A Comparison of Quantitative R1 and Cortical Thickness in Identifying Age, Lifespan Dynamics, and Disease States of the Human Cortex.

Brain development and aging are complex processes that unfold in multiple brain regions simultaneously. Recently, models of brain age prediction have aroused great interest, as these models can potentially help to understand neurological diseases and elucidate basic neurobiological mechanisms. We test whether quantitative magnetic resonance imaging can contribute to such age prediction models. Using R1, the longitudinal rate of relaxation, we explore lifespan dynamics in cortical gray matter. We compare R1 with cortical thickness, a well-established biomarker of brain development and aging. Using 160 healthy individuals (6-81 years old), we found that R1 and cortical thickness predicted age similarly, but the regions contributing to the prediction differed. Next, we characterized R1 development and aging dynamics. Compared with anterior regions, in posterior regions we found an earlier R1 peak but a steeper postpeak decline. We replicate these findings: firstly, we tested a subset (N = 10) of the original dataset for whom we had additional scans at a lower resolution; and second, we verified the results on an independent dataset (N = 34). Finally, we compared the age prediction models on a subset of 10 patients with multiple sclerosis. The patients are predicted older than their chronological age using R1 but not with cortical thickness.

[Increased incidence of hepatocellular and intrahepatic cholangiocellular carcinoma in northeast Germany]. / Zunahme des hepatozellulären und des intrahepatischen cholangiozellulären Karzinoms im Nordosten Deutschlands.

BACKGROUND AND OBJECTIVE: Hepatocellular cancer (HCC) is one of the five most common cancers worldwide. In Western countries the incidence of both HCC and intrahepatic cholangiocellular cancer (iCCC) has increased quite dramatically in the last 20 years. It was the aim of this study to assess the epidemiological changes of both cancers in the Northeast of Germany. METHODS: Using the data base of the Joint German Cancer Registry of the New Federal States and of Berlin, the age- and world-population-adjusted incidence of HCC and iCCC and their 5-year survival were calculated. The states of Brandenburg, Mecklenburg-Vorpommern and Saxony were chosen for this study because of the high quality of their registration base. RESULTS: In men the age-adjusted incidence of HCC increased from 3.6 in 1976 to 5.7 in 2002, the absolute number of newly diagnosed HCCs rising from 192 to 383 males within this period. In women the incidence was much lower. While only 30 males and 36 females were diagnosed with iCCC in 1976, in 2002 there were 64 men and 75 women with iCCC. In 1976, the corresponding age-adjusted incidence was 0.5 in men and 0.4 in women. Up to 2002 the incidence of iCCC rose to 0.8 and 0.6, respectively. The cumulative 5-year survival of HCC and iCCC was less than 10% for each. Comparison of the early period (1978-1979) with the later one (1998-1999) demonstrated a statistically significant improvement in survival for HCC. This was most likely due to earlier diagnosis and treatment of HCC. CONCLUSION: In the Northeast of Germany the incidence of both HCC and iCCC have increased markedly in the last 20 years. The recently improved survival of HCC patients most likely reflects earlier diagnosis and treatment.