AA amyloidosis in Aby and Siam is associated with specific apoSAA protein sequences and whether this is breed specific. In this study, DNA from one Siam and two DSH cats revealed on Southern blot three bands suggesting at least three genes or gene clusters. The SAA cDNAs of hepatic mRNA from three Abys, five Siams and five DSHs were amplified by RT-PCR, cloned and sequenced. Siams and Abys had limited SAA sequence variability. All five Siams, three of which were positive for amyloid, had the amyloidogenic Siam SAA and the amyloidogenic Aby SAA sequence. Two of the Abys, both with amyloid, had the amyloidogenic Aby SAA sequence. The third Aby, without amyloid, missed its amyloidogenic sequence. The SAA sequences of the DSHs found in the present preliminary survey, suggested a possible tendency for more variability, whereas the amyloidogenic Siam as well as the amyloidogenic Aby sequence were found once. Up to five different sequences were found in a single animal. All five DSHs, moreover, had a specific sequence lacking in the Siams and Abys. The present results, especially those of the Siams, favor that in addition to the occurrence of amyloid associated SAA genes other factors such as infections and inflammatory processes are involved in the development of phenotypical amyloidosis.     

More differences between HNPCC-related and sporadic carcinomas from the endometrium as compared to the colon

PURPOSE: Recognition of hereditary nonpolyposis colorectal cancer (HNPCC)-related endometrial carcinoma from sporadic carcinoma by histologic features as compared with colonic cases. STUDY DESIGN: Case-control study. METHODS AND MATERIALS: From the files of the Nijmegen Hereditary Cancer Clinic, HNPCC-related (n = 6) endometrial and colorectal (n = 18) carcinomas were selected. For every HNPCC-related tumor, 2 sporadic control cases were included. The tumors were evaluated for the following 7 pathologic features: tumor differentiation, T-stage, growth pattern, presence of Crohn-like lymphoid reaction, mucinous differentiation, presence of lymphangioinvasive growth, and the amount of tumor-infiltrating lymphocytes. RESULTS: HNPCC-related endometrial carcinomas were significantly more often poorly differentiated (83% versus 27%), more often showed the presence of a Crohn-like lymphoid reaction (100% versus 13%) and lymphangioinvasive growth (67% versus 0%), and high number of tumor-infiltrating lymphocytes were more often present (100% versus 36%) compared with sporadic endometrial carcinomas. The differences between HNPCC and sporadic colorectal cancer specimens were less discriminating. CONCLUSIONS: HNPCC-related endometrial carcinomas are characterized by poor differentiation, more frequent Crohn-like lymphoid reaction, lymphangioinvasive growth and more tumor-infiltrating lymphocytes. These features therefore might form the basis for selecting patients for counseling in a hereditary cancer clinic or testing for microsatellite instability or mutation analysis of mismatch repair genes, especially when they are of relatively young age.     

Rationale for superficial injection techniques in lymphatic mapping in breast cancer patients

One of the most avidly debated issues in lymphatic mapping is where the tracers are best deposited in patients with breast cancer. The four superficial approaches are easy to perform and have several other distinct advantages. They are based on the hypothesis that the entire breast parenchyma and the overlying skin drain to a common node in the axilla because of their common embryological origin. Evidence is presented that casts doubt upon the correctness of this assumption. Tracer administration close to the tumor site appears to be the safest approach for the time being. Excellent results can be obtained with this latter approach, despite the fact that it is technically more demanding.     

Motor unit characteristics in healthy subjects and those with postpoliomyelitis syndrome: a high-density surface EMG study

The purpose of this study was to identify optimal ways to detect neurogenic changes with high-density surface electromyography (HD-sEMG). For this purpose, we searched for the variables that most clearly discriminated between postpoliomyelitis and healthy subjects. We obtained HD-sEMG from the quadriceps muscle at different force levels in nine subjects with postpoliomyelitis syndrome and in matched healthy controls. Single motor unit action potentials (MUAPs), extracted from the HD-sEMG signal and the raw signal itself, were analyzed. Areas under the curve of the extracted MUAP waveform, indicating motor unit size, perfectly separated both groups. Raw signal analysis showed significant differences between groups for the monopolarly recorded amplitude up to 60% of maximal force and for the level of interference at higher force levels (40-100% force). We conclude that with HD-sEMG it is possible to detect neurogenic motor unit changes noninvasively, both by analysis of the raw signal itself and by analysis of extracted single MUAPs. The diagnostic yield of the single MUAP analysis is clearly higher. These findings point toward applications for clinical practice and invite further studies exploring the diagnostic value of HD-sEMG.     

Effects of soy-derived isoflavones and a high-fat diet on spontaneous mammary tumor development in Tg.NK (MMTV/c-neu) mice

Phytoestrogens such as isoflavonoids and lignans have been postulated as breast cancer protective constituents in soy and whole-grain cereals. We investigated the ability of isoflavones (IFs) and flaxseed to modulate spontaneous mammary tumor development in female heterozygous Tg.NK (MMTV/c-neu) mice. Two different exposure protocols were applied, either from 4 wk of age onward (postweaning) or during gestation and lactation (perinatal). In the postweaning exposure study, mice were fed IFs or flaxseed in a high-fat diet. In addition, flaxseed in a low-fat diet was tested. Postweaning exposure to IFs and flaxseed tended to accelerate the onset of mammary adenocarcinoma development, although tumor burden at necropsy was not changed significantly. Perinatal IF exposure resulted in enhanced mammary gland differentiation, but palpable mammary tumor onset was not affected. However, tumor burden at necropsy in the perinatal exposure study was significantly increased in the medium- and high-IF dose groups. Comparison of both exposure scenarios revealed a strongly accelerated onset of tumor growth after perinatal high-fat diet exposure compared with the low-fat diet. This study shows that breast cancer-modulating effects of phytoestrogens are dependent both on the background diet and on the timing of exposure in the life cycle.     

Risks of ancient practices in modern times

Swaddling, ie, wrapping the child to restrict movement, is an ancient practice. In the Netherlands, it is becoming increasingly popular as an intervention for excessive crying in infants. However, one must be well aware of the potential risks. We present the case reports of a twin boy and girl who had been swaddled and kept in a heated room for several days. On admission to the hospital, both infants suffered from severe hypovolemic shock, hyperthermia, and secondary respiratory insufficiency. The girl developed multiple organ dysfunction syndrome and died, whereas the boy had an uneventful recovery. When swaddling is being considered as an intervention for excessive crying in infants, parents have to be well-informed about the possible side effects and about additional measures that they may have to take to make it a safe intervention.